Chapter 8: Pathologic Fractures

Alexandre Arkader, John P. Dormans

Chapter Outline

Introduction

In normal circumstances, children and adolescents are prone to fractures caused by forces encountered during their high level of activity. Whenever the structural characteristics and strength of the bone are compromised, by a localized or generalized process, the risk of fractures is increased. The definition of a pathologic fracture is one that occurs through abnormal bone. The combination of a previous bone abnormality and a fracture poses special challenges in the decision-making and management of these injuries. Pathologic fractures may result from a localized or generalized bone weakness, resulting from an intrinsic or extrinsic process. Examples of localized bone weakness caused by an intrinsic process are tumors or tumor-like lesions; generalized causes because of an extrinsic process include osteopenia or osteoporosis of different etiologies. 
The evaluation of a child with a pathologic fracture starts with detailed history and physical examination. The past medical history, use of medications, and prodromic symptoms may lead to the diagnosis. Some key points include the patient's age, as some predisposing conditions are more common in specific age groups (Table 8-1); and the presence of pain, which can raise suspicion toward a bone lesion or localized weakening process. Radiographic evaluation is the next step, and helps differentiating between a localized (e.g., tumor) and a generalized process (e.g., osteoporosis). If a bone lesion is identified the five questions should be answered for a differential diagnosis. 
Table 8-1
Common Predisposing Factors for Pathologic Fractures by Peak Age Incidence
Age (Years) Benign Lesions Malignant Tumors Generalized Causes
0–5 Eosinophilic granuloma
Osteomyelitis
Metastatic tumors (neuroblastoma, Wilm)
Leukemia
Ewing sarcoma
Neuromuscular diseases (medications, disuse osteopenia)
Osteogenesis imperfecta
5–10 Unicameral bone cyst
Aneurysmal bone cyst
Nonossifying fibroma
Osteochondroma
Fibrous dysplasia
Enchondromatosis/Ollier
Neurofibromatosis/Congenital pseudarthrosis of the tibia
Leukemia
Osteogenic sarcoma
Ewing sarcoma
Neuromuscular diseases (medications, disuse osteopenia)
Osteogenesis imperfecta
Other medications (e.g., steroids)
Rickets
Dietary deficiencies
Osteopetrosis
Bone marrow diseases
10–20 Unicameral bone cyst
Aneurysmal bone cyst
Nonossifying fibroma
Osteochondroma
Fibrous dysplasia
Chondroblastoma
Giant cell tumor
Leukemia
Lymphoma
Osteogenic sarcoma
Ewing sarcoma
Neuromuscular diseases (medications, disuse osteopenia)
Other medications (e.g., steroids)
Stress fractures
Dietary deficiencies
Bone marrow diseases
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  1.  
    Where is the lesion? Different bone lesions are seen more frequently in specific areas of the body and the bone (Figs. 8-1 and 8-2).
  2.  
    What is the lesion's size and extent? Aggressive lesions tend to be larger and grow faster. Exceptions include fibrous dysplasia (FD) that may involve not only the entire bone but also several bones at the same time and nonetheless is a benign condition. Multiple lesions or generalized bone weakness may pose another challenge in the prevention and management of pathologic fractures.
  3.  
    What is the lesion doing to the bone? The pattern of bone involvement and/or destruction plays an important role in the bone strength. For example, lytic lesions (e.g., unicameral bone cyst [UBC]) put the bone at a much higher risk of pathologic fracture than blastic lesions (e.g., osteoblastoma).
  4.  
    What is the bone's response? If the bone has time to “compensate” for its destruction caused by a lesional process, new bone formation and cortical thickening may be observed and will to some point prevent or delay apathologic fracture.
  5.  
    Soft tissue mass? The presence of an associated soft tissue mass may be an indication of a more aggressive, perhaps malignant process; furthermore, the cortical adjacent to the associated soft tissue mass will often be severely weakened or destructed.
Figure 8-1
Schematic distribution of the most common benign and malignant bone lesions seen in the long bones in children.
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Figure 8-2
Schematic distribution of the most common benign and malignant bone tumors seen in the spine in children.
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One of the challenges dealing with a “weakened” bone is to predict the likelihood of fracture. The combination of bending and torsional rigidity measured noninvasively with quantitative CT was found to be more accurate for predicting pathologic fracture through benign bone lesions in children than the standard radiographic criteria (42% to 61% accuracy).129,253 
An important consideration in the management of pathologic fracture is that the underlying cause often needs to be addressed to achieve fracture healing; therefore, the treatment plan must consider both the treatment of the fracture and its underlying cause, at times deviating from the classic principles of pediatric fractures. 
This chapter describes the clinical and radiographic features of the most common causes of pediatric pathologic fractures, including specific patterns of injury and special concerns of treatment. The goals are to warn and prepare the orthopedic surgeon for the correct diagnostic approach and management of these lesions. 

Tumors or Tumor-Like Processes

Benign tumors can be classified according to their aggressiveness (Table 8-2). Stage 1, or latent benign lesions, are usually asymptomatic, discovered incidentally, and seldom associated with pathologic fracture. Stage 2 lesions are intermediate in behavior, and stage 3, or aggressive benign lesions, are usually symptomatic, grow rapidly, and may be associated with pathologic fracture. 
Table 8-2
Classification of Benign Lesions According to Their Aggressiveness
Stage 1, Latent Benign
Asymptomatic
Often discovered incidentally
Seldom associated with pathologic fracture
Stage 2, Active Benign
Majority
Tend to grow steadily
May be symptomatic
Stage 3, Aggressive Benign
Generally symptomatic
Discomfort, usually tender
May be associated with pathologic fracture
Growth rapid
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Unicameral Bone Cyst

Unicameral bone cyst (UBC), also known as simple bone cyst, is a benign, active or latent, solitary cystic lesion that usually involves the metaphysis or metadiaphysis of long bones. In the order of decreasing frequency, UBCs are most commonly seen in the proximal humerus, proximal femur, proximal tibia, distal tibia, distal femur, calcaneous, distal humerus, radius, fibula, ilium, ulna, and rib.201,202 Although the etiology is unknown, one of the most accepted theories is that UBC is caused by obstruction of the drainage of interstitial fluid.54,57 
UBCs are classified based on their proximity to the adjacent growth plate. Active cysts are close to the physeal line, and inactive or latent cysts have “migrated” away from the growth plate as longitudinal growth occurs and therefore are far from the epiphysis.202,202 
The vast majority of patients are younger than 20 years old.54,275 The male-to-female ratio is about 2:1.46,202 UBCs are often asymptomatic and, in approximately 80% of cases, the initial presentation is with a pathologic fracture following minor trauma.49,76,77,275 The fractures are usually incomplete or minimally displaced, and tend to heal uneventfully. In approximately 10% of the cases the cyst heals following the fracture.5,73,75 Lower extremity fractures, particularly around the hip, often need surgical intervention. 
Plain radiographs are usually diagnostic; UBC is a well-defined, centrally located, radiolucent/lytic cystic lesion with narrow zone of transition. Cortical thinning and mild expansion are common. When a pathologic fracture occurs, there is periosteal reaction and occasionally the typical “fallen fragment” sign is visualized (fragment of bone “floating” inside the fluid-filled cystic cavity). CT is useful for lesions located in areas that are of difficult visualization on plain films (e.g., spine, pelvis) and to rule out minimally displaced fractures. Magnetic resonance imaging (MRI) is sometimes used for differential diagnosis of atypical UBCs. Although the characteristics are nonspecific, UBCs usually present as low-to-intermediate signals on T1-weighted images and a bright and homogeneous signals on T2-weighted images (Fig. 8-3).184 
Figure 8-3
A 10-year-old boy presented with arm pain after low-energy trauma, 5 days prior.
 
Anteroposterior (A) and lateral (B) radiographs of the right humerus show a nondisplaced pathologic fracture (A-arrow) through a lytic lesion in the proximal humerus. The lesion is difficult to visualize and the periosteal reaction is also of concern (B-arrow). T2-weighted MRI images show a well-defined, fluid-filled cystic lesion, with fluid–fluid levels (D-arrow) and no soft tissue mass or other worrisome signs in the coronal (C) and axial (D) cuts. The diagnosis was consistent with unicameral bone cyst and conservative treatment was recommended.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs of the right humerus show a nondisplaced pathologic fracture (A-arrow) through a lytic lesion in the proximal humerus. The lesion is difficult to visualize and the periosteal reaction is also of concern (B-arrow). T2-weighted MRI images show a well-defined, fluid-filled cystic lesion, with fluid–fluid levels (D-arrow) and no soft tissue mass or other worrisome signs in the coronal (C) and axial (D) cuts. The diagnosis was consistent with unicameral bone cyst and conservative treatment was recommended.
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Figure 8-3
A 10-year-old boy presented with arm pain after low-energy trauma, 5 days prior.
Anteroposterior (A) and lateral (B) radiographs of the right humerus show a nondisplaced pathologic fracture (A-arrow) through a lytic lesion in the proximal humerus. The lesion is difficult to visualize and the periosteal reaction is also of concern (B-arrow). T2-weighted MRI images show a well-defined, fluid-filled cystic lesion, with fluid–fluid levels (D-arrow) and no soft tissue mass or other worrisome signs in the coronal (C) and axial (D) cuts. The diagnosis was consistent with unicameral bone cyst and conservative treatment was recommended.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs of the right humerus show a nondisplaced pathologic fracture (A-arrow) through a lytic lesion in the proximal humerus. The lesion is difficult to visualize and the periosteal reaction is also of concern (B-arrow). T2-weighted MRI images show a well-defined, fluid-filled cystic lesion, with fluid–fluid levels (D-arrow) and no soft tissue mass or other worrisome signs in the coronal (C) and axial (D) cuts. The diagnosis was consistent with unicameral bone cyst and conservative treatment was recommended.
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The differential diagnosis includes aneurysmal bone cyst (ABC), nonossifying fibroma, FD (especially for diaphyseal tumors), brown tumor of hyperparathyroidism, and osteomyelitis. 
With time, UBCs tend to stabilize in size and “migrate” away from the growth plate. Although some lesions heal or disappear spontaneously at puberty,201,202 the majority will persist into adulthood (Table 8-3). 
 
Table 8-3
Staging of Unicameral Bone Cysts
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Table 8-3
Staging of Unicameral Bone Cysts
Active Inactive or “Latent”
Age of the patient <10–12 years >12 years
Location Abutting the physis Separated from physis by a zone of normal cancellous bone
Radiographic appearance Single cavity Multiloculated cavity
Intralesional pressure >30 cm H2O 6–10 cm H2O
Pathology Thin shiny membrane, few osteocytes, little or no hemosiderin, osteoclasts Thick membrane, frequent giant cells, cholesterol slits, hemosiderin, osteoblasts
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Lesions that have the typical radiographic appearance and therefore do not warrant biopsy for diagnostic confirmation, particularly those lesions in non–weight-bearing bones, can be followed with serial radiographs. 
Large lesions that involve more than 50% to 80% of the bone diameter and lesions that are associated with marked cortical thinning are at high risk of fractures and may warrant prophylactic treatment.126,254 Lesions of weight-bearing bones, especially around the hip, are best addressed before a fracture (Fig. 8-4). Although several attempts have been made to predict the true risk of pathologic fracture associated with bone cysts, most of the data are related to other lesions, particularly among adults (Fig. 8-5). CT has been shown to be useful for predicting the likelihood of fracture. This method uses a computerized regression system and may help deciding which cysts warrant intervention.254 
Figure 8-4
Classification system for the treatment of pathologic fractures of the proximal femur associated with bone cysts in children.
 
A: In type IA, a moderately sized cyst is present in the middle of the femoral neck. There is enough bone in the femoral neck and lateral proximal femur (lateral buttress) to allow fixation with cannulated screws, avoiding the physis, after curettage and bone grafting. B: In type IB, a large cyst is present at the base of the femoral neck. There is enough bone proximally in the femoral neck but there is loss of lateral buttress, so a pediatric hip screw and a side plate should be considered rather than cannulated screws after curettage and bone grafting. C, D: In type II A-B, a large lesion is present in the femoral neck, so there is not enough bone beneath the physis to accept screws. There are two options for treatment of these bone cysts: (i) after curettage and bone grafting, parallel smooth pins across the physis can be used in combination with spica cast; (ii) the patient can be treated in traction until the fracture heals (with subsequent spica cast) followed by curettage and bone grafting. E, F: In type IIIA-B, the physis is closing or closed. The lateral buttress is present in type IIIA hips, so cannulated screws can be used to stabilize the fracture after curettage and bone grafting. In type IIIB hips, the loss of lateral buttress makes it necessary to use a pediatric hip screw and a side plate following curettage and bone grafting. In all types, we recommend spica cast immobilization after surgery.
A: In type IA, a moderately sized cyst is present in the middle of the femoral neck. There is enough bone in the femoral neck and lateral proximal femur (lateral buttress) to allow fixation with cannulated screws, avoiding the physis, after curettage and bone grafting. B: In type IB, a large cyst is present at the base of the femoral neck. There is enough bone proximally in the femoral neck but there is loss of lateral buttress, so a pediatric hip screw and a side plate should be considered rather than cannulated screws after curettage and bone grafting. C, D: In type II A-B, a large lesion is present in the femoral neck, so there is not enough bone beneath the physis to accept screws. There are two options for treatment of these bone cysts: (i) after curettage and bone grafting, parallel smooth pins across the physis can be used in combination with spica cast; (ii) the patient can be treated in traction until the fracture heals (with subsequent spica cast) followed by curettage and bone grafting. E, F: In type IIIA-B, the physis is closing or closed. The lateral buttress is present in type IIIA hips, so cannulated screws can be used to stabilize the fracture after curettage and bone grafting. In type IIIB hips, the loss of lateral buttress makes it necessary to use a pediatric hip screw and a side plate following curettage and bone grafting. In all types, we recommend spica cast immobilization after surgery.
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Figure 8-4
Classification system for the treatment of pathologic fractures of the proximal femur associated with bone cysts in children.
A: In type IA, a moderately sized cyst is present in the middle of the femoral neck. There is enough bone in the femoral neck and lateral proximal femur (lateral buttress) to allow fixation with cannulated screws, avoiding the physis, after curettage and bone grafting. B: In type IB, a large cyst is present at the base of the femoral neck. There is enough bone proximally in the femoral neck but there is loss of lateral buttress, so a pediatric hip screw and a side plate should be considered rather than cannulated screws after curettage and bone grafting. C, D: In type II A-B, a large lesion is present in the femoral neck, so there is not enough bone beneath the physis to accept screws. There are two options for treatment of these bone cysts: (i) after curettage and bone grafting, parallel smooth pins across the physis can be used in combination with spica cast; (ii) the patient can be treated in traction until the fracture heals (with subsequent spica cast) followed by curettage and bone grafting. E, F: In type IIIA-B, the physis is closing or closed. The lateral buttress is present in type IIIA hips, so cannulated screws can be used to stabilize the fracture after curettage and bone grafting. In type IIIB hips, the loss of lateral buttress makes it necessary to use a pediatric hip screw and a side plate following curettage and bone grafting. In all types, we recommend spica cast immobilization after surgery.
A: In type IA, a moderately sized cyst is present in the middle of the femoral neck. There is enough bone in the femoral neck and lateral proximal femur (lateral buttress) to allow fixation with cannulated screws, avoiding the physis, after curettage and bone grafting. B: In type IB, a large cyst is present at the base of the femoral neck. There is enough bone proximally in the femoral neck but there is loss of lateral buttress, so a pediatric hip screw and a side plate should be considered rather than cannulated screws after curettage and bone grafting. C, D: In type II A-B, a large lesion is present in the femoral neck, so there is not enough bone beneath the physis to accept screws. There are two options for treatment of these bone cysts: (i) after curettage and bone grafting, parallel smooth pins across the physis can be used in combination with spica cast; (ii) the patient can be treated in traction until the fracture heals (with subsequent spica cast) followed by curettage and bone grafting. E, F: In type IIIA-B, the physis is closing or closed. The lateral buttress is present in type IIIA hips, so cannulated screws can be used to stabilize the fracture after curettage and bone grafting. In type IIIB hips, the loss of lateral buttress makes it necessary to use a pediatric hip screw and a side plate following curettage and bone grafting. In all types, we recommend spica cast immobilization after surgery.
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Figure 8-5
 
Anterior–posterior (A) and lateral (B) radiographs of a 10-year-old who came in with chronic hip pain of several weeks duration. There is a well-defined, lytic lesion in the proximal femur, presenting with cortical thinning and some periosteal reaction, suggesting a healing stress pathologic fracture through a unicameral bone cyst. The patient underwent biopsy to confirm the diagnosis, followed by curettage and bone grafting, supplemented by internal fixation to improve the lateral buttress (C and D).
 
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
Anterior–posterior (A) and lateral (B) radiographs of a 10-year-old who came in with chronic hip pain of several weeks duration. There is a well-defined, lytic lesion in the proximal femur, presenting with cortical thinning and some periosteal reaction, suggesting a healing stress pathologic fracture through a unicameral bone cyst. The patient underwent biopsy to confirm the diagnosis, followed by curettage and bone grafting, supplemented by internal fixation to improve the lateral buttress (C and D).
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Figure 8-5
Anterior–posterior (A) and lateral (B) radiographs of a 10-year-old who came in with chronic hip pain of several weeks duration. There is a well-defined, lytic lesion in the proximal femur, presenting with cortical thinning and some periosteal reaction, suggesting a healing stress pathologic fracture through a unicameral bone cyst. The patient underwent biopsy to confirm the diagnosis, followed by curettage and bone grafting, supplemented by internal fixation to improve the lateral buttress (C and D).
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
Anterior–posterior (A) and lateral (B) radiographs of a 10-year-old who came in with chronic hip pain of several weeks duration. There is a well-defined, lytic lesion in the proximal femur, presenting with cortical thinning and some periosteal reaction, suggesting a healing stress pathologic fracture through a unicameral bone cyst. The patient underwent biopsy to confirm the diagnosis, followed by curettage and bone grafting, supplemented by internal fixation to improve the lateral buttress (C and D).
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Although spontaneous resolution of UBCs following fracture may occur in up to 15% of the cases (Fig. 8-6), pathologic fractures associated with UBCs do not always heal uneventfully; malunion, growth arrest, and avascular necrosis are some of the reported complications.142,182 
Figure 8-6
A 6-year-old boy presented with shoulder pain after a fall.
 
Anteroposterior (A) and lateral (B) radiographs of the right proximal humerus show a pathologic fracture through a well-defined, lytic lesion in the proximal humeral metaphysis. The fracture presented some comminution that gave the appearance of fallen leaf sign (arrow). This lesion was consistent with unicameral bone cyst and conservative treatment with a fracture brace and sling was initiated. Six weeks after the injury, radiographs (C, D) show consolidation of the fracture and healing of the cyst. The patient was symptom free and returned to full physical activities.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs of the right proximal humerus show a pathologic fracture through a well-defined, lytic lesion in the proximal humeral metaphysis. The fracture presented some comminution that gave the appearance of fallen leaf sign (arrow). This lesion was consistent with unicameral bone cyst and conservative treatment with a fracture brace and sling was initiated. Six weeks after the injury, radiographs (C, D) show consolidation of the fracture and healing of the cyst. The patient was symptom free and returned to full physical activities.
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Figure 8-6
A 6-year-old boy presented with shoulder pain after a fall.
Anteroposterior (A) and lateral (B) radiographs of the right proximal humerus show a pathologic fracture through a well-defined, lytic lesion in the proximal humeral metaphysis. The fracture presented some comminution that gave the appearance of fallen leaf sign (arrow). This lesion was consistent with unicameral bone cyst and conservative treatment with a fracture brace and sling was initiated. Six weeks after the injury, radiographs (C, D) show consolidation of the fracture and healing of the cyst. The patient was symptom free and returned to full physical activities.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs of the right proximal humerus show a pathologic fracture through a well-defined, lytic lesion in the proximal humeral metaphysis. The fracture presented some comminution that gave the appearance of fallen leaf sign (arrow). This lesion was consistent with unicameral bone cyst and conservative treatment with a fracture brace and sling was initiated. Six weeks after the injury, radiographs (C, D) show consolidation of the fracture and healing of the cyst. The patient was symptom free and returned to full physical activities.
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Author's Preferred Method

We recommend treating the fracture conservatively prior to definitive treatment of the cyst. The main reasons are to allow possible spontaneous healing of the cyst and to make it easier to treat a stable bone, rather than two moving parts. The exception is select proximal femur fractures that may need rigid internal fixation. 
Our preferred technique is a minimally invasive approach that combines aspiration, cystogram, biopsy, curettage, intramedullary decompression, and grafting with medical-grade calcium'.73,76 Complete cyst healing is achieved in over 80% of the cases. 

Surgical Technique

  •  
    Under fluoroscopic guidance, a Jamshidi trocared needle (CardinalHalth, Dublin, OH) is percutaneously inserted into the cyst cavity, preferably in the middle of the cyst.
  •  
    The cyst is aspirated to confirm the presence of straw-colored fluid.
  •  
    Three to 10 mL of Renografin dye (E.R. Squibb, Princeton, NJ) is injected to perform a cystogram and confirm the single fluid-filled cavity.
  •  
    A 0.5-cm longitudinal incision is then made over the site of the aspiration and a 6-mm arthroscopy trocar is advanced into the cyst cavity through the same cortical hole. The cortical entry is then enlarged manually.
  •  
    Under fluroscopic guidance, percutaneous removal of the cyst lining is done with curved curettes and a pituitary rongeur.
  •  
    An angled curette and/or flexible intramedullary nail is used to perform the intramedullary decompression in one direction (toward diaphysis) or in both directions (if the growth plate is far enough to avoid injury).
  •  
    Bone grafting is done with medical-grade calcium sulfate pellets (Osteoset, Wright Medical Technology, Arlington, TN) inserted through the same cortical hole and deployed to completely fill the cavity. The pellets do not offer structural support but act as scaffolding for new bone formation and cyst healing. Angled curettes can be used to advance pellets into the medullary canal, which also confirms adequate decompression. Tight packing of the cyst is preferred.
  •  
    The wound is closed in a layered fashion.

Aneurysmal Bone Cyst

ABCs are benign, locally aggressive bone tumors.257 They are well-defined, eccentric, expansile, osteolytic, blood-filled lesions usually seen in the metaphyseal region of long bones (65% of cases) or in the posterior elements of the spine. ABCs have a tendency to expand beyond the width of the epiphyseal plate. Approximately 75% of ABCs are seen in patients younger than 20 years old, and 50% are seen in individuals between 10 and 20 years of age.46,62 The estimated incidence is of approximately 1.4 cases per 100,000, representing 1.5% of all primary bone tumors.62 
In the order of decreasing frequency, the most commonly involved bones in the appendicular skeleton are the femur (∼20%), tibia (∼17%), spine (∼15%), humerus (∼13%), pelvis (∼8%), and fibula (∼7%).62 The spine is involved in up to 27% of the cases,46,62 with the posterior elements being the most common site with frequent extension into the vertebral body.39,98 The lumbar vertebrae are the most commonly affected.39 
The etiology of ABCs is still unknown. The neoplastic basis of primary ABCs has been in part demonstrated by the chromosomal translocation t(16; 17)(q22; p13) that places the ubiquitin protease USP6 gene under the regulatory influence of the highly active osteoblast cadherin 11 gene, which is strongly expressed in bones.210 There is a fairly high incidence of ABCs associated with other benign and malignant tumors such as UBCs, nonossifying fibromas, FD, and osteogenic sarcoma.65,174,186 The most common presenting symptom is localized pain and/or swelling of less than 6 months duration; spinal lesions may present with radicular pain.46,69,98,104,159 
On plain radiographs, ABCs present as an eccentric lytic lesion. Although usually the overlying cortex is intact, sometimes cortical disruption is identified. When that occurs, periosteal reaction is seen.37,159 Cystic septation is common, giving rise to the so-called soap bubble or honeycomb appearance. Lesions in the short tubular bones, such as the metacarpals and metatarsals, are commonly more central. Lesions near the growth plate tend to expand beyond the width of the adjacent epiphysis (Fig. 8-7), which can be a useful way to differentiate ABCs from UBCs which do not commonly expand as much beyond the width of the epiphysis. MRI is often helpful in obtaining better definition of axial lesions and in demonstrating the characteristic double density fluid level, septation, low signal on T1 images, and high intensity on T2 images; however, these findings are not pathognomonic for ABC.262 
Figure 8-7
Anterior–posterior (A) and lateral (B) radiographs of a 12-year-old who suffered a fall and developed acute left hip pain and inability to ambulate.
 
There is a pathologic fracture through a well-defined, lytic and loculated lesion in the proximal femur, with cortical thinning, no soft tissue mass or periosteal reaction. The patient underwent biopsy confirming the diagnosis of aneurysmal bone cyst, followed by curettage and allografting, supplemented by internal fixation with a variable hip screw and a cannulated antirotational screw (C, D). The 4 years follow-up, short after hardware removal, shows no signs of recurrence or persistence of the lesion (E and F).
 
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
There is a pathologic fracture through a well-defined, lytic and loculated lesion in the proximal femur, with cortical thinning, no soft tissue mass or periosteal reaction. The patient underwent biopsy confirming the diagnosis of aneurysmal bone cyst, followed by curettage and allografting, supplemented by internal fixation with a variable hip screw and a cannulated antirotational screw (C, D). The 4 years follow-up, short after hardware removal, shows no signs of recurrence or persistence of the lesion (E and F).
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There is a pathologic fracture through a well-defined, lytic and loculated lesion in the proximal femur, with cortical thinning, no soft tissue mass or periosteal reaction. The patient underwent biopsy confirming the diagnosis of aneurysmal bone cyst, followed by curettage and allografting, supplemented by internal fixation with a variable hip screw and a cannulated antirotational screw (C, D). The 4 years follow-up, short after hardware removal, shows no signs of recurrence or persistence of the lesion (E and F).
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Figure 8-7
Anterior–posterior (A) and lateral (B) radiographs of a 12-year-old who suffered a fall and developed acute left hip pain and inability to ambulate.
There is a pathologic fracture through a well-defined, lytic and loculated lesion in the proximal femur, with cortical thinning, no soft tissue mass or periosteal reaction. The patient underwent biopsy confirming the diagnosis of aneurysmal bone cyst, followed by curettage and allografting, supplemented by internal fixation with a variable hip screw and a cannulated antirotational screw (C, D). The 4 years follow-up, short after hardware removal, shows no signs of recurrence or persistence of the lesion (E and F).
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
There is a pathologic fracture through a well-defined, lytic and loculated lesion in the proximal femur, with cortical thinning, no soft tissue mass or periosteal reaction. The patient underwent biopsy confirming the diagnosis of aneurysmal bone cyst, followed by curettage and allografting, supplemented by internal fixation with a variable hip screw and a cannulated antirotational screw (C, D). The 4 years follow-up, short after hardware removal, shows no signs of recurrence or persistence of the lesion (E and F).
View Original | Slide (.ppt)
There is a pathologic fracture through a well-defined, lytic and loculated lesion in the proximal femur, with cortical thinning, no soft tissue mass or periosteal reaction. The patient underwent biopsy confirming the diagnosis of aneurysmal bone cyst, followed by curettage and allografting, supplemented by internal fixation with a variable hip screw and a cannulated antirotational screw (C, D). The 4 years follow-up, short after hardware removal, shows no signs of recurrence or persistence of the lesion (E and F).
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X
Campanacci et al.46 have classified ABCs into three groups. An aggressive cyst has signs of reparative osteogenesis with ill-defined margins and no periosteal shell. An active cyst has an incomplete periosteal shell and a defined margin between the lesion and the host bone. An inactive cyst has a complete periosteal shell and a sclerotic margin between the cyst and the long bone (Fig. 8-8). 
Figure 8-8
Classification of morphologic types of aneurysmal bone cyst.
 
(From Campanna R, Bettelli G, Biagini R, et al. Aneurysmal cysts of long bones. Ital J Orthop Traumatol. 1985; XI:421–429, with permission.)
(From 


Campanna R,

Bettelli G,

Biagini R
, et al.
Aneurysmal cysts of long bones.
Ital J Orthop Traumatol.
1985;
XI:421–429, with permission.)
View Original | Slide (.ppt)
Figure 8-8
Classification of morphologic types of aneurysmal bone cyst.
(From Campanna R, Bettelli G, Biagini R, et al. Aneurysmal cysts of long bones. Ital J Orthop Traumatol. 1985; XI:421–429, with permission.)
(From 


Campanna R,

Bettelli G,

Biagini R
, et al.
Aneurysmal cysts of long bones.
Ital J Orthop Traumatol.
1985;
XI:421–429, with permission.)
View Original | Slide (.ppt)
X
Pathologic fractures occur in 11% to 35% of long bone lesions.98,159 The humerus and femur are the most common sites of pathologic fracture.98,158 The incidence of pathologic fracture associated with spinal lesions is approximately 20%.39,69,104 Conservative treatment with immobilization is usually inappropriate as a definitive treatment for pathologic fractures of ABCs. Although the pathologic fracture will heal, ABCs do not spontaneously heal and may enlarge; furthermore, tissue sampling is often needed for diagnosis confirmation. 
Recurrence rates following intralesional curettage and bone grafting are as high as 30%.74,109,269 Several authors have shown that the recurrence is higher among younger children.24,60,74,98 Freiberg et al.98 treated ABCs with curettage and bone grafting in seven patients younger than 10 years of age and noted recurrence in five of the seven patients at an average of 8 months after the first procedure. Because of this high recurrence rate, several authors attempted the use of adjuvant, such as cryosurgery and cementation.183,239 

Author's Preferred Method

Four-Step Approach Resection

This technique has been previously described with reported recurrence rate for appendicular lesions around 8%.74,104 We recommend the use of headlamps for enhanced illumination and loupes for magnification. An image intensifier is available for intraoperative confirmation of complete tumor excision and appropriate bone grafting. Diagnostic tissue confirmation is an essential part of this technique. For large spinal tumors, preoperative embolization is recommended (Fig. 8-9). If instrumentation is needed after spine tumors resection, we recommend titanium or cobalt chrome instrumentation that gives a much better visualization of the spine on future MRIs (less artifact) than stainless steel (Fig. 8-10). 
Figure 8-9
A 9-year-old boy presented with low back pain and abdominal discomfort.
 
On plain radiographs of the abdomen (A), an expansile lesion (arrow) involving the left posterior elements of L1 was visualized. Axial T2-weighted MRI (B) and an axial CT scan image (C) show the microfractures at the pedicle and lamina level (arrow) and the fluid–fluid levels. The patient underwent open biopsy that confirmed the diagnosis of aneurysmal bone cyst, followed by a 4-step approach excision and bone grafting. Limited instrumentation of the spine was performed because of stability compromise (D). Nowadays the authors preferred technique is pedicle screw fixation and fusion one level above and below the involved vertebra.
On plain radiographs of the abdomen (A), an expansile lesion (arrow) involving the left posterior elements of L1 was visualized. Axial T2-weighted MRI (B) and an axial CT scan image (C) show the microfractures at the pedicle and lamina level (arrow) and the fluid–fluid levels. The patient underwent open biopsy that confirmed the diagnosis of aneurysmal bone cyst, followed by a 4-step approach excision and bone grafting. Limited instrumentation of the spine was performed because of stability compromise (D). Nowadays the authors preferred technique is pedicle screw fixation and fusion one level above and below the involved vertebra.
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Figure 8-9
A 9-year-old boy presented with low back pain and abdominal discomfort.
On plain radiographs of the abdomen (A), an expansile lesion (arrow) involving the left posterior elements of L1 was visualized. Axial T2-weighted MRI (B) and an axial CT scan image (C) show the microfractures at the pedicle and lamina level (arrow) and the fluid–fluid levels. The patient underwent open biopsy that confirmed the diagnosis of aneurysmal bone cyst, followed by a 4-step approach excision and bone grafting. Limited instrumentation of the spine was performed because of stability compromise (D). Nowadays the authors preferred technique is pedicle screw fixation and fusion one level above and below the involved vertebra.
On plain radiographs of the abdomen (A), an expansile lesion (arrow) involving the left posterior elements of L1 was visualized. Axial T2-weighted MRI (B) and an axial CT scan image (C) show the microfractures at the pedicle and lamina level (arrow) and the fluid–fluid levels. The patient underwent open biopsy that confirmed the diagnosis of aneurysmal bone cyst, followed by a 4-step approach excision and bone grafting. Limited instrumentation of the spine was performed because of stability compromise (D). Nowadays the authors preferred technique is pedicle screw fixation and fusion one level above and below the involved vertebra.
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Figure 8-10
When dealing with pathologic fractures secondary to tumors or tumor-like processes of the spine, if instrumentation is needed, titanium instrumentation allows much better postoperative visualization with both CT and MRI for the detection of tumor recurrence as compared with standard stainless-steel instrumentation.
 
A: Postoperative MRI of the spine with standard stainless-steel instrumentation showing a large degree of artifact that makes interpretation difficult. B: Preoperative CT scan of a patient with an ABC of the spine. C: Postoperative CT scan of the same patient showing an adequate view of the surgical area. D: Postoperative MRI of a patient with a previous spinal tumor again adequately showing the surgical site to monitor for recurrence or persistent tumor.
A: Postoperative MRI of the spine with standard stainless-steel instrumentation showing a large degree of artifact that makes interpretation difficult. B: Preoperative CT scan of a patient with an ABC of the spine. C: Postoperative CT scan of the same patient showing an adequate view of the surgical area. D: Postoperative MRI of a patient with a previous spinal tumor again adequately showing the surgical site to monitor for recurrence or persistent tumor.
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A: Postoperative MRI of the spine with standard stainless-steel instrumentation showing a large degree of artifact that makes interpretation difficult. B: Preoperative CT scan of a patient with an ABC of the spine. C: Postoperative CT scan of the same patient showing an adequate view of the surgical area. D: Postoperative MRI of a patient with a previous spinal tumor again adequately showing the surgical site to monitor for recurrence or persistent tumor.
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Figure 8-10
When dealing with pathologic fractures secondary to tumors or tumor-like processes of the spine, if instrumentation is needed, titanium instrumentation allows much better postoperative visualization with both CT and MRI for the detection of tumor recurrence as compared with standard stainless-steel instrumentation.
A: Postoperative MRI of the spine with standard stainless-steel instrumentation showing a large degree of artifact that makes interpretation difficult. B: Preoperative CT scan of a patient with an ABC of the spine. C: Postoperative CT scan of the same patient showing an adequate view of the surgical area. D: Postoperative MRI of a patient with a previous spinal tumor again adequately showing the surgical site to monitor for recurrence or persistent tumor.
A: Postoperative MRI of the spine with standard stainless-steel instrumentation showing a large degree of artifact that makes interpretation difficult. B: Preoperative CT scan of a patient with an ABC of the spine. C: Postoperative CT scan of the same patient showing an adequate view of the surgical area. D: Postoperative MRI of a patient with a previous spinal tumor again adequately showing the surgical site to monitor for recurrence or persistent tumor.
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A: Postoperative MRI of the spine with standard stainless-steel instrumentation showing a large degree of artifact that makes interpretation difficult. B: Preoperative CT scan of a patient with an ABC of the spine. C: Postoperative CT scan of the same patient showing an adequate view of the surgical area. D: Postoperative MRI of a patient with a previous spinal tumor again adequately showing the surgical site to monitor for recurrence or persistent tumor.
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Surgical Technique

  •  
    Under fluoroscopic guidance, a small longitudinal incision is made over the cyst. No flaps are created, and the dissection is carried down to the lesion level. The cyst wall is usually easily penetrated with curettes. Care should be taken to control eventual significant bleeding at the time of cyst penetration.
  •  
    Lesional tissue is than retrieved and sent for frozen section for diagnostic confirmation.
  •  
    Upon diagnostic confirmation, the cortical window is enlarged using roungers or a high-speed burr to allow appropriate visualization and excision. Using angled and straight curettes of different sizes, the intralesional resection/curettage is performed (Step 1).
  •  
    After the first step, the high-speed burr is used to extend the intralesional margins as well to excise any residual tumoral cells (Step 2).
  •  
    Step 3 entails the use of electrocautery. This has two goals: First, it helps identify residual tumor pockets and second, has the theoretical capability of killing residual tumor cells.
  •  
    Adjuvant in the form of phenol solution 5% is used for appendicular lesions (Step 4).
  •  
    The lesion is now completely excised and bone grafting is performed, usually using a combination of allograft cancellous cubes and demineralized bone matrix paste. Tight packing of the cyst is preferred. Alternatively a bone substitute, such as tricalcium phosphate, may be used for immediate structural support.
  •  
    Internal fixation is done on case-by-case basis. Lesions of weight-bearing bones, particularly of the proximal femur, and some large vertebral lesions may warrant internal fixation/instrumentation following the four-step approach.
  •  
    The wound is closed in a layered fashion. Drain is used as needed and should exit the skin in line with the excision.

Fibrous Cortical Defects and Nonossifying Fibromas

Fibrous cortical defects (FCDs) are the most common bone tumor or tumor-like condition seen in the growing child. Both FCDs and the larger variant known as nonossifying fibroma (NOF) may be associated with pathologic fractures in children. Pathologic fractures through these lesions occur more commonly in boys between 6 and 14 years old.64 
FCDs are small, well-defined, intracortical, metaphyseal lesions surrounded by a sclerotic rim with localized cortical thinning, ranging from 1 to 2 cm in diameter and most commonly found in the distal femur, proximal tibia, and fibula. FCDs can be incidentally found on radiographic studies of the lower extremity in approximately 25% of pediatric patients.64 In view of their usually asymptomatic nature, it is difficult to estimate the true incidence. They usually require no treatment other than observation. 
NOFs present at a similar age as FCDs and follow a similar distribution of bone involvement; however, multiple lesions are present in approximately one-third of patients.79 Radiographically, they present as a well-defined, eccentric radiolucent cyst-like lesion of the metaphysis that may be mostly intracortical or intramedullary and are usually larger than 4 cm,15 sometimes extending across a substantial portion of the width of the long bone.64 NOFs are also usually asymptomatic unless a pathologic fracture is present.15,64 
Several authors have suggested that FCDs and NOFs may regress spontaneously with time.79,83 Typically, this tumor remains asymptomatic and is commonly an incidental radiographic finding. However, lesions with extensive cortical involvement can cause pain because of pathologic fractures. Fractures through NOFs heal uneventfully but the lesion persists, and refracture may occur, but the incidence is low (Fig. 8-11).15,64,79,83 
Figure 8-11
A 13-year-old girl sustained a fall from her own height and developed pain and deformity around the right shoulder.
 
Anterior–posterior (A) and lateral (B) plain films show a pathologic fracture through a well-defined, eccentric, cortical based lesion in the proximal humerus metaphysis. There is sharp sclerotic rim and the lesion was clinically diagnosed as nonossifying fibroma. After 4 weeks of conservative treatment, the fractured healed (C, D) in a few degrees of varus and the lesion persisted.
Anterior–posterior (A) and lateral (B) plain films show a pathologic fracture through a well-defined, eccentric, cortical based lesion in the proximal humerus metaphysis. There is sharp sclerotic rim and the lesion was clinically diagnosed as nonossifying fibroma. After 4 weeks of conservative treatment, the fractured healed (C, D) in a few degrees of varus and the lesion persisted.
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Anterior–posterior (A) and lateral (B) plain films show a pathologic fracture through a well-defined, eccentric, cortical based lesion in the proximal humerus metaphysis. There is sharp sclerotic rim and the lesion was clinically diagnosed as nonossifying fibroma. After 4 weeks of conservative treatment, the fractured healed (C, D) in a few degrees of varus and the lesion persisted.
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Figure 8-11
A 13-year-old girl sustained a fall from her own height and developed pain and deformity around the right shoulder.
Anterior–posterior (A) and lateral (B) plain films show a pathologic fracture through a well-defined, eccentric, cortical based lesion in the proximal humerus metaphysis. There is sharp sclerotic rim and the lesion was clinically diagnosed as nonossifying fibroma. After 4 weeks of conservative treatment, the fractured healed (C, D) in a few degrees of varus and the lesion persisted.
Anterior–posterior (A) and lateral (B) plain films show a pathologic fracture through a well-defined, eccentric, cortical based lesion in the proximal humerus metaphysis. There is sharp sclerotic rim and the lesion was clinically diagnosed as nonossifying fibroma. After 4 weeks of conservative treatment, the fractured healed (C, D) in a few degrees of varus and the lesion persisted.
View Original | Slide (.ppt)
Anterior–posterior (A) and lateral (B) plain films show a pathologic fracture through a well-defined, eccentric, cortical based lesion in the proximal humerus metaphysis. There is sharp sclerotic rim and the lesion was clinically diagnosed as nonossifying fibroma. After 4 weeks of conservative treatment, the fractured healed (C, D) in a few degrees of varus and the lesion persisted.
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The size of the lesion seems to correlate directly to the risk of pathologic fracture.15 Arata et al.15 noted that all pathologic fractures associated with NOFs in the lower extremity occurred through lesions involving more than 50% of the transverse cortical diameter. These large lesions were defined as exhibiting more than 50% cortical involvement on anteroposterior (AP) and lateral radiographic studies and a height measurement of more than 33 mm.15 In their series, 43% of the pathologic fractures through NOFs were in the distal tibia. Although the authors recommended careful observation of these large NOFs, they suggested that “prophylactic curettage and bone grafting be considered if there is a reasonable chance of fracture.”15 Their series does not include any large lesion meeting their size criteria that did not fracture, and their hypothesis has never been tested in any published series. Drennan et al.79 suggested that large NOFs causing pain might predispose to fracture and recommended prophylactic curettage and bone grafting for select larger lesions. 
Easley and Kneisel83 reported that although absolute size parameters were helpful in predicting pathologic fracture, they did not imply a requirement for prophylactic curettage and bone grafting. In their series, 13 (59%) large NOFs had not had pathologic fracture despite exceeding the previously established size threshold. In the nine (41%) patients in whom pathologic fracture occurred, healing was uneventful after closed reduction and cast immobilization, and no refractures occurred. They suggested that most patients with large NOFs can be monitored without intervention, because previous studies support spontaneous resolution of most of these lesions.15,64,79 All fractured NOFs in their series healed with closed reduction and immobilization. 
Fractures are usually treated with immobilization until healing is obtained. Surgery is necessary only if the residual lesion of significant size to predispose the patient to further pathologic fractures, if there is chronic pain suggesting a stress fracture, or if there is doubt about the nature of the lesion.15,83 

Author's Preferred Method

Treatment is based on the size and location of the lesion and the type of pathologic fracture. Small lesions without fracture can be observed and may require 1 to 3 years to spontaneously resolve. Large lesions of the lower extremity in active children, even if they are assymptomatic, should either be followed carefully with serial radiographic studies or should undergo curettage and bone grafting to avoid pathologic fracture. Although absolute size parameters may be useful in predicting pathologic fracture, they do not imply a requirement for prophylactic curettage and bone grafting. Most patients with large NOFs can be monitored without surgical intervention, and fractures can be successfully managed with nonoperative treatment. Our experience is that a considerable number of incidentally discovered large NOFs do not fracture. Although we cannot readily identify an accurate denominator, we infer that many large NOFs remain unindentified and nonproblematic. Patient and family wishes and the individual's activity demands also influence the decision. Given the historic evidence for spontaneous resolution and favorable healing characteristics of NOFs, patients with lesions larger than 50% of the width of the bone should be approached individually, especially in the presence of clinical symptoms (Fig. 8-12). 
Figure 8-12
An 11-year-old boy fell while playing baseball and developed acute pain over the right distal leg/ankle area.
 
Anteroposterior (A) and lateral (B) radiographs of the right ankle show a spiral fracture through a well-defined, eccentric lesion in the lateral distal aspect of the tibia metaphysis. There is narrow zone of transition and a sclerotic border. The lesion was thought to be consistent with a nonossifying fibroma, and the fracture was allowed to heal for 5 weeks (C, D). The patient then underwent biopsy confirming the diagnosis, followed by curettage and bone grafting. Four months postoperatively (E, F) the lesion is completely healed and the patient resumed normal physical activities.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs of the right ankle show a spiral fracture through a well-defined, eccentric lesion in the lateral distal aspect of the tibia metaphysis. There is narrow zone of transition and a sclerotic border. The lesion was thought to be consistent with a nonossifying fibroma, and the fracture was allowed to heal for 5 weeks (C, D). The patient then underwent biopsy confirming the diagnosis, followed by curettage and bone grafting. Four months postoperatively (E, F) the lesion is completely healed and the patient resumed normal physical activities.
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Anteroposterior (A) and lateral (B) radiographs of the right ankle show a spiral fracture through a well-defined, eccentric lesion in the lateral distal aspect of the tibia metaphysis. There is narrow zone of transition and a sclerotic border. The lesion was thought to be consistent with a nonossifying fibroma, and the fracture was allowed to heal for 5 weeks (C, D). The patient then underwent biopsy confirming the diagnosis, followed by curettage and bone grafting. Four months postoperatively (E, F) the lesion is completely healed and the patient resumed normal physical activities.
View Original | Slide (.ppt)
Figure 8-12
An 11-year-old boy fell while playing baseball and developed acute pain over the right distal leg/ankle area.
Anteroposterior (A) and lateral (B) radiographs of the right ankle show a spiral fracture through a well-defined, eccentric lesion in the lateral distal aspect of the tibia metaphysis. There is narrow zone of transition and a sclerotic border. The lesion was thought to be consistent with a nonossifying fibroma, and the fracture was allowed to heal for 5 weeks (C, D). The patient then underwent biopsy confirming the diagnosis, followed by curettage and bone grafting. Four months postoperatively (E, F) the lesion is completely healed and the patient resumed normal physical activities.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs of the right ankle show a spiral fracture through a well-defined, eccentric lesion in the lateral distal aspect of the tibia metaphysis. There is narrow zone of transition and a sclerotic border. The lesion was thought to be consistent with a nonossifying fibroma, and the fracture was allowed to heal for 5 weeks (C, D). The patient then underwent biopsy confirming the diagnosis, followed by curettage and bone grafting. Four months postoperatively (E, F) the lesion is completely healed and the patient resumed normal physical activities.
View Original | Slide (.ppt)
Anteroposterior (A) and lateral (B) radiographs of the right ankle show a spiral fracture through a well-defined, eccentric lesion in the lateral distal aspect of the tibia metaphysis. There is narrow zone of transition and a sclerotic border. The lesion was thought to be consistent with a nonossifying fibroma, and the fracture was allowed to heal for 5 weeks (C, D). The patient then underwent biopsy confirming the diagnosis, followed by curettage and bone grafting. Four months postoperatively (E, F) the lesion is completely healed and the patient resumed normal physical activities.
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Enchondroma

Enchondromas are latent or active benign cartilaginous tumors. These lesions are often incidentally found, but the most common presenting symptom is pain associated at times with swelling. The most common sites of involvement in decreasing order of frequency are the phalanges, metacarpals, metatarsals, humerus, and femur. Pathologic fracture is commonly the presenting symptom for enchondromas located in the phalanges of the hands or feet, but is rare for enchondromas in other locations.105 
On plain radiographs, enchondromas are usually central intramedullary lesions with stippled calcification of the cartilage tumor matrix. Larger lesions may cause cortical thinning and scalloping and predisposal to pathologic fractures (Fig. 8-13). 
Figure 8-13
A 17-year-old girl with developmental delays sustained a fall and developed pain and deformity around the right proximal humerus.
 
Radiographs of the proximal humerus (A, B) demonstrated a pathologic fracture through a right proximal humerus metaphyseal lesion. There is some matrix formation with speckled calcification, some cortical thinning/scalloping, but no soft tissue mass, gross cortical disruption, or other worrisome signs. The lesion was clinically consistent with enchondroma.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs of the proximal humerus (A, B) demonstrated a pathologic fracture through a right proximal humerus metaphyseal lesion. There is some matrix formation with speckled calcification, some cortical thinning/scalloping, but no soft tissue mass, gross cortical disruption, or other worrisome signs. The lesion was clinically consistent with enchondroma.
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Figure 8-13
A 17-year-old girl with developmental delays sustained a fall and developed pain and deformity around the right proximal humerus.
Radiographs of the proximal humerus (A, B) demonstrated a pathologic fracture through a right proximal humerus metaphyseal lesion. There is some matrix formation with speckled calcification, some cortical thinning/scalloping, but no soft tissue mass, gross cortical disruption, or other worrisome signs. The lesion was clinically consistent with enchondroma.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs of the proximal humerus (A, B) demonstrated a pathologic fracture through a right proximal humerus metaphyseal lesion. There is some matrix formation with speckled calcification, some cortical thinning/scalloping, but no soft tissue mass, gross cortical disruption, or other worrisome signs. The lesion was clinically consistent with enchondroma.
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Children may present with multiple enchondromas or enchondromatosis (Ollier disease), which is commonly seen between 2 and 10 years of age. Although the lesion itself is similar to a solitary enchondroma, deformity and shortening of the extremity because of growth disturbance may occur (Fig. 8-14).273 A typical radiographic finding of enchondromatosis is the presence of linear radiolucencies extending from the metaphysis down the shaft of the long bone, frequently seen in the hands. 
Figure 8-14
An 8-year-old boy presented with pain and swelling of the ulnar border of his right hand.
 
A: Radiographic studies showed an expansile, lucent lesion of the diaphysis of the patient's right fifth metacarpal with microfractures. The patient had an open incisional biopsy with frozen section, which was consistent with enchondroma with subsequent curettage and bone grafting. B: Gross appearance of material removed at the time of surgery, which is consistent with enchondroma. C: At 6-month follow-up, the fracture is well healed, and there is no sign of recurrent tumor.
A: Radiographic studies showed an expansile, lucent lesion of the diaphysis of the patient's right fifth metacarpal with microfractures. The patient had an open incisional biopsy with frozen section, which was consistent with enchondroma with subsequent curettage and bone grafting. B: Gross appearance of material removed at the time of surgery, which is consistent with enchondroma. C: At 6-month follow-up, the fracture is well healed, and there is no sign of recurrent tumor.
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Figure 8-14
An 8-year-old boy presented with pain and swelling of the ulnar border of his right hand.
A: Radiographic studies showed an expansile, lucent lesion of the diaphysis of the patient's right fifth metacarpal with microfractures. The patient had an open incisional biopsy with frozen section, which was consistent with enchondroma with subsequent curettage and bone grafting. B: Gross appearance of material removed at the time of surgery, which is consistent with enchondroma. C: At 6-month follow-up, the fracture is well healed, and there is no sign of recurrent tumor.
A: Radiographic studies showed an expansile, lucent lesion of the diaphysis of the patient's right fifth metacarpal with microfractures. The patient had an open incisional biopsy with frozen section, which was consistent with enchondroma with subsequent curettage and bone grafting. B: Gross appearance of material removed at the time of surgery, which is consistent with enchondroma. C: At 6-month follow-up, the fracture is well healed, and there is no sign of recurrent tumor.
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When enchondromatosis is associated with multiple hemangiomas, it is known as Maffucci syndrome.175 In this syndrome, 30% of patients have one or more pathologic fractures.175 Approximately half of these fractures go on to delayed union or nonunion. Skeletal deformities tend to stabilize at maturity (Fig. 8-15). Sarcomatous degeneration has been reported in approximately 15% of patients.175 
Figure 8-15
Multiple enchondromatosis.
 
A: A 10-year-old girl with multiple enchondromas sustained a spontaneous pathologic fracture of the femur while running. The lateral radiograph shows overriding of the fracture. B: At 3-year follow-up, the fracture is well healed. C: The anteroposterior radiograph of the hand in this patient demonstrated multiple expansile enchondromas of the small bones. D: A radiograph of the humerus shows the streaked-mud appearance of the lateral humerus (arrow).
A: A 10-year-old girl with multiple enchondromas sustained a spontaneous pathologic fracture of the femur while running. The lateral radiograph shows overriding of the fracture. B: At 3-year follow-up, the fracture is well healed. C: The anteroposterior radiograph of the hand in this patient demonstrated multiple expansile enchondromas of the small bones. D: A radiograph of the humerus shows the streaked-mud appearance of the lateral humerus (arrow).
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Figure 8-15
Multiple enchondromatosis.
A: A 10-year-old girl with multiple enchondromas sustained a spontaneous pathologic fracture of the femur while running. The lateral radiograph shows overriding of the fracture. B: At 3-year follow-up, the fracture is well healed. C: The anteroposterior radiograph of the hand in this patient demonstrated multiple expansile enchondromas of the small bones. D: A radiograph of the humerus shows the streaked-mud appearance of the lateral humerus (arrow).
A: A 10-year-old girl with multiple enchondromas sustained a spontaneous pathologic fracture of the femur while running. The lateral radiograph shows overriding of the fracture. B: At 3-year follow-up, the fracture is well healed. C: The anteroposterior radiograph of the hand in this patient demonstrated multiple expansile enchondromas of the small bones. D: A radiograph of the humerus shows the streaked-mud appearance of the lateral humerus (arrow).
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Asymptomatic lesions can be observed. Biopsy may be necessary when the identity of the lesion is uncertain. Symptomatic lesions respond well to curettage and bone grafting.105,273 Treatment should be individualized for displaced fractures. 

Author's Preferred Method

For asymptomatic patients with small lesions with classic radiographic findings, biopsy is not necessary. Curettage and bone grafting are necessary for those lesions with acute or impending pathologic fracture, or in cases of continued pain. Fixation is not necessary for lesions of the short tubular bones but may be necessary for lesions of the proximal femur or long bone of the lower extremity. Standard fracture care is adequate to treat most pathologic fractures, but the bone quality may be compromised by the tumor and it may be difficult fixation. 

Osteochondroma

Osteochondromas are one of the most common tumors of bone in children, and clinical symptoms are usually related to irritation of the surrounding soft-tissue structures. The radiographic appearance is pathognomonic, with a continuity of the host bone cortex with the outer cortex of the lesion and intramedullary cavities, in the same fashion. Although fractures associated with osteochondromas are rare, they may occur through the base or stalk of a pedunculated tumor (Fig. 8-16).51 Fractures through osteochondromas should be treated conservatively; however, excision in the acute phase may be considered because the fragment is “floating free” in the soft tissues. The cartilage cap surrounding the lesion should always be removed to avoid the risk of recurrence. 
Figure 8-16
A 13-year-old girl presented with right knee pain following direct trauma to that area 10 days prior.
 
On anteroposterior (A) and lateral (B) radiographs, there was a pathologic fracture through the base of a pedunculated osteochondroma (arrow). The patient was very tender around that area and elected surgical excision. Immediately after excision (C, D), there was improvement of the symptoms. Four weeks later, she returned to full activities.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
On anteroposterior (A) and lateral (B) radiographs, there was a pathologic fracture through the base of a pedunculated osteochondroma (arrow). The patient was very tender around that area and elected surgical excision. Immediately after excision (C, D), there was improvement of the symptoms. Four weeks later, she returned to full activities.
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Figure 8-16
A 13-year-old girl presented with right knee pain following direct trauma to that area 10 days prior.
On anteroposterior (A) and lateral (B) radiographs, there was a pathologic fracture through the base of a pedunculated osteochondroma (arrow). The patient was very tender around that area and elected surgical excision. Immediately after excision (C, D), there was improvement of the symptoms. Four weeks later, she returned to full activities.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
On anteroposterior (A) and lateral (B) radiographs, there was a pathologic fracture through the base of a pedunculated osteochondroma (arrow). The patient was very tender around that area and elected surgical excision. Immediately after excision (C, D), there was improvement of the symptoms. Four weeks later, she returned to full activities.
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Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is a rare group of disorders with a wide spectrum of clinical presentation, where the constant pathologic finding is the “Langerhans cell.” The present nomenclature defines solitary osseous lesion as eosinophilic granuloma (EG). The annual incidence of LCH is at 6 per million children per year.31 Males are affected to a slightly higher degree than females.43,133 It is predominantly a disease of childhood, with more than 50% of cases diagnosed between the ages of 1 and 15, and peak in incidence between the ages of 1 and 4.31,43 The clinical course of the disease is quite variable, with some forms undergoing seemingly spontaneous remission. The disease can be localized to a bone or single system, or multifocal involving multiple bones and/or systems. 
Bone pain is the initial symptom in 50% to 90% of the patients with osseous lesion.72 Other reported symptoms in osseous LCH include swelling, tenderness, pathologic fractures, diminished hearing, and otitis media (mastoid lesions) or loose teeth (mandible lesions). Vertebral collapse may produce pain and spasm, torticollis may be seen with cervical spine lesions, and kyphosis might develop with thoracic lesions but neurologic symptoms are uncommon.97,174,224 
The radiographic appearance is highly variable, but often lesions are radiolucent with well-defined margins, with or without surrounding sclerosis. Skeletal lesions may be solitary or multiple. Most long bone lesions involve the diaphysis or metaphysis, with destructive osteolysis and overlying expansion by periosteal layering.43 Epiphyseal involvement is rare but may occur. 
Vertebral destruction with complete collapse of the vertebral body is classically referred to as “vertebra plana.” Adjacent intervertebral disc height is usually maintained (Fig. 8-17). Spinal lesions can be classified based on the amount and pattern of maximal vertebral collapse103: Grade I (0% to 50% of collapse), grade II (51% to 100%), or grade III (limited to the posterior elements); and A (symmetric collapse) or B (asymmetric collapse). 
Figure 8-17
A 5-year-old boy presented with a history of several months of intermittent back pain and recent development of right inguinal pain.
 
On pelvic radiographs (A) a lytic lesion of the right superior pubic rami is visualized (arrow). There is no soft tissue mass, periosteal reaction, or other worrisome signs. The lumbar spine radiographs (B, C) show a classic “vertebra plana” of L3 (arrow). (D) Sagittal T1-weighted MRI shows no soft tissue mass or other associated lesions, no compromise of the spinal canal and no extension to the posterior elements. The pelvic lesion was biopsied and a diagnosis of polyostotis Langerhans cell histiocytosis was made.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
On pelvic radiographs (A) a lytic lesion of the right superior pubic rami is visualized (arrow). There is no soft tissue mass, periosteal reaction, or other worrisome signs. The lumbar spine radiographs (B, C) show a classic “vertebra plana” of L3 (arrow). (D) Sagittal T1-weighted MRI shows no soft tissue mass or other associated lesions, no compromise of the spinal canal and no extension to the posterior elements. The pelvic lesion was biopsied and a diagnosis of polyostotis Langerhans cell histiocytosis was made.
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Figure 8-17
A 5-year-old boy presented with a history of several months of intermittent back pain and recent development of right inguinal pain.
On pelvic radiographs (A) a lytic lesion of the right superior pubic rami is visualized (arrow). There is no soft tissue mass, periosteal reaction, or other worrisome signs. The lumbar spine radiographs (B, C) show a classic “vertebra plana” of L3 (arrow). (D) Sagittal T1-weighted MRI shows no soft tissue mass or other associated lesions, no compromise of the spinal canal and no extension to the posterior elements. The pelvic lesion was biopsied and a diagnosis of polyostotis Langerhans cell histiocytosis was made.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
On pelvic radiographs (A) a lytic lesion of the right superior pubic rami is visualized (arrow). There is no soft tissue mass, periosteal reaction, or other worrisome signs. The lumbar spine radiographs (B, C) show a classic “vertebra plana” of L3 (arrow). (D) Sagittal T1-weighted MRI shows no soft tissue mass or other associated lesions, no compromise of the spinal canal and no extension to the posterior elements. The pelvic lesion was biopsied and a diagnosis of polyostotis Langerhans cell histiocytosis was made.
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Biopsy is usually necessary to confirm the diagnosis and also to differentiate LCH from malignancies that may present with similar radiographic appearance. Biopsy can usually be done minimally invasively through the pedicle. One should not violate posterior ligaments or progressive kyphosis will result. If nonspine sites are biopsy-proven LCH, and the spine involvement is classic for vertebra plana, a biopsy of the spine may not be needed. Once the diagnosis is established, treatment options include observation or curettage and bone grafting.43,108,133 Surgical intervention is uncommon. Localized kyphosis is present, but can usually be treated with a brace (TLSO) for approximately 3 months. Chemotherapy with prednisone and vinblastine is indicated for cases of multiple bone involvement or visceral disease.16 Pathologic fracture is uncommon in patients with LCH. Standard fracture care is usually sufficient for pathologic fractures. 

Malignant Bone Tumors and Metastasis

Pathologic fractures can sometimes be the presenting symptom of a malignant bone tumor (Fig. 8-18). The two most common primary bone malignancies in children are osteosarcoma and Ewing sarcoma. Destructive bone lesions can also be caused by metastasis, being more common than primary tumors in certain age groups. Careful staging and biopsy20,250 are critical in the approach to children with bone tumors. However, biopsy is not done without risks. One of the main complications following biopsies is pathologic fracture caused by a decrease in the torsional strength of the bone following cortical drilling. To prevent a pathologic fracture, an oval hole with smooth edges should be used, preferably in areas of less stress for weight-bearing bones. Sometimes, the biopsy hole can be filled with bone cement or other grafting material. Because most bone sarcomas are associated to a large soft-tissue mass that can be sampled, drilling of the bone may be avoided. 
Figure 8-18
A 13-year-old boy presented with several months history of right arm pain and recent increase in pain following minor trauma.
 
Anteroposterior (A) and lateral (B) radiographs show a minimally displaced midshaft humeral pathologic fracture (arrow) through a poorly defined, permeative, aggressive-looking diaphyseal lesion. C: T2-weighted axial MRI shows a huge soft tissue mass associated with the bone lesion and involvement of the neurovascular bundle. The patient was diagnosed with Ewing sarcoma, received neoadjuvant chemotherapy, and had a shoulder disarticulation (D), followed by postoperative chemotherapy.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs show a minimally displaced midshaft humeral pathologic fracture (arrow) through a poorly defined, permeative, aggressive-looking diaphyseal lesion. C: T2-weighted axial MRI shows a huge soft tissue mass associated with the bone lesion and involvement of the neurovascular bundle. The patient was diagnosed with Ewing sarcoma, received neoadjuvant chemotherapy, and had a shoulder disarticulation (D), followed by postoperative chemotherapy.
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Figure 8-18
A 13-year-old boy presented with several months history of right arm pain and recent increase in pain following minor trauma.
Anteroposterior (A) and lateral (B) radiographs show a minimally displaced midshaft humeral pathologic fracture (arrow) through a poorly defined, permeative, aggressive-looking diaphyseal lesion. C: T2-weighted axial MRI shows a huge soft tissue mass associated with the bone lesion and involvement of the neurovascular bundle. The patient was diagnosed with Ewing sarcoma, received neoadjuvant chemotherapy, and had a shoulder disarticulation (D), followed by postoperative chemotherapy.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Anteroposterior (A) and lateral (B) radiographs show a minimally displaced midshaft humeral pathologic fracture (arrow) through a poorly defined, permeative, aggressive-looking diaphyseal lesion. C: T2-weighted axial MRI shows a huge soft tissue mass associated with the bone lesion and involvement of the neurovascular bundle. The patient was diagnosed with Ewing sarcoma, received neoadjuvant chemotherapy, and had a shoulder disarticulation (D), followed by postoperative chemotherapy.
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One of the major advances in the care of children with extremity sarcoma has been the development of limb-sparing surgical techniques for local control of the tumor. Pathologic fracture has previously been cited as a contraindication to limb salvage because of concerns about tumor dissemination by fracture hematoma, and inability in obtaining free margins following resection. Several studies, however, have shown that pathologic fractures eventually heal during neoadjuvant chemotherapy and may not preclude limb salvage, or affect survival rates (Fig. 8-19).89,278 Abudu et al.1 reviewed the surgical treatment and outcome of pathologic fractures in 40 patients with localized osteosarcoma and found that limb-sparing surgery with adequate margins could be achieved in many patients but that there was a 19% recurrence rate, without compromising overall survival. Scully et al.241 reviewed the surgical treatment of 18 patients with osteosarcoma and pathologic fractures. Of the 10 patients who had limb-sparing surgery, three had local recurrences and six had distant recurrences. Although the distant recurrence rate for patients undergoing amputation was no different from the rate for those undergoing limb salvage, the difference in local tumor control approached statistical significance. All patients who developed local recurrence died. The authors stated that surgical treatment should be individualized. Bacci et al.21 compared the disease-free survival and overall survival of 46 patients with nonmetastatic osteogenic sarcoma of the extremity and pathologic fracture to a cohort of 689 patients without pathologic fracture and found no significant difference. Limb-sparing surgery was possible and appropriate in carefully selected patients as long as wide margins could be safely achieved. 
Figure 8-19
An 8-year-old girl sustained a pathologic fracture of the femur after falling off her bicycle.
 
She denied symptoms previous to this injury. The radiographs (A, B) showed a grossly displaced fracture through a poorly defined, mixed lesion in the midshaft of the femur (arrow); there is disorganized periosteal reaction with sunburst sign. T2-weighted coronal (C), and axial (D) MRI showed extensive soft tissue mass; the neurovascular bundle (arrow) does not seem do be involved by the tumor mass. The patient underwent biopsy that confirmed osteogenic sarcoma and fracture stabilization with an external fixator at a referring institute. Note that the external fixator pins were inappropriately placed too far from the tumor and fracture site (E) postoperative appearance following Van Ness rotationplasty. The patient is continuously free of disease, 5 years after surgery. Flexion and extension of the ankle, now used as a knee (F and G).
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
She denied symptoms previous to this injury. The radiographs (A, B) showed a grossly displaced fracture through a poorly defined, mixed lesion in the midshaft of the femur (arrow); there is disorganized periosteal reaction with sunburst sign. T2-weighted coronal (C), and axial (D) MRI showed extensive soft tissue mass; the neurovascular bundle (arrow) does not seem do be involved by the tumor mass. The patient underwent biopsy that confirmed osteogenic sarcoma and fracture stabilization with an external fixator at a referring institute. Note that the external fixator pins were inappropriately placed too far from the tumor and fracture site (E) postoperative appearance following Van Ness rotationplasty. The patient is continuously free of disease, 5 years after surgery. Flexion and extension of the ankle, now used as a knee (F and G).
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She denied symptoms previous to this injury. The radiographs (A, B) showed a grossly displaced fracture through a poorly defined, mixed lesion in the midshaft of the femur (arrow); there is disorganized periosteal reaction with sunburst sign. T2-weighted coronal (C), and axial (D) MRI showed extensive soft tissue mass; the neurovascular bundle (arrow) does not seem do be involved by the tumor mass. The patient underwent biopsy that confirmed osteogenic sarcoma and fracture stabilization with an external fixator at a referring institute. Note that the external fixator pins were inappropriately placed too far from the tumor and fracture site (E) postoperative appearance following Van Ness rotationplasty. The patient is continuously free of disease, 5 years after surgery. Flexion and extension of the ankle, now used as a knee (F and G).
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Figure 8-19
An 8-year-old girl sustained a pathologic fracture of the femur after falling off her bicycle.
She denied symptoms previous to this injury. The radiographs (A, B) showed a grossly displaced fracture through a poorly defined, mixed lesion in the midshaft of the femur (arrow); there is disorganized periosteal reaction with sunburst sign. T2-weighted coronal (C), and axial (D) MRI showed extensive soft tissue mass; the neurovascular bundle (arrow) does not seem do be involved by the tumor mass. The patient underwent biopsy that confirmed osteogenic sarcoma and fracture stabilization with an external fixator at a referring institute. Note that the external fixator pins were inappropriately placed too far from the tumor and fracture site (E) postoperative appearance following Van Ness rotationplasty. The patient is continuously free of disease, 5 years after surgery. Flexion and extension of the ankle, now used as a knee (F and G).
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
She denied symptoms previous to this injury. The radiographs (A, B) showed a grossly displaced fracture through a poorly defined, mixed lesion in the midshaft of the femur (arrow); there is disorganized periosteal reaction with sunburst sign. T2-weighted coronal (C), and axial (D) MRI showed extensive soft tissue mass; the neurovascular bundle (arrow) does not seem do be involved by the tumor mass. The patient underwent biopsy that confirmed osteogenic sarcoma and fracture stabilization with an external fixator at a referring institute. Note that the external fixator pins were inappropriately placed too far from the tumor and fracture site (E) postoperative appearance following Van Ness rotationplasty. The patient is continuously free of disease, 5 years after surgery. Flexion and extension of the ankle, now used as a knee (F and G).
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She denied symptoms previous to this injury. The radiographs (A, B) showed a grossly displaced fracture through a poorly defined, mixed lesion in the midshaft of the femur (arrow); there is disorganized periosteal reaction with sunburst sign. T2-weighted coronal (C), and axial (D) MRI showed extensive soft tissue mass; the neurovascular bundle (arrow) does not seem do be involved by the tumor mass. The patient underwent biopsy that confirmed osteogenic sarcoma and fracture stabilization with an external fixator at a referring institute. Note that the external fixator pins were inappropriately placed too far from the tumor and fracture site (E) postoperative appearance following Van Ness rotationplasty. The patient is continuously free of disease, 5 years after surgery. Flexion and extension of the ankle, now used as a knee (F and G).
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Pathologic fracture after limb-sparing surgery is another major complication, occurring most commonly after allograft reconstruction but also after limb salvage with endoprosthetic reconstruction.30,272 Berrey et al.30 reviewed 43 patients with fractures through a massive allograft used for limb reconstruction after resection of tumors. Four fractures healed with immobilization alone, and the remainder of patients attained satisfactory results with open reduction and grafting, replacement of the internal fixation device, or total joint replacement. San-Julian and Canadell238 reported on 12 patients with 14 fractures (10.2% of 137 patients with allograft for limb-sparing surgery in their series). They recommended intramedullary fixation whenever possible to reduce the incidence of allograft fracture. 
Pathologic fractures can also occur in children with metastatic disease but are less common than in adults. Furthermore, most are microfractures and can be successfully managed conservatively. 

Author's Preferred Method

For all suspicious lesions, careful staging and biopsy are the appropriate initial approach. Experience in the management of children with musculoskeletal sarcomas, and access to special diagnostic modalities, such as immunohistochemistry and cytogenetics, will decrease the chances of mismanagement and misdiagnosis. The decision for or against limb-sparing surgery in patients with pathologic fracture associated with a bone sarcoma should be individualized based on factors such as the fracture displacement, fracture stability, histologic and radiographic response to chemotherapy, and, most important, the ability to achieve wide margins for local tumor control. Pathologic fractures that occur after reconstruction through allograft or endoprosthetic reconstruction often can be successfully treated with bone grafting or exchange of allograft or endoprosthesis. 

Fibrous Dysplasia

FD is a benign bone abnormality characterized by replacement of normal bone and marrow by fibrous–osseous tissue (woven bone formed by metaplasia with poorly oriented bone trabeculae) resulting in decrease of strength, deformity, and pathologic fracture. The disease may involve a single bone (monostotic FD) or several (poliostotic FD). When bone disease is associated with café-au-lait skin hyperpigmentation and endocrine dysfunction, it is referred as McCune–Albright syndrome.209 
The diagnosis of FD is usually made between 5 and 15 years of age. Often, the lesions are asymptomatic and a pathologic fracture may be the presenting symptom. Fractures of long bones are generally minimally displaced or incomplete, many being microfractures and presenting with pain and swelling.171 The bones most commonly affected are the femur, tibia, humerus, radius, facial bones, pelvis, ribs, and phalanges. The sites of fracture in decreasing order of frequency are the proximal femur, tibia, ribs, and bones of the face. The age of first fracture, number of fractures, and fracture rate are related to the severity of the metabolic derangement. The endocrinopathies are often associated with phosphaturia that causes a rickets-type effect on the normal skeleton and is related to increased incidence of fractures.171 Although the fractures heal rapidly, endosteal callus is poorly formed and periosteal callus is normal. With mild deformity, the cortex thickens on the concave side of the long bone. Nonunion is rare in monostotic FD, but can occur in polyostotic disease. Spine involvement occurs with polyostotic FD, and limb-length discrepancy is common.121 In one series of 37 patients with polyostotic FD, nearly 85% had at least one fracture and 40% had an average of three fractures.121 
On plain radiographs, FD is seen as well-defined, mostly lytic and central lesion, located in the metaphysis or diaphysis of long bones. The borders are commonly sclerotic and the metaplastic woven bone comprising the lesion creates the classic “ground-glass” appearance (Fig. 8-20). Bowing and/or angular deformity of tibia and femur are often seen. In distinguishing polyostotic from monostotic FD, skeletal surveys and sometimes technetium bone scans are recommended. 
Figure 8-20
A 6-year-old girl presented with right arm acute pain after hitting the elbow in the bathtub.
 
Radiographs of the humerus (A, B) show a nondisplaced pathologic fracture through a humeral diaphyseal lesion (arrow). The lesion is well defined, mostly lytic but with definite matrix, cortical thinning, no periosteal reaction. MRI T1-(C) and T2-weighted (D) coronal images demonstrate absence of soft tissue mass or other aggressiveness signs. Bone scan shows increased activity at the lesion and fracture site (arrow) E: The patient underwent open incisional biopsy that confirmed the diagnostic of fibrous dysplasia.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs of the humerus (A, B) show a nondisplaced pathologic fracture through a humeral diaphyseal lesion (arrow). The lesion is well defined, mostly lytic but with definite matrix, cortical thinning, no periosteal reaction. MRI T1-(C) and T2-weighted (D) coronal images demonstrate absence of soft tissue mass or other aggressiveness signs. Bone scan shows increased activity at the lesion and fracture site (arrow) E: The patient underwent open incisional biopsy that confirmed the diagnostic of fibrous dysplasia.
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Figure 8-20
A 6-year-old girl presented with right arm acute pain after hitting the elbow in the bathtub.
Radiographs of the humerus (A, B) show a nondisplaced pathologic fracture through a humeral diaphyseal lesion (arrow). The lesion is well defined, mostly lytic but with definite matrix, cortical thinning, no periosteal reaction. MRI T1-(C) and T2-weighted (D) coronal images demonstrate absence of soft tissue mass or other aggressiveness signs. Bone scan shows increased activity at the lesion and fracture site (arrow) E: The patient underwent open incisional biopsy that confirmed the diagnostic of fibrous dysplasia.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs of the humerus (A, B) show a nondisplaced pathologic fracture through a humeral diaphyseal lesion (arrow). The lesion is well defined, mostly lytic but with definite matrix, cortical thinning, no periosteal reaction. MRI T1-(C) and T2-weighted (D) coronal images demonstrate absence of soft tissue mass or other aggressiveness signs. Bone scan shows increased activity at the lesion and fracture site (arrow) E: The patient underwent open incisional biopsy that confirmed the diagnostic of fibrous dysplasia.
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Conservative treatment with immobilization is indicated for most fractures that occur in conjunction with monostotic FD. Surgery is indicated for fractures through severely deformed long bones (especially in the lower extremities), and those through large cystic areas. Fractures in polyostotic disease often require more aggressive treatment. 
Fractures of the femur can be treated conservatively in young patients, but after adolescence, recurrent deformity after surgery is less common, and curettage and grafting with internal fixation should be considered, especially for large lesions through deformed bones.121 Stephenson et al.258 found that in patients younger than 18 years of age, closed treatment or curettage and bone grafting alone of lower extremity fractures gave unsatisfactory results, but internal fixation produced more satisfactory outcomes. 
Proximal femoral pathologic fractures are especially troublesome because of the propensity for malunion with coxa vara resembling a shepherd's crook.71 For fractures through small lesions, either cast immobilization or curettage with grafting can be used100; for larger lesions, internal fixation is necessary. For severe shepherd's crook deformity, medial displacement valgus osteotomies with internal fixation may be needed to restore the biomechanical stability of the hip. Both painful lesions without fracture and impending pathologic fractures can be treated with internal fixation. Spine fractures are rare but can be treated with bed rest followed by immobilization with an orthosis.114 
The main challenge in bone grafting FD is the potential for resorption and transformation into FD. Autogenous cancellous graft has the higher likelihood to become FD, and cortical allograft is the least likely to be transformed.71 The use of bisphosphonates, primarily pamidronate, may offer hope for a medical treatment for patients with severe FD. Pamidronate is a second-generation bisphosphonate that has had documented success in selected patients with the disease. It is a potent inhibitor of bone resorption and has a lasting effect on bone turnover. The major effect is decreased bone pain. Improved bone density with pamidronate therapy has also been demonstrated.209 

Author's Preferred Method of Treatment

Conservative treatment with immobilization is indicated for most fractures in children with monostotic FD, especially in the upper extremities. Because fractures in patients with polyostotic FD usually occur through very abnormal bone and can result in marked deformity, internal fixation is often needed. 
Curettage and grafting are indicated for fractures through severely deformed long bones and those through large cystic areas, with appropriate internal fixation for the location and age. Bone graft is often reabsorbed and transformed into FD, allograft has a lower likelihood to be reabsorbed than autograft. Recently, the use of coral as bone substitute has been shown to be an alternative.71 
For proximal femur pathologic fractures one must be vigilant and ready to intervene at any sign of varus deformity. Femoral neck fractures can be stabilized in situ with a cannulated screw or compression screw and side plate. Varus deformity is best treated with valgus osteotomy of the subtrochanteric region and internal fixation early in the course of the disease to restore the normal neck shaft angle and mechanical axis. Intramedullary load-sharing fixation is preferred for juvenile patients with femoral shaft fractures, total bone fixation is the ideal and second-generation intramedullary nails should be used when possible. 

Osteofibrous Dysplasia

Osteofibrous dysplasia (OD) is a rare developmental tumor-like fibro-osseous condition. Most patients present before the age of 5 years, ranging from 0 to 15 years of age.47,216 Clinically, there is usually a painless enlargement of the tibia with slight to moderate anterior or anterolateral bowing. The disease process is almost always confined to one tibia, but the ipsilateral fibula can also be involved. Although distal and proximal lesions can occur, midshaft involvement is the most frequent. Pathologic fractures occur in approximately one-third of patients; but are usually incomplete (e.g., stress fractures, microfractures) or minimally displaced and heal well with conservative treatment.47 Pseudarthrosis is rare but sometimes delayed union may be a problem. 
OD presents as a well-defined, eccentric, intracortical, lytic lesion usually located in the middle third of the tibia, extending proximally or distally.216 The cortex overlying the lesion is expanded and thinned, and in the medullary canal, a dense band of sclerosis borders the lesion with narrowing of the medullary canal. Single areas of radiolucency may be present and have a ground-glass appearance, but often there are several areas of involvement with a bubble-like appearance (Fig. 8-21). Intralesional curettage and grafting lead to local recurrence in over 60% of the cases.47 Wide extraperiosteal resection can be performed for aggressive lesions and present with lower rate of recurrence.168 Some authors6,155 recommend bracing until skeletal maturity. 
Figure 8-21
Anterior–posterior and lateral radiographs (A and B) of a 10 year-old female who sustained a ground level fall at school and developed acute pain in the midshaft tibia.
 
Note the eccentric, well-defined nature of this mostly lytic lesion in the diaphysis. There is an incomplete transverse fracture and the posterior cortex is spared. The lesion was consistent with osteofibrous dysplasia and the child did well with conservative treatment as seen in the images 3 months and 12 months after the pathologic fracture (C and D).
 
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
Note the eccentric, well-defined nature of this mostly lytic lesion in the diaphysis. There is an incomplete transverse fracture and the posterior cortex is spared. The lesion was consistent with osteofibrous dysplasia and the child did well with conservative treatment as seen in the images 3 months and 12 months after the pathologic fracture (C and D).
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Figure 8-21
Anterior–posterior and lateral radiographs (A and B) of a 10 year-old female who sustained a ground level fall at school and developed acute pain in the midshaft tibia.
Note the eccentric, well-defined nature of this mostly lytic lesion in the diaphysis. There is an incomplete transverse fracture and the posterior cortex is spared. The lesion was consistent with osteofibrous dysplasia and the child did well with conservative treatment as seen in the images 3 months and 12 months after the pathologic fracture (C and D).
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
Note the eccentric, well-defined nature of this mostly lytic lesion in the diaphysis. There is an incomplete transverse fracture and the posterior cortex is spared. The lesion was consistent with osteofibrous dysplasia and the child did well with conservative treatment as seen in the images 3 months and 12 months after the pathologic fracture (C and D).
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Pathologic fractures heal conservatively. In cases of recurrent fracture or rapid progression, wide extraperiosteal resection and grafting may be indicated.47 Open reduction with bone grafting and internal fixation may be recommended for fractures with angular deformity. Bracing is recommended to prevent fractures and angular deformity. 

Neurofibromatosis

Neurofibromatosis (NF), also known as von Recklinghausen disease (NF type-1), is an autosomal dominant condition with variable penetrance that occurs in one in 2,500 to 3,000 live births.63 It affects neural tissue, vascular structures, skin, and the skeleton. The clinical diagnosis is based on the presence of at least two of these signs: Multiple café-au-lait spots (six or more >5 mm); family history of NF (first degree relative); biopsy-proven neurofibroma (two or more neurofibromas or one plexiform neurofibroma); skeletal deformity (e.g., pseudarthrosis of the tibia, hemihypertrophy, or a short, angular scoliosis); Lisch nodules (two or more); axillary or inguinal freckling.63 
Approximately 20% of normal children have one or two café-au-lait spots with a diameter of more than 0.5 cm, therefore five or more café-au-lait spots are needed to suggest the diagnosis of NF.63 Café-au-lait spots are not usually seen until 5 or 6 years of age.63 The presence of a biopsy-proven neurofibroma is a valuable criterion for diagnosis, but tends not to be clinically apparent until the child is 12 years or older.63 Approximately 5% of NF patients develop pseudarthrosis of long bones; the tibia is the most commonly affected. On the other hand, 55% of the cases of congenital pseudarthroses of the tibia are thought to be associated with NF.63 The appearance of pseudarthroses and their resistance to treatment may be associated to a deficiency of bone formation secondary to mesodermal dysplasia. Anterior bowing of the leg develops at an average age of 8 months and fracture and pseudarthrosis at an average of 1 year. Therefore, the term congenital pseudarthrosis is misleading because the majority of patients do not have pseudarthrosis at birth.199 Pseudarthroses may also occur in the radius, ulna, femur, clavicle, and humerus.27,44,199 
Children with NF-type 1 have a general tendency toward osteopenia and osteoporosis, suggesting an abnormal underlying bone phenotype. This may be a reason as why there is a high incidence of pseudarthrosis, nonunion, and poor bone healing associated with NF.82 
The radiographic presentation of tibial involvement is with anterolateral bowing and loss of the medullary canal, or cystic lesion, followed by fracture.44,63,82 Patients with established pseudarthroses present with narrowing or obliteration of the medullary, sclerosis, and anterolateral angulation. Pseudarthrosis of the fibula may also be present and leads to valgus deformity of the ankle. 
Tibia bowing in an infant or child tends to eventually fracture; however, simple osteotomy to correct angular deformity accelerates the progression to pseudarthrosis and is usually not indicated as a stand-alone treatment. Bracing may be helpful in preventing fracture and angular deformity, but is ineffective in the treatment of an established pseudarthrosis. Once pathologic fracture occurs, casting will likely fail but may be attempted. Surgical treatment of pseudarthrosis includes excision of the hypotrophic bone ends followed by grafting and internal and/or external fixation. Grafting alternatives include auto (e.g., vascularized fibula, iliac crest) or allografting and periosteal grafting. Fixation is done through intramedullary nailing, or external fixation for compression of the pseudarthrosis and concurrent callotastic lengthening. All of these methods may be complicated by further pathologic fracture and nonunion. The rate of success ranges from 7% to 90%. A prophylactic bypass grafting of the prepseudarthrotic tibia in NF has been performed with some success (Fig. 8-22).261 More recently, authors have been reporting on the use of recombinant human bone morphogenetic protein with promising results.92,166 
Figure 8-22
 
A: A 2-year-old boy with neurofibromatosis presented with anterolateral bowing, sclerosis, and partial obliteration of the medullary canal of the tibia without fracture. B: A modified McFarland technique for prophylactic bypass grafting was performed as shown. C: Immediate postsurgical radiographs of the tibia after prophylactic bypass grafting. D: Three years later, radiographs show continued growth of the tibia without fracture but some absorption of the allograft and relative loss of structural support by the allograft related to continued growth.
 
(From Dormans JP. Modified sequential McFarland bypass procedure for prepseudarthrosis of the tibia. J Orthop Tech. 1995; 3:176–180, with permission.)
A: A 2-year-old boy with neurofibromatosis presented with anterolateral bowing, sclerosis, and partial obliteration of the medullary canal of the tibia without fracture. B: A modified McFarland technique for prophylactic bypass grafting was performed as shown. C: Immediate postsurgical radiographs of the tibia after prophylactic bypass grafting. D: Three years later, radiographs show continued growth of the tibia without fracture but some absorption of the allograft and relative loss of structural support by the allograft related to continued growth.
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Figure 8-22
A: A 2-year-old boy with neurofibromatosis presented with anterolateral bowing, sclerosis, and partial obliteration of the medullary canal of the tibia without fracture. B: A modified McFarland technique for prophylactic bypass grafting was performed as shown. C: Immediate postsurgical radiographs of the tibia after prophylactic bypass grafting. D: Three years later, radiographs show continued growth of the tibia without fracture but some absorption of the allograft and relative loss of structural support by the allograft related to continued growth.
(From Dormans JP. Modified sequential McFarland bypass procedure for prepseudarthrosis of the tibia. J Orthop Tech. 1995; 3:176–180, with permission.)
A: A 2-year-old boy with neurofibromatosis presented with anterolateral bowing, sclerosis, and partial obliteration of the medullary canal of the tibia without fracture. B: A modified McFarland technique for prophylactic bypass grafting was performed as shown. C: Immediate postsurgical radiographs of the tibia after prophylactic bypass grafting. D: Three years later, radiographs show continued growth of the tibia without fracture but some absorption of the allograft and relative loss of structural support by the allograft related to continued growth.
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Amputation should be considered and discussed with the family early when previous operative interventions have been unsuccessful. Amputation is usually Syme's, with prosthetic fitting around the pseudarthrosis. In a gait analysis study, Karol et al.144 compared 12 patients with previously operated and healed congenital pseudarthroses of the tibia with four children with amputations for final treatment of congenital pseudarthroses of the tibia. They found marked disturbance of gait and muscle strength in patients with healed congenital pseudarthroses of the tibia. They concluded that patients with early onset of disease, early surgery, and trans-ankle fixation had more inefficient gaits than amputees. 
Patients with forearm pseudarthroses can be pain free and function may be satisfactory with observation or splinting. However, persistence of an ulnar pseudarthrosis in a growing child may lead to bowing of the radius and posterior lateral subluxation or dislocation of the radial head. Union after conventional bone grafting and fixation has been reported in only a small number of patients with congenital pseudarthrosis of the forearm.27 Many of these patients require multiple conventional bone grafting procedures and often years of immobilization. The results of treatment of congenital pseudarthrosis of the forearm in NF by free vascularized fibular grafts are encouraging.187 Other surgical options include excision of the ulnar pseudarthrosis to avoid a later tethering effect on the growing radius and fusion of the distal radius and ulnar joint.7 
Extreme care should be taken in the surgical treatment of children with NF, as complications are common. Hypertension is present in up to 16% of children with NF.270 The periosteum is less adherent to the bone, and extensive subperiosteal hemorrhage may result from a trauma, an osteotomy, or other surgical procedure.279 

Author's Preferred Method of Treatment

The treatment of congenital pseudarthrosis of the tibia remains controversial. When a child presents with prepseudarthrosis (angulation without fracture), either bypass grafting with fibular allograft or bracing are reasonable options. Once pseudarthrosis has developed, our preference is inserting an intramedullary rod and bone grafting of both the tibia and fibula when possible (Fig. 8-23). If these procedures fail, free vascularized fibula transfer or resection and bone transport with circular frame techniques can be considered. Amputation and prosthetic fitting should be considered early in patients with failure of the techniques mentioned above and severe shortening and a stiff ankle and foot. Conservative options, such as bracing or observation, for upper extremity pseudarthroses may be justified in a patient with a nonprogressive deformity and a satisfactory functional use of the extremity. Conventional bone grafting and fixation procedures for treatment of pseudarthrosis of the upper extremity have very limited success, and other approaches should be considered. 
Figure 8-23
A 19-month-old girl presented with right leg bowing and recent inability to bear weight on that extremity.
 
The patient has neurofibromatosis type 1 with associated café-au-lait spots (A). Anteroposterior (B) and lateral (C) radiographs of the tibia and fibula show pseudarthrosis of the tibia diaphysis associated with intramedullary obliteration and bone thinning at the pseudarthrosis level. The fibula presents anterior-lateral deformity and partial obliteration of the medullary canal without fracture. Postoperative images (D, E) following excision of the pseudarthrosis, fibular osteotomy, iliac bone graft and periosteum grafting, and fixation with a William rod.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
The patient has neurofibromatosis type 1 with associated café-au-lait spots (A). Anteroposterior (B) and lateral (C) radiographs of the tibia and fibula show pseudarthrosis of the tibia diaphysis associated with intramedullary obliteration and bone thinning at the pseudarthrosis level. The fibula presents anterior-lateral deformity and partial obliteration of the medullary canal without fracture. Postoperative images (D, E) following excision of the pseudarthrosis, fibular osteotomy, iliac bone graft and periosteum grafting, and fixation with a William rod.
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Figure 8-23
A 19-month-old girl presented with right leg bowing and recent inability to bear weight on that extremity.
The patient has neurofibromatosis type 1 with associated café-au-lait spots (A). Anteroposterior (B) and lateral (C) radiographs of the tibia and fibula show pseudarthrosis of the tibia diaphysis associated with intramedullary obliteration and bone thinning at the pseudarthrosis level. The fibula presents anterior-lateral deformity and partial obliteration of the medullary canal without fracture. Postoperative images (D, E) following excision of the pseudarthrosis, fibular osteotomy, iliac bone graft and periosteum grafting, and fixation with a William rod.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
The patient has neurofibromatosis type 1 with associated café-au-lait spots (A). Anteroposterior (B) and lateral (C) radiographs of the tibia and fibula show pseudarthrosis of the tibia diaphysis associated with intramedullary obliteration and bone thinning at the pseudarthrosis level. The fibula presents anterior-lateral deformity and partial obliteration of the medullary canal without fracture. Postoperative images (D, E) following excision of the pseudarthrosis, fibular osteotomy, iliac bone graft and periosteum grafting, and fixation with a William rod.
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Congenital Insensitivity to Pain

Congenital insensitivity to pain is a rare hereditary sensory neuropathy disorder characterized by the absence of normal subjective and objective responses to noxious stimuli in patients with intact central and peripheral nervous systems. The cause is unknown, but sporadic reports have appeared in the orthopedic literature.23,117,161 
The orthopedic manifestations of congenital insensitivity to pain include recurrent fractures, osteomyelitis, and neuropathic joints. Although the lower extremities are most commonly affected, the spine may also be involved with gross and unstable spondylolisthesis. Limb-length discrepancy may occur from chronic physeal damage. Lack of pain perception is associated with the development of Charcot joints, which may lead to later neuropathic arthropathy, especially around the knees and ankles. Although fracture healing usually occurs, the arthropathy is progressive, eventually resulting in gross deformity and instability. In addition to the absence of deep pain, the patients have impaired temperature sensation. 
The differential diagnosis includes a spectrum of closely related sensory disorders including congenital sensory neuropathy, hereditary sensory radicular neuropathy, familial sensory neuropathy with anhidrosis, and familial dysautonomia (Riley–Day syndrome). Acquired conditions with pain insensitivity include syringomyelia, diabetes mellitus, tabes dorsalis, alcoholism, and leprosy. Loss of protective sensation promotes self-mutilation, burns, bruises, and fractures. The disease often comes to light when the child develops teeth and then bites his or her tongue, lips, and fingers. 
Management should aim at education and prevention of injury. Prevention of joint disease is the best early option.23,117 Joint injury should be recognized and treated early to prevent progression to gross arthropathy. Early diagnosis and treatment of fractures is important, usually by conservative manners.117,161 In a severely unstable, degenerated joint, arthrodesis may eventually be appropriate; however, poor healing, nonunion, and pseudarthrosis are common in neuropathic joints (Fig. 8-24). Infection rate is also increased, and it is important to make the differentiation between fracture and infection.23 The condition appears to improve with time with the gradual recovery of pain sensation. 
Figure 8-24
This 6-year-old child with anhidrosis, congenital insensitivity to pain, and attention deficit disorder presented with a history of swollen ankles and knees.
 
Anteroposterior (A) and lateral (B) radiographs show Charcot changes in the subtalar joint with calcaneal and distal fibular fractures. Anteroposterior (C) and lateral (D) radiographs of the right knee show large, loose osteochondral fragments, medial subluxation of the femur on the tibia, and extensive periosteal new bone formation in the distal femur. Soft tissue shadows are consistent with her huge knee hemarthrosis. More than 100 mL of sterile serosan guineous fluid was aspirated from the knee at her initial visit. The effusion quickly returned in the days following the aspiration. Because management with casts at another hospital resulted in significant skin breakdown, we stabilized the knees with removable hinged braces. The effusions improved but did not resolve.
Anteroposterior (A) and lateral (B) radiographs show Charcot changes in the subtalar joint with calcaneal and distal fibular fractures. Anteroposterior (C) and lateral (D) radiographs of the right knee show large, loose osteochondral fragments, medial subluxation of the femur on the tibia, and extensive periosteal new bone formation in the distal femur. Soft tissue shadows are consistent with her huge knee hemarthrosis. More than 100 mL of sterile serosan guineous fluid was aspirated from the knee at her initial visit. The effusion quickly returned in the days following the aspiration. Because management with casts at another hospital resulted in significant skin breakdown, we stabilized the knees with removable hinged braces. The effusions improved but did not resolve.
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Figure 8-24
This 6-year-old child with anhidrosis, congenital insensitivity to pain, and attention deficit disorder presented with a history of swollen ankles and knees.
Anteroposterior (A) and lateral (B) radiographs show Charcot changes in the subtalar joint with calcaneal and distal fibular fractures. Anteroposterior (C) and lateral (D) radiographs of the right knee show large, loose osteochondral fragments, medial subluxation of the femur on the tibia, and extensive periosteal new bone formation in the distal femur. Soft tissue shadows are consistent with her huge knee hemarthrosis. More than 100 mL of sterile serosan guineous fluid was aspirated from the knee at her initial visit. The effusion quickly returned in the days following the aspiration. Because management with casts at another hospital resulted in significant skin breakdown, we stabilized the knees with removable hinged braces. The effusions improved but did not resolve.
Anteroposterior (A) and lateral (B) radiographs show Charcot changes in the subtalar joint with calcaneal and distal fibular fractures. Anteroposterior (C) and lateral (D) radiographs of the right knee show large, loose osteochondral fragments, medial subluxation of the femur on the tibia, and extensive periosteal new bone formation in the distal femur. Soft tissue shadows are consistent with her huge knee hemarthrosis. More than 100 mL of sterile serosan guineous fluid was aspirated from the knee at her initial visit. The effusion quickly returned in the days following the aspiration. Because management with casts at another hospital resulted in significant skin breakdown, we stabilized the knees with removable hinged braces. The effusions improved but did not resolve.
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Diseases of the Bone Marrow

Gaucher Disease

Gaucher disease is a hereditary disorder of lipid metabolism. It is the most common lysosomal storage disease and is caused by deficient production and activity of the lysosomal enzyme beta-glucosidase (glucocerebrosidase), resulting in progressive accumulation of glucosylceramide (glucocerebroside) in macrophages of the reticuloendothelial system in the spleen, liver, and bone marrow. The most common sphingolipidosis, is inherited as an autosomal recessive trait,146 with most cases noted in Ashkenazic Jews of eastern European origin. There are three types of Gaucher disease: Type I represents more than 90% of all cases and is the most common type seen by orthopedic surgeons—it presents as a chronic nonneuropathic disease with visceral (spleen and liver) and osseous involvement, also known as the adult form, although patients present during childhood146; Type II is an acute, neuropathic disease with central nervous system involvement and early infantile death; and Type III is a subacute nonneuropathic type with chronic central nervous system involvement. Types II and III are both characterized as either infantile or juvenile, and are notable for severe progressive neurologic disease, usually being fatal. 
Osseous lesions are a result of marrow accumulation and present with Erlenmeyer flask appearance of the metaphyseal bone, osteonecrosis (ON) (particularly of the femoral head), and pathologic fractures, especially of the spine and femoral neck. Bone lesions are most common in the femur, but they also occur in the pelvis, vertebra, humerus, and other locations. Infiltration of bone by Gaucher cells leads to vessel thrombosis, compromising the medullary vascular supply and leading to localized ON of the long bones. ON of the femoral head occurs in most patients in whom the disease is diagnosed in childhood. 
Pathologic fractures, especially of the femoral neck or shaft after biopsy, and of the spine, are usually best managed conservatively. Katz et al.146 reported 23 pathologic fractures in nine children with Gaucher disease; seven had multiple fractures. In decreasing order of frequency, the site of involvement included the distal femur, basilar neck of the femur, spine, and proximal tibia. Fractures of the long bones were transverse and usually in the metaphysis. Fractures of the spine were either wedge-shaped or centrally depressed at the end plate. The factors predisposing these children to fracture included significant medullary space infiltration, cortical bone erosion, ON, and associated disuse osteoporosis.146 
In another report of 53 patients with Gaucher disease aged 9 to 18 years,148 11 children had vertebral fractures, usually at two or three sites in each patient, with either anterior wedging, central vertebral collapse, or total rectangular collapse. Most patients had relief of their pain after 1 to 4 months of conservative treatment; two required decompression laminectomies, and one had a posterior lateral fusion to stabilize the spine. 
Katz et al.147 found that fractures of the upper extremities in Gaucher disease were prone to occur in areas of prior crisis. Although external callus formed in 6 to 8 weeks in most patients, complete healing with internal callus took almost 2 years in some. Both delayed union and nonunion233 have been reported in older patients with Gaucher disease. 
Pathologic femoral neck fractures with minimal associated trauma in children with Gaucher disease often heal with a varus malunion and minimal subsequent remodeling; ON of the femoral head also can be associated with femoral neck fractures.112 Goldman and Jacobs112 described the presence of a mixed density of the femoral neck on radiograph with narrowing of the medial cortex as a risk factor for fracture. 

Author's Preferred Method of Treatment

Conservative immobilization with nonweight bearing is suggested for long bone fractures when appropriate. Stable fractures of the femoral neck should be treated by immobilization with frequent follow-up radiographs; internal fixation should be used in unstable femoral neck fractures. Preoperative planning is important, and the anesthesiologist must recognize that patients with Gaucher disease may be prone to upper airway obstruction because of infiltration of the upper airway with glycolipids and abnormal clotting function, even when clotting tests are normal.264 

Sickle Cell Disease

The term sickle cell disease (SCD) characterizes conditions caused by the presence of sickle cell hemoglobin (HbS). The most common type of SCD, HbS-S, is a homozygous recessive condition in which individuals inherit the HbS globin gene from each parent. SCD has systemic effects particularly on splenic function and on the central nervous, renal, hepatic, and musculoskeletal systems. SCD affects approximately one in 400 African Americans. Sickle cell trait affects 8% to 10% of the African American population and other groups less frequently. With sickle cell trait, each individual has inherited a beta-S globin gene and a beta-A globin gene. Clinical manifestations of sickle cell trait usually are not apparent. The presence of this abnormal hemoglobin in red blood cells causes them to be mechanically fragile, and when they are deoxygenated, the cells assume a sickle shape, which makes them prone to clumping with blockage of the small vessels of the spleen, kidneys, and bones. Chronic hemolytic anemia is present in most severely affected patients, and marrow hyperplasia is found in both the long bones and the short tubular bones. The prevalence of osteopenia and osteoporosis in young adults with SCD is extremely high and that can be related or predisposed to pathologic fractures.196 These disorders are diagnosed by hemoglobin electrophoresis. 
Pathologic fractures of the long bones in SCD occur frequently28,85 and may be the first symptom of the disorder. Children with SCD often have undiagnosed osteopenia or osteoporosis (Fig. 8-25).196 Pathologic fractures are often seen in association with osteomyelitis.85 In a series of 81 patients with 198 long bone infarcts with occasional concurrent osteomyelitis, Bohrer36 found a 25% incidence of fractures associated to femoral lesions, and 20% with humeral lesions. Ebong85 reported pathologic fractures in 20% of patients with SCD and osteomyelitis. The most common site was the femur. The fractures are transverse and commonly located in the shaft of the long bone, and although minimal trauma is needed to cause them, they often have significant displacement.36 The exact mechanism for pathologic fracture in these patients is unclear; and although it is often associated with bone infarct, the fracture is seldom through the infracted area. Marrow hyperplasia may be a major contributing factor; not only does the hypercellular bone marrow expand the medullary canal with thinning of both trabecular and cortical bone, but it also extends into widened Haversian and Volkmann canals. This process may weaken the bone leading to fractures. Finally, children with SCD have significant deficits in the whole body bone mineral content that persist despite adjustment for poor growth and decreased lean mass; therefore, these children maybe at increased risk for fragility fractures and suboptimal peak bone mass.45 The healing process seems unaffected, and union usually occurs at the usual rate. 
Figure 8-25
A 4-year-old boy with sickle cell disease presented with acute onset of right arm pain, swelling, increased warmth, and low grade fever.
 
The initial radiographs (A, B) show a poorly defined area of lucency in the proximal humeral metaphysis (arrow). T2-weighted sagittal (C) and axial (D) MRI show intramedullary changes (enhancement) and periosteal reaction/abscess with no soft tissue mass. The clinical diagnosis of osteomyelitis was initially made and the patient was started on intravenous antibiotics. Three weeks later, there was little clinical improvement and new radiographs showed pathologic fracture/insufficiency fracture through the proximal humeral metaphysis (E, F) (arrow). The patient underwent a biopsy that showed that this was an infarct with no superimposed infection. After clinical treatment, the patient's symptoms improved. At 6-months follow-up, he was completely asymptomatic and the radiographs showed remodeling and continued growth (G).
The initial radiographs (A, B) show a poorly defined area of lucency in the proximal humeral metaphysis (arrow). T2-weighted sagittal (C) and axial (D) MRI show intramedullary changes (enhancement) and periosteal reaction/abscess with no soft tissue mass. The clinical diagnosis of osteomyelitis was initially made and the patient was started on intravenous antibiotics. Three weeks later, there was little clinical improvement and new radiographs showed pathologic fracture/insufficiency fracture through the proximal humeral metaphysis (E, F) (arrow). The patient underwent a biopsy that showed that this was an infarct with no superimposed infection. After clinical treatment, the patient's symptoms improved. At 6-months follow-up, he was completely asymptomatic and the radiographs showed remodeling and continued growth (G).
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Figure 8-25
A 4-year-old boy with sickle cell disease presented with acute onset of right arm pain, swelling, increased warmth, and low grade fever.
The initial radiographs (A, B) show a poorly defined area of lucency in the proximal humeral metaphysis (arrow). T2-weighted sagittal (C) and axial (D) MRI show intramedullary changes (enhancement) and periosteal reaction/abscess with no soft tissue mass. The clinical diagnosis of osteomyelitis was initially made and the patient was started on intravenous antibiotics. Three weeks later, there was little clinical improvement and new radiographs showed pathologic fracture/insufficiency fracture through the proximal humeral metaphysis (E, F) (arrow). The patient underwent a biopsy that showed that this was an infarct with no superimposed infection. After clinical treatment, the patient's symptoms improved. At 6-months follow-up, he was completely asymptomatic and the radiographs showed remodeling and continued growth (G).
The initial radiographs (A, B) show a poorly defined area of lucency in the proximal humeral metaphysis (arrow). T2-weighted sagittal (C) and axial (D) MRI show intramedullary changes (enhancement) and periosteal reaction/abscess with no soft tissue mass. The clinical diagnosis of osteomyelitis was initially made and the patient was started on intravenous antibiotics. Three weeks later, there was little clinical improvement and new radiographs showed pathologic fracture/insufficiency fracture through the proximal humeral metaphysis (E, F) (arrow). The patient underwent a biopsy that showed that this was an infarct with no superimposed infection. After clinical treatment, the patient's symptoms improved. At 6-months follow-up, he was completely asymptomatic and the radiographs showed remodeling and continued growth (G).
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Author's Preferred Method of Treatment

Pathologic fractures in patients with SCD usually heal with conservative treatment. Furthermore, operative management may be hazardous. Extreme care must be taken to oxygenate the patient's tissues adequately during the procedure, and ideally, elective procedures should be preceded by transfusion regimen to raise hemoglobin levels to 10 g/dL and prevent perioperative complications. Intravenous hydration is very important, with one and a half to two times the daily fluid requirements needed in addition to routine replacement of fluid losses. The use of a tourniquet in surgery for patients with SCD is somewhat controversial. 
ON of the femoral head is an especially difficult problem in patients with SCD. Treatment options range from conservative measures such as physical therapy and rest, to surgery such as core decompression, although some have shown no difference in the final outcome.204 Patients with total head involvement may require femoral or pelvic osteotomies, and total joint replacement is occasionally needed in young adults. 

Leukemia

Leukemia accounts for over 30% of cases of childhood cancer. Acute lymphocytic leukemia is one of the most common malignant diseases in childhood and accounts for 80% of pediatric leukemias. There is an increased occurrence of lymphoid leukemias in patients with Down syndrome, immunodeficiencies, and ataxic telangiectasia. The peak incidence occurs at 4 years of age. 
Leukemic involvement of bones and joints is common. Skeletal lesions occur more frequently in leukemic children than in adults because leukemic cells can quickly replace the smaller marrow reserves in children. Approximately 50% to 75% of children with acute leukemia develop radiographic skeletal manifestations during the course of their disease; however, there are no pathognomonic osseous manifestations.232,250 Pathologic fractures can be seen in up to a third of the patients.154,232,250 Diffuse osteopenia is the most frequent radiographic finding (Fig. 8-26).250 Nonspecific juxtaepiphyseal lucent lines are often seen and are a result of generalized metabolic dysfunction. Sclerotic bands of bone trabeculae are more typical in older children. Lucencies and periostitis may mimic osteomyelitis. A characteristic lesion seen within a month of onset of symptoms is a radiolucent metaphyseal band adjacent to the physis232,250; these are usually bilateral and vary from 2 to 15 mm in width. Osteolytic lesions with punctate areas of radiolucency are found in the metaphysis and can either appear moth-eaten or as a confluent radiolucency. Periosteal reaction often is present with osteolytic lesions and is most common in the posterior cortex of the distal femoral metaphysis, the medial neck of the femur, and the diaphysis of the tibia and fibula.250 Most bone lesions in leukemia improve after treatment and tend to progress with worsening of the disease. 
Figure 8-26
This 8-year-old girl presented with back pain, fever, malaise, and weight loss.
 
Lateral radiographs (A) of the spine showed diffuse osteopenia and compression/insufficiency fractures of the vertebral body (arrows). T1-weighted sagittal MRI (B) confirms disease process within the vertebral body (arrow) and no soft tissue mass or intraspinal involvement. She was diagnosed with acute lymphoblastic leukemia.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Lateral radiographs (A) of the spine showed diffuse osteopenia and compression/insufficiency fractures of the vertebral body (arrows). T1-weighted sagittal MRI (B) confirms disease process within the vertebral body (arrow) and no soft tissue mass or intraspinal involvement. She was diagnosed with acute lymphoblastic leukemia.
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Figure 8-26
This 8-year-old girl presented with back pain, fever, malaise, and weight loss.
Lateral radiographs (A) of the spine showed diffuse osteopenia and compression/insufficiency fractures of the vertebral body (arrows). T1-weighted sagittal MRI (B) confirms disease process within the vertebral body (arrow) and no soft tissue mass or intraspinal involvement. She was diagnosed with acute lymphoblastic leukemia.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Lateral radiographs (A) of the spine showed diffuse osteopenia and compression/insufficiency fractures of the vertebral body (arrows). T1-weighted sagittal MRI (B) confirms disease process within the vertebral body (arrow) and no soft tissue mass or intraspinal involvement. She was diagnosed with acute lymphoblastic leukemia.
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The risk of pathologic fractures usually decreases with treatment. Fracture is most commonly associated with osteoporosis of the spine, resulting in vertebral collapse (compression fracture). The thoracic vertebrae are the most commonly involved. Fractures occasionally occur at other locations and usually after minor trauma.192,205 A bone scan may aid in identifying clinically silent areas but may not correlate with areas of obvious destruction on radiographs. 

Author's Preferred Method of Treatment

Prompt diagnosis and initiation of chemotherapy is the main step in the treatment of pathologic fractures associated to leukemia. Most fractures are stable microfractures and can be treated with conservative immobilization with emphasis on early ambulation to avoid further osteopenia. For vertebral fractures, a back brace or thoracolumbosacral orthosis is often used to alleviate symptoms. 

Hemophilia

Hemophilia is a sex-linked recessive disorder of the clotting mechanism that presents most commonly as a functional deficiency of either factor VIII (hemophilia A) or factor IX (hemophilia B). Classic hemophilia, or hemophilia A, has an incidence of 1 per 10,000 live male births in the United States.4 Christmas disease, or hemophilia B, occurs in 1 per 40,000 live births. 
When hemophilia is suspected, screening tests should be performed, including platelet count, bleeding time, prothrombin time, and partial thromboplastin time. Deficiency of factor VIII, the most common form of hemophilia, causes a marked prolongation in the partial thromboplastin time. Specific factor assays can document the type of hemophilia. The severity of the deficiency correlates with the circulating levels of factors VIII and/or IX. The disease is classified as severe when clotting activity is less than 1%, moderate when clotting activity is 1% to 5%, and mild when clotting activity is more than 5% (Table 8-4). Early diagnosis and aggressive management are the keys to lessening complications. 
Table 8-4
Severity of Hemophilia Correlated with Plasma Factor Activity Levels
Degree of Hemophilia Percentage of Factor Clinical Characteristics
Mild 20–60% Usually clinically occult, excessive bleeding after major trauma or surgery
Moderate 5–20% Excessive bleeding during surgery and after minor trauma
Moderately severe 1–5% Excessive bleeding with mild injury and infrequent spontaneous hemarthrosis
Severe >1% Frequent excessive bleeding with trauma and spontaneous bleeding into the soft tissue and joints
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Musculoskeletal involvement includes acute hemarthroses (knee, elbow, and ankle, in decreasing order of frequency), soft tissue and muscle bleeds, acute compartment syndrome, carpal tunnel syndrome, femoral nerve neuropraxia, early degenerative arthritis, and fractures (Table 8-5). 
 
Table 8-5
Grades of Articular Involvement
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Table 8-5
Grades of Articular Involvement
Grade 1 Transitory synovitis; no bleeding sequelae and with no more than three episodes in 3 months
Grade 2 Permanent synovitis with increased joint size, synovial thickening, and limitation of movement
Grade 3 Chronic arthropathy with axial deformity and muscular atrophy
Grade 4 Ankylosis
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Should a child with hemophilia require operative management, the orthopedist and the hematologist should work closely together. Preoperatively, the patient should be tested for the presence of inhibitor and a test dose of factor replacement should be given to determine the biologic half-life of that factor for that particular patient.4 Elective surgery is usually contraindicated in the presence of inhibitor. Most authors recommend a level of factor activity during surgery ranging from 70% to 100%,4,221 although others believe that 50% is adequate.217 Tourniquets are recommended for extremity surgery. The use of routine drains is not advised, but 24 hours of suction drainage is favored by some.4,221 Factor levels are checked immediately after surgery and then at least daily. Factor VIII is given every 6 hours, and factor IX is given every 8 hours. In the immediate postoperative period, factor levels are maintained at 30% to 40%, and maintained at that level until sutures are removed. During the rehabilitative period, maintenance levels should range from 20% to 50% immediately before sessions of physical therapy.4,217,221 Intramuscular injections should be avoided, as should aspirin compounds and nonsteroidal anti-inflammatory medications that affect platelet function. Acetaminophen, celecoxib, and codeine are safe oral analgesics.145 In the past, hemophiliac patients had an increased risk of operative infections and delayed wound healing, but aggressive replacement therapy has minimized those problems.221 
Fracture risk does not seem to be increased in patients with hemophilia,35,231 but decreased bone density is frequent. Most authors have noted that healing of fractures proceeds primarily with endosteal callus and very little periosteal callus.96 Joint dislocations are rare in hemophiliac patients. Most fractures are treated conservatively with immobilization.169 Factor replacement is important especially during the first week, and recommended levels vary from 20% to 50%.3,4,35,96,132 Circumferential casting is associated with the risk of swelling from bleeding, leading to subsequent compartment syndrome and skin necrosis. A splint, or well-padded, soft dressing may be preferable immediately after injury, and a cast should be applied once active swelling has stopped.132 Fractures of the femur can be treated with traction and subsequent spica casting.35,169 Nonetheless, some authors consider skeletal traction hazardous because of the risk of infection or bleeding.4,132 Replacement therapy is advisable whereas fractures are manipulated and casts are changed. Most authors think that open reduction and internal fixation should be performed in hemophiliac patients for fractures that would customarily be treated with such methods.4,35 External fixators are not commonly used for patients with hemophilia; however, Lee et al.170 described the use of external fixators for nine patients undergoing arthrodesis of infected joints, or treatment of open fractures. One major complication occurred in a patient who developed inhibitors. They concluded that external fixators can be used safely in hemophilic patients without inhibitors and prolonged factor replacement is not required.170 

Author's Preferred Method of Treatment

Collaboration between the orthopedist and the hematologist is important in providing care for children with hemophilia. Most fractures in children with hemophilia can be treated with either traction or cast techniques. Care must be taken to avoid complications related to compression in these patients, and a mono- or bivalved, well-padded cast is safe. Operative treatment should be reserved for fractures that normally require surgery, and the usual pre- and perioperative precautions for hemophiliac patients are observed. 

Osteomyelitis

The pattern of pediatric osteomyelitis in North America has changed during the past several decades. Although the typical clinical picture of acute onset of pain, associated with fever and inability, or refusal to bear weight is still seen, subtle presentations and more aggressive ones have become frequent. Among the potential reasons for these changes are the increased use of empiric antibiotics, and the increased number of aggressive community-acquired pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). Osteomyelitis can be classified according to the age of onset (neonatal, childhood, and adult osteomyelitis); causative organism (pyogenic and granulomatous infections); onset (acute, subacute, and chronic); and routes of infection (hematogenous and direct inoculation). Although the acute form is still the most common, subacute osteomyelitis, or Brodie abscess, and chronic recurrent multifocal osteomyelitis are seen more frequently.141 Chronic osteomyelitis is defined as symptoms present for longer than 1 month (Fig. 8-27 and Table 8-6). 
Figure 8-27
Classification of subacute osteomyelitis.
 
Type 1A, punched-out radiolucency suggestive of eosinophilic granuloma. Type 1B, similar but with sclerotic margin; classic Brodie abscess. Type II, metaphyseal lesion with loss of cortical bone. Type III, diaphyseal lesion with excessive cortical reaction. Type IV, lesion with onionskin layering of subperiosteal bone. Type V, concentric epiphyseal radiolucency. Type VI, osteomyelitic lesion of vertebral body.
 
(From Dormans JP, Drummond DS. Pediatric hematogenous osteomyelitis: new trends in presentation, diagnosis, and treatment. J Am Acad Orthop Surg. 1994; 2:333–341, with permission.)
Type 1A, punched-out radiolucency suggestive of eosinophilic granuloma. Type 1B, similar but with sclerotic margin; classic Brodie abscess. Type II, metaphyseal lesion with loss of cortical bone. Type III, diaphyseal lesion with excessive cortical reaction. Type IV, lesion with onionskin layering of subperiosteal bone. Type V, concentric epiphyseal radiolucency. Type VI, osteomyelitic lesion of vertebral body.
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Figure 8-27
Classification of subacute osteomyelitis.
Type 1A, punched-out radiolucency suggestive of eosinophilic granuloma. Type 1B, similar but with sclerotic margin; classic Brodie abscess. Type II, metaphyseal lesion with loss of cortical bone. Type III, diaphyseal lesion with excessive cortical reaction. Type IV, lesion with onionskin layering of subperiosteal bone. Type V, concentric epiphyseal radiolucency. Type VI, osteomyelitic lesion of vertebral body.
(From Dormans JP, Drummond DS. Pediatric hematogenous osteomyelitis: new trends in presentation, diagnosis, and treatment. J Am Acad Orthop Surg. 1994; 2:333–341, with permission.)
Type 1A, punched-out radiolucency suggestive of eosinophilic granuloma. Type 1B, similar but with sclerotic margin; classic Brodie abscess. Type II, metaphyseal lesion with loss of cortical bone. Type III, diaphyseal lesion with excessive cortical reaction. Type IV, lesion with onionskin layering of subperiosteal bone. Type V, concentric epiphyseal radiolucency. Type VI, osteomyelitic lesion of vertebral body.
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Table 8-6
Comparison of Acute and Subacute Hematogenous Osteomyelitis
Presentation Subacute Acute
Pain Mild Severe
Fever Few patients Majority
Loss of function Minimal Marked
Prior antibiotics Often (30–40%) Occasional
Elevated white blood cell count Few Majority
Elevated erythrocyte sedimentation rate Majority Majority
Blood cultures Few positive 50% positive
Bone cultures 60% positive 85% positive
Initial x-ray study Frequently abnormal Often normal
Site Any location (may cross physis) Usually metaphysis
 

From Dormans JP, Drummond DS. Pediatric hematogenous osteomyelitis: new trends in presentation, diagnosis, and treatment. J Am Acad Ortho Surg. 1994; 2:333–341.

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Changes in plain radiographs are only present in 20% of patients in the first 2 weeks of disease; the earliest finding is soft-tissue swelling/loss of defined deep soft tissue planes. Because of this early insensitivity of plain radiographic studies, isotope-scanning techniques have been used to aid in diagnosis with varying rates of success. MRI has up to 98% sensitivity and 100% specificity for early detection of osteomyelitis.158 MRI detects increased intramedullary water and decreased fat content, which occurs when there is inflammatory exudate, edema, hyperemia, and ischemia, all of which are present in infection.158 In proven osteomyelitis, abnormal technetium scans are seen in 63% to 90% of patients.134 
In 1932, Capener and Pierce50 reviewed 1,068 patients with osteomyelitis and found only 18 pathologic fractures (∼1.7% incidence), 13 of which occurred in the femur. They thought these fractures were because of delayed recognition of the infection or inadequate treatment. Other factors include disuse osteopenia, presence of a weak involucrum, and excessive surgical removal of involved bone. In that preantibiotic era, most of the fractures were sustained after surgical treatment of the osteomyelitis, and the authors believed that conservation of the involucrum and proper immobilization could have prevented these injuries. Daoud and Saighi Bouaouina67 reported on 34 patients with hematogenous osteomyelitis complicated by pathologic fracture, pseudarthrosis, or significant segmental bone loss. The tibia was affected in 24 cases, the femur was affected in 8 cases, and the humerus was affected in 2 cases. Pathologic fracture of the proximal femoral has been reported in neonatal osteomyelitis.20 Although rare, hematogenous osteomyelitis has also been reported at the site of a closed fracture.48,242 Canale et al.48 reported three children with osteomyelitis after closed fracture. They pointed out that progressive pain and swelling at a fracture site during healing are suggestive of possible osteomyelitis. Daoud et al.66 reported 35 children with proximal femur osteomyelitis with associated septic arthritis. The incidence of ON of the femoral head was approximately 50% both in the group that was treated with arthroscopy and in the group in which no surgery had been done. They postulated that ON of the femoral head may be because of compression by abscess of the vessels lying on the posterior superior femoral neck. The complications of fracture, dislocation, and displacement of the capital femoral epiphysis occurred in two-thirds of their patients, and these usually were patients who presented long after an acute phase of the disease. They recommended surgical drainage of septic hips, and reduction and stabilization of hips with ON using skin traction and plaster immobilization for 40 to 60 days. Atypical osteomyelitis associated with bone lesion and risk of fracture has been described in rubella and cytomegalic inclusion disease.235 
Pathologic fractures associated with osteomyelitis are usually associated with neglected or chronic osteomyelitis, neonatal osteomyelitis, or septic arthritis. They may be difficult to treat and be associated with complications, such as malunion and growth disturbance (Fig. 8-28). Tudisco et al.267 reported on 26 patients with chronic osteomyelitis with average follow-up of 23 years. Approximately 15% had shortening and angular deformity of the affected limb. In children with chronic osteomyelitis, the purulent material elevates the periosteum and a supportive involucrum develops. Sequestrectomy of a portion of the necrotic diaphysis while leaving the supportive involucrum is often needed to bring the infection under control. Daoud and Saighi-Bouaouina67 recommended early debridement followed by antibiotic therapy for up to 6 months. Prolonged cast immobilization was necessary. They obtained healing in 33 of 34 patients with pathologic fractures or pseudarthroses caused by osteomyelitis. The mean healing time of fractures was 5 months in patients with involucrum. Patients with active infection and without involucrum required debridement, antibiotics, and subsequent treatment with corticocancellous iliac graft, for a mean healing time of 8.7 months; whereas patients without active infection and without involucrum were treated with prolonged immobilization, cancellous bone graft, and supplemented by fixation. 
Figure 8-28
A 7-year-old boy presented with classic picture of septic arthritis of the right hip.
 
He underwent promptly irrigation and débridement of the hip. On follow-up just a few weeks later, plain radiographs demonstrated a lytic area in the femoral neck (A, B) (arrow) and blood work showed increased creative protein and sedimentation rate. The patient underwent repeated irrigation of the hip and drilling of the lytic area (osteomyelitis) in the femoral neck. Two months later, he developed collapse (pathologic fracture) of the femoral head with gross deformity of the proximal femur (C, D), especially in the lateral views (D) with decreased range of motion.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
He underwent promptly irrigation and débridement of the hip. On follow-up just a few weeks later, plain radiographs demonstrated a lytic area in the femoral neck (A, B) (arrow) and blood work showed increased creative protein and sedimentation rate. The patient underwent repeated irrigation of the hip and drilling of the lytic area (osteomyelitis) in the femoral neck. Two months later, he developed collapse (pathologic fracture) of the femoral head with gross deformity of the proximal femur (C, D), especially in the lateral views (D) with decreased range of motion.
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Figure 8-28
A 7-year-old boy presented with classic picture of septic arthritis of the right hip.
He underwent promptly irrigation and débridement of the hip. On follow-up just a few weeks later, plain radiographs demonstrated a lytic area in the femoral neck (A, B) (arrow) and blood work showed increased creative protein and sedimentation rate. The patient underwent repeated irrigation of the hip and drilling of the lytic area (osteomyelitis) in the femoral neck. Two months later, he developed collapse (pathologic fracture) of the femoral head with gross deformity of the proximal femur (C, D), especially in the lateral views (D) with decreased range of motion.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
He underwent promptly irrigation and débridement of the hip. On follow-up just a few weeks later, plain radiographs demonstrated a lytic area in the femoral neck (A, B) (arrow) and blood work showed increased creative protein and sedimentation rate. The patient underwent repeated irrigation of the hip and drilling of the lytic area (osteomyelitis) in the femoral neck. Two months later, he developed collapse (pathologic fracture) of the femoral head with gross deformity of the proximal femur (C, D), especially in the lateral views (D) with decreased range of motion.
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Author's Preferred Method of Treatment

With early recognition and appropriate treatment, acute osteomyelitis rarely leads to a pathologic fracture. When pathologic fracture occurs (Fig. 8-29), it is usually associated to a neglected chronic osteomyelitis or, rarely, neonatal osteomyelitis or septic arthritis. The most important step in the treatment of fracture associated with osteomyelitis is to control the underlying infection. This requires biopsy for culture and sensitivities, drainage and debridement of the infection with appropriate immobilization and antibiotic therapy (Table 8-7). In advanced infections, sequestrectomy may be necessary. MRI is useful in identifying the sequestrum; an attempt should be made to leave as much supporting involucrum as possible at the time of sequestrectomy. Bone transport and lengthening may be valuable in certain cases. Prolonged immobilization with either plaster casts or external fixation devices may be needed, and segmental bone loss can be treated with bone transport or grafting. 
Figure 8-29
This lateral radiograph of the humeral shaft of a 17-year-old boy shows a pathologic fracture through chronic osteomyelitis of the humerus.
(Case courtesy of B. David Horn, MD.)
(Case courtesy of B. David Horn, MD.)
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Table 8-7
Initial Antibiotic Therapy for Osteomyelitis
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Table 8-7
Initial Antibiotic Therapy for Osteomyelitis
Patient Type Probable Organism Initial Antibiotic
Neonate Group B Streptocuccus, S. aureus, Gram-negative rods (H. influenza) Cefotaxime (100–120 mg/kg/24 h) or oxacillin and gentamicin (5–7.5 mg/kg/24 h)
Infants and children S. aureus (90%) if allergic to penicillin* if allergic to penicillin and cephalosporins* Oxacillin (150 mg/kg/24 h) Cefazolin (100 mg/kg/24 h) Clindamycin (25–40 mg/kg/24 h) or Vancomycin (40 mg/kg/24 h)
Sickle cell disease S. aureus or Salmonella Oxacillin and ampicillin or chloramphenicol or cefotaxime (100–120 mg/kg/24 h)
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Pathologic Fractures after Limb Lengthening

Limb lengthening has evolved dramatically over the past several decades. Surgeons experienced with lengthening techniques can now correct problems that previously had no satisfactory solution. Complications with the Wagner method, popular 20 to 30 years ago, were as high as 92%.130,181 Newer techniques, using gradual lengthening with either monolateral fixators or fine wire fixators, such as the Ilizarov fixator, have decreased the complication rate. 
Fractures that occur in association with limb lengthening fall into three general categories: (1) fractures through pin tracks, (2) fractures through regenerated bone, or (3) fractures through bone weakened by disuse osteoporosis. Fractures that occur through holes left after removal of screws or fine wires generally occur a few weeks after device removal. The incidence of these fractures can be minimized by protective weight bearing after removal of the device and using the smallest possible screw diameter that is appropriate for the fixation device needed. Fractures through regenerated bone are true pathologic fractures. The bone that is formed by distraction callotasis must be subjected to normal weight-bearing forces over a period of time before normal bony architecture is established. Fractures that occur through the lengthening gap can occur either soon after removal of the fixator or years later (Fig. 8-30). Various reports describe fractures through regenerative bone occurring as late as 2 to 8 years after lengthening.181,200 The incidence of fractures has been reported to be as high as 50% for Wagner lengthening, but only 3% for newer techniques.90,130,179,200,212,223 At present, most lengthenings are performed through the metaphysis, which has a larger bone diameter and better blood supply than the diaphysis (where Wagner lengthening was done).179,213 When fractures occur in regenerated bone, they can be treated with simple cast immobilization. However, because this method further promotes osteopenia, many surgeons reapply a fixator, correct any malalignment caused by the fracture, and compress at the fracture site until healing. To ensure that the regenerated bone can bear the forces of normal activity, a variety of imaging methods have been used.33 When the regenerated bone attains the density and ultrastructural appearance (development of the cortex and the medullary canal) of the adjacent bone, fixator removal is generally safe. Some authors have reported on decreased incidence of fractures combining lengthening with internal fixation (intramedullary nail or submuscular plating).138,214 
Figure 8-30
 
Radiograph of a 15-year-old boy with achondroplasia (A) who underwent femoral lengthening with a monolateral external fixator for limb-length discrepancy (B). The procedure and the lengthening were uneventful and the device was removed after four cortices were visualized on radiographs (C, D). Less than 2 months after external fixator removal, the patient fell and had a pathologic femoral fracture through the regenerated bone (E). He underwent open reduction and internal fixation with an intramedullary device and the fracture healed in approximately 3 months (F, G).
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiograph of a 15-year-old boy with achondroplasia (A) who underwent femoral lengthening with a monolateral external fixator for limb-length discrepancy (B). The procedure and the lengthening were uneventful and the device was removed after four cortices were visualized on radiographs (C, D). Less than 2 months after external fixator removal, the patient fell and had a pathologic femoral fracture through the regenerated bone (E). He underwent open reduction and internal fixation with an intramedullary device and the fracture healed in approximately 3 months (F, G).
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Radiograph of a 15-year-old boy with achondroplasia (A) who underwent femoral lengthening with a monolateral external fixator for limb-length discrepancy (B). The procedure and the lengthening were uneventful and the device was removed after four cortices were visualized on radiographs (C, D). Less than 2 months after external fixator removal, the patient fell and had a pathologic femoral fracture through the regenerated bone (E). He underwent open reduction and internal fixation with an intramedullary device and the fracture healed in approximately 3 months (F, G).
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Figure 8-30
Radiograph of a 15-year-old boy with achondroplasia (A) who underwent femoral lengthening with a monolateral external fixator for limb-length discrepancy (B). The procedure and the lengthening were uneventful and the device was removed after four cortices were visualized on radiographs (C, D). Less than 2 months after external fixator removal, the patient fell and had a pathologic femoral fracture through the regenerated bone (E). He underwent open reduction and internal fixation with an intramedullary device and the fracture healed in approximately 3 months (F, G).
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiograph of a 15-year-old boy with achondroplasia (A) who underwent femoral lengthening with a monolateral external fixator for limb-length discrepancy (B). The procedure and the lengthening were uneventful and the device was removed after four cortices were visualized on radiographs (C, D). Less than 2 months after external fixator removal, the patient fell and had a pathologic femoral fracture through the regenerated bone (E). He underwent open reduction and internal fixation with an intramedullary device and the fracture healed in approximately 3 months (F, G).
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Radiograph of a 15-year-old boy with achondroplasia (A) who underwent femoral lengthening with a monolateral external fixator for limb-length discrepancy (B). The procedure and the lengthening were uneventful and the device was removed after four cortices were visualized on radiographs (C, D). Less than 2 months after external fixator removal, the patient fell and had a pathologic femoral fracture through the regenerated bone (E). He underwent open reduction and internal fixation with an intramedullary device and the fracture healed in approximately 3 months (F, G).
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Pathologic fracture can also be caused by osteopenia and joint contractures that can occur after months in an external fixation device. Some children, because of pain or anxiety, are reluctant to bear sufficient weight on their fixator devices, putting them at risk for disuse osteoporosis. Joint contractures can be related to either the lengthening or insufficient rehabilitation during and after lengthening. Many of the fractures caused by these causes are avoidable; when they do occur, appropriate immobilization or internal fixation is used. 

Fractures in Conditions that Weaken Bone

Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) are a heterogeneous group of inherited disorders in which the structure and function of type I collagen is altered. The fragile bone is susceptible to frequent fractures and progressive deformity. OI is identifiable in 1 in 20,000 total births, with an overall prevalence of approximately 16 cases per million index patients.59 The wide spectrum of clinical severity—from perinatal lethal forms to clinically silent forms—reflects the tremendous genotypic heterogeneity (more than 150 different mutations of the type I procollagen genes COL1A1 and COL1A2 have been described). Most forms of OI are the result of mutations in the genes that encode the pro alpha1 and pro alpha2 polypeptide chains of type I collagen.208 Histologic findings reveal a predominance of woven bone, an absence of lamellar bone, and thinning of the cortical bone with osteopenia. As the molecular basis of this continuum of severity is further elucidated, the phenotypic groupings of the various classifications and subclassifications may seem arbitrary. From a practical viewpoint of orthopedic care, patients with OI can be divided into two groups. One group of patients with severe disease who develop long-bone deformity through repetitive fractures often needing surgical treatment, and another group of patients with mild disease with frequent fractures, but most injuries responding well to closed treatment. 
Children with severe OI may present with a short trunk, marked deformity of lower extremities, prominence of the sternum, triangular faces, thin skin, muscle atrophy, and ligamentous laxity, some develop kyphoscoliosis,119,198 basilar impression,245 and deafness (caused by otosclerosis).120 Children with OI usually have normal intelligence. Blue sclera, a classic finding in certain forms of OI, can also be present in normal infants, as well as in children with hypophosphatasia, osteopetrosis, Marfan syndrome, and Ehlers–Danlos syndrome. Children with OI also have a greater incidence of airway anomalies, thoracic anatomy abnormalities, coagulation dysfunction, hyperthyroidism, and an increased tendency to develop perioperative malignant hyperthermia.260 Pathologic fractures may present with swelling of the extremity, pain, low-grade fever, and a radiograph showing exuberant, hyperplastic, callus formation. The callus may occur without obvious fracture and can have a distinct butterfly shape, as opposed to the usual fusiform callus of most healing fractures. The femur is the most common site of pathologic fractures.228 
The radiographic findings vary (Fig. 8-31). In severe OI, there is marked osteoporosis, thin cortical bone, and evidence of past fracture with angular malunion. Both anterior and lateral bowing of the femur and anterior bowing of the tibia are common. Spinal radiographs may show compression of the vertebrae between the cartilaginous disc spaces (so-called codfish vertebra). 
Figure 8-31
This 10-month-old boy with a history of osteogenesis imperfecta presented with a right thigh pain and swelling and refusal to bear weight.
 
Anteroposterior (A) and lateral (B) radiographs of the right femur show the extraordinarily abundant, hyperplastic callus—with the characteristic butterfly shape—that can occur in osteogenesis imperfecta. This appearance may be mistaken for an infection or a neoplastic process.
Anteroposterior (A) and lateral (B) radiographs of the right femur show the extraordinarily abundant, hyperplastic callus—with the characteristic butterfly shape—that can occur in osteogenesis imperfecta. This appearance may be mistaken for an infection or a neoplastic process.
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Figure 8-31
This 10-month-old boy with a history of osteogenesis imperfecta presented with a right thigh pain and swelling and refusal to bear weight.
Anteroposterior (A) and lateral (B) radiographs of the right femur show the extraordinarily abundant, hyperplastic callus—with the characteristic butterfly shape—that can occur in osteogenesis imperfecta. This appearance may be mistaken for an infection or a neoplastic process.
Anteroposterior (A) and lateral (B) radiographs of the right femur show the extraordinarily abundant, hyperplastic callus—with the characteristic butterfly shape—that can occur in osteogenesis imperfecta. This appearance may be mistaken for an infection or a neoplastic process.
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The diagnosis of OI is based on clinical and radiographic findings. There is no specific laboratory diagnostic test, although fibroblast cell culture can detect the collagen abnormality in 85% of OI patients.58 In the absence of multiple fractures, the initial radiographic diagnosis can be difficult. It is crucial, but often difficult, to distinguish OI from nonaccidental injury.153,197 Unexplained fractures in mild, undiagnosed OI can drag a family through unnecessary legal proceedings; conversely, a child with OI may be abused but not exhibit classic fracture patterns (e.g., corner fractures) owing to the fragility of their bones. 
Fractures tend to occur before skeletal maturity. Most pathologic fractures are transverse, diaphyseal, minimally displaced, and heal at a relatively normal rate.245 Moorefield and Miller198 reported on 951 fractures in a series of 31 patients, 91% of which occurred before skeletal maturity. Fractures of the femur and tibia predominated, followed by the humerus. Recurrent fractures may result in coxa vara, genu valgum, and leg-length discrepancy. Olecranon sleeve (apophysis) avulsion fractures are essentially pathognomonic of OI (Fig. 8-32).260 Zionts and Moon281 reviewed 17 fractures of the olecranon apophysis in 10 children with mild OI; 15 of these were treated operatively. The same injury presented in the opposite extremity 1 to 70 months after the initial fracture in seven of the 10 patients. All fractures had healed by the time of cast removal; however, two refractured. The authors concluded that with careful follow-up, cast immobilization can be used for minimally displaced fractures, but operative management is suggested for displaced fractures. The high rate of bilaterality suggests that children who sustain this fracture should be counseled about the possible risks of injury to the opposite extremity.281 Displaced fractures of the apophysis of the olecranon should be treated with open reduction and internal fixation using tension band technique or compression screw fixation.260 
Figure 8-32
A 13-year-old boy with mild osteogenesis imperfecta presented after a fall on an outstretched arm, with inability to move his elbow, pain, and swelling.
 
Radiographs showed a displaced olecranon fracture (A). This fracture pattern is commonly seen in children with osteogenesis imperfecta and is quite uncommon in healthy children. The patient underwent open reduction and internal fixation. The fracture healed after 6 weeks (B).
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs showed a displaced olecranon fracture (A). This fracture pattern is commonly seen in children with osteogenesis imperfecta and is quite uncommon in healthy children. The patient underwent open reduction and internal fixation. The fracture healed after 6 weeks (B).
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Figure 8-32
A 13-year-old boy with mild osteogenesis imperfecta presented after a fall on an outstretched arm, with inability to move his elbow, pain, and swelling.
Radiographs showed a displaced olecranon fracture (A). This fracture pattern is commonly seen in children with osteogenesis imperfecta and is quite uncommon in healthy children. The patient underwent open reduction and internal fixation. The fracture healed after 6 weeks (B).
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs showed a displaced olecranon fracture (A). This fracture pattern is commonly seen in children with osteogenesis imperfecta and is quite uncommon in healthy children. The patient underwent open reduction and internal fixation. The fracture healed after 6 weeks (B).
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Although nonunion may occur, callus formation is usually adequate in OI and most nonunions seem to be associated with inadequate fixation after osteotomies and fractures.2 Gamble et al.101 emphasized the problem with a report of 12 nonunions in 10 patients. Sub-optimal treatment of the initial fracture was identified in half of the patients. 
The role of medical therapy in the prevention of fractures associated to OI has been well established. Bisphosphonates are a potent inhibitor of bone resorption and have been used with good results. Among the advantages of using bisphosphonates are good short-term safety (particularly with regard to renal function), significant reduction in chronic bone pain, decrease in the rate of fractures, gain in muscle force, increase in density and size of vertebral bodies, thickening of bone cortex, and increase growth rate.13,110,111,280 Some of the reported negative effects, include decrease in bone remodeling rate, growth plate abnormalities, and delay in the healing of osteotomy.110 Glorieux et al.111 and Zeitlin et al.280 showed that administering cyclical intravenous pamidronate to children with OI reduces bone pain and fracture incidence and increase bone density and level of ambulation, with minimal side effects. Falk et al.94 concurred with most of these findings, but concluded that long-term follow-up is required to prove whether bisphosphonate therapy will decrease fracture rates and increase mobility in children with moderate-to-severe OI.94 Sakkers et al.235 reported a reduction of long bones fracture risk using oral treatment with olpadronate at a daily dose of 10 mg. 
Gene therapy for OI has been attempted; however, because most of the mutations in OI are dominant negative, supplying the normal gene without silencing the abnormal gene may not be beneficial.208 Nonetheless, potential new therapies for OI have been tested in cell culture systems, animal models, and patients and may offer hope for the future development of successful therapies. 
The orthopedist caring for children with OI must balance standard fracture care with the goal of minimizing immobilization to avoid a vicious circle: Immobilization, weakness, and osteopenia, then refracture.8,198 Plaster splints and casts, braces, and air splint have all been used.34,106,198 Protected weight bearing with customized splints and/or braces can add support to limbs weakened by fragile and deformed bone, and is thought to reduce the incidence of lower extremity fractures. 
Load-sharing devices (such as intramedullary rods) are used for internal fixation of long bone fractures or osteotomies in children with OI. Plates and screws should be avoided. In patients with severe OI and angular deformities and/or recurrent fractures, osteotomy and internal fixation may improve function and reduce the incidence of fractures in weight-bearing bones (Fig. 8-33). Porat et al.220 reported an increased number of ambulatory patients (from 45% to 75%) after intramedullary rodding. The amount of bowing that requires osteotomy has not been defined. Traditionally, multiple osteotomy and rodding procedures (Sofield technique) involved extensive incisions with significant soft-tissue stripping and blood loss. Sijbrandij247 reported a percutaneous technique in which the deformity is straightened by closed osteoclasis and Rush pins are inserted along the proximal axis of the long bones, partially transfixing them to stabilize them in a new alignment. Most centers now use limited incisions, thus minimizing blood loss and periosteal stripping, while ensuring optimally placed osteotomies and efficient, controlled instrumentation. The choice of fixation device should be based on the age of the patient and the width of the medullary canal of the bone. Both fixed-length rods220,255 and extensible or telescoping rods22,101,206,220 are used. Skeletally mature patients and patients with very small medullary canals are best treated with nonelongating rods, whereas skeletally immature patients with adequate width of the medullary canal are best treated with extensible rods.101 Complications after osteotomies and intramedullary fixation include fracture at the rod tip, migration of the fixation device, joint penetration, loosening of components of extensible rods, and fractures through the area of uncoupled rods. 
Figure 8-33
This 8-year-old girl presented with pain and deformity around the right hip after minor trauma.
 
The patient had a known history of osteogenesis perfecta. Initial radiographs (A, B) showed grossly displaced fracture of the proximal femur in the subtrochanteric area. The patient underwent closed reduction and internal fixation with titanium elastic nails, and the fracture healed after 5 weeks, with good alignment in both anteroposterior (C) and lateral (D) views. The nails were slightly prominent and the family elected removal of the hardware (E, F). Three months after removal of the hardware, the patient presented with new trauma to that region followed by pain. Radiographs showed a minimally displaced transverse fracture in the subtrochanteric region (arrow) associated with varus and anterior angulation of the proximal femur (G, H). The patient underwent a Sofield procedure with Rush rods as the internal fixation. Ten weeks after the procedure, there was complete healing at the osteotomy/fracture site and adequate femoral alignment (I, J).
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
The patient had a known history of osteogenesis perfecta. Initial radiographs (A, B) showed grossly displaced fracture of the proximal femur in the subtrochanteric area. The patient underwent closed reduction and internal fixation with titanium elastic nails, and the fracture healed after 5 weeks, with good alignment in both anteroposterior (C) and lateral (D) views. The nails were slightly prominent and the family elected removal of the hardware (E, F). Three months after removal of the hardware, the patient presented with new trauma to that region followed by pain. Radiographs showed a minimally displaced transverse fracture in the subtrochanteric region (arrow) associated with varus and anterior angulation of the proximal femur (G, H). The patient underwent a Sofield procedure with Rush rods as the internal fixation. Ten weeks after the procedure, there was complete healing at the osteotomy/fracture site and adequate femoral alignment (I, J).
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The patient had a known history of osteogenesis perfecta. Initial radiographs (A, B) showed grossly displaced fracture of the proximal femur in the subtrochanteric area. The patient underwent closed reduction and internal fixation with titanium elastic nails, and the fracture healed after 5 weeks, with good alignment in both anteroposterior (C) and lateral (D) views. The nails were slightly prominent and the family elected removal of the hardware (E, F). Three months after removal of the hardware, the patient presented with new trauma to that region followed by pain. Radiographs showed a minimally displaced transverse fracture in the subtrochanteric region (arrow) associated with varus and anterior angulation of the proximal femur (G, H). The patient underwent a Sofield procedure with Rush rods as the internal fixation. Ten weeks after the procedure, there was complete healing at the osteotomy/fracture site and adequate femoral alignment (I, J).
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Figure 8-33
This 8-year-old girl presented with pain and deformity around the right hip after minor trauma.
The patient had a known history of osteogenesis perfecta. Initial radiographs (A, B) showed grossly displaced fracture of the proximal femur in the subtrochanteric area. The patient underwent closed reduction and internal fixation with titanium elastic nails, and the fracture healed after 5 weeks, with good alignment in both anteroposterior (C) and lateral (D) views. The nails were slightly prominent and the family elected removal of the hardware (E, F). Three months after removal of the hardware, the patient presented with new trauma to that region followed by pain. Radiographs showed a minimally displaced transverse fracture in the subtrochanteric region (arrow) associated with varus and anterior angulation of the proximal femur (G, H). The patient underwent a Sofield procedure with Rush rods as the internal fixation. Ten weeks after the procedure, there was complete healing at the osteotomy/fracture site and adequate femoral alignment (I, J).
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
The patient had a known history of osteogenesis perfecta. Initial radiographs (A, B) showed grossly displaced fracture of the proximal femur in the subtrochanteric area. The patient underwent closed reduction and internal fixation with titanium elastic nails, and the fracture healed after 5 weeks, with good alignment in both anteroposterior (C) and lateral (D) views. The nails were slightly prominent and the family elected removal of the hardware (E, F). Three months after removal of the hardware, the patient presented with new trauma to that region followed by pain. Radiographs showed a minimally displaced transverse fracture in the subtrochanteric region (arrow) associated with varus and anterior angulation of the proximal femur (G, H). The patient underwent a Sofield procedure with Rush rods as the internal fixation. Ten weeks after the procedure, there was complete healing at the osteotomy/fracture site and adequate femoral alignment (I, J).
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The patient had a known history of osteogenesis perfecta. Initial radiographs (A, B) showed grossly displaced fracture of the proximal femur in the subtrochanteric area. The patient underwent closed reduction and internal fixation with titanium elastic nails, and the fracture healed after 5 weeks, with good alignment in both anteroposterior (C) and lateral (D) views. The nails were slightly prominent and the family elected removal of the hardware (E, F). Three months after removal of the hardware, the patient presented with new trauma to that region followed by pain. Radiographs showed a minimally displaced transverse fracture in the subtrochanteric region (arrow) associated with varus and anterior angulation of the proximal femur (G, H). The patient underwent a Sofield procedure with Rush rods as the internal fixation. Ten weeks after the procedure, there was complete healing at the osteotomy/fracture site and adequate femoral alignment (I, J).
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Postoperative bracing is suggested for lower extremity fractures. Upper extremity fractures may also undergo prolonged splinting after removal of fracture fixation. Immobilization also may be adequate to treat stable, minimally displaced fractures just distal or proximal to the intramedullary rods.101 

Author's Preferred Method of Treatment

Protected weight bearing is the goal for patients with severe OI. Close follow-up is necessary in the first few years of life, with protective splinting or soft cast for fractures. Orthoses are constructed for bracing of the lower extremities to aid in both standing and ambulation. Standing frames are also used. Once ambulatory, the child is advanced to the use of a walker or independent ambulation. Bisphosphonates should be considered at an early age, prior to fractures and deformity. The length of treatment is still debatable. Severe bowing of the extremities especially after recurrent fractures is an indication for osteotomy and intramedullary rodding. Whenever possible, surgery is delayed until 6 or 7 years of age to allow for better fixation and decrease the chance of recurrence. We recommend extensible rods in skeletally immature patients and nonelongating rods in older patients. 

Osteopetrosis

Osteopetrosis is a condition in which excessive density of bone occurs as a result of abnormal function of osteoclasts.17,219 The resultant bone of these children is dense, brittle, and highly susceptible to pathologic fracture. The incidence of osteopetrosis is approximately 1 per 200,000 births. The inherent problem is a failure of bone resorption with continuing bone formation and persistent primary spongiosa. Osteopetrosis is classified into three main forms: Malignant autosomal recessive, intermediate autosomal recessive, and benign autosomal dominant; and basically presents as a severe infantile type or a milder form that presents later in life. Although the number of osteoclasts present in the affected bone is variable, in the severe form of this disease, the osteoclasts may be increased but function poorly.243 
Radiographically, the bones have a dense, chalk-like appearance (Fig. 8-34). The spinal column may have a sandwich or “rugger jersey” appearance because of dense, sclerotic bone at each end plate of the vertebrae and less involvement of the central portion. The long bones tend to have a dense, marble-like appearance and may have an Erlenmeyer flask shape at their ends owing to deficient cutback remodeling. Radiolucent transverse bands may be present in the metaphysis of the long bones, and these may represent a variable improvement in the resorption defect during growth of the child. There may be bowing of the bones because of multiple fractures, spondylolysis, or coxa vara.123,219 The small bones of the hands and feet may show a bone-within-bone appearance with increased density around the periphery. The unusual radiographic appearance may initially obscure occult nondisplaced fractures. 
Figure 8-34
Anteroposterior radiograph of the pelvis of an 8-year-old boy with osteopetrosis.
 
Note the typical increased bone density and obliteration of the medullary canal.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Note the typical increased bone density and obliteration of the medullary canal.
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Figure 8-34
Anteroposterior radiograph of the pelvis of an 8-year-old boy with osteopetrosis.
Note the typical increased bone density and obliteration of the medullary canal.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Note the typical increased bone density and obliteration of the medullary canal.
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Pathologic fractures are quite common in patients with osteopetrosis (Fig. 8-35).38,143,219,243 Patients with a severe form of the disease have more fractures than those with presentation later in childhood. Patients with autosomal dominant osteopetrosis with rugger jersey spine and endobones of the pelvis (type II) are six times more likely to have fractures than patients with only sclerosis of the cranial vault (type I).38 
Figure 8-35
This 2-year-old with osteopetrosis presented with forearm pain.
 
An anteroposterior radiograph shows the characteristic increased bone density and absence of a medullary canal, especially in the distal radius and ulna. There is a typical transverse, nondisplaced fracture (arrow) in the distal ulnar diaphysis.
An anteroposterior radiograph shows the characteristic increased bone density and absence of a medullary canal, especially in the distal radius and ulna. There is a typical transverse, nondisplaced fracture (arrow) in the distal ulnar diaphysis.
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Figure 8-35
This 2-year-old with osteopetrosis presented with forearm pain.
An anteroposterior radiograph shows the characteristic increased bone density and absence of a medullary canal, especially in the distal radius and ulna. There is a typical transverse, nondisplaced fracture (arrow) in the distal ulnar diaphysis.
An anteroposterior radiograph shows the characteristic increased bone density and absence of a medullary canal, especially in the distal radius and ulna. There is a typical transverse, nondisplaced fracture (arrow) in the distal ulnar diaphysis.
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Patients with the severe, congenital disease have transverse or short oblique fractures of the diaphysis, particularly the femur. Distal physeal fractures with exuberant callus may be confused with osteomyelitis.195 Common locations for fractures include the inferior neck of the femur, the proximal third of the femoral shaft, and the proximal tibia.17,195 Upper extremity fractures are also frequent.17 The onset of callus formation after fracture in osteopetrosis is variable.17 Although some believe that fractures in osteopetrosis heal at a normal rate219 others report delayed union and nonunion.17 Hasenhuttl123 observed that in one patient with recurrent fractures of the forearm, each succeeding fracture took longer to heal, with the last fracture taking nearly 5 months to unite. 
The orthopedist treating fractures in children with osteopetrosis should follow the principles of standard pediatric fracture care, with additional vigilance for possible delayed union (Fig. 8-36).123,243 Immobilization is prolonged when delayed union is recognized. Armstrong et al.17 surveyed the membership of the Pediatric Orthopaedic Society of North America and compiled the combined experience of 58 pediatric orthopedic surgeons with experience treating pathologic fractures in osteopetrosis. In this comprehensive review, they concluded that nonoperative treatment should be strongly considered for most diaphyseal fractures of the upper and lower limbs in children, but surgical management is recommended for femoral neck fractures and coxa vara. Open treatment of osteopetrotic fractures with fixation is technically difficult because of bone rigidity/density, and absence of intramedullary canal/sclerosis. Armstrong et al.17 cautioned, “the surgeon should expect to use several drill bits and possibly more than one power driver.” 
Figure 8-36
 
A: This 9-year-old with osteopetrosis sustained similar bilateral subtrochanteric fractures of the femur over a 2-year period. Anteroposterior (A) and lateral (B) femoral radiographs show a healing transverse subtrochanteric fracture of the left femoral. C: One year later, at age 10, she sustained a similar right transverse minimally displaced subtrochanteric femur fracture, which was treated with reduction and a spica cast. D: This anteroposterior radiograph taken at age 14 years shows that both proximal femoral fractures have healed and there is mild residual coxa vara, especially on the right side.
A: This 9-year-old with osteopetrosis sustained similar bilateral subtrochanteric fractures of the femur over a 2-year period. Anteroposterior (A) and lateral (B) femoral radiographs show a healing transverse subtrochanteric fracture of the left femoral. C: One year later, at age 10, she sustained a similar right transverse minimally displaced subtrochanteric femur fracture, which was treated with reduction and a spica cast. D: This anteroposterior radiograph taken at age 14 years shows that both proximal femoral fractures have healed and there is mild residual coxa vara, especially on the right side.
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Figure 8-36
A: This 9-year-old with osteopetrosis sustained similar bilateral subtrochanteric fractures of the femur over a 2-year period. Anteroposterior (A) and lateral (B) femoral radiographs show a healing transverse subtrochanteric fracture of the left femoral. C: One year later, at age 10, she sustained a similar right transverse minimally displaced subtrochanteric femur fracture, which was treated with reduction and a spica cast. D: This anteroposterior radiograph taken at age 14 years shows that both proximal femoral fractures have healed and there is mild residual coxa vara, especially on the right side.
A: This 9-year-old with osteopetrosis sustained similar bilateral subtrochanteric fractures of the femur over a 2-year period. Anteroposterior (A) and lateral (B) femoral radiographs show a healing transverse subtrochanteric fracture of the left femoral. C: One year later, at age 10, she sustained a similar right transverse minimally displaced subtrochanteric femur fracture, which was treated with reduction and a spica cast. D: This anteroposterior radiograph taken at age 14 years shows that both proximal femoral fractures have healed and there is mild residual coxa vara, especially on the right side.
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In addition to these technical difficulties, patients with osteopetrosis are at risk for excessive bleeding and infection, related to the hematopoietic dysfunction caused by obliteration of the marrow cavity.243 Procedures should be avoided if the platelet count is less than 50,000 mm, and preoperative platelet transfusions may be necessary.243 Prophylactic antibiotic coverage is advised. Minor procedures should be performed percutaneously whenever possible.243 
In the past, primary medical treatment for osteopetrosis included transfusions, splenectomy, calcitriol, and adrenal corticosteroids, but these techniques have proved ineffectual.227,268 Stimulation of host osteoclasts has been attempted with calcium restriction, calcitriol, steroids, parathyroid hormone, and interferon. Bone marrow transplantation for severe infantile osteopetrosis has proved to be an effective means of treatment for some patients; however, it does not guarantee survival, and it may be complicated by hypercalcaemia.53,56,107 

Pyknodysostosis

Pyknodysostosis, also known as Maroteaux-Lamy syndrome, is a rare syndrome of short stature and generalized sclerosis of the entire skeleton. The dense brittle bones of affected children are highly susceptible to pathologic fractures. Pyknodysostosis is inherited as an autosomal recessive trait, with an incidence estimated as 1.7 per 1 million births. Mutations in the gene encoding cathepsin K, a lysosomal cysteine protease localized exclusively in osteoclasts is responsible for this disease.99 The long bones are sclerotic with poorly formed medullary canals; histologic sections show attenuated Haversian canal systems. Patients with pyknodysostosis have short stature, a hypoplastic face, a nose with a parrot-like appearance, and both frontal and occipital bossing. Bulbous distal phalanges of the fingers and toes with spooning of the nails are common. Coxa vara, coxa valgum, genu valgum, kyphosis, and scoliosis may be present. Results of laboratory studies usually are normal. 
Radiographs show a sclerotic pattern very similar to that of osteopetrosis. In pyknodysostosis, however, the medullary canal is present but poorly formed, and a faint trabecular pattern is seen. Such sclerotic bone is also seen in Engelmann's disease, but clinically those patients are tall and eventually develop muscle weakness. The distal femur in a patient with pyknodysostosis usually has an Erlenmeyer flask deformity similar to that found in patients with Gaucher disease.29 
Although pathologic fractures are thought to be less common in pyknodysostosis than in OI, almost all patients with pyknodysostosis reported in the literature have had pathologic fractures.25 Edelson et al.86 reported 14 new cases of pyknodysostosis from a small Arab village. They described a hangman fracture of C2 in a 2-year-old child that went on to asymptomatic nonunion. There was 100% incidence of spondylolysis in their patients aged 9 years or older, with most located at L4 to L5. Lower extremity fractures are the most common, and clinical deformity of both the femur and tibia is frequent. The fractures are usually transverse and diaphyseal, and heal with scanty callus.194 The fracture line can persist for nearly 3 years after clinical union, with an appearance similar to a Looser line. Overall, fractures tend to heal readily in childhood, but nonunion can be a problem in adulthood. 

Rickets

Rickets is a disease of growing children caused by either a deficiency of vitamin D or an abnormality of its metabolism. The osteoid of the bone is not mineralized, and broad unossified osteoid seams form on the trabeculae. With failure of physeal mineralization, the zone of provisional calcification widens and the ingrowth of blood vessels into the zone is disrupted. In the rickets of renal failure, the effects of secondary hyperparathyroidism (bone erosion and cyst formation) are also present. Before widespread fortification of common foods, vitamin D deficiency was a common cause of rickets, but other diseases affecting the metabolism of vitamin D have become a more common cause. Regardless of the underlying cause, the various types of rickets share similar clinical and radiographic features (Fig. 8-37). Although many of the metabolic findings are the same, there are some differences. 
Figure 8-37
Lower extremity radiograph of an 18-month-old boy with rickets.
 
Note the severe bowing, physeal irregularities and widening with flaring of distal tibial metaphysis.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Note the severe bowing, physeal irregularities and widening with flaring of distal tibial metaphysis.
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Figure 8-37
Lower extremity radiograph of an 18-month-old boy with rickets.
Note the severe bowing, physeal irregularities and widening with flaring of distal tibial metaphysis.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Note the severe bowing, physeal irregularities and widening with flaring of distal tibial metaphysis.
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Both pathologic fractures215,252 and epiphyseal displacement113 can occur in rickets. The treatment of rickets depends on identification of the underlying cause. In addition to nutritional rickets, many other diseases can affect vitamin D metabolism, and their treatment is necessary before the clinical rickets can be resolved (Table 8-8). 
 
Table 8-8
Rickets: Metabolic Abnormalities
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Table 8-8
Rickets: Metabolic Abnormalities
Disorder Cause 1,25(OH)2 Vitamin D Parathyroid Hormone Calcium P Alkaline Phosphate
Vitamin D deficiency rickets Lack of vitamin D in the diet ↓ or →
Gastrointestinal rickets Decreased gastrointestinal absorption of vitamin D or calcium ↓ or →
Vitamin D-dependent rickets Reduced 1,25(OH)2 vitamin D production ↓↓
Vitamin D-resistant rickets—end-organ insensitivity Intestinal cell insensitivity to vitamin D causing decreased calcium absorption ↑ or →
Renal osteodystrophy Renal failure causing decreased vitamin D synthesis, phosphate retention, hypocalcemia, and secondary hyperparathyroidism ↓↓ ↑↑
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Nutritional Rickets Inadequate dietary vitamin D and lack of exposure to sunlight can lead to a vitamin D deficiency. Pathologic fractures from vitamin D deficiency rickets also occur in children on certain diets: Unsupplemented breast milk, diets restricted by religious beliefs, and fat diets.87,165 Fractures are treated with both cast immobilization and correction of the vitamin deficiency by oral vitamin D supplementation. Oral calcium supplements also may be necessary, and patients should consume a vitamin D-fortified milk source. 
Rickets in Malabsorption Celiac disease caused by gluten-sensitive enteropathy affects intestinal absorption of fat-soluble vitamins (such as vitamin D), resulting in rickets. Biopsy of the small intestine shows characteristic atrophy of the villi. Treatment is oral vitamin D and a gluten-free diet. Infants with short gut syndrome may have vitamin D-deficiency rickets. This syndrome may develop after intestinal resection in infancy for volvulus or necrotizing enterocolitis, in intestinal atresia, or after resection of the terminal ileum and the ileocecal valve.265 Pathologic fractures have been reported, and treatment is immobilization and administration of vitamin D2 with supplemental calcium gluconate. 
Hepatobiliary disease is also associated with rickets.128,157 With congenital biliary atresia, the bile acids, essential for the intestinal absorption of vitamin D, are inadequate. By the age of 3 months, nearly 60% of patients with biliary atresia may have rickets.157 Intravenous vitamin D is often needed for effective treatment of these patients. After appropriate surgical correction of the hepatic syndrome, the bone disease gradually improves (Fig. 8-38). The pathologic fractures that develop in these disorders128 can be treated with immobilization. 
Figure 8-38
This 18-year-old boy with sclerosing cholangitis and a history of steroid use presented with several months of worsening low back pain.
 
A: Lateral radiograph of his lumbar spine shows marked osteopenia, collapsed codfish vertebrae with sclerotic end plates and widened disc spaces and Schmorl nodes. B: This MRI shows flattened concave vertebrae that are smaller in most locations than the adjacent intervertebral discs. He was successfully treated with 3 months in a thoraco-lumbar-sacral-orthosis brace, followed by weaning from the brace and conditioning exercises.
A: Lateral radiograph of his lumbar spine shows marked osteopenia, collapsed codfish vertebrae with sclerotic end plates and widened disc spaces and Schmorl nodes. B: This MRI shows flattened concave vertebrae that are smaller in most locations than the adjacent intervertebral discs. He was successfully treated with 3 months in a thoraco-lumbar-sacral-orthosis brace, followed by weaning from the brace and conditioning exercises.
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Figure 8-38
This 18-year-old boy with sclerosing cholangitis and a history of steroid use presented with several months of worsening low back pain.
A: Lateral radiograph of his lumbar spine shows marked osteopenia, collapsed codfish vertebrae with sclerotic end plates and widened disc spaces and Schmorl nodes. B: This MRI shows flattened concave vertebrae that are smaller in most locations than the adjacent intervertebral discs. He was successfully treated with 3 months in a thoraco-lumbar-sacral-orthosis brace, followed by weaning from the brace and conditioning exercises.
A: Lateral radiograph of his lumbar spine shows marked osteopenia, collapsed codfish vertebrae with sclerotic end plates and widened disc spaces and Schmorl nodes. B: This MRI shows flattened concave vertebrae that are smaller in most locations than the adjacent intervertebral discs. He was successfully treated with 3 months in a thoraco-lumbar-sacral-orthosis brace, followed by weaning from the brace and conditioning exercises.
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Epilepsy may affect bone in a number of ways such as restriction of physical activity, cerebral palsy, or other coexisting morbidities. Also, the use of anticonvulsant therapy can interfere with the hepatic metabolism of vitamin D and result in rickets and pathologic fractures.237 Fewer fractures occur in institutionalized patients receiving vitamin D prophylaxis.244 
Ifosfamide, a chemotherapeutic agent used for treatment of different sarcomas, can cause hypophosphatemic rickets in children. The onset of rickets may occur anywhere from 2 to 14 months after chemotherapy and can be corrected with the administration of oral phosphates.263 Other mineral deficiencies such as magnesium (a cofactor for parathyroid hormone) can cause rare forms of rickets. 
Rickets and Very-Low–Birth-Weight Infants Very-low–birth-weight infants (1,500 g or less) can have pathologic fractures. In one study of 12 very-low–birth-weight infants, the incidence of pathologic fracture was 2.1%, nearly twice the rate of other premature infants with a birth weight of more than 1,500 g.9 The fractures are likely caused by a nutritional osteomalacia that may evolve into frank rickets in nearly 30% of very-low–birth-weight infants.9,156 Eighty percent of both calcium and phosphorus is acquired during the last trimester of pregnancy, when the intrauterine growth rate is exponential, and almost two-thirds of the birth weight is gained.149,229 Bone loss can be graded by either loss of cortical bone of the humerus or loss of bone of the distal radius.156 Other than craniotabes (thinning and softening of the skull bone with widening of the sutures and fontanelles), the clinical signs of rickets are generally lacking in these patients. The risk factors predisposing these patients to both rickets and fractures include hepatobiliary disease,157,263 prolonged total parenteral nutrition, chronic lung disease,9 necrotizing enterocolitis, patent ductus arteriosus, and physical therapy with passive range-of-motion exercises.156 In a prospective study of 78 low-birth-weight infants, Koo et al.156 observed a 73% incidence of rickets with associated pathologic fractures in patients with a birth weight of 800 g or less and only a 15% incidence of rickets with fractures in patients with a birth weight ranging from 1,000 to 1,500 g. In most cases, pathologic fractures in very-low–birth-weight infants are found incidentally on chest radiograph or gastrointestinal studies. The fractures may be suspected when physical examination reveals swelling and decreased movement of an extremity. The differential diagnosis of these fractures is limited but important: OI, copper deficiency syndrome, child abuse, and pathologic fracture from overzealous physical therapy. 
In the series reported by Amir et al.,8,9 (1.2%) of 973 preterm infants had fractures; 11 of 12 had more than one fracture. Radiographically, osteopenia is first seen at the fourth week of life. Typically, rib fractures are next seen at 6 to 8 weeks of life, then fractures of the long bones at 11 to 12 weeks.229 In one study, 54% of fractures were in the upper extremities, 18% in the lower extremities, 22% in the ribs, and approximately 6% in either the scapula or the clavicle.156 Most long bone fractures are metaphyseal and may be transverse or green-stick with either angulation or complete displacement.9 Callus is seen at the fracture site in less than a week, and complete remodeling occurs in 6 to 12 months.9,156 Passive range-of-motion exercises for these infants, by both physical therapists and parents should be avoided. Rib fractures have been associated with vigorous chest physiotherapy. Care also should be taken even with routine manipulation of the extremities during nursing care, and special care should be taken in restraining the extremities during surgical procedures.156 Splinting and soft dressing are choices for pathologic fractures of the long bones in very-low–birth-weight infants. The prognosis is excellent for most of these fractures because they go on to complete remodeling within 12 months. Preventive measures are important to minimize the risk of fracture in low-birth-weight infants. Their nutritional need for high levels of calcium, phosphorus, and vitamin D should be recognized. Alternating high levels of calcium with low levels of phosphorus in hyperalimentation solutions can help meet these needs. Because growth arrest is possible after fractures, follow-up over the first 2 to 3 years of life is advised. 
Rickets and Renal Osteodystrophy Renal osteodystrophy is common in patients with end-stage renal failure, typically developing 1 to 2 years after the diagnosis of kidney disease.135 The clinical syndrome is a combination of rickets and secondary hyperparathyroidism with marked osteoporosis. Affected children develop renal rickets as a result of chronic nephritis, pyelonephritis, congenitally small kidneys, or cystinosis.252 They present with short stature, bone pain, muscle weakness, delayed sexual development, and bowing of the long bones. Identification of the renal disorder is important because patients presenting with rickets caused by obstructive uropathy may respond to surgical treatment of the renal disease. 
Specific deformities include genu valgum (most common), genu varum, coxa vara, and varus deformities of the ankle.14,68 These deformities are most common in patients diagnosed before 3 years of age. Davids et al.68 showed that periods of metabolic instability, characterized as an alkaline phosphatase of 500 U for at least 10 months, were associated with progression of deformity. With the adolescent growth spurt, osseous deformities can accelerate rapidly over a matter of weeks.68 
Radiographs show rickets and osteopenia with osteitis fibrosa cystica.14 Osteoclastic cysts (brown tumors) may form. Metaphyseal cortical erosions occur in the lateral clavicle, distal ulna and radius, neck of the humerus, medial femoral neck, medial proximal tibia, and middle phalanges of the second and third fingers.135 In renal osteodystrophy, the Looser zone may represent a true stress fracture and, with minor trauma, may extend across the full thickness of the bone with development of a true fracture (Fig. 8-39). Callus may be scanty in patients with fractures who have untreated renal disease, but in patients on hemodialysis, abundant callus may form at the fracture site.14 Phalangeal quantitative ultrasound may be a useful method to assess bone quality and fracture risk in children and adolescents with bone and mineral disorders. 
Figure 8-39
This 12-year-old girl with rickets associated with chronic kidney disease presented with complaints of knocked knees and wrist pain.
 
Hip to ankle radiographs (A) showed typical rickets changes with valgus deformity at the knee level. Looser lines around the distal femur, and physeal widening. Wrist images (B, C) demonstrated marked physeal widening and metaphyseal flare of the distal radius and ulna.
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Hip to ankle radiographs (A) showed typical rickets changes with valgus deformity at the knee level. Looser lines around the distal femur, and physeal widening. Wrist images (B, C) demonstrated marked physeal widening and metaphyseal flare of the distal radius and ulna.
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Figure 8-39
This 12-year-old girl with rickets associated with chronic kidney disease presented with complaints of knocked knees and wrist pain.
Hip to ankle radiographs (A) showed typical rickets changes with valgus deformity at the knee level. Looser lines around the distal femur, and physeal widening. Wrist images (B, C) demonstrated marked physeal widening and metaphyseal flare of the distal radius and ulna.
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Hip to ankle radiographs (A) showed typical rickets changes with valgus deformity at the knee level. Looser lines around the distal femur, and physeal widening. Wrist images (B, C) demonstrated marked physeal widening and metaphyseal flare of the distal radius and ulna.
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In renal osteodystrophy, pathologic fractures of the long bones, rib fractures, vertebral compression fractures, and epiphyseal displacement of the epiphyses occur frequently. Fractures occur in areas of metaphyseal erosion or through cysts. Immobilization is used to treat pathologic fractures through both generalized weakened bone and brown tumors. Once the underlying bone disease is under control, open procedures such as curettage of cysts with bone grafting and open reduction of fractures may be considered when appropriate. Internal fixation is preferable to external fixation. Preoperative tests needed for these patients include electrolytes, calcium, phosphorus, and alkaline phosphatase. Before surgery they may need dialysis, phosphate adjustment, either medical correction of hyperparathyroidism, or chelation therapy for aluminium toxicity. Postoperative infection may be more common in patients who are on corticosteroid therapy after renal transplantation.202 
The incidence of epiphyseal displacement in children with renal osteodystrophy ranges from 20% to 30%.152 Sites of involvement include the distal femur, proximal femur, and proximal humerus, the heads of both the metatarsals and metacarpals, and the distal radial and ulnar epiphyses.152 In the proximal femur, both femoral neck fractures and slipped capital femoral epiphysis occur.113 Possible explanations for displacement of the proximal femoral epiphysis include metaphyseal erosion with subsequent fracture,113,152 and a layer of fibrous tissue that forms between the physis and the metaphysis because of the destructive effects of the renal osteodystrophy. The warning signs and risk factors for slipped capital femoral epiphysis in renal osteodystrophy include subperiosteal erosion of the medial femoral neck, increasing width of the physis, bilateral coxa vara, male gender, and an age between 10 and 20 years (Fig. 8-40).113 With erosion of the cortex of the inferior medial femoral neck, the femoral head collapses, decreasing the neck shaft angle, and subjecting the physis to shear forces as it assumes a vertical orientation. The slip is bilateral in up to 95% of the patients and it is usually stable.178,210 
Figure 8-40
This 13-year-old boy with renal osteodystrophy presented with bilateral hip and thigh pain.
 
A: Anteroposterior pelvic radiograph shows widening of the proximal femoral physes with sclerosis. Slipped capital femoral epiphyses were diagnosed. B: This anteroposterior pelvic radiograph taken 9 months after surgery shows narrowing of the physis and no evidence of further displacement of the capital femoral epiphyses.
 
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
A: Anteroposterior pelvic radiograph shows widening of the proximal femoral physes with sclerosis. Slipped capital femoral epiphyses were diagnosed. B: This anteroposterior pelvic radiograph taken 9 months after surgery shows narrowing of the physis and no evidence of further displacement of the capital femoral epiphyses.
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Figure 8-40
This 13-year-old boy with renal osteodystrophy presented with bilateral hip and thigh pain.
A: Anteroposterior pelvic radiograph shows widening of the proximal femoral physes with sclerosis. Slipped capital femoral epiphyses were diagnosed. B: This anteroposterior pelvic radiograph taken 9 months after surgery shows narrowing of the physis and no evidence of further displacement of the capital femoral epiphyses.
(Figures reproduced with permission from The Children's Orthopaedic Center, Los Angeles, CA.)
A: Anteroposterior pelvic radiograph shows widening of the proximal femoral physes with sclerosis. Slipped capital femoral epiphyses were diagnosed. B: This anteroposterior pelvic radiograph taken 9 months after surgery shows narrowing of the physis and no evidence of further displacement of the capital femoral epiphyses.
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The aggressive medical treatment of renal osteodystrophy, including administration of vitamin D, calcitriol, hemodialysis, renal transplantation, and parathyroidectomy, has improved the long-term survival and quality of life for these patients. Temporary limitation of weight bearing is recommended if there is little metaphyseal erosion, minimal coxa vara, and if fusion of the physis is expected within 1 to 2 years. Continuing displacement of the proximal femoral epiphysis may occur even after pinning, because the fixation holds poorly, possibly because the wide radiolucent zone of the femoral neck in this disorder is not true physis, but rather poorly mineralized woven bone and fibrous tissue. 
Smooth pins can be used to stabilize the epiphysis temporarily until medical treatment resolves the underlying bone disease and avoids definitive physeal closure.178 For patients younger than 5 years, Hartjen and Koman122 recommended treatment of slipped capital femoral epiphysis with reduction through Buck traction and fixation with a single specially fabricated 4.5-mm cortical screw. The distal threads of the screw were machined off so that only the smooth shank of the screw extended across the physis. Subtrochanteric osteotomy with fixation or total hip arthroplasty may be necessary in older patients with severe coxa vara after slipped capital femoral epiphysis.113 
Renal Osteodystrophy Complicated by Aluminium Toxicity Oppenheim et al.211 noted the contribution of aluminium toxicity to the development of fractures in renal osteodystrophy. Because phosphorus restriction is important in children with renal disease, aluminium hydroxide has been commonly used as a phosphate binder.11 Aluminium intoxication causes defective mineralization. Multiple pathologic fractures may occur with poor healing. Serum aluminium levels are not diagnostic, but the use of deferoxamine, a chelation agent, in an infusion test may provide the diagnosis. A bone biopsy is often necessary. After treatment of the renal disease with correction of the aluminium toxicity by chelation agents, acute fractures will heal. Severe bowing of the long bones caused by fractures can be treated with multiple osteotomies with intramedullary Rush rod or plate fixation.211 Recurrence of the syndrome is prevented by use of aluminium-free phosphate-binding agents such as calcium carbonate.237 

Author's Preferred Method of Treatment

Recognition of the underlying metabolic abnormalities is the most important aspect in the care of all of these injuries. Most fractures of the long bones respond readily to cast or splint immobilization, with concurrent aggressive medical treatment of the underlying metabolic disease. Slipped capital femoral epiphysis may be the first presenting sign of renal failure.113 A slipped capital femoral epiphysis should be stabilized with in situ screw fixation in older children, and multiple screws should be considered because the underlying metaphyseal bone is quite soft. For treatment of progressive slipped capital femoral epiphysis in very young children, some form of unthreaded fixation seems most logical. Femoral neck fractures are treated with anatomic reduction and internal fixation. The underlying bone disease should be medically treated to ensure success of open procedures. Significant cysts should be treated with curettage and bone grafting. Angular deformities of the long bones should be corrected when the patient is close to maturity. 

Idiopathic Osteoporosis

Osteoporosis in children is generally associated with congenital diseases such as OI or metabolic disorders such as Cushing syndrome. Rarely, children develop idiopathic osteoporosis with pathologic fractures. The etiology in healthy children is likely multifactorial and incompletely understood. Poor calcium intake during the adolescent growth spurt may play some role. Symptoms can persist for 1 to 4 years after diagnosis, with spontaneous resolution in most patients after the onset of puberty. The only consistent metabolic abnormality is a negative calcium balance with high rates of fecal excretion of calcium.131 This finding supports the hypothesis that idiopathic juvenile osteoporosis results from intestinal malabsorption of calcium. Biopsy specimens show a quantitative decrease in the amount of bone that has been linked to both increased resorption139 and primary failure bone formation.251 
Idiopathic osteoporosis is characteristically seen 2 years prior to puberty, but age at presentation may range from 4 to 16 years.251 It usually presents with bone pain, deformities, and fractures. Although many children present with back pain as the only complaint, the most severely affected present with generalized skeletal pain.139,251 Patients may have difficulty walking, and their symptoms may be initiated by mild trauma. Unique metaphyseal impaction fractures are a hallmark of this disorder.131 In a review of 40 patients with idiopathic osteoporosis, Smith251 observed that 87% had vertebral fractures and 42% had metaphyseal fractures. 
Generally, 30% of bone mass must be absent before osteoporosis is detected on radiographs.163 Radiographs of the spine show decreased density in the central areas of the vertebral bodies, and clarity of the dense vertebral end plates is increased. The long bones lose trabecular anatomy and show thinning of the cortex.131,249 Some authors have noticed that it is mostly a disorder of cancellous bone, reflecting a decreased modelling activity on the endocortical surface of the internal cortex.226 Some of the issues when dealing with idiopathic osteoporosis in children include the usually difficult interpretation of bone densitometry and turnover markers and poorly established guidelines regarding prevention and treatment of bone fragility. Once symptoms begin, a mildly lucent area of newly formed bone, so called neo-osseous porosis, is observable in the metaphysis (Fig. 8-41). This is considered weaker than the surrounding bone, which formed before onset of the disease.252 
Figure 8-41
 
A: Multiple pathologic fractures in a previously healthy teenage boy who developed idiopathic osteoporosis. This anteroposterior radiograph of the right knee and this lateral radiograph (B) demonstrate a displaced distal femoral metaphyseal fracture with apex posterior angulation. C: This was treated with closed reduction and percutaneous pinning and application of a cast. D: This lateral radiograph shows satisfactory alignment with the pins in place. E: A few months later, he sustained a left proximal femoral fracture, which was treated with a spica cast. F: This anteroposterior pelvic radiograph taken 3 years later shows healed proximal femoral fractures with varus angulation and severe osteopenia of the pelvis and femora with profusion of both acetabuli.
A: Multiple pathologic fractures in a previously healthy teenage boy who developed idiopathic osteoporosis. This anteroposterior radiograph of the right knee and this lateral radiograph (B) demonstrate a displaced distal femoral metaphyseal fracture with apex posterior angulation. C: This was treated with closed reduction and percutaneous pinning and application of a cast. D: This lateral radiograph shows satisfactory alignment with the pins in place. E: A few months later, he sustained a left proximal femoral fracture, which was treated with a spica cast. F: This anteroposterior pelvic radiograph taken 3 years later shows healed proximal femoral fractures with varus angulation and severe osteopenia of the pelvis and femora with profusion of both acetabuli.
View Original | Slide (.ppt)
A: Multiple pathologic fractures in a previously healthy teenage boy who developed idiopathic osteoporosis. This anteroposterior radiograph of the right knee and this lateral radiograph (B) demonstrate a displaced distal femoral metaphyseal fracture with apex posterior angulation. C: This was treated with closed reduction and percutaneous pinning and application of a cast. D: This lateral radiograph shows satisfactory alignment with the pins in place. E: A few months later, he sustained a left proximal femoral fracture, which was treated with a spica cast. F: This anteroposterior pelvic radiograph taken 3 years later shows healed proximal femoral fractures with varus angulation and severe osteopenia of the pelvis and femora with profusion of both acetabuli.
View Original | Slide (.ppt)
Figure 8-41
A: Multiple pathologic fractures in a previously healthy teenage boy who developed idiopathic osteoporosis. This anteroposterior radiograph of the right knee and this lateral radiograph (B) demonstrate a displaced distal femoral metaphyseal fracture with apex posterior angulation. C: This was treated with closed reduction and percutaneous pinning and application of a cast. D: This lateral radiograph shows satisfactory alignment with the pins in place. E: A few months later, he sustained a left proximal femoral fracture, which was treated with a spica cast. F: This anteroposterior pelvic radiograph taken 3 years later shows healed proximal femoral fractures with varus angulation and severe osteopenia of the pelvis and femora with profusion of both acetabuli.
A: Multiple pathologic fractures in a previously healthy teenage boy who developed idiopathic osteoporosis. This anteroposterior radiograph of the right knee and this lateral radiograph (B) demonstrate a displaced distal femoral metaphyseal fracture with apex posterior angulation. C: This was treated with closed reduction and percutaneous pinning and application of a cast. D: This lateral radiograph shows satisfactory alignment with the pins in place. E: A few months later, he sustained a left proximal femoral fracture, which was treated with a spica cast. F: This anteroposterior pelvic radiograph taken 3 years later shows healed proximal femoral fractures with varus angulation and severe osteopenia of the pelvis and femora with profusion of both acetabuli.
View Original | Slide (.ppt)
A: Multiple pathologic fractures in a previously healthy teenage boy who developed idiopathic osteoporosis. This anteroposterior radiograph of the right knee and this lateral radiograph (B) demonstrate a displaced distal femoral metaphyseal fracture with apex posterior angulation. C: This was treated with closed reduction and percutaneous pinning and application of a cast. D: This lateral radiograph shows satisfactory alignment with the pins in place. E: A few months later, he sustained a left proximal femoral fracture, which was treated with a spica cast. F: This anteroposterior pelvic radiograph taken 3 years later shows healed proximal femoral fractures with varus angulation and severe osteopenia of the pelvis and femora with profusion of both acetabuli.
View Original | Slide (.ppt)
X
Serum calcium, phosphorus, and alkaline phosphatase levels are usually normal.131 Low plasma calcitriol, a vitamin D metabolite that aids calcium absorption in the gut, has been observed in juvenile osteoporosis.185 
Lower extremity and vertebral fractures are common, but fractures of the proximal humerus, radius, ulna, and ribs may also occur.131 Metaphyseal fractures can start as hairline cracks that gradually extend across the width of the shaft, and with further collapse in the femoral shaft, the cracks may telescope into the distal femur, with later distortion of the femoral condyle.131 Long bone shaft fractures are either transverse or oblique, and the callus formed seems to be normal.131 No clear-cut effective medical treatment has been found for idiopathic juvenile osteoporosis.131,139 Many patients have been treated by both vitamin D and calcium supplements with equivocal benefit, and usually mineralization of the skeleton does not improve until puberty, when the disease spontaneously resolves. Low-dose pamidronate may be indicated in the treatment of childhood osteoporosis.102 

Iatrogenic Osteoporosis

Osteoporosis Associated with Cancer Treatment Osteoporosis is commonly seen in children who are undergoing cancer therapy. The cause of reduced bone mineral density is multifactorial. The disease itself may play a role (e.g., acute lymphoblastic leukemia, malignant bone tumors), but specifically the treatment including corticosteroids, chemotherapy (e.g., methotrexate, ifosfomide), and radiation (such as brain radiation that can reduce growth hormone secretion and cause hypogonadotropic hypogonadism), can contribute to the development of osteoporosis.236 Methotrexate, for example, is believed to inhibit osteogenesis, causing both delayed union and nonunion of fractures.224 The incidence of pathologic fractures after methotrexate use ranges from 19% to 57%.163,224,256 
Generalized demineralization of the skeleton is seen with marked radiolucency of the metaphyseal regions of the long bones. Radiographic changes in the metaphysis and epiphysis resemble those seen in scurvy.224 Minimally displaced transverse fractures occur in the long bones of both the upper and lower extremities and the small bones of the feet.224,256 
Schwartz and Leonidas239 cautioned that stress fractures of the long bones that can occur after methotrexate therapy can be mistaken for recurrence of leukemia. If feasible from an oncologic viewpoint, methotrexate should be discontinued to allow these fractures to heal in a cast. The cast immobilization itself may result in additional osteopenia and fractures even though methotrexate is discontinued.239 Patients with severe osteoporosis and bone pain without fracture also respond to a halt in methotrexate therapy.224 Prevention is the key and physical activity, adequate vitamin D intake, and sometimes bisphosphonates are some of the options.236 
Immobilization Osteoporosis Immobilization of an extremity for fracture treatment can result in loss of as much as a 44% of mineralization of trabecular bone. Immobilization leads to bone resorption, especially in unstressed areas.163 Osteoporosis may persist for 6 months after an injury, but bone density returns to normal in most by 1 year.91 Nilsson and Westlin207 found a residual decrease in bone mineralization of the distal femur of 7% at nearly 11 years of follow-up in a study of 30 patients. Persistent osteoporosis after cast immobilization for fracture can also contribute to refracture. 

Primary Hyperparathyroidism

Primary hyperparathyroidism in childhood is extremely rare. Although the exact incidence remains unknown, it results from hyperplasia of the parathyroid gland. Symptoms are associated with high serum calcium and inappropriate parathyroid hormone level, causing increased osteoclastic activity, leading to general demineralization of the skeleton and hypercalcemia. In severely affected patients, osteitis fibrosa cystica may develop with fibrous tissue replacement of bone and formation of cysts. In a large retrospective study, among the 44 children and adolescents, ranging in age from 6 to 18 (mean 13) years, 83% were symptomatic and 43% had nephrolithiasis. Two had multiple endocrine neoplasias.182 
A particularly severe form of primary hyperparathyroidism seen in infants is congenital primary hyperparathyroidism, which results from an autosomal recessive trait84 and is lethal without parathyroidectomy. These patients may present with difficulty breathing, hypotonia, poor feeding with constipation, and failure to thrive. Serum calcium is markedly increased in most patients, but a gradual rise above normal serum levels may occur in some infants with serial measurements. Radiographs reveal demineralization of the skeleton. Marked resorption is present in the femoral necks and distal tibias, with decreased trabeculae and poorly defined cortices.84 Periosteal elevation is common, and when it is severe, the long bones may actually look cloaked with new bone (Fig. 8-42). Periosteal resorption of the bone of the middle phalanges is believed to be characteristic of this disease. Brown tumors are rare in infancy. 
Figure 8-42
 
A: Newborn with hyperparathyroidism. There is marked demineralization of bone, and marked resorption is present in the proximal femurs (arrows). B: Periosteal elevation is present along the ulna (arrows).
 
(Courtesy of Bruce Mewborne, MD.)
A: Newborn with hyperparathyroidism. There is marked demineralization of bone, and marked resorption is present in the proximal femurs (arrows). B: Periosteal elevation is present along the ulna (arrows).
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Figure 8-42
A: Newborn with hyperparathyroidism. There is marked demineralization of bone, and marked resorption is present in the proximal femurs (arrows). B: Periosteal elevation is present along the ulna (arrows).
(Courtesy of Bruce Mewborne, MD.)
A: Newborn with hyperparathyroidism. There is marked demineralization of bone, and marked resorption is present in the proximal femurs (arrows). B: Periosteal elevation is present along the ulna (arrows).
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X
In older children and adolescents, the clinical presentation is subtler. Weakness, anorexia, and irritability are present in 50% of patients, and constipation is present in 28%.32 Renal calculi also are present in 25% of patients, and polyuria, excessive thirst, bone pain, abdominal distension, pancreatitis, and swelling of the knees are occasionally present.32 Approximately 50% of older patients have osteopenia and other osseous signs of hyperparathyroidism.32 The serum calcium is only moderately elevated in many patients, but 24-hour urine calcium excretion is abnormally high.32 If the diagnosis is uncertain, selective venous catheterization for parathyroid hormone can be done, localizing the gland by either ultrasound, CT, or MRI. 
Pathologic fractures of the long bones are common in patients with hyperparathyroidism, especially in infancy. Vertebral fractures, which occur in 4.4% of adult patients,55 are rare in infancy. Increased levels of parathyroid hormone results in decreased function and numbers of osteoblasts, and hence delayed union of pathologic fractures may occur, mostly in adults.162 Most fractures are successfully treated with simple immobilization. Occasionally, a fracture through a cyst or brown tumor requires curettage and bone grafting after a period of initial healing.276 

Cushing Syndrome

Endogenous Cushing syndrome in children is a rare disorder that is most frequently caused by pituitary or adrenocortical tumors, resulting in excessive production of cortisol and its related compounds. If the hyperactivity of the adrenal cortex is caused by pituitary gland stimulation, the syndrome is known as Cushing disease. In children, hypercortisolism is most often caused by carcinoma, adenoma, hyperplasia of the adrenal cortex,189 or exogenous corticosteroid therapy. The elevated adrenal corticosteroids inhibit the formation of osteoblasts, resulting in increased resorption of the bone matrix and decreased bone formation.140 
Presenting symptoms include failure to thrive, short stature with excessive weight gain, moon faces, presence of a buffalo hump, hirsutism, weakness, and hypertension.140,173,189 Cutaneous striae are rare, and the genitalia are of normal size. Mortality is over 50%.189 In older children, the clinical picture is somewhat different: Truncal obesity, short stature, a lowered hairline, acne, weakness, emotional lability, hirsutism, cutaneous striae, hypertension, and ecchymosis. 
Radiographic findings may include severe osteopenia and a retarded bone age. Fractures of the ribs, vertebrae, and long bones have been reported in children with Cushing syndrome.189 In terms of diagnostic studies, it has been shown that a single cortisol value at midnight followed by overnight high-dosage dexamethasone test led to rapid and accurate confirmation and diagnostic differentiation, respectively, of hypercortisolemia caused by pituitary and adrenal tumors.26 
The primary treatment of Cushing syndrome of childhood is total adrenalectomy.189 The associated fractures usually can be treated with standard immobilization techniques, but care should be taken not to increase the extent of osteopenia through excessive immobilization. In patients taking steroids, dose modification is attempted when possible. Also, children and adolescents who have Cushing syndrome may have significant alterations in body composition that result in a small but significant decrease in bone mass and increase in visceral adiposity. Long-term monitoring of body fat and bone mass should be mandatory after treatment.173 

Scurvy

Scurvy occurs in children who eat inadequate amounts of fresh fruit or vegetables leading to depletion in vitamin C. It takes up to 6 to 12 months before symptoms arise, and those may include asthenia, vascular purpura, bleeding, and gum abnormalities. In 80% of cases, the manifestations of scurvy include musculoskeletal symptoms consisting of arthralgia, myalgia, hemarthrosis, and muscular hematomas.93 Because vitamin C is essential for normal collagen formation, deficiency results in defective osteogenesis, vascular breakdown, delayed healing, and wound dehiscence. Children may experience severe lower limb pain related to subperiosteal bleeding. Although scurvy is often caused by a dietary deficiency of vitamin C,203 both aspirin and phenytoin are associated with decreased plasma levels of ascorbic acid. Vitamin C deficiency may also be present in myelomeningocele, although its contribution to fracture in that population is unclear. Infants with scurvy may present with irritability, lower extremities tenderness, weakness, pseudoparalysis, and possibly bleeding gums (if teeth have erupted). Subperiosteal hemorrhages may exist as well as hemorrhage into the subcutaneous tissues, muscles, urinary system, and gastrointestinal tract.248 Anemia is also a common finding. In developing countries, older children with scurvy presenting with inability to walk may be misdiagnosed as having poliomyelitis.225 
Radiographs may show osteolysis, joint space loss, ON, osteopenia, and/or periosteal proliferation. Trabecular and cortical osteoporosis is common.93 Profound demineralization is evident. In advanced disease, the long bones become almost transparent with a ground-glass appearance and extreme thinning of the cortex. Calcium accumulates in the zone of provisional calcification adjacent to the physis and becomes densely white (Fränkel line). Fractures generally occur in the scurvy line (Trummerfeld zone)—the radiolucent juxtaepiphyseal area above Fränkel line where the matrix is not converted to bone. Dense lateral spurs, known as the Pelken sign, may be seen.240,248 A characteristic finding of scurvy is the corner sign in which a peripheral metaphyseal defect exists where fibrous tissue replaces absorbed cortex and cartilage.115 Cupping of the metaphysis is common in both scurvy and rickets; in rickets, the metaphysis is ragged, whereas in scurvy, the metaphysis is sharply outlined.115 The epiphysis becomes ringed with a thin, dense line (Wimberger sign). The periosteal elevation caused by hemorrhage calcifies within 10 days of treatment with vitamin C (Fig. 8-43). 
Figure 8-43
Scurvy.
 
A: A 10-month-old boy presented with a 2-week history of refusal to walk with tenderness of the lower extremities. He had a history of milk and cereal intake only. There are signs of scurvy in the metaphysis (large arrow). The dense white line in the zone of the provisional calcification of the distal femur is known as the Fränkel line. The radiolucent juxtaepiphyseal line above the white line is known as the scurvy line. The peripheral metaphyseal defect, where fibrous tissue replaces absorbed cortex in cartilage, is known as the corner sign. Wimberger sign is a thin, dense line surrounding the epiphysis (small arrow). B: This is a child with healing scurvy. There is marked periosteal calcification around the distal tibia (arrows). C: A newborn with scurvy. Periosteal hemorrhage has become calcified in the bones of the lower extremity (arrows).
 
(Courtesy of Bruce Mewborne, MD.)
A: A 10-month-old boy presented with a 2-week history of refusal to walk with tenderness of the lower extremities. He had a history of milk and cereal intake only. There are signs of scurvy in the metaphysis (large arrow). The dense white line in the zone of the provisional calcification of the distal femur is known as the Fränkel line. The radiolucent juxtaepiphyseal line above the white line is known as the scurvy line. The peripheral metaphyseal defect, where fibrous tissue replaces absorbed cortex in cartilage, is known as the corner sign. Wimberger sign is a thin, dense line surrounding the epiphysis (small arrow). B: This is a child with healing scurvy. There is marked periosteal calcification around the distal tibia (arrows). C: A newborn with scurvy. Periosteal hemorrhage has become calcified in the bones of the lower extremity (arrows).
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A: A 10-month-old boy presented with a 2-week history of refusal to walk with tenderness of the lower extremities. He had a history of milk and cereal intake only. There are signs of scurvy in the metaphysis (large arrow). The dense white line in the zone of the provisional calcification of the distal femur is known as the Fränkel line. The radiolucent juxtaepiphyseal line above the white line is known as the scurvy line. The peripheral metaphyseal defect, where fibrous tissue replaces absorbed cortex in cartilage, is known as the corner sign. Wimberger sign is a thin, dense line surrounding the epiphysis (small arrow). B: This is a child with healing scurvy. There is marked periosteal calcification around the distal tibia (arrows). C: A newborn with scurvy. Periosteal hemorrhage has become calcified in the bones of the lower extremity (arrows).
View Original | Slide (.ppt)
Figure 8-43
Scurvy.
A: A 10-month-old boy presented with a 2-week history of refusal to walk with tenderness of the lower extremities. He had a history of milk and cereal intake only. There are signs of scurvy in the metaphysis (large arrow). The dense white line in the zone of the provisional calcification of the distal femur is known as the Fränkel line. The radiolucent juxtaepiphyseal line above the white line is known as the scurvy line. The peripheral metaphyseal defect, where fibrous tissue replaces absorbed cortex in cartilage, is known as the corner sign. Wimberger sign is a thin, dense line surrounding the epiphysis (small arrow). B: This is a child with healing scurvy. There is marked periosteal calcification around the distal tibia (arrows). C: A newborn with scurvy. Periosteal hemorrhage has become calcified in the bones of the lower extremity (arrows).
(Courtesy of Bruce Mewborne, MD.)
A: A 10-month-old boy presented with a 2-week history of refusal to walk with tenderness of the lower extremities. He had a history of milk and cereal intake only. There are signs of scurvy in the metaphysis (large arrow). The dense white line in the zone of the provisional calcification of the distal femur is known as the Fränkel line. The radiolucent juxtaepiphyseal line above the white line is known as the scurvy line. The peripheral metaphyseal defect, where fibrous tissue replaces absorbed cortex in cartilage, is known as the corner sign. Wimberger sign is a thin, dense line surrounding the epiphysis (small arrow). B: This is a child with healing scurvy. There is marked periosteal calcification around the distal tibia (arrows). C: A newborn with scurvy. Periosteal hemorrhage has become calcified in the bones of the lower extremity (arrows).
View Original | Slide (.ppt)
A: A 10-month-old boy presented with a 2-week history of refusal to walk with tenderness of the lower extremities. He had a history of milk and cereal intake only. There are signs of scurvy in the metaphysis (large arrow). The dense white line in the zone of the provisional calcification of the distal femur is known as the Fränkel line. The radiolucent juxtaepiphyseal line above the white line is known as the scurvy line. The peripheral metaphyseal defect, where fibrous tissue replaces absorbed cortex in cartilage, is known as the corner sign. Wimberger sign is a thin, dense line surrounding the epiphysis (small arrow). B: This is a child with healing scurvy. There is marked periosteal calcification around the distal tibia (arrows). C: A newborn with scurvy. Periosteal hemorrhage has become calcified in the bones of the lower extremity (arrows).
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X
Fractures and epiphyseal displacement may occur in both infants and older children with scurvy.115,180,240,248 The most common sites of fracture, in the order of frequency, are the distal femur, proximal humerus, costochondral junction of the ribs, and distal tibia.115 Fractures of the long bones generally are nondisplaced metaphyseal buckle fractures with mild angulation. In contrast, marked epiphyseal displacement occurs with a moderate amount of callus present even in untreated patients. Exuberant callus forms once vitamin C is administered. Standard immobilization, with administration of vitamin C, is adequate for most fractures. Remodeling potential is high in these patients.240 Even healed fractures that may appear to have undergone growth arrest should be observed, because there is potential for continued growth with medical treatment.248 For infants who are older than 12 months of age and have begun weight bearing, spine films are recommended to rule out vertebral fractures.180 
The literature regarding fracture treatment in scurvy consists primarily of case reports. Hoeffel et al.127 reported on a 14-month-old girl with scurvy with bilateral distal femoral epiphysis displacement. This condition resolved after treatment with vitamin C, but limb-length discrepancy developed on one side. In two patients with distal femoral fractures, healing led to cupping of the metaphysis with an appearance similar to that in central growth arrest.248 

Copper Deficiency and Scurvy-Like Syndrome

Copper is a vital trace element needed in the production of collagen. Copper deficiency results in a decreased number of collagen crosslinks, with adverse effects on both bone and blood vessels.116 Copper deficiency can occur by 3 months in low–birth-weight infants125 and after prolonged total parenteral nutrition. Copper deficiency can also develop as a result of excessive supplemental zinc ingestion.40 Another cause of copper deficiency is disruption of one gene on the X chromosome causing a defect in the process of copper absorption, with consequent deficiency of available copper at the cellular level, resulting in abnormalities of collagen formation and brain maturation, leading to early death.271 
Infants at risk for nutritional copper deficiency are those who are primarily milk fed and are on semistarvation diets with concurrent vomiting and diarrhea.61 Both rib and wrist enlargement are frequent,116 and neutropenia is common.125 The diagnosis is commonly based on clinical presentation and decreased levels of serum copper. 
Rarely, disruption of the copper controlling gene on chromosome 13 is associated with accumulation of excess copper in the body, initially in the liver and brain. With time, copper accumulates in the kidneys, causing renal damage and osteoarticular changes (e.g., osteoporosis, osteomalacia, and pathologic fractures).271 
Radiographic findings in copper deficiency syndrome are very similar to those in rickets, including metaphyseal cupping, flaring, demineralization of the skeleton, and subperiosteal elevation with calcification.61,116 There are some radiographic differences between scurvy and copper deficiency syndrome. The corner sign is frequently absent in copper deficiency, the metaphyseal spurs are not strictly lateral but sickle shaped, and radiolucent bands of the metaphysis are absent.116 Bone age also is frequently retarded. Pathologic fractures have been reported in copper deficiency syndrome. Cordano et al.61 noted prompt healing of a distal femoral fracture in an infant, but the fracture recurred before treatment of the copper deficiency. Such injuries can be treated like those in scurvy, with simple immobilization and concurrent correction of the copper deficiency. 

Fractures in Neuromuscular Disease

Cerebral Palsy

Neuromuscular diseases, such as cerebral palsy (CP) may be associated with osteoporosis. The main causes of low bone density and osteoporosis in children and adolescents with CP are lack of activity, nutritional, and pharmacologic treatments (e.g., anticonvulsivants drugs).218 
In a review of 1,232 institutionalized patients with cerebral palsy, Mclvor and Samilson191 documented 134 extremity fractures, primarily in quadriplegics. When the mechanism of injury was known, most of these fractures were the consequence of a fall, often associated with seizure activity. Approximately 46% of these fractures involved the femoral shaft, 6% were fractures of the head or neck of the femur, 15% involved the tibia and fibula, and 13% were humeral fractures. These authors believed that contracture or paralytic dislocation of the hip joint predisposed these patients to femoral fractures. Presedo et al.222 reported on 156 children with CP who were treated for fractures. The mean age at the time of the first fracture was 10 years; 66% of patients had spastic quadriplegia, of those 83% were nonambulatory. Most fractures (82%) occurred in the lower limbs. The main risk factor was nonambulatory CP child on anticonvulsant therapy.223 In another large multicenter study including 364 children with moderate-to-severe motor impairment, the rate of fracture was 4% per year. Children with greater body fat, feeding gastrostomy, and history of fracture were at highest risk of fractures.259 Leet et al.172 reported on 418 children with CP: 243 (58%) had quadriplegia, 120 (29%) had diplegia, and 55 (13%) hemiplegia. Of these, 366 were spastic, 23 mixed tone, 13 athetoid, and 16 classified as others. Pathologic fractures were seen in 50 children (12%). Older age at first fracture and use of valproic acid were predictive of fractures and defined a group of children who may benefit from treatment interventions to increase bone density. 
The diagnosis may be delayed because patients are often noncommunicative. Anticonvulsant therapy may contribute to osteoporosis; low levels of serum vitamin D were seen in 42% of patients in one series.167 
Although long-bone fractures in patients with cerebral palsy heal quickly with abundant callus, their treatment through either closed or open methods can be quite difficult. In a large series of patients, McIvor and Samilson191 recommended closed treatment through skeletal traction, hip spica cast, or long-leg cast. Approximately 65% of the femoral shaft fractures and 86% of distal femoral fractures went on to malunion. Despite malunion, most patients regained their prefracture function. Nearly 21% of their patients had refractures, and the authors believed that this was because of disuse osteopenia, inadequate reduction, or joint contractures. Closed treatment of these fractures can be complicated by the development of decubitus ulcers. Closed fractures, especially those of the femur, can become open injuries during treatment, owing to spasticity or inadequate immobilization.191 The healing time of femoral fractures treated through immobilization varies from 1 to 3.5 months.191 Fractures of the humerus have been treated with light hanging-arm casts or sling-and-swath bandages. Hip nails with side plates, compression plates, and intramedullary fixations also have been used for femoral shaft fractures in patients with CP. The mean healing time has been 5.3 months.191 
Heinrich et al.124 treated four femoral fractures in young patients with CP with flexible intramedullary nails with good outcomes. Femoral neck fractures may require in situ pinning, but observation may be adequate in asymptomatic bedridden patients. Although he advocated open fixation of some lower extremity fractures in patients with developmental delays, Sherk244 cautioned that some patients may have inadequate motivation to resume ambulation even with successful healing of their injuries. Medical management of these patients must also be emphasized. In patients with cerebral palsy and multiple fractures, Lee and Lyne167 recommended metabolic supplementation, along with traditional fracture care. 
In a randomized controlled trial of standing program impact on bone mineral density in nonambulant children with CP, participation in 50% longer periods of standing (in either upright or semiprone standing frames) improved vertebral but not proximal tibial volumetric trabecular bone mineral density. The authors concluded that such intervention might reduce the risk of vertebral fractures but is unlikely to reduce the risk of lower limb fractures in children with CP.52 
Fractures of the distal pole of the patella have been reported in children with CP caused by spasticity of the extensor mechanism of the knee in the presence of established knee flexion contracture.176,234 Lloyd-Roberts et al.176 reported on eight patients with this injury who presented with deterioration in walking and decreased endurance. All had knee flexion contractures. Seven of the eight patients complained of pain and local tenderness at the distal pole of the patella. In a series of 88 patients, fragmentation was seen in only 8%.234 Children predisposed to distal pole patellar fractures are spastic ambulalors with flexion contractures of the knees, patella alta, and a history of falls. Extension casting maybe helpful in symptomatic patients.234 If conservative treatment is unsatisfactory, then hamstring lengthening with correction of the knee flexion contracture can result in both healing of the fracture and relief of symptoms.176,234 Some authors176 also have excised the avulsed distal pole of the patella to relieve chronic symptoms. 
Although less common than metaphyseal and diaphyseal fractures, epiphyseal separations may occur. In a report of nine epiphyseal separations involving the distal femur and proximal humerus, in four severely affected children with spastic quadriplegic CP, the clinical-radiologic features confirmed the cause to be scurvy. The fractures healed nicely with treatment with vitamin C and splintage.18 

Author's Preferred Method of Treatment

Prevention is an important part of managing fractures in children with CP. Traditionally, long-leg casts or spica casts were used after multiple muscle lengthening or hip osteotomies, then after several weeks, the cast was removed and therapy had begun. After cast treatment, however, the osteopenia was worse, the joints were stiff, and fractures—especially in the distal femoral metaphysis—occurred during therapy or transfers. Foam abduction pillows and knee immobilizers and an intensive therapy program in the immediate postoperative period may avoid the deconditioning, osteopenia, and joint stiffness that develop after prolonged cast immobilization. In ambulatory children who need hip osteotomies, use of rigid internal fixation allows standing and gait training within 2 weeks, preventing not only osteopenia but also the risk that the child may never regain the full level of preoperative function after a prolonged period of cast immobilization. 
The goal of fracture care in CP is to restore the child to his or her prefracture level of function. In nonambulatory children with CP, one goal should be to preserve the ability to transfer. In children with severe CP, some degree of both malunion and shortening may be accepted. The patients' spasticity and inability to communicate make them prone to skin problems, so casts should be properly applied and well padded, usually with felt and polyurethane foam. Extra padding should be placed over the patella, anterior ankle, and heel, and a snug cast mould should be placed above the calcaneus to prevent proximal migration of the heel. If the patient is ambulatory, conventional forms of fracture treatment may be used (Fig. 8-44). When indicated fixation with titanium elastic intramedullary nails can be a very effective way to treat femoral fractures (Fig. 8-45). 
Figure 8-44
An 11-year-old boy with total body involvement cerebral palsy was receiving physical therapy when he developed pain and swelling around the left knee.
 
Radiographs showed displaced femoral supracondylar fracture (A, B). To be able to fit to the brace adequately, closed reduction and percutaneous pinning was performed (C, D). The fracture healed in good alignment and the pins were removed after 6 weeks (E, F).
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs showed displaced femoral supracondylar fracture (A, B). To be able to fit to the brace adequately, closed reduction and percutaneous pinning was performed (C, D). The fracture healed in good alignment and the pins were removed after 6 weeks (E, F).
View Original | Slide (.ppt)
Radiographs showed displaced femoral supracondylar fracture (A, B). To be able to fit to the brace adequately, closed reduction and percutaneous pinning was performed (C, D). The fracture healed in good alignment and the pins were removed after 6 weeks (E, F).
View Original | Slide (.ppt)
Figure 8-44
An 11-year-old boy with total body involvement cerebral palsy was receiving physical therapy when he developed pain and swelling around the left knee.
Radiographs showed displaced femoral supracondylar fracture (A, B). To be able to fit to the brace adequately, closed reduction and percutaneous pinning was performed (C, D). The fracture healed in good alignment and the pins were removed after 6 weeks (E, F).
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs showed displaced femoral supracondylar fracture (A, B). To be able to fit to the brace adequately, closed reduction and percutaneous pinning was performed (C, D). The fracture healed in good alignment and the pins were removed after 6 weeks (E, F).
View Original | Slide (.ppt)
Radiographs showed displaced femoral supracondylar fracture (A, B). To be able to fit to the brace adequately, closed reduction and percutaneous pinning was performed (C, D). The fracture healed in good alignment and the pins were removed after 6 weeks (E, F).
View Original | Slide (.ppt)
X
Figure 8-45
A 12-year-old girl with cerebral palsy and in-house-walking capabilities had an unwitnessed trauma to the right thigh, developing pain and deformity.
 
Radiographs showed a displaced fracture of the femoral shaft (A, B). The patient underwent closed reduction followed by titanium elastic nail fixation. At 6 weeks follow-up, there was abundant callus formation (C, D).
 
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs showed a displaced fracture of the femoral shaft (A, B). The patient underwent closed reduction followed by titanium elastic nail fixation. At 6 weeks follow-up, there was abundant callus formation (C, D).
View Original | Slide (.ppt)
Radiographs showed a displaced fracture of the femoral shaft (A, B). The patient underwent closed reduction followed by titanium elastic nail fixation. At 6 weeks follow-up, there was abundant callus formation (C, D).
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Figure 8-45
A 12-year-old girl with cerebral palsy and in-house-walking capabilities had an unwitnessed trauma to the right thigh, developing pain and deformity.
Radiographs showed a displaced fracture of the femoral shaft (A, B). The patient underwent closed reduction followed by titanium elastic nail fixation. At 6 weeks follow-up, there was abundant callus formation (C, D).
(Figures reproduced with permission from The Childrens Orthopaedic Center, Los Angeles, CA.)
Radiographs showed a displaced fracture of the femoral shaft (A, B). The patient underwent closed reduction followed by titanium elastic nail fixation. At 6 weeks follow-up, there was abundant callus formation (C, D).
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Radiographs showed a displaced fracture of the femoral shaft (A, B). The patient underwent closed reduction followed by titanium elastic nail fixation. At 6 weeks follow-up, there was abundant callus formation (C, D).
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Distal femoral buckle fractures in nonambulatory children are safely treated with a knee immobilizer. For metaphyseal distal femur fractures adjacent to contracted knee, casting can be used to improve limb alignment (pseudo-osteotomy). If a long-leg cast is used for a fracture of the lower extremity and the joint of the involved side is dislocated, the rigid cast may function as a lever arm, with the posterior fracture of the proximal femur beyond the cast (Fig. 8-46). 
Figure 8-46
Casting in neuromuscular fractures.
 
A: A polyurethane foam short-leg cast is being placed on a patient. Two long rectangular sheets of foam (arrows) are placed anteriorly and posteriorly over the stockinette, and Webril padding is wrapped around the foam. B: A long toe plate is needed to prevent injury to the foot of the patient. C: A thick, protective cuff of foam is formed by folding the polyurethane toward the center of the cast with the stockinette (arrow). D: The Webril must be wrapped quite snugly to compress the foam against the underlying extremity evenly (black arrow). Extra foam is placed over the anterior ankle and over the Achilles tendon to prevent proximal migration of the foot in the cast. A plaster cast is usually applied and covered with a layer of fiberglass for strength. A lateral radiograph verifies the position of the heel in the cast (white arrow).
A: A polyurethane foam short-leg cast is being placed on a patient. Two long rectangular sheets of foam (arrows) are placed anteriorly and posteriorly over the stockinette, and Webril padding is wrapped around the foam. B: A long toe plate is needed to prevent injury to the foot of the patient. C: A thick, protective cuff of foam is formed by folding the polyurethane toward the center of the cast with the stockinette (arrow). D: The Webril must be wrapped quite snugly to compress the foam against the underlying extremity evenly (black arrow). Extra foam is placed over the anterior ankle and over the Achilles tendon to prevent proximal migration of the foot in the cast. A plaster cast is usually applied and covered with a layer of fiberglass for strength. A lateral radiograph verifies the position of the heel in the cast (white arrow).
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Figure 8-46
Casting in neuromuscular fractures.
A: A polyurethane foam short-leg cast is being placed on a patient. Two long rectangular sheets of foam (arrows) are placed anteriorly and posteriorly over the stockinette, and Webril padding is wrapped around the foam. B: A long toe plate is needed to prevent injury to the foot of the patient. C: A thick, protective cuff of foam is formed by folding the polyurethane toward the center of the cast with the stockinette (arrow). D: The Webril must be wrapped quite snugly to compress the foam against the underlying extremity evenly (black arrow). Extra foam is placed over the anterior ankle and over the Achilles tendon to prevent proximal migration of the foot in the cast. A plaster cast is usually applied and covered with a layer of fiberglass for strength. A lateral radiograph verifies the position of the heel in the cast (white arrow).
A: A polyurethane foam short-leg cast is being placed on a patient. Two long rectangular sheets of foam (arrows) are placed anteriorly and posteriorly over the stockinette, and Webril padding is wrapped around the foam. B: A long toe plate is needed to prevent injury to the foot of the patient. C: A thick, protective cuff of foam is formed by folding the polyurethane toward the center of the cast with the stockinette (arrow). D: The Webril must be wrapped quite snugly to compress the foam against the underlying extremity evenly (black arrow). Extra foam is placed over the anterior ankle and over the Achilles tendon to prevent proximal migration of the foot in the cast. A plaster cast is usually applied and covered with a layer of fiberglass for strength. A lateral radiograph verifies the position of the heel in the cast (white arrow).
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Myelomeningocele

Children with myelomeningocele are at a high risk of pathologic fractures of the lower extremities. The etiology is multifactorial but results from decreased bone mineral density because of disuse (nonambulators), immobilization after reconstructive surgical procedures, and increased urinary calcium loss.177 Numerous other factors predispose these patients to fracture. For example, children with flail limbs tend to pick up one leg and drop it out of the way when they roll over in bed or twist around while in a sitting position, and this may be enough force to cause a fracture. Because protective sensation is absent, the child can neither anticipate impending injury nor be aware of injury once it has occurred. 
The incidence of fractures in children with myelomeningocele ranges from 12% to 31%.80,81 The location of these fractures, in the order of decreasing frequency, are midshaft of the femur, distal femur, midshaft of the tibia, proximal femur, femoral neck, distal femoral physis, and proximal tibia.80 Fractures may involve any segment of the bone, it's usually a result of a minor trauma, and often incomplete or impacted.177 They tend to heal rapidly, except for physeal fractures, and nonunion is rare.80,274 
The level of neurologic involvement also affects the incidence of fractures. In a series of 76 fractures, Lock and Aronson177 found that 41% occurred with neurologic deficit at the thoracic level, 36% occurred with deficit at the upper lumbar level, and only 13% occurred in patients with lower lumbar or sacral deficits. Nearly 86% of these fractures occurred before 9 years of age, and 76% were associated with cast immobilization. Most fractures after immobilization occur within 4 weeks of cast removal.81,177,193 In addition to the inherent disuse osteoporosis from immobilization, casting causes stiffness of joints with concentration of force on the osteoporotic bone adjacent to the joints.177 Boytim et al.42 reported neonatal fractures in six infants with myelomeningocele and concluded that the risk of fracture was 17% for patients with thoracic or high lumbar level deficits with significant contracture of the lower extremities. The authors cautioned that particular care must be used to avoid fractures in these patients during physical therapy, positioning for radiographs, or surgical procedures. Fractures associated with spina bifida are, however, most commonly seen in early adolescence.19 
Norton and Foley (1959)209 stated that “the quality of bone developed by activity appears to be the best protection against pathologic fractures,” and the orthopedist should assist spina bifida patients in maintaining the highest activity level possible. Stable fractures of the long bones may not require complete or rigid immobilization.81 Femoral shaft fractures have been treated with padding and sandbags, skin traction of anesthetic limbs may cause massive skin necrosis and is contra-indicated.80 Skeletal traction usually is inadvisable because of problems with decubitus ulcers and poor fixation to atrophic bone.80 Preventive measures include limiting cast immobilization after reconstructive surgery. Solid side cushions may prevent fractures that occur when patients catch their lower extremities in bed rails. 
Fractures of the physes in patients with myelomeningocele are relatively uncommon and difficult to diagnose.150 The clinical presentation may mimic infection, with elevated temperature and swelling, redness, and local warmth at the fracture site.230,266 Fractures of the proximal tibia may be confused with septic arthritis of the knee, with swelling up to the midthigh and limited knee flexion. Both the white blood cell count and erythrocyte sedimentation rate are often elevated. Immobilization of these injuries usually results in a dramatic decrease in swelling and redness of the extremity within 2 to 3 days of casting. With healing, the radiographic picture can be alarming, with epiphyseal plate widening, metaphyseal fracture, and periosteal elevation. The radiographic differential diagnoses should include osteomyelitis, sarcoma, leukemia, and Charcot joint.88 Physeal fractures require lengthy immobilization with strict avoidance of weight bearing to avoid destructive repetitive trauma to the physis.88 Either a plaster cast or a snug-fitting total-contact orthosis is suggested for immobilization, and union can be determined by return of the physis to normal width on radiographs. Kumar et al.160 emphasized that application of a long-leg cast for 8 to 12 weeks is necessary to obtain satisfactory healing of physeal fractures of the tibia, and weight bearing is to be avoided until union occurs. 
Recurrent trauma to the physis, from either continued walking or passive joint motion after injury, results in an exuberant healing reaction (Fig. 8-47).88 Repetitive trauma delays resumption of normal endochondral ossification, resulting in abnormal thickening of the cartilage in the zone of hypertrophy and the physeal widening seen on radiographs. In a study of 19 chronic physeal fractures, Rodgers et al.231 compared MRI with histology and found that adjacent to this thickened, disorganized zone of hypertrophy is juxtametaphyseal fibrovascular tissue that enhances gadolinium on MRI. Delayed union is common, and premature growth arrest occurs in 29% to 55% of patients.177 
Figure 8-47
A 10-year-old boy with low-lumbar spina bifida and community ambulation (with braces) presented with chronic bilateral leg/ankle pain.
 
Anteroposterior (A, C) and lateral (B, D) radiographs of both tibia and fibula show stress/insufficiency fracture of the distal tibial physis associated with extensive periosteal bone formation, characteristic of myelomeningocele.
Anteroposterior (A, C) and lateral (B, D) radiographs of both tibia and fibula show stress/insufficiency fracture of the distal tibial physis associated with extensive periosteal bone formation, characteristic of myelomeningocele.
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Figure 8-47
A 10-year-old boy with low-lumbar spina bifida and community ambulation (with braces) presented with chronic bilateral leg/ankle pain.
Anteroposterior (A, C) and lateral (B, D) radiographs of both tibia and fibula show stress/insufficiency fracture of the distal tibial physis associated with extensive periosteal bone formation, characteristic of myelomeningocele.
Anteroposterior (A, C) and lateral (B, D) radiographs of both tibia and fibula show stress/insufficiency fracture of the distal tibial physis associated with extensive periosteal bone formation, characteristic of myelomeningocele.
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Anschuetz et al.12 reported a unique syndrome in three patients with myelomeningocele and fracture. These children sustained fractures of the lower extremities during long-term immobilization and with cast removal went on to dramatic cardiopulmonary distress with increased pulse rate, hypotension, and increased respiratory rate. Fever also developed with decreased hematocrit levels. They suggested that the etiology of this problem was loss of intravascular volume into the fracture sites and recommended intravenous replacement of fluid losses, along with careful splinting of associated fractures. 
Lock and Aronson177 used Webril immobilization for an average of 1 to 3 weeks in their patients with fractures and discontinued immobilization when callus was visible. They found similar outcomes in patients treated with Webril dressings and those treated with casts; however, there was much less difficulty with pressure sores in the group treated with Webril dressings. Kumar et al.160 used a polyurethane padded long-leg posterior plaster splint for metaphyseal and diaphyseal fractures for 3 weeks, followed by bracing. Drennan and Freehafer80 recommend a well-padded cast for 2 to 3 weeks for infants with fracture and braces or Webril immobilization for incomplete fractures that followed surgery. Injuries with deformity were placed in a cast. Mobilization was begun as soon as practical to prevent further osteopenia, as early as 2 weeks after injury. Lock and Aronson177 cautioned that brace treatment of acute fractures may cause pressure sores. Drummond et al.81 reported on 18 fractures treated by closed techniques that resulted in three malunions, two shortenings, and two episodes of pressure sores; one patient had four refractures. Drabu and Walker78 noted a mean loss of knee movement of 58 degrees in 67% of fractures about the knee. The stiffness began 2 months after fracture and was well established by 6 months but resolved almost completely in all patients 3 years after injury. They suggested that aggressive physical therapy to restore knee motion is probably not necessary in these injuries. 
Operative fixation of fractures in children with myelomeningocele is associated with a high rate of infection. Bailey-Dubow rods may be valuable in multiple recurrent pathologic fractures of the femoral or tibial shaft. If operative treatment is necessary, it should be noted that the incidence of malignant hyperthermia is higher in patients with myelomeningocele than in other children.10 
Life-threatening anaphylactic reactions caused by latex allergy in children with myelomeningocele have been reported with increasing frequency.77,177 Minor allergic reactions, such as rash, edema, hives, and respiratory symptoms, are common when children with myelodysplasia are exposed to latex products such as gloves, catheters, and balloons. Between 18% and 40% of children with myelodysplasia are allergic to latex.95 Meeropol et al.193 emphasized that every child with myelomeningocele should be screened for latex allergy, and those with a positive history should be evaluated individually by the anesthesiologist for preoperative prophylaxis. Current preoperative prophylaxis begins 24 hours before surgery and is continued for 24 hours after surgery. Medications used include diphenhydramine 1 mg/kg every 6 hours (maximum 50 mg), methylprednisolone l mg/kg every 6 hours (maximum 125 mg), and cimetidine 5 mg/kg every 6 hours (maximum 300 mg). A latex-free environment must also be provided throughout the hospitalization. 

Author's Preferred Method of Treatment

In nonambulatory patients, mild malunion and shortening can be tolerated, and stable or minimally angulated fractures can be treated with either polyurethane splints or Webril dressings. Fractures with significant deformity may require reduction and immobilization in a cast heavily padded with polyurethane foam. In children who walk, fractures should be carefully aligned with heavily padded casts that allow continued protective weight bearing, if possible. Hip spica casts may be necessary for femoral shaft fractures. Fractures of the proximal femur should be treated by immobilization and any later deformity corrected by osteotomy. Any patient considered for operative intervention should be treated prophylactly with latex-free gloves and equipment. Physeal fractures are best treated with semi-rigid fiberglass or immobilizer for short period of time (2–3 weeks) to avoid further osteopenia and other fractures. Long-term follow-up is encouraged for physeal injuries because of the risk of growth arrest. 

Muscular Dystrophy

Fractures of the lower extremity in children with Duchenne muscular dystrophy must be managed so as not to cause premature loss of the ability to walk190 or transfer.137 In patients 9 to 10 years old, increasing muscle weakness and joint contractures contribute to falls, and a loss of normal muscle bulk and fat limit the cushioning on impact.246 Patients in lower extremity braces seem to sustain fewer fractures in falls, probably because the overlying orthoses provide some protection.246 Patients confined to a wheelchair can fall because they have poor sitting balance, and fractures are frequent because these patients are more osteoporotic than ambulatory individuals.246 
Corticosteroid therapy given to children with Duchenne muscular dystrophy to prolong mobility has been shown to increase the rate of osteoporosis and consequently, increase the risk of fracture. In a chart review of 143 boys with genetically confirmed dystrophinopathies, boys treated with steroids ambulated independently 3.3 years longer than the untreated group and had a lower prevalence of scoliosis. However, vertebral compression fractures occurred in 32% of the treated group, whereas no vertebral fractures were seen in the nontreatment group; long-bone fractures were 2.6 times greater in steroid-treated patients.151 A study of 33 boys with Duchenne muscular dystrophy demonstrated the incidence of vertebral fractures in these patients after the initiation of corticosteroid treatment; 40 months after commencement of steroids the first vertebral fracture emerged, and by 100 months of treatment, approximately 75% of patients had sustained a vertebral fracture.41 
Concentric “osseous atrophy” occurs in the long bones of patients with Duchenne muscular dystrophy; osteoporosis is also common.188 Osteoporosis is most profound in the lower extremities and begins to develop early while still ambulating. Consequently, frequent fractures may result in loss of ambulation.164 Larson and Henderson164 reported that bone density in the proximal femur was profoundly diminished even when gait was minimally affected, and then progressively decreased to nearly four standard deviations below age-matched normal. Fractures are seldom displaced and are frequently minimally painful because there is minimal muscle spasm.246 Fractures tend to heal rapidly. The most commonly fractured bone is the femur followed by the proximal humerus.137,246 
There are two goals of fracture care in children with muscular dystrophy: Limb stability and maintenance of maximal function during fracture healing. In ambulatory patients, treatment methods should allow children to maintain the ability to walk as the fracture heals. When ambulatory ability is tenuous, even minor bruises or ankle sprains may end walking ability. As little as 1 week in a wheelchair can prematurely end ambulation; patients at bed rest for more than 2 weeks will likely lose the ability to ambulate.190 Hsu136 reported that 25% of ambulatory patients with muscular dystrophy lost the ability to walk after sustaining fractures. In one of these patients, the ankle was casted in 20 degrees of plantarflexion, and the resulting contracture prevented ambulation at the end of treatment. 
Treatment of specific fractures should be individualized. Upper extremity fractures can be treated with lightweight slings.246 Lower extremity fractures can be treated with either light walking casts or long-leg double upright braces.246 Splints also can be used until the patients are pain free. Routine activities are begun as soon as possible. Protected standing and ambulation with physical therapy are crucial in maintaining independent ambulation (Fig. 8-48). 
Figure 8-48
 
This 15-year-old domiciliary-ambulatory boy with Duchenne muscular dystrophy who sustained a fall at home had this displaced femoral shaft fracture (A, B). Because of his prefracture ambulatory status, he underwent closed reduction and intramedullary fixation of his fracture (C–E).
This 15-year-old domiciliary-ambulatory boy with Duchenne muscular dystrophy who sustained a fall at home had this displaced femoral shaft fracture (A, B). Because of his prefracture ambulatory status, he underwent closed reduction and intramedullary fixation of his fracture (C–E).
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This 15-year-old domiciliary-ambulatory boy with Duchenne muscular dystrophy who sustained a fall at home had this displaced femoral shaft fracture (A, B). Because of his prefracture ambulatory status, he underwent closed reduction and intramedullary fixation of his fracture (C–E).
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Figure 8-48
This 15-year-old domiciliary-ambulatory boy with Duchenne muscular dystrophy who sustained a fall at home had this displaced femoral shaft fracture (A, B). Because of his prefracture ambulatory status, he underwent closed reduction and intramedullary fixation of his fracture (C–E).
This 15-year-old domiciliary-ambulatory boy with Duchenne muscular dystrophy who sustained a fall at home had this displaced femoral shaft fracture (A, B). Because of his prefracture ambulatory status, he underwent closed reduction and intramedullary fixation of his fracture (C–E).
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This 15-year-old domiciliary-ambulatory boy with Duchenne muscular dystrophy who sustained a fall at home had this displaced femoral shaft fracture (A, B). Because of his prefracture ambulatory status, he underwent closed reduction and intramedullary fixation of his fracture (C–E).
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Hsu and Garcia-Ariz137 reported on 20 femoral fractures in 16 patients with muscular dystrophy. Six of the seven ambulatory patients were able to walk after treatment. In the nonambulatory patients in this series, most had supracondylar femoral fractures which were splinted for 2 to 3 weeks, with emphasis on physical therapy to maintain functional abilities. Although union was achieved rapidly, hip and knee flexion contractures often increased in these patients and up to 20 degrees of angulation of the fracture was routinely accepted. One patient with slipped capital femoral epiphysis was treated successfully with pinning in situ. 

Author's Preferred Method of Treatment

The first goal of fracture treatment in children with muscular dystrophy is to avoid making matters worse. The patient should be mobilized as soon as possible in a lightweight cast or orthosis. Aggressive physical therapy should be used to maintain functional status. In a very young child, midshaft femoral fractures can be treated by traction and hip spica techniques, but in an older patient, ambulatory cast bracing might be a better choice. 

Arthrogryposis

Arthrogryposis is a group of rare and heterogeneous disorders affecting children in whom there are at least two or more joint contractures in multiple body areas. There are at least a few hundred arthrogrypotic syndromes. Arthrogryposis has an incidence of 3 in 10,000 live births.277 Although the etiology is unknown and likely multifactorial, there is a lack of fetal joint movement after initially normal development, leading to collagen proliferation, fibrotic replacement of muscle, a marked thickening of joint capsules, taut ligaments, and capsular tightness resulting in joint stiffness.118 Dislocations can occur with severe shortening of the involved muscles. 
Fractures may occur in 25% of infants with arthrogryposis.70 A difficult delivery or forceful manipulation of the extremities can lead to fracture.70 Diamond and Alegado70 reported 16 fractures in nine infants with arthrogryposis; an ipsilateral dislocated hip was present in 35% of patients. Most fractures involved the femur, with the remainder mostly tibial fractures, one humeral fracture, and one clavicle fracture. Epiphyseal separations occurred in the proximal tibia, distal femur, and proximal humerus. Clinical symptoms included poor feeding, irritability, and fussiness when handled. The involved extremity was thickened, and there was often an increased white blood cell count. Plain radiographs after acute injury, especially with epiphyseal separations, were not helpful, and arthrogram was used in one patient to evaluate a distal femoral epiphyseal separation. With healing, these fractures develop exuberant callus with rapid union and ready remodeling of angulated midshaft fractures. 
Short-term immobilization is adequate to treat nondisplaced fractures in these patients (Fig. 8-49). Postnatal fractures are most common in patients with either knee contracture or dislocation of the hip, and postnatal injury could possibly be reduced by avoidance of forceful manipulation of these extremities. Older patients with lower extremity contractures do not seem to have increased risk for pathologic fractures. 
Figure 8-49
A 4-year-old boy with arthrogryposis and bilateral knee extension contracture presented with swelling and pain around the knee.
 
Initial films show minimally displaced transverse fracture through the distal femoral metaphysis (A, B) (arrow). After 4 weeks in a long-leg cast, radiographs show new bone formation (C, D) (arrow) and good alignment of the fracture in both views.
Initial films show minimally displaced transverse fracture through the distal femoral metaphysis (A, B) (arrow). After 4 weeks in a long-leg cast, radiographs show new bone formation (C, D) (arrow) and good alignment of the fracture in both views.
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Figure 8-49
A 4-year-old boy with arthrogryposis and bilateral knee extension contracture presented with swelling and pain around the knee.
Initial films show minimally displaced transverse fracture through the distal femoral metaphysis (A, B) (arrow). After 4 weeks in a long-leg cast, radiographs show new bone formation (C, D) (arrow) and good alignment of the fracture in both views.
Initial films show minimally displaced transverse fracture through the distal femoral metaphysis (A, B) (arrow). After 4 weeks in a long-leg cast, radiographs show new bone formation (C, D) (arrow) and good alignment of the fracture in both views.
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