Chapter 53: Distal Femur Fractures

Cory A. Collinge, Donald A. Wiss

Chapter Outline

Introduction to Distal Femur Fractures

Although less frequent than fractures around the hip, distal femur fractures are relatively common injuries and present considerable challenges in management. No single method of management has overcome all of the problems associated with this injury. Prior to 1970, most supracondylar fractures were treated nonoperatively; however, angulatory deformities, knee joint incongruity, loss of knee motion, as well as the complications of recumbency led to better methods of treatment.14,21,30 During the past 40 years, operative techniques and implants have dramatically improved, and internal fixation is recommended for most displaced distal femoral fractures in adults. The goals of treatment are anatomic reduction of the articular surface, restoration of limb alignment, length, and rotation, and stable fixation that allows for early mobilization. Nonetheless, internal fixation of the distal femur can be difficult for several reasons: thin cortices, a wide medullary canal, compromised bone stock, and fracture comminution that make stable internal fixation often difficult to achieve.15,86 Although better methods of fixation have dramatically improved clinical results, the operative management of these difficult fractures is not uniformly successful. 

Assessment of Distal Femur Fractures

Mechanisms of Injury for Distal Femur Fractures

The mechanism of injury for most supracondylar fractures is thought to be axial loading with varus, valgus, or rotational forces. A bimodal distribution of high-energy trauma in younger patients and lower energy in elderly patients is typically seen with these injuries. However, higher-energy injuries in elderly patients are not uncommon. In younger patients, supracondylar fractures often occur following high-energy trauma related to motor vehicle or motorcycle accidents. In these patients there may be considerable fracture displacement, comminution, open wounds, and soft tissue injuries.24,103 On the other hand, in elderly osteoporotic patients, supracondylar fractures frequently occur after a ground level fall on a flexed knee. Notching of the anterior cortex of the distal femur while making femoral chamfer cuts during knee arthroplasty may predispose the distal femur to fracture.3,80 
Predictable deformities occur after a distal femur fracture and are produced primarily by the direction of the initial fracture displacement and secondarily by the contraction of the thigh musculature (Fig. 53-1). Spasm and irritability in the quadriceps, hamstrings, and adductors often lead to limb shortening with varus angulation at the fracture site. Muscle contraction of the gastrocnemius often produces an apex posterior angulation and displacement of the distal fragment. In fractures with intracondylar extension, soft tissue attachments to the respective femoral condyles tend to produce splaying and rotational malalignment of the condyles that contributes to joint incongruity. These forces must be overcome during the fracture reduction and the internal fixation device must be strong enough to prevent redisplacement. 
Figure 53-1
Diagram of typical distal femur fracture pattern and deforming muscle forces.
Rockwood-ch053-image001.png
View Original | Slide (.ppt)
X

Associated Injuries with Distal Femur Fractures

High-energy forces sufficient to fracture the distal femur may also lead to concomitant injuries in the same extremity or more distant locations and associated nonskeletal injuries are common. These injuries and their sequelae (e.g., pulmonary problems) may delay definitive fracture fixation for days or even weeks. Delayed fixation increases the technical difficulty of the procedure, contributes to patient morbidity, and may compromise the goals of treatment. Temporizing external fixation has been used effectively in these circumstances to stabilize the fracture, prevent further local soft tissue trauma, and improve patient mobilization (Fig. 53-2).35,68 
Figure 53-2
Photograph demonstrating a temporizing external fixator spanning used in a patient with a distal femur fracture.
Rockwood-ch053-image002.png
View Original | Slide (.ppt)
X
In patients injured as the result of a high-energy trauma, ipsilateral hip and femoral shaft fractures occasionally occur and may complicate treatment. Furthermore, in up to 50% of these patients there is proximal fracture extension into the femoral diaphysis.103 Ipsilateral injuries to the tibia, ankle, and foot are also common. Approximately 5% to 10% of distal femur fractures are open injuries. The site of the open wound is usually in the anterior thigh proximal to the patella that may damage the quadriceps muscle and extensor mechanism. Although the femoral and popliteal arteries are in close proximity to the distal femur, vascular injury is less common than in patients with a knee dislocation. This potentially catastrophic injury must not be overlooked and a complete vascular examination is mandatory. 
In elderly frail patients with lower-energy distal femur fracture, mortality rates are similar to that of the hip fracture population. Periprosthetic distal femur fractures and those in patients with dementia, heart failure, advanced renal disease, and metastasis have reduced survival compared to age-matched controls.97 In fact, the age-adjusted Charlson Comorbidity Index was found to serve as a useful tool to predict survival in these patients.95,97 Surgical delay greater than 4 days has also been shown to increase the 6-month and 1-year mortality rates. 

Open Distal Femur Fractures

Approximately 5% to 10% of distal femur fractures are open injuries.24,103 The traumatic wound is nearly always anterior and is associated with a variable degree of damage to the extensor mechanism. As with all fractures, urgent but thoughtful treatment is required. Early appropriate antibiotic administration followed by thorough surgical debridement and irrigation of the open fracture and traumatic wounds are crucial steps in the prevention of infection.70,71 Serial debridements may be necessary in many type III open fractures: antibiotic beads or a wound VAC are useful tools in this setting. Immediate internal fixation is not indicated for all fracture patterns or patient conditions. The risk–benefit ratio to the patient must be carefully assessed when contemplating primary internal fixation. Early temporizing fracture stabilization for open fractures is particularly useful in patients with multiple injuries, massive and mutilating limb injuries, open fractures and vascular injuries, and open intra-articular fractures. Advantages of immediate internal or external fixation in these fractures include stabilization of the fracture and surrounding soft tissues, ease of wound care, pain relief, and mobilization of the patient and the injured limb (Fig. 53-2).35,68 Nonetheless, immediate internal fixation in open supracondylar fractures must be tempered by the increased risk of infection as a consequence of further soft tissue dissection and interference with local blood supply. If infection develops, it may affect not only the fracture site but also the knee joint. 
In stable patients with type II, III, and IIIA open supracondylar fractures, many fracture surgeons favor definitive internal fixation after debridement of the traumatic wounds, if the wounds can be made “clean.” Nonetheless, most grade IIIB and IIIC open distal femur fractures are more safely managed with knee-spanning external fixation and delayed internal fixation. Subsequent definitive surgery can be carefully planned with optimal operating room personnel and resources, or transfer to a tertiary center better equipped to handle complex fractures. Dealing with these complex injuries and their surrounding controversies such as how much to debride, or how and when to graft may be best left to experienced fracture surgeons (Ricci et al.).77 

Vascular Injuries Associated with Distal Femur Fractures

Vascular injury associated with supracondylar femur fractures is uncommon, but is a potentially devastating injury constellation. Most injuries to the superficial or profunda femoral arteries occur after fractures of the femoral shaft. On the other hand, blunt injury to the popliteal artery most commonly occurs with knee dislocations or displaced fractures of the proximal tibia. It is surprising, therefore, that the incidence of popliteal artery injury is so low after supracondylar fracture because the vascular bundle is tethered proximally in the hiatus of the adductor magnus muscle and distally by the arch of the soleus. These tight attachments leave little room for skeletal distortion after fracture. Vessel injury can be caused by direct laceration or contusion of the artery or vein by fracture fragments or indirectly by stretching, leading to intimal damage. Clinical examination of the leg for signs of ischemia with evaluation of pulses and motor and sensory function is essential. 
Indications for arteriography with intra-arterial injection or CT angiography include an absent or diminished pulse, expanding hematoma, diminished ankle–ankle index, bruit, persistent arterial bleeding, and injury to anatomically related nerves. Displaced supracondylar fractures in close proximity to the femoral or popliteal vessels despite apparent normal peripheral pulses may have occult vascular injury patterns and require careful judgment regarding the need for exploration or angiography. If any doubt exists about the integrity of the vessels, a consultation with a vascular surgeon is recommended. 
The treatment of arterial injury in conjunction with supracondylar femur fractures depends on the severity of the ischemia and amount of time elapsed since the injury. If distal pulses are present (indicating distal tissue perfusion), the fracture should be stabilized first. If arterial compromise is severe or the time elapsed from injury is more than 6 hours, re-establishment of circulation takes priority. Consideration should be given to rapid application of an external fixator to restore length and provide stability before arterial reconstruction. A temporary vascular shunt followed by definitive vascular repair may be useful. Arterial repairs are usually accomplished by interposition vein grafts or synthetic grafts. Whenever possible, concomitant femoral or popliteal vein injuries should be repaired. One of the most common and preventable mistakes is to repair the vessel with the fracture in a displaced position. During subsequent fixation of the fracture, manipulation of overriding fragments can disrupt the vascular anastomosis. This problem can be avoided or minimized by the use of an external fixator or a femoral distractor to maintain length and alignment before the vascular repair. Fasciotomy of the lower leg should be considered in all patients with ischemia time exceeding 6 hours and those with tenseness of the fascial compartments after reperfusion or extensive soft tissue injuries. Compartment pressure monitoring may be helpful in borderline cases. 
In patients with massive open wounds with vascular injury (type IIIC) or those in extremis, primary amputation may be indicated. This is particularly true if the injury is associated with sciatic or posterior tibial nerve disruption. The goal of aggressive limb salvage should be functional viability, not just a perfused limb. 

Concomitant Ligament Injuries with Distal Femur Fractures

Concomitant ligamentous injuries to the knee are uncommonly associated with distal femur fractures and are not usually diagnosed preoperatively. Infrequently, bony avulsion injuries to the collateral or cruciate ligaments can be identified on the initial injury radiographs. Midsubstance tears and capsular disruptions cannot be assessed clinically at the time of injury because of pain and guarding. The anterior cruciate ligament is the most commonly injured ligament. In supracondylar fractures with significant comminution of the articular surface, the anterior cruciate ligament can be detached with one of the fracture fragments. Whenever possible, this osteochondral fragment should be repaired at the time of fixation of the supracondylar fracture. There is no consensus regarding the timing of treatments of midsubstance tears of the cruciate ligaments associated with supracondylar fractures. Primary repairs, ligament augmentation, and formal reconstruction are made much more difficult by the presence of the fracture and associated internal fixation devices. Large-caliber drill holes, or tunnels, made through the intercondylar notch of the femur for ligament reconstruction are usually contraindicated. They may cause further comminution of the fracture, compromise the stability of internal fixation, or be technically impossible because of the fixation hardware. Primary ligament repair or reconstruction prolongs operating time and may increase the risk of postoperative infection, intra-articular adhesions, or loss of knee motion. Initial nonoperative treatment of midsubstance tears of the cruciate ligaments is recommended. Protected motion in conjunction with a knee orthosis together with vigorous rehabilitation may obviate the need for late reconstructive surgery in some patients. In those patients with persistent functional disability, late ligament reconstruction can be undertaken once the fracture has healed and the hardware can be removed safely. 

Periprosthetic Distal Femur Fractures

Distal femur fractures following total knee replacement are increasing in incidence with an estimated frequency of 0.3% to 2.5%.1,3 These complex injuries are likely to increase as the number of knee replacements continues to rise. Treatment is often difficult, and until recently, most published studies report relatively small numbers of patients. Risk factors for fractures include osteopenia, rheumatoid arthritis, prolonged corticosteroid therapy, anterior notching of the femoral cortex, and revision arthroplasty. Nonoperative treatment is commonly associated with prolonged periods of traction, malalignment, and knee stiffness. Operative treatment, particularly revision arthroplasty, is a major surgical undertaking that often requires a long-stem or custom implant. 
Treatment of displaced and comminuted fractures is based on the integrity of the knee prosthesis. If the prosthesis is loose, revision arthroplasty with a stemmed prosthesis is favored. If the femoral component is stable, the advantages of internal fixation with a locked plate or retrograde nail appear to outweigh nonoperative care. Internal fixation, correctly done, prevents malalignment while allowing early ambulation and knee motion. Locked plating, in particular, has decreased complications after periprosthetic distal femur fracture and improved results. Periprosthetic fractures of the distal femur are considered in more detail in Chapter 23

Signs and Symptoms of Distal Femur Fractures

All patients suspected of a distal femur fracture require a thorough history and physical examination. Significant bleeding into the thigh may occur after femur fractures at any level, and evaluation for signs of shock should be investigated and aggressively treated. Collaboration with a general trauma surgeon or internal medical specialist is strongly recommended when there are significant associated injuries or medical comorbidities. 
Clinical examination invariably reveals tenderness, fracture crepitance with thigh swelling, and limb deformity with shortening and external rotation if the fracture is displaced. The skin should be examined for bruising, contusion, or open fracture. Other injuries to the same extremity should be suspected when there is pain or swelling in the limb above or below the fracture site. A careful neurovascular examination must be performed and documented including the presence or absence of distal pulses and sensorimotor assessment. If there are differences in distal pulses between the injured and noninjured sides, or there is suspicion of an occult vascular injury, ankle–ankle indices should be checked. If the results between sides are within 10%, then vascular injury is unlikely.58 Conventional and CT angiography are also useful tools when evaluating for vascular injury. A gentle reduction and splinting of the injured limb should be performed early after arrival to the emergency department, if not already done by prehospital caregivers. 

Imaging and other Diagnostic Studies for Distal Femur Fractures

An anteroposterior (AP) and lateral radiograph of the knee and femur should be obtained and is usually sufficient for diagnosis. In most patients, x-rays of the pelvis, ipsilateral hip, and femoral shaft are necessary to rule out associated injuries. Additional radiographs are obtained as dictated by the clinical examination. Traction radiographs are helpful if there is significant shortening and deformity and provide a better understanding of the fracture geometry. This can often be combined with the reduction and splinting process in the emergency department or in the operating room if a spanning external fixator is being placed. 
CT scans with axial, coronal, and sagittal reconstruction of the distal femur are an important adjunct to plain radiographs and are recommended with juxta-articular involvement. Intra-articular injuries can be better delineated and a number of potentially important occult fractures identified. For example, one study showed a 40% rate of coronal plane (Hoffa) fractures with intercondylar fractures, many of which are missed on plain radiographs.63 
Osteoporosis is present in many elderly patients with distal femur fracture and may influence the method of treatment. If osteoporosis is evident on plain radiographs, a loss of 40% or more bone density has occurred.36 Although the importance of considering osteoporotic bone in designing a construct is obvious, these patients should be educated and treated to avoid future fractures. 

Classification of Distal Femur Fractures

There is no universally accepted method of classification for distal femur fractures. Essentially all classifications distinguish among extra-articular, intra-articular, and isolated condylar lesions. Fractures are further subdivided according to the degree and direction of displacement, amount of comminution, and involvement of the joint surfaces. Unfortunately, anatomic fracture classifications fail to address the conditions commonly associated with supracondylar femur fractures, which often influence the treatment or outcome. These factors, which play a dynamic role in management, determine the “personality” of a fracture. Among these are (1) amount of fracture displacement, (2) degree of comminution, (3) extent of soft tissue injury, (4) associated neurovascular injuries, (5) magnitude of joint involvement, (6) degree of osteoporosis, (7) presence of multiple trauma, and (8) complex ipsilateral injuries (i.e., patella or plateau fractures). 
We prefer the OTA fracture classification54 because it is easy to use and applicable to most parts of the skeleton. It distinguishes between extra-articular (type A), partial articular (type B), and complete articular (type C) injuries, and accounts for fracture complexity (Fig. 53-3). A basic treatment plan for distal femur fractures usually can be formulated based on this classification system. Because of the large number of fracture patterns seen in clinical practice, however, some fractures do not fit neatly into any classification scheme. This emphasizes the fact that every patient must be individually evaluated and the “personality” of the fracture must be considered in selecting the method of treatment. 
Figure 53-3
OTA classification of distal femur fractures (33A-C).
 
(From Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium—2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma. 2007;21:S1–S133.)
(From Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium—2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma. 2007;21:S1–S133.)
View Original | Slide (.ppt)
Figure 53-3
OTA classification of distal femur fractures (33A-C).
(From Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium—2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma. 2007;21:S1–S133.)
(From Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium—2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma. 2007;21:S1–S133.)
View Original | Slide (.ppt)
X

Outcome Measures for Distal Femur Fractures

Many scoring instruments have been used for outcomes after trauma around the knee and for distal femur fractures. These include the Western Ontario and McMaster University Osteoarthritis (WOMAC) index,6 the Lysholm knee function scale,7 and individual systems proposed by Sanders et al.,83 Leung,52 Neer et al.,62 and others. For general or “whole body” outcomes, the Short Musculoskeletal Functional Assessment (SMFA)4 and Short Form-36 (SF-36)13,56 are commonly used instruments that allow for comparison versus other injuries and uninjured controls. Recently, geriatric-specific outcomes scores, the Barthel index and the Parker scores have been applied to elderly patients with distal femur fractures.44,97 In the same study population, these authors showed that mortality at an average of 5 years was over 50%. 

Pathoanatomy and Applied Anatomy Relating to Distal Femur Fractures

The supracondylar area of the femur is defined as the zone between the femoral condyles and the junction of the metaphysis with the femoral diaphysis. This comprises approximately the distal 15 cm of the femur, as measured from articular surface. It is important to distinguish extra-articular fractures from intercondylar as well as diaphyseal fractures of the distal femur because the methods of treatment and prognosis are considerably different. 

Applied Anatomy of the Distal Femur Bone

The shaft of the femur is cylindrical or teardrop shaped, but at the lower end it broadens into two curved condyles (Fig. 53-4). If viewed on end, the shape of the distal femur is trapezoidal with the posterior part of the condyle wider than the anterior creating about 25-degree inclination angle on the medial surface and 15 degrees on the lateral surface.15 This becomes important when placing implants across the condyles from lateral to medial because on AP radiographs implants placed anteriorly that appear to be of appropriate length may be too long and cause painful irritation.57 Anteriorly, the articular surfaces of the two condyles come together to form a deep groove for articulation with the patella. Posteriorly, they are separated by the intercondylar fossa that gives attachment to the cruciate ligaments of the knee. The contact surface for the patella includes parts of both condyles, but is derived predominantly from the lateral condyle, which is broader and extends farther proximally. The lateral epicondyle arising from the lateral condylar surface gives origin to the fibular collateral ligament. Immediately below the lateral epicondyle is an oblique groove where the popliteus tendon resides. The medial femoral condyle is longer than the lateral condyle and extends farther distally. Its medial surface is convex and contains an epicondyle that gives attachment to the tibial collateral ligament. Situated on the proximalmost part of the condyle is the adductor tubercle, into which the tendon of the adductor magnus muscle inserts. 
Figure 53-4
 
A: Diagram of the distal femur demonstrating the typical anatomy. When instrumenting the distal femur, particular attention must be given to the obliquity of the anterior joint surface when viewed on end (taller laterally than medially), B: and the trapezoidal shape of the condyles when viewed on end (wider posteriorly than anteriorly), as well as the presence of the patellofemoral joint and intercondylar notch C.
A: Diagram of the distal femur demonstrating the typical anatomy. When instrumenting the distal femur, particular attention must be given to the obliquity of the anterior joint surface when viewed on end (taller laterally than medially), B: and the trapezoidal shape of the condyles when viewed on end (wider posteriorly than anteriorly), as well as the presence of the patellofemoral joint and intercondylar notch C.
View Original | Slide (.ppt)
Figure 53-4
A: Diagram of the distal femur demonstrating the typical anatomy. When instrumenting the distal femur, particular attention must be given to the obliquity of the anterior joint surface when viewed on end (taller laterally than medially), B: and the trapezoidal shape of the condyles when viewed on end (wider posteriorly than anteriorly), as well as the presence of the patellofemoral joint and intercondylar notch C.
A: Diagram of the distal femur demonstrating the typical anatomy. When instrumenting the distal femur, particular attention must be given to the obliquity of the anterior joint surface when viewed on end (taller laterally than medially), B: and the trapezoidal shape of the condyles when viewed on end (wider posteriorly than anteriorly), as well as the presence of the patellofemoral joint and intercondylar notch C.
View Original | Slide (.ppt)
X

Applied Anatomy of the Knee Joint

Normally the knee joint is oriented parallel to the ankle and ground. The anatomic axis of the femoral shaft relative to the knee averages about 6 or 7 degrees of valgus, with some variability between individuals (range 2 to 10 degrees) (Fig. 53-5). The contralateral limb (if not injured) can be used to radiographically define the limb axis for each person. The expanded femoral and corresponding tibial condyles are adapted for the direct forward transmission of weight. During weight bearing, the two condyles rest on the horizontal plane of the tibial condyles and the shaft of the femur inclines inferomedially. This inclination is an expression of the greater width of the body at the hips than the knees. 
Figure 53-5
Typical anatomical limb axis of the lower extremity.
 
Note the 6 to 10 degrees distal femoral valgus.
Note the 6 to 10 degrees distal femoral valgus.
View Original | Slide (.ppt)
Figure 53-5
Typical anatomical limb axis of the lower extremity.
Note the 6 to 10 degrees distal femoral valgus.
Note the 6 to 10 degrees distal femoral valgus.
View Original | Slide (.ppt)
X

Applied Anatomy of the Soft Tissues About the Distal Femur

There are three major muscle groups in the thigh: the adductors, quadriceps, and hamstrings. The latter two cross the knee and are integral to its function. Anteriorly, the quadriceps muscles provide power to the knee extensor apparatus and are supplied by the femoral nerve. The quadriceps muscle distally becomes tendon and envelopes the patella and terminates via the patellar tendon at the tibial tubercle. Posteriorly, the “hamstring” muscles that flex the knee are supplied by the sciatic nerve. The semitendinosus and semimembranosus muscles terminate medially and biceps femoris laterally on the proximal tibia as multiple tendon insertions. The gastrocnemius muscle bellies also cross the posterior aspect of the knee from their origin in the supracondylar area. 
The femoral artery and vein run anteromedially through the midthigh in Hunter canal between the extensor and adductor compartments, beneath the sartorius muscle. The femoral vessels pierce the adductor magnus approximately 10 cm above the knee to enter the posterior compartment and join the sciatic nerve in the popliteal fossa. The popliteal fossa is diamond shaped and is bounded superiorly by semimembranosus and semitendinosus medially and by the biceps femoris laterally. The inferior boundaries are the two heads of the gastrocnemius. At this level, the femoral vessels are renamed the popliteal artery and vein, and the sciatic nerve has branched into the tibial and peroneal nerves. In the popliteal fossa, the artery is deep and medial to the popliteal vein and tibial nerve. 

Distal Femur Fracture Treatment Options

Nonoperative Treatment of Distal Femur Fractures

Indications/Contraindications for Nonoperative Treatment of Distal Femur Fractures

Although nonoperative treatment was the treatment of choice prior to 1970, its use now is reserved for a few situations: reliable patients with a nondisplaced fracture, in nonambulatory patients (e.g., paraplegia), in patients with significant underlying medical diseases (e.g., severe cardiopulmonary risk) or imminent death, infected fractures or severely contaminated open fractures (e.g., type IIIB), and environments that lack modern internal fixation devices or intraoperative fluoroscopy. Nonoperative treatment of a displaced distal femur fracture includes closed reduction with skeletal traction with or without subsequent cast bracing. This method requires confinement to bed, is time consuming and expensive, and is not well suited for multiply injured or elderly patients.21,30 Although the risks of surgery are avoided with closed methods, the risks of nonoperative treatment may be significant and potentially severe including deep venous thrombosis, pulmonary embolus, decubitus ulcer, pneumonia, urinary retention, and others. 

Techniques for Nonoperative Treatment of Distal Femur Fractures

Most fractures can be reduced by skeletal traction through a proximal tibial pin or a distal femoral pin. However, placement of a distal femoral pin can be difficult because of significant soft tissue swelling, hemarthrosis, and fracture comminution. If nonoperative therapy is chosen, insertion of a femoral traction pin under fluoroscopy in a radiology suite or operating room should be considered.21,22,30 Alternatively, longitudinal tibial pin traction with a second vertical force applied through a distal femoral pin may improve the quality of reduction. 20 to 30 lb (9.07 to 13.6 kg) of traction is required to reduce supracondylar fractures in adults. Once length and alignment are restored, the weight can often be decreased. Traction is instituted with a Thomas splint and Pearson knee attachment. Conversion to Neufeld rolling traction should be considered if duration of traction is expected to exceed 2 or 3 weeks.12 Isolated tibial pin traction is recommended for patients in whom planned internal fixation is delayed more than 24 hours (Table 53-1). 
 
Table 53-1
Distal Femur Fractures
View Large
Table 53-1
Distal Femur Fractures
Nonoperative Treatment
Indications Relative Contraindications
Nondisplaced fractures in a reliable patient that can comply with weight-bearing precautions Distal femur fractures in the vast majority of patients
Severe comorbidities
Nonambulatory patient with significant comorbidities
Austere environment where quality surgical treatment is not expected
X
The goal of nonsurgical treatment is not anatomical reduction of the fracture fragments but reasonable restoration of overall length and axial alignment. Because of the proximity of the fracture to the knee joint, small degrees of malalignment may have adverse long-term effects on the joint mechanics. Although treatment must be individualized for each patient, no more than 7 degrees of malalignment in the coronal plane (mediolateral) should be accepted. Whenever possible, malalignment in the sagittal plane (AP) should not exceed 7 to 10 degrees. Limb shortening of 1 to 1.5 cm usually does not compromise the functional result and can be addressed with a shoe lift, if necessary. Except in unusual circumstances, articular incongruity of more than 2 mm should not be accepted. While in traction, patients should be encouraged to attempt limited knee flexion. When the acute soft tissue swelling has subsided, tenderness at the fracture site is minimal, and x-rays show early callus formation, the patient can be transferred to a fracture brace. This can be made from plaster, fiberglass, or polyethylene and should allow full knee motion. A fracture brace is usually placed between 3 and 6 weeks after injury, correlating clinical signs and symptoms and radiographic evidence of callus formation. It should be applied with the limb in extension, external rotation, and slight valgus. At the proximal end, the fracture brace should be molded into a quadrilateral socket to prevent rotation. In this position, varus, the most frequent postcasting complication, is minimized. Another common error is failure to include the entire fracture within the fracture brace. Nonoperative management should not lull the surgeon into false sense of security. Careful attention to details of fracture reduction and the mechanics of cast brace application are crucial to the success of the procedure. Clinical and radiographic follow-up at 1, 2, and 3 weeks after cast brace application is necessary to prevent unrecognized loss of reduction. The brace is worn until the fracture is healed, which is usually by the end of the fourth month. 

Outcomes of Nonoperative Treatment of Distal Femur Fractures

Most reports comparing nonoperative to operative therapy predate modern internal fixation methods. Early attempts at internal fixation of distal femur fractures were associated with a high incidence of malunion, nonunion, and infection. Because of these poor early operative results, numerous authors concluded that nonoperative methods were preferable. For example, Neer et al.62 reviewed a large series of supracondylar fractures and reported in 1967 good results in 84% of patients treated nonoperatively, but only 54% good results in surgically treated patients. Despite “generally good results,” Neer pointed out several pitfalls with the use of traction therapy, including excessive deformity, stiffness of the knee joint, and many of the complications of bed rest. Only one study, published by Butt et al. in 1996,14 has assessed nonoperative versus operative treatment for distal femur fractures. They compared elderly patients treated with skeletal traction for 3 to 6 weeks followed by cast bracing with those treated operatively using a supracondylar screw and side plate (i.e., dynamic condylar screw [DCS]). The results overwhelmingly favored operative treatment with a threefold decreased risk for complications of immobilization (DVT, UTI, pressure sores, and pneumonia) and a 33% risk reduction for poor results. 

Operative Treatment of Distal Femur Fractures

Indications for Operative Treatment of Distal Femur Fractures

In the past 40 years internal fixation of displaced supracondylar femoral fractures have gained widespread acceptance as operative techniques and implants have improved. Until the introduction of fixed angle plating and modern retrograde nails, thin cortices, osteoporosis, a wide intramedullary canal, and fracture comminution made stable fixation of these injuries difficult to achieve and maintain. The combination of properly designed implants, a better understanding of soft tissue handling, and improved anesthetic methods have made internal fixation practical for the vast majority of patients. The goals of operative treatment of distal femur fractures are anatomic reduction of the articular surface, restoration of limb alignment and length, stable internal fixation, rapid mobilization, and early functional rehabilitation of the knee. Using minimally invasive approaches together with improved implants (e.g., locked plating and improved retrograde intramedullary nails) have made the treatment of distal femur fractures much more successful. As a result, the operative treatment of distal femur fractures should be considered for virtually all displaced distal femur fractures in physiologically stable adults. 
Several treatment options are available, each with advantages and disadvantages and are dependent to a large degree on the fracture pattern, host factors, and the surgeon’s experience and resources. These options are discussed in more detail below. 

Osteosynthesis of Distal Femur Fractures with Plates and Screws

In the 1970s and early 1980s, distal femur fractures were most commonly treated with an anatomically contoured, but angular unstable (nonlocking) distal femur plate (e.g., condylar buttress plate). Relatively high complication rates were reported, which adversely affected clinical results, including infection, nonunion or delayed union, malunion (especially varus collapse), the need for bone graft, and knee stiffness owing to delayed mobility.59,61,62,64,86,92 Subsequently, alternative methods were proposed, including double plating82 and the use of plates for endosteal substitution,57 which met with varying success. 
About this time, Mast et al.57 and others began popularizing indirect reduction of the fracture with minimal soft tissue stripping to improve the fracture biology. There were also advances in plate-screw design where fixed angle implants such as the 95-degree angled blade plate (ABP) (Fig. 53-6) and DCS (Fig. 53-7), which provided dramatically improved stability compared to prior implants. When these two methods were combined, dramatically improved rates of bone healing with fewer complications were found compared with historical controls.9,65 However, insertion of these implants was technically demanding limiting their widespread use. 
Figure 53-6
Distal femur fracture treated with a 95-degree angled blade plate.
 
The device provides indirect resistance to varus and other forces by the fixed angled design of the blade.
The device provides indirect resistance to varus and other forces by the fixed angled design of the blade.
View Original | Slide (.ppt)
Figure 53-6
Distal femur fracture treated with a 95-degree angled blade plate.
The device provides indirect resistance to varus and other forces by the fixed angled design of the blade.
The device provides indirect resistance to varus and other forces by the fixed angled design of the blade.
View Original | Slide (.ppt)
X
Figure 53-7
Distal femur fracture treated with a 95-degree dynamic condylar screw (DCS).
Rockwood-ch053-image007.png
View Original | Slide (.ppt)
X
More recently, “locked plating” systems have been developed in which screws are inserted that lock into the plate, forming a fixed angle construct. Most of these systems were designed for insertion through minimally invasive techniques, which have been shown to decrease problems with fracture healing and infection.53,65,74,75,87,89,99,103 One example, the Less Invasive Stabilization System or LISS (Synthes USA, Paoli, PA) was the first system to use these technologies and gain widespread popularity (Fig. 53-8). This system was designed as an “internal fixator” in which the plate was applied using minimally invasive techniques after fracture reduction and fixed with unicortical locking screws so that the plate was not compressed to bone to minimize the effect on the local blood supply (Fig. 53-9).26 Condylar fixation with locking screws is mechanically superior to earlier implants (e.g., blade plate or DCS) by spreading out fixation points among a number of screws (Fig. 53-10). Multiple published studies have shown the distal femoral LISS to be effective in achieving stable fixation with good short-term results.1,47,48,73,88,89,103 A variety of other plating systems have since been developed that offer additional advantages for distal femur fractures including better anatomic contouring, improved fixation in the condylar segment, and options for conventional screws, bicortical or unicortical solid locking screws, and cannulated nonlocking or locking screws. The mechanics of fracture healing using these implants are better but still incompletely understood and surgeons are investigating novel ideas for optimizing this mechanical environment by modulating the degree of stiffness and mobility in the fixation construct.33,79 
Figure 53-8
Distal femur fracture treated using the LISS distal femur plating system, which creates a fixed angle titanium plate–screw construct.
Rockwood-ch053-image008.png
View Original | Slide (.ppt)
X
Figure 53-9
The LISS system is designed to be applied as an internal fixator using minimally invasive approaches.
 
A: The plate is inserted via a lateral submuscular tunnel with the radiolucent guide arm or handle. B: The plate is stabilized to the grossly reduced distal femur at both ends with a pin through the radiolucent guide arm. C: The fracture reduction is fine-tuned then additional points of fixation are inserted, including self-drilling, self-tapping unicortical locking screws. D: Definitive fixation is applied.
A: The plate is inserted via a lateral submuscular tunnel with the radiolucent guide arm or handle. B: The plate is stabilized to the grossly reduced distal femur at both ends with a pin through the radiolucent guide arm. C: The fracture reduction is fine-tuned then additional points of fixation are inserted, including self-drilling, self-tapping unicortical locking screws. D: Definitive fixation is applied.
View Original | Slide (.ppt)
A: The plate is inserted via a lateral submuscular tunnel with the radiolucent guide arm or handle. B: The plate is stabilized to the grossly reduced distal femur at both ends with a pin through the radiolucent guide arm. C: The fracture reduction is fine-tuned then additional points of fixation are inserted, including self-drilling, self-tapping unicortical locking screws. D: Definitive fixation is applied.
View Original | Slide (.ppt)
Figure 53-9
The LISS system is designed to be applied as an internal fixator using minimally invasive approaches.
A: The plate is inserted via a lateral submuscular tunnel with the radiolucent guide arm or handle. B: The plate is stabilized to the grossly reduced distal femur at both ends with a pin through the radiolucent guide arm. C: The fracture reduction is fine-tuned then additional points of fixation are inserted, including self-drilling, self-tapping unicortical locking screws. D: Definitive fixation is applied.
A: The plate is inserted via a lateral submuscular tunnel with the radiolucent guide arm or handle. B: The plate is stabilized to the grossly reduced distal femur at both ends with a pin through the radiolucent guide arm. C: The fracture reduction is fine-tuned then additional points of fixation are inserted, including self-drilling, self-tapping unicortical locking screws. D: Definitive fixation is applied.
View Original | Slide (.ppt)
A: The plate is inserted via a lateral submuscular tunnel with the radiolucent guide arm or handle. B: The plate is stabilized to the grossly reduced distal femur at both ends with a pin through the radiolucent guide arm. C: The fracture reduction is fine-tuned then additional points of fixation are inserted, including self-drilling, self-tapping unicortical locking screws. D: Definitive fixation is applied.
View Original | Slide (.ppt)
X
Figure 53-10
Differing designs of condylar fixation for plates used for repairing distal femur fractures.
 
From left to right, the 95-degree blade plate, DCS, modern fixed angle locking plate, and variable angle locking plate.
From left to right, the 95-degree blade plate, DCS, modern fixed angle locking plate, and variable angle locking plate.
View Original | Slide (.ppt)
Figure 53-10
Differing designs of condylar fixation for plates used for repairing distal femur fractures.
From left to right, the 95-degree blade plate, DCS, modern fixed angle locking plate, and variable angle locking plate.
From left to right, the 95-degree blade plate, DCS, modern fixed angle locking plate, and variable angle locking plate.
View Original | Slide (.ppt)
X
Preoperative Planning for ORIF of Distal Femur Fractures.
The surgical plan is designed to allow increasing surgical efficiency and minimizing surgical errors (Fig. 53-11).19 The plan should critically assess the qualities of the fracture to determine the optimal implant choice, whether a direct or indirect reduction is required, and whether a percutaneous technique can be employed. In circumstances where hospital inventory is limited, a preoperative plan also ensures that all necessary implants are available, especially longer plate lengths, which may require special order. 
Figure 53-11
 
A comprehensive preoperative plan allows for a more efficient operative experience where potential errors or omissions may be made “on paper.”
A comprehensive preoperative plan allows for a more efficient operative experience where potential errors or omissions may be made “on paper.”
View Original | Slide (.ppt)
Figure 53-11
A comprehensive preoperative plan allows for a more efficient operative experience where potential errors or omissions may be made “on paper.”
A comprehensive preoperative plan allows for a more efficient operative experience where potential errors or omissions may be made “on paper.”
View Original | Slide (.ppt)
X
The preoperative plan should also take into consideration how intraoperative imaging will be used. High-quality radiographs are absolutely critical for proper implant placement into the femoral condyles, and preventable errors may adversely affect outcomes. Before draping, the C-arm should be brought in to confirm that correct views can be obtained, unhindered by overlap of the contralateral limb. A quality image of the opposite “well” limb is often useful as a template for repair. 
General endotracheal anesthesia is preferred to allow for complete muscle paralysis; however, spinal or other regional techniques are occasionally indicated. The patient is positioned supine on a radiolucent flat-top (Jackson) table. The anesthesia team should understand that complete muscle paralysis is necessary to help regain length and overcome the powerful deforming muscle forces crossing the fracture. The entire limb is draped free into the field to allow manipulation of the extremity, which will also assist intraoperative fluoroscopy. One may consider draping in the contralateral limb, which may act as a clinical and radiographic “control” and mobilizing it out of the way, if desired. 
Positioning for ORIF of Distal Femur Fractures.
For plating or nailing, the setup is similar (Fig. 53-12). The patient is positioned supine on a radiolucent table. A “bump” is used beneath the ipsilateral hip to allow the leg to remain in a neutral or slightly internally rotated position. The entire lower extremity and hip region should be prepped and draped to allow proximal extension of the surgical exposure, if necessary. If an external fixator is in place, it is carefully cleansed as part of the prep and can be used as a grip to control the limb for remaining prep. Iodine- or saline-moistened sponges can be placed around the pin sites and held in place with elastic gauze to isolate them from the operative field. If bone grafting is anticipated (rare), the iliac crest can be prepped into the sterile field. In many cases a sterile tourniquet can be used for part or all of the case. It is important to confirm that an unhindered AP and lateral view with fluoroscopy can be obtained (Table 53-2). 
Figure 53-12
A typical operative setup for surgery of a distal femur fracture.
 
Patient is positioned supine on a flat top radiolucent table. The C-arm is brought in from the opposite side. Reduction aids include the femoral distractor (length, gross axial alignment, and rotation) and a towel roll (sagittal plane).
Patient is positioned supine on a flat top radiolucent table. The C-arm is brought in from the opposite side. Reduction aids include the femoral distractor (length, gross axial alignment, and rotation) and a towel roll (sagittal plane).
View Original | Slide (.ppt)
Figure 53-12
A typical operative setup for surgery of a distal femur fracture.
Patient is positioned supine on a flat top radiolucent table. The C-arm is brought in from the opposite side. Reduction aids include the femoral distractor (length, gross axial alignment, and rotation) and a towel roll (sagittal plane).
Patient is positioned supine on a flat top radiolucent table. The C-arm is brought in from the opposite side. Reduction aids include the femoral distractor (length, gross axial alignment, and rotation) and a towel roll (sagittal plane).
View Original | Slide (.ppt)
X
 
Table 53-2
ORIF of Distal Femur Fractures
View Large
Table 53-2
ORIF of Distal Femur Fractures
Preoperative Planning Checklist
  •  
    OR Table: Radiolucent “flat top” table
  •  
    Position/positioning aids: Supine. Bump to internally rotate operative hip
  •  
    Draping: Drape wide to allow for access to proximal femur and long plate. Consider draping in opposite leg (allows for clinical and radiographic “control” and mobilizing it out of the way as needed.
  •  
    Antibiotics: Broad spectrum prophylaxis
  •  
    Anesthesia: Pharmacologic muscle paralysis
  •  
    Fluoroscopy location: From contralateral side
  •  
    Equipment: Universal distractor (or external fixator), fixed angle plates, radiolucent guides if considering MIPO technique, large bone clamps
  •  
    Tourniquet (sterile/nonsterile): Sterile—most effective for articular portion of surgery, may aid in metaphyseal reduction
  •  
    Surgical approaches: Must balance goals of access to bone for reduction (preserving biology) and implant construction (mechanics). Radiolucent guides are available for minimally invasive surgery (MIPO).
  •  
    Intra-articular injury, if present: Displaced intra-articular injury should be anatomically reduced and carefully assessed. Clamps, K-wires provisionally for reduction and lag screws definitively.
 

Reduction: Traction is critical, usually with a universal distractor (or external fixator, if present). Sagittal plane alignment with a well-placed large bump or towel roll. Coronal plane alignment can be corrected with Schantz pin joysticks, well applied clamps, or plate application itself.

  •  
    Assessment of reduction: Critical evaluation of radiographic alignment intraoperatively, including (1) bony axial alignment, length, and rotation and (2) appropriate positioning of implants. The contralateral side is a useful template.
X
Surgical Approaches for ORIF of Distal Femur Fractures.
Decisions on the surgical approach are made based on the fracture pattern and the need for access to the articular surface for reduction, and implant location based on the preoperative plan. For extra-articular fractures, minimally invasive submuscular or formal open plating or retrograde nailing are recommended. Importantly, using either approach, reduction is gained using indirect methods. If reduction is difficult in minimally invasive plating (MIPO), the lateral incision can easily be extended to accommodate for reduction and plating. Other approaches, as outlined below are also available under certain circumstances. 
Lateral Approach for ORIF of Distal Femur Fractures: Standard Open Technique.
A direct lateral approach is the most commonly used exposure for open reduction and plating of the distal femur (Fig. 53-13).39 The skin incision is longitudinal and distally centered over the lateral epicondyle. It should be long enough to allow gentle soft tissue retraction. The length of the incision should be determined based on the preoperative plan. The fascia lata is incised in line with its fibers exposing the vastus lateralis, which is reflected off the intermuscular septum along the linea aspera in an anterior direction. Perforators are identified and ligated or cauterized. This careful dissection is started distally and carried proximally. Wide soft tissue stripping is avoided and no soft tissue dissection should be performed on the medial side of the femur to minimize disruption of the soft tissues. Visualization of the articular surface of the lateral condyle is satisfactory, but exposure of the intercondylar notch and medial condyle are more limited. When more access to the joint is needed, the incision can be extended distally and curved medially to allow for greater patellar subluxation. A tibial tubercle osteotomy can be performed (rare) to allow for reflection of the extensor mechanism and wide articular exposure. Knee flexion must be restricted for a period of time after tibial tubercle osteotomy; thus its use has been limited. 
Figure 53-13
Lateral open approach to the distal femur.
 
A: Lateral skin incision. B: The plane of incision is through the lateral iliotibial band and between the vastus lateralis and the lateral intermuscular septum to the bone. C: Visualization of the lateral femoral condyle with the lateral approach.
A: Lateral skin incision. B: The plane of incision is through the lateral iliotibial band and between the vastus lateralis and the lateral intermuscular septum to the bone. C: Visualization of the lateral femoral condyle with the lateral approach.
View Original | Slide (.ppt)
Figure 53-13
Lateral open approach to the distal femur.
A: Lateral skin incision. B: The plane of incision is through the lateral iliotibial band and between the vastus lateralis and the lateral intermuscular septum to the bone. C: Visualization of the lateral femoral condyle with the lateral approach.
A: Lateral skin incision. B: The plane of incision is through the lateral iliotibial band and between the vastus lateralis and the lateral intermuscular septum to the bone. C: Visualization of the lateral femoral condyle with the lateral approach.
View Original | Slide (.ppt)
X
If exposure of the distal femur is planned for repair of intercondylar fractures (OTA type C), the authors favor using an anterolateral approach, a modification of lateral parapatellar arthrotomy (Fig. 53-14).94 This provides adequate access to the articular surfaces (although perhaps not quite as much as tibial tubercle osteotomy), and can be extended proximally into the quadriceps mechanism as an extensile anterolateral approach to include the femoral shaft. The extensor mechanism is divided longitudinally, not horizontally; thus, concerns about its repair failing or additionally restricting mobility are minimized. The vastus lateralis is elevated off the lateral femoral cortex as in the standard lateral approach. Both reduction and stabilization of the condyles, as well as plate application and fixation, can be applied through this approach. Medial soft tissue dissection should be avoided. In some cases, an approach that is open distally and proximally can be used in which the plate and screws are fitted and fixed directly in these areas, but the intermediate tissues are mobilized only by the submuscular plate insertion. This approach adds the enhanced biology of minimally invasive methods while still allowing the surgeon to be confident in plate placement and allow for direct screw insertion. 
Figure 53-14
Anterolateral approach to the articular distal femur.
 
A: A lateral parapatellar incision allows for excellent visualization of the articular surface for reduction and lateral implant insertion. B: More proximally, the exposure is extended by splitting the vastus intermedius muscle/tendon. (Adapted from Hoppenfeld S, deBoer P, Buckley R. Surgical exposures in orthopaedics: The anatomic approach. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2009; Starr AJ, Jones AL, Reinert CM. The “swashbuckler”: A modified anterior approach for fractures of the distal femur. J Orthop Trauma. 1999;13(2):138–140.)
A: A lateral parapatellar incision allows for excellent visualization of the articular surface for reduction and lateral implant insertion. B: More proximally, the exposure is extended by splitting the vastus intermedius muscle/tendon. (Adapted from Hoppenfeld S, deBoer P, Buckley R. Surgical exposures in orthopaedics: The anatomic approach. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2009; Starr AJ, Jones AL, Reinert CM. The “swashbuckler”: A modified anterior approach for fractures of the distal femur. J Orthop Trauma. 1999;13(2):138–140.)
View Original | Slide (.ppt)
Figure 53-14
Anterolateral approach to the articular distal femur.
A: A lateral parapatellar incision allows for excellent visualization of the articular surface for reduction and lateral implant insertion. B: More proximally, the exposure is extended by splitting the vastus intermedius muscle/tendon. (Adapted from Hoppenfeld S, deBoer P, Buckley R. Surgical exposures in orthopaedics: The anatomic approach. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2009; Starr AJ, Jones AL, Reinert CM. The “swashbuckler”: A modified anterior approach for fractures of the distal femur. J Orthop Trauma. 1999;13(2):138–140.)
A: A lateral parapatellar incision allows for excellent visualization of the articular surface for reduction and lateral implant insertion. B: More proximally, the exposure is extended by splitting the vastus intermedius muscle/tendon. (Adapted from Hoppenfeld S, deBoer P, Buckley R. Surgical exposures in orthopaedics: The anatomic approach. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2009; Starr AJ, Jones AL, Reinert CM. The “swashbuckler”: A modified anterior approach for fractures of the distal femur. J Orthop Trauma. 1999;13(2):138–140.)
View Original | Slide (.ppt)
X
Lateral Approach for ORIF of Distal Femur Fractures: Minimally Invasive Technique.
If a minimally invasive technique is used for plating of selected distal femur fractures, a 5- to 6-cm lateral incision limited to the area of the lateral condyle and distal metaphysis is used (Fig. 53-15).47,51,85,88 The incision is placed slightly more distal than often estimated to allow for retrograde submuscular plate insertion. Condylar screws are placed through the incision used for plate insertion. Proximal screws are placed using multiple stab incisions or a short open lateral approach and a radiolucent guide. In this setting, a longer plate may be desirable to increase construct stability and minimize dissection in the zone of injury. 
Figure 53-15
Minimally invasive lateral approach to the distal femur.
 
The skin and iliotibial (IT) band incisions are moved slightly distal to the lateral femoral condyle to allow for retrograde submuscular plate insertion. A tunnel along the lateral distal femur can be made with an elevator or with the tip of the plate itself.
The skin and iliotibial (IT) band incisions are moved slightly distal to the lateral femoral condyle to allow for retrograde submuscular plate insertion. A tunnel along the lateral distal femur can be made with an elevator or with the tip of the plate itself.
View Original | Slide (.ppt)
Figure 53-15
Minimally invasive lateral approach to the distal femur.
The skin and iliotibial (IT) band incisions are moved slightly distal to the lateral femoral condyle to allow for retrograde submuscular plate insertion. A tunnel along the lateral distal femur can be made with an elevator or with the tip of the plate itself.
The skin and iliotibial (IT) band incisions are moved slightly distal to the lateral femoral condyle to allow for retrograde submuscular plate insertion. A tunnel along the lateral distal femur can be made with an elevator or with the tip of the plate itself.
View Original | Slide (.ppt)
X
Medial Approach for ORIF of Distal Femur Fractures.
The medial approach to the distal femur is used for ORIF of displaced medial condyle fractures (B2 and B3) or to repair other unstable injuries not well repaired from the lateral side. Approach along the posterior border of the vastus medialis obliquus (VMO) muscle is recommended, the so called “sub-VMO approach” (Fig. 53-16).25 A straight medial skin incision is made over the adductor tubercle and extended proximally into the distal thigh. Proximal extension with this approach should be performed carefully, as the femoral vessels pierce the adductor magnus 10 to 12 cm above the knee joint. If necessary, an intraoperative Doppler examination may be useful to identify the path of the vessels and avoid iatrogenic injury. The fascia over the VMO is incised longitudinally and the muscle belly retracted proximally and anteriorly, then the VMO tendon is incised transversely in the anterior direction toward the patella where the tenotomy is extended distally as a medial parapatellar arthrotomy while leaving a cuff to repair to. Care should be taken to protect the medial collateral ligament and medial meniscus. If a surgeon is using a medial approach to supplement lateral fixation, he or she should minimize soft tissue stripping to the absolute least amount possible to avoid problems with healing and/or infection. 
Figure 53-16
Medial approach to the distal femur is facilitated by a VMO sparing approach.
 
The muscle is elevated proximally and an “L” shaped tenotomy (dotted line) is performed distally which includes a medial parapatellar limb. A: The medial arthrotomy allows excellent access to the comminuted articular injury (mostly medial, (B) so that repair (C, D) can be performed.
The muscle is elevated proximally and an “L” shaped tenotomy (dotted line) is performed distally which includes a medial parapatellar limb. A: The medial arthrotomy allows excellent access to the comminuted articular injury (mostly medial, (B) so that repair (C, D) can be performed.
View Original | Slide (.ppt)
Figure 53-16
Medial approach to the distal femur is facilitated by a VMO sparing approach.
The muscle is elevated proximally and an “L” shaped tenotomy (dotted line) is performed distally which includes a medial parapatellar limb. A: The medial arthrotomy allows excellent access to the comminuted articular injury (mostly medial, (B) so that repair (C, D) can be performed.
The muscle is elevated proximally and an “L” shaped tenotomy (dotted line) is performed distally which includes a medial parapatellar limb. A: The medial arthrotomy allows excellent access to the comminuted articular injury (mostly medial, (B) so that repair (C, D) can be performed.
View Original | Slide (.ppt)
X

Surgical Technique for ORIF of Distal Femur Fractures with Angular Stable Plates and Screws

ORIF of OTA Type A Distal Femur Fractures

ORIF Through Open Lateral Approaches and Locked Plating with Anatomically Contoured Lateral Condylar Plate.
Accurate fracture reduction is critical in restoring normal function and has been the “holy grail” with MIPO or nailing when using indirect reduction techniques. Although modern implants and biologic sparing techniques have decreased the incidence of delayed union and nonunion compared with historical methods of ORIF, the incidence of malalignment has increased significantly.20,48,85,89 There is a considerable learning curve with indirect reduction methods, and particular attention to detail is required to avoid malreduction and subsequent malunion. 
Indirect reduction of the metaphyseal or metadiaphyseal portion of the fracture is achieved by a combination of methods (an illustrative case is shown in Fig. 53-17A–E).19,57 In simple fracture patterns, reduction using manual longitudinal traction alone may suffice. A well placed pointed reduction forceps or “King Tong” clamp can also aid reduction by holding the fracture in proper position. The authors have found the universal (femoral) distractor to be a valuable tool and it is used by the authors in all cases where there is displacement resulting in shortening. Placed anteriorly into the femoral shaft proximally and anchored in the proximal tibia (or distal femur), distraction usually restores overall length and alignment. Initial overdistraction permits gentle teasing of comminuted fracture fragments into near-anatomic position. A large or medium sterile towel roll or bump can be effective at controlling sagittal alignment; moving it distally or proximally even a few centimeters may be very helpful. Finally, if correctly applied, periarticular plates can fine-tune the reduction by pulling the bone to the anatomically contoured plate using conventional screws. Combining standard cortical screws to lag the bone to the plate followed by locked screws to aid in construct stability is a useful tactic and employs benefits of both screw types. It is important to remember that if a combination of nonlocking screws and locking screws is used in any given fracture fragment, the nonlocked cortical screws must be inserted first in that fragment before any locking screws are inserted (lag before you lock), or the fixation of the nonlocked screws can be compromised. 
Figure 53-17
Illustrative case of open plating for nonarticular (33-A) distal femur fracture.
 
A: Injury radiographs show periprosthetic fracture. B: Open lateral approach with repair using a number of indirect reduction methods, including femoral distractor, towel roll, King Tong clamp on plate. C: A pointed reduction clamp placed carefully through muscle finishes the reduction and additional screws are applied. D: A biologically friendly open lateral approach to the distal femur has been achieved. E: Postoperative radiographs.
A: Injury radiographs show periprosthetic fracture. B: Open lateral approach with repair using a number of indirect reduction methods, including femoral distractor, towel roll, King Tong clamp on plate. C: A pointed reduction clamp placed carefully through muscle finishes the reduction and additional screws are applied. D: A biologically friendly open lateral approach to the distal femur has been achieved. E: Postoperative radiographs.
View Original | Slide (.ppt)
Figure 53-17
Illustrative case of open plating for nonarticular (33-A) distal femur fracture.
A: Injury radiographs show periprosthetic fracture. B: Open lateral approach with repair using a number of indirect reduction methods, including femoral distractor, towel roll, King Tong clamp on plate. C: A pointed reduction clamp placed carefully through muscle finishes the reduction and additional screws are applied. D: A biologically friendly open lateral approach to the distal femur has been achieved. E: Postoperative radiographs.
A: Injury radiographs show periprosthetic fracture. B: Open lateral approach with repair using a number of indirect reduction methods, including femoral distractor, towel roll, King Tong clamp on plate. C: A pointed reduction clamp placed carefully through muscle finishes the reduction and additional screws are applied. D: A biologically friendly open lateral approach to the distal femur has been achieved. E: Postoperative radiographs.
View Original | Slide (.ppt)
X
Plain radiographs or intraoperative fluoroscopy must be carefully scrutinized to assess limb alignment, rotation, and length. This is especially true in comminuted fracture patterns in which mismatch of the width of the major fragments or cortices cannot be compared to judge rotation or length. A radiolucent ruler may be helpful to avoid unrecognized shortening and the contralateral limb may be used for comparison as a radiographic template. Excessive external rotation is not uncommon after this particular form of treatment, as the weight of the leg and/or targeting device often rotates the distal segment. Rotation is checked clinically and compared with the contralateral limb. 
There is often a “constant” fragment along the posterior cortex above the condyles (Figs. 53-18 and 53-19; also see Figure 53-1) that is well visualized on a lateral fluoroscopic image that is very useful for gauging reduction in flexion–extension and can be captured with large pointed reduction forceps to key in the reduction. Alternatively, an anterior to posteriorly placed Schantz pin can be used as a joystick to grossly correct this deformity. If this produces an anatomic reduction, a 3.5- or 4.5-mm lag screw can often be placed from anterior to posterior across this typically oblique fracture and a lateral neutralization plate can be applied. In more transverse fractures, once reduction is achieved, one or two stout (2- to 3.2-mm) provisional K-wires or guidewires can be placed obliquely through the nonarticular part of the medial femoral condyle and aimed across the fracture and slightly anterior into the shaft segment so that it lies anterior to the path of the plate. 
Figure 53-18
Diagram of a modern locking plate being applied to the distal femur.
 
A: The plate should be well centered on the lateral surface. B, C: Anatomically contoured plating systems use an alignment pin distally which is placed at 95 to 98 degrees relative to the femoral shaft designed to be parallel to the articular surface in an average human. D: Reduction is achieved and pins are applied for provisional fixation. E, F: Additional pins can be placed for cannulated screws or drilled for solid locked screws.
A: The plate should be well centered on the lateral surface. B, C: Anatomically contoured plating systems use an alignment pin distally which is placed at 95 to 98 degrees relative to the femoral shaft designed to be parallel to the articular surface in an average human. D: Reduction is achieved and pins are applied for provisional fixation. E, F: Additional pins can be placed for cannulated screws or drilled for solid locked screws.
View Original | Slide (.ppt)
Figure 53-18
Diagram of a modern locking plate being applied to the distal femur.
A: The plate should be well centered on the lateral surface. B, C: Anatomically contoured plating systems use an alignment pin distally which is placed at 95 to 98 degrees relative to the femoral shaft designed to be parallel to the articular surface in an average human. D: Reduction is achieved and pins are applied for provisional fixation. E, F: Additional pins can be placed for cannulated screws or drilled for solid locked screws.
A: The plate should be well centered on the lateral surface. B, C: Anatomically contoured plating systems use an alignment pin distally which is placed at 95 to 98 degrees relative to the femoral shaft designed to be parallel to the articular surface in an average human. D: Reduction is achieved and pins are applied for provisional fixation. E, F: Additional pins can be placed for cannulated screws or drilled for solid locked screws.
View Original | Slide (.ppt)
X
Figure 53-19
Illustrative case of minimally invasive plating for nonarticular (33-A) distal femur fracture (reduction measures shown in Fig. 53-20).
 
A: Injury x-rays. B: Intraoperative sequence of instrumentation. The plate is used as a reduction aid and helps ensure quality alignment and optimal instrumentation. “Perfect” AP and lateral images must be used. B1: The plate is well positioned on AP view and centered on lateral view. The distalmost guidepin in placed parallel to the joint on the AP view and should be seen as travelling slightly posterior and distal on lateral view (white arrow). On lateral imaging, pins and screws should be confined in the distal femur by Blumensaat’s line and the subchondral line of the patellofemoral joint. B2: The condyles are brought to the plate to aid in reduction and minimize prominence. B3: The shaft is brought to the plate with a lag screw to finalize alignment and additional fixation screws are applied. C: Plate application and screw insertion though a short lateral incision over the lateral femoral condyle using radiolucent targetter. Indirect reduction aids are seen, including femoral distractor, well-placed towel roll, and periarticular clamp. D: Intraoperative photographs and fluoroscopy images. E: 9-month follow-up radiographs show healed fractures.
A: Injury x-rays. B: Intraoperative sequence of instrumentation. The plate is used as a reduction aid and helps ensure quality alignment and optimal instrumentation. “Perfect” AP and lateral images must be used. B1: The plate is well positioned on AP view and centered on lateral view. The distalmost guidepin in placed parallel to the joint on the AP view and should be seen as travelling slightly posterior and distal on lateral view (white arrow). On lateral imaging, pins and screws should be confined in the distal femur by Blumensaat’s line and the subchondral line of the patellofemoral joint. B2: The condyles are brought to the plate to aid in reduction and minimize prominence. B3: The shaft is brought to the plate with a lag screw to finalize alignment and additional fixation screws are applied. C: Plate application and screw insertion though a short lateral incision over the lateral femoral condyle using radiolucent targetter. Indirect reduction aids are seen, including femoral distractor, well-placed towel roll, and periarticular clamp. D: Intraoperative photographs and fluoroscopy images. E: 9-month follow-up radiographs show healed fractures.
View Original | Slide (.ppt)
A: Injury x-rays. B: Intraoperative sequence of instrumentation. The plate is used as a reduction aid and helps ensure quality alignment and optimal instrumentation. “Perfect” AP and lateral images must be used. B1: The plate is well positioned on AP view and centered on lateral view. The distalmost guidepin in placed parallel to the joint on the AP view and should be seen as travelling slightly posterior and distal on lateral view (white arrow). On lateral imaging, pins and screws should be confined in the distal femur by Blumensaat’s line and the subchondral line of the patellofemoral joint. B2: The condyles are brought to the plate to aid in reduction and minimize prominence. B3: The shaft is brought to the plate with a lag screw to finalize alignment and additional fixation screws are applied. C: Plate application and screw insertion though a short lateral incision over the lateral femoral condyle using radiolucent targetter. Indirect reduction aids are seen, including femoral distractor, well-placed towel roll, and periarticular clamp. D: Intraoperative photographs and fluoroscopy images. E: 9-month follow-up radiographs show healed fractures.
View Original | Slide (.ppt)
Figure 53-19
Illustrative case of minimally invasive plating for nonarticular (33-A) distal femur fracture (reduction measures shown in Fig. 53-20).
A: Injury x-rays. B: Intraoperative sequence of instrumentation. The plate is used as a reduction aid and helps ensure quality alignment and optimal instrumentation. “Perfect” AP and lateral images must be used. B1: The plate is well positioned on AP view and centered on lateral view. The distalmost guidepin in placed parallel to the joint on the AP view and should be seen as travelling slightly posterior and distal on lateral view (white arrow). On lateral imaging, pins and screws should be confined in the distal femur by Blumensaat’s line and the subchondral line of the patellofemoral joint. B2: The condyles are brought to the plate to aid in reduction and minimize prominence. B3: The shaft is brought to the plate with a lag screw to finalize alignment and additional fixation screws are applied. C: Plate application and screw insertion though a short lateral incision over the lateral femoral condyle using radiolucent targetter. Indirect reduction aids are seen, including femoral distractor, well-placed towel roll, and periarticular clamp. D: Intraoperative photographs and fluoroscopy images. E: 9-month follow-up radiographs show healed fractures.
A: Injury x-rays. B: Intraoperative sequence of instrumentation. The plate is used as a reduction aid and helps ensure quality alignment and optimal instrumentation. “Perfect” AP and lateral images must be used. B1: The plate is well positioned on AP view and centered on lateral view. The distalmost guidepin in placed parallel to the joint on the AP view and should be seen as travelling slightly posterior and distal on lateral view (white arrow). On lateral imaging, pins and screws should be confined in the distal femur by Blumensaat’s line and the subchondral line of the patellofemoral joint. B2: The condyles are brought to the plate to aid in reduction and minimize prominence. B3: The shaft is brought to the plate with a lag screw to finalize alignment and additional fixation screws are applied. C: Plate application and screw insertion though a short lateral incision over the lateral femoral condyle using radiolucent targetter. Indirect reduction aids are seen, including femoral distractor, well-placed towel roll, and periarticular clamp. D: Intraoperative photographs and fluoroscopy images. E: 9-month follow-up radiographs show healed fractures.
View Original | Slide (.ppt)
A: Injury x-rays. B: Intraoperative sequence of instrumentation. The plate is used as a reduction aid and helps ensure quality alignment and optimal instrumentation. “Perfect” AP and lateral images must be used. B1: The plate is well positioned on AP view and centered on lateral view. The distalmost guidepin in placed parallel to the joint on the AP view and should be seen as travelling slightly posterior and distal on lateral view (white arrow). On lateral imaging, pins and screws should be confined in the distal femur by Blumensaat’s line and the subchondral line of the patellofemoral joint. B2: The condyles are brought to the plate to aid in reduction and minimize prominence. B3: The shaft is brought to the plate with a lag screw to finalize alignment and additional fixation screws are applied. C: Plate application and screw insertion though a short lateral incision over the lateral femoral condyle using radiolucent targetter. Indirect reduction aids are seen, including femoral distractor, well-placed towel roll, and periarticular clamp. D: Intraoperative photographs and fluoroscopy images. E: 9-month follow-up radiographs show healed fractures.
View Original | Slide (.ppt)
X
Plate application has become more complex with the introduction of locked implants, but also potentially more effective with multiple options for screw placement.19,34,57,73 Screws can be standard or locked, cannulated or noncannulated, bicortical or unicortical, and plates can be inserted open or through minimally invasive approaches. When using most plates (not polyaxial) as a reduction tool it is important to align the most distal locking screws (or their guidewires) parallel to the knee joint to ensure that the 5 to 8 degrees or so of valgus built into the plate is achieved (Figs. 53-18 and 53-19B). Plates with polyaxial screws also have similar alignment guides to ensure restoration of the appropriate valgus alignment, but these and subsequent condylar screws must be applied thoughtfully. All nonlocked screws must be inserted into the proximal or distal segment before any locked screws are placed. If a stable OTA type A1 fracture is well reduced, compression should be applied to increase stability, promote primary bone healing, and allow for earlier weight bearing. Eccentric drilling, the articulated tensioner, and a push–pull screw with a large Verbrugge clamp are three effective methods for producing compression across stable fracture patterns. Nonetheless, only when the medial cortex is restored can the plate be effectively loaded. Properly done, the plate is placed under tension and in theory subject to load sharing, rather than load bearing. In cases with significant comminution, the plate is fixed to the proximal and distal fracture, bridging the zone of comminution.57 In this environment, the plate acts as an internal splint. However, the fracture fragments spanned by the plate are left undisturbed and capable of rapid consolidation if their soft tissue attachments have been respected. 
In comminuted fracture patterns, reduction is almost always best achieved with the aid of a femoral distractor or an external fixator. Most of the reduction methods used for simple fractures are applicable to comminuted fractures. We have found that it is often easier to reduce the fracture to the plate rather than the plate to the fracture in complex fracture patterns. In this situation the plate must be used to aid reduction. It is important to re-emphasize that the most distal locking screws must be parallel to the joint surface as assessed on AP image as a guide for restoring limb alignment. 
The length of the plate and the number and placement of screws are based on the preoperative plan. In general, we favor treating comminuted and osteoporotic fractures with less soft tissue dissection, longer plates, more screws in each segment, and more locked screws. In general, a longer plate with spaced screws provides better mechanical stability compared with shorter plates and clustered screws. When selecting plate length, there should be eight or more screw holes above the most proximal aspect of the fracture if possible.78 Reference the position of the plate to Blumensaat’s line and the subchondral margin of the trochlear groove (Figs. 53-4 and 53-19B). The plate is centered on the lateral aspect of the femur and a K-wire is applied in a wire hole in the plate (if available) or cannulated wire guide. With the plate centered on the distal diaphyseal fracture fragment it is provisionally fixed close to the fracture. Intraoperative fluoroscopy is used to confirm fracture alignment and implant position. The guidepin closest to the joint is typically designed to restore varus–valgus alignment if placed parallel to the joint axis (Figs. 53-18 and 53-19B). A series of cortical screws followed by locked screws (hybrid technique) allows the benefits of both screw types to be realized. The condylar segment is stabilized predominately with locked screws. The surgeon should be careful when placing the most distal and posterior screw in the condylar segment; if this hole is posterior to Blumensaat’s line, a short (e.g., 28 mm) screw should be placed to avoid violating the intercondylar notch. An intraoperative notch view may be helpful to prevent this problem. 
Minimally Invasive Plating of Distal Femur Fractures with Anatomically Contoured Lateral Condylar Plates.
The successful use of MIPO for the treatment of complex fractures is technique dependent and there is a substantial learning curve. The principles of fixation while preserving the fracture biology are similar to those for open plating. An illustrative case is shown in Figure 53-19. The majority of the operation is performed though a short lateral incision over the lateral femoral condyle (Figs. 53-15 and 53-19). With MIPO techniques, a radiolucent targeting device is often used as a handle to insert the plate extraperiosteally on the lateral femur through a submuscular tunnel beneath the vastus lateralis. Periarticular plates are designed to fit the anatomy of the distal femur and are applied along the metaphyseal flare and lateral condyle of the distal femur by sliding it proximally and distally. Once the plate is inserted, a mini-open approach can be performed at the proximal end of the plate to ensure that the plate is centered on the lateral side of the femur. Alternatively, all shaft screws can be inserted through the targeting device, but the surgeon must be certain that the plate is well centered on both the AP and lateral fluoroscopic views proximally to ensure accurate screw fixation. A locking cannulated drill sleeve can be inserted into the most proximal screw hole to add stability through the aiming device. The plate is centered on bone both proximally and distally and oriented flush with the lateral femoral condyle. A large periarticular clamp can be used distally to gently hold the bone to the plate, which also aids in sagittal plane fracture reduction. Any gross adjustment of fracture reduction is done before provisional fixation using K-wires or a drill bit through the cannulated stabilization guide. Many supracondylar femur fractures have some degree of comminution and the goal is restoration of length, alignment, and rotation. A standard nonlocking screw or “push–pull” device can be applied to “pull” the shaft of the femur toward the plate, which fine-tunes the varus–valgus alignment and augments stability of the provisional construct (Fig. 53-19B). The opposite uninjured limb can be used as a template in comminuted cases in which the bony landmarks on the injured side are fractured. Coronal plane alignment (varus–valgus), flexion–extension, as well as rotation, must be confirmed before definitive fixation when using indirect reduction methods. High-quality intraoperative imaging is mandatory. Restoration of limb alignment in rotation and length is assessed in a similar fashion as described for open plating using indirect reduction. 
95-Degree Condylar Blade Plate and Dynamic Condylar Screw Device Fixation of Distal Femur Fractures.
The use of a 95-degree blade plate or DCS is used less frequently today (Figs. 53-6 and 53-7). Periarticular locked plates have replaced these nonlocked implants for most fractures. The 95-degree condylar blade plate remains a useful implant, although we use it most often for stabilization of nonunions and malunions.2 There is a large body of literature from both North America and Europe documenting success with this implant.9,37 When used by an experienced surgeon, this device can restore alignment and provide stable internal fixation. Because it is a stout fixed angled device, it provides excellent control of the fracture. Nevertheless, placement of the 95-degree ABP is a technically demanding procedure because the surgeon is required to place the blade correctly in three planes simultaneously. Incorrect insertion of the chisel and blade will result in condylar malalignment, resulting in malunion (Fig. 53-20). A technique using three guidepins is very useful for correctly applying the blade to restore limb alignment; this is summarized in Figure 53-20.57 The first guidewire is inserted parallel to the knee joint distally. A second one follows the inclination of the anterior articular surface of the femur (patellofemoral joint). A third guidewire is the definitive or summation guidewire and parallels the first two wires. The correct starting point for the insertion of the seating chisel (for the blade plate) or triple reamer (for the DCS) is in the anterior half of the femoral condyles—in a line with the femoral shaft and exactly parallel to the summation guidewire. The starting point is 1.5 to 2.5 cm proximal to the articular margin of the knee joint. In young patients with hard bone, insertion of a seating chisel for the blade plate may be difficult. To prevent iatrogenic comminution, a window should be created and predrilled to receive the seating chisel. Once the window is precut, the seating chisel is inserted to a predetermined distance. It is important to remember that the distal femur is trapezoidal and the medial cortex slopes 25 degrees or so (Fig. 53-4). When using either the blade plate (or DCS), the tip of the implant should be at least 5 to 10 mm short of the medial femoral cortex to prevent inadvertent penetration. This technique leaves little room for error in an already fractured bone. There is a learning curve associated with use of the blade plate before consistent and reproducibly good results are achieved. It can be used in intra-articular fractures, provided the distal lateral femoral condyle is intact. In cases in which comminution extends distally and laterally compromising fixation, an anatomically contoured locked plate is preferred. 
Figure 53-20
Application of a 95-degree angled blade plate can be more accurately applied using a “summation” pin and misapplication of the plate predictably yields deformity.
 
A: Proper insertion point for the seating chisel (and blade). B–D: Use of a summation pin (pin 3) is demonstrated where pins 1 and 2 are placed parallel to the femorotibial and patellofemoral joints, respectively. E: The blade is inserted parallel to the summation pin. F–L: Varying types of errant blade application in the condylar segment will cause predictable deformities, and must be avoided.
A: Proper insertion point for the seating chisel (and blade). B–D: Use of a summation pin (pin 3) is demonstrated where pins 1 and 2 are placed parallel to the femorotibial and patellofemoral joints, respectively. E: The blade is inserted parallel to the summation pin. F–L: Varying types of errant blade application in the condylar segment will cause predictable deformities, and must be avoided.
View Original | Slide (.ppt)
Figure 53-20
Application of a 95-degree angled blade plate can be more accurately applied using a “summation” pin and misapplication of the plate predictably yields deformity.
A: Proper insertion point for the seating chisel (and blade). B–D: Use of a summation pin (pin 3) is demonstrated where pins 1 and 2 are placed parallel to the femorotibial and patellofemoral joints, respectively. E: The blade is inserted parallel to the summation pin. F–L: Varying types of errant blade application in the condylar segment will cause predictable deformities, and must be avoided.
A: Proper insertion point for the seating chisel (and blade). B–D: Use of a summation pin (pin 3) is demonstrated where pins 1 and 2 are placed parallel to the femorotibial and patellofemoral joints, respectively. E: The blade is inserted parallel to the summation pin. F–L: Varying types of errant blade application in the condylar segment will cause predictable deformities, and must be avoided.
View Original | Slide (.ppt)
X
Several authors have reported favorable results in supracondylar femur fractures using a 95-degree DCS (Fig. 53-8).65,83 This device is based on the compression screw commonly used in hip fractures. The implant shares many of the features of a compression hip screw, making it familiar to most surgeons and therefore easier to master. Other advantages include its ability to apply interfragmentary compression across the femoral condyles, better purchase in osteoporotic bone, and the need for only two-plane alignment. By allowing a degree of freedom in the sagittal plane, insertion of this device is technically easier than a 95-degree blade plate. The major disadvantage with the DCS plate is the bulky size of the implant at the screw–plate junction. This frequently requires removal of considerable bone from the lateral femoral condyle to ensure a low-profile fit, whereas the “shoulder” of this device is more prominent than that of a comparable ABP or other distal femur plates. In many patients this causes knee symptoms as the iliotibial band slides over the prominent edge of the implant. In low supracondylar fractures, the condylar screw may not provide as much rotational control of the distal fragment as the 95-degree blade plate. At least one additional screw placed through the plate and anchored in the distal fragment is necessary to ensure stable fixation. The principles of plate application and maintaining biology are similar to other methods of plating. 

ORIF of OTA Type B Distal Femur Fractures

Isolated fractures of the medial or lateral femoral condyle are uncommon. ORIF is the most reliable method to ensure articular surface restoration. In patients with good bone quality in whom anatomic reduction is achieved with closed means, the fracture may be stabilized with several percutaneous lag screws, but this scenario is quite uncommon. In displaced fractures, an open approach and plate fixation along with lag screws is routinely used. A direct lateral or medial approach may be used for simple B1 fracture patterns in which anatomic reduction of the joint can be gained without arthrotomy. In fractures with articular comminution, a medial or lateral parapatellar approach is preferred and extended proximally as necessary. Fixation of the articular surface must be anatomic and stable, as shearing stresses are common even without weight bearing. With the typical vertical condylar fracture (medial or lateral), the use of a contoured antiglide plate with supplemental lag screws is recommended (Figs. 53-21 and 53-22). Occasionally, a medial or lateral condyle fracture will occur associated with a femoral shaft fracture. As open reduction is usually indicated for the distal articular injury via an open arthrotomy, once the condyle is rigidly stabilized the shaft fracture might be treated with a carefully applied retrograde nail (Fig. 53-23). 
Figure 53-21
Illustrative case of OTA 33 lateral condyle fracture dislocation treated with open reduction and internal fixation with a buttress plate and lag screws.
 
Ligament repair was performed medially as there was substantial residual instability after fracture repair. A: Injury radiographs. B: Injury CT. C: Postoperative radiographs. D: 10-month follow-up radiographs.
Ligament repair was performed medially as there was substantial residual instability after fracture repair. A: Injury radiographs. B: Injury CT. C: Postoperative radiographs. D: 10-month follow-up radiographs.
View Original | Slide (.ppt)
Figure 53-21
Illustrative case of OTA 33 lateral condyle fracture dislocation treated with open reduction and internal fixation with a buttress plate and lag screws.
Ligament repair was performed medially as there was substantial residual instability after fracture repair. A: Injury radiographs. B: Injury CT. C: Postoperative radiographs. D: 10-month follow-up radiographs.
Ligament repair was performed medially as there was substantial residual instability after fracture repair. A: Injury radiographs. B: Injury CT. C: Postoperative radiographs. D: 10-month follow-up radiographs.
View Original | Slide (.ppt)
X
Figure 53-22
Illustrative case of OTA B-type fracture of the lateral condyle associated with a femoral shaft fracture.
 
Open reduction and internal fixation of the open distal femur fracture provided and opportunity for access to the intercondylar notch for retrograde nailing. A, B: Injury plain radiographs and CT. C: The condylar fracture is treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. D: Postoperative x-rays.
Open reduction and internal fixation of the open distal femur fracture provided and opportunity for access to the intercondylar notch for retrograde nailing. A, B: Injury plain radiographs and CT. C: The condylar fracture is treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. D: Postoperative x-rays.
View Original | Slide (.ppt)
Figure 53-22
Illustrative case of OTA B-type fracture of the lateral condyle associated with a femoral shaft fracture.
Open reduction and internal fixation of the open distal femur fracture provided and opportunity for access to the intercondylar notch for retrograde nailing. A, B: Injury plain radiographs and CT. C: The condylar fracture is treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. D: Postoperative x-rays.
Open reduction and internal fixation of the open distal femur fracture provided and opportunity for access to the intercondylar notch for retrograde nailing. A, B: Injury plain radiographs and CT. C: The condylar fracture is treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. D: Postoperative x-rays.
View Original | Slide (.ppt)
X
Figure 53-23
Illustrative case of coronally oriented OTA 33 fracture of the lateral condyle is occasionally seen with shaft fractures and often seen with more complex distal femur fractures.
 
Importantly, these are often missed as in this case example. These are well treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. A, B: Postnailing plain radiographs and CT. C: Postoperative x-rays.
Importantly, these are often missed as in this case example. These are well treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. A, B: Postnailing plain radiographs and CT. C: Postoperative x-rays.
View Original | Slide (.ppt)
Figure 53-23
Illustrative case of coronally oriented OTA 33 fracture of the lateral condyle is occasionally seen with shaft fractures and often seen with more complex distal femur fractures.
Importantly, these are often missed as in this case example. These are well treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. A, B: Postnailing plain radiographs and CT. C: Postoperative x-rays.
Importantly, these are often missed as in this case example. These are well treated with open reduction and internal fixation using screws countersunk along the edge of the articular surface. A, B: Postnailing plain radiographs and CT. C: Postoperative x-rays.
View Original | Slide (.ppt)
X
A coronally oriented shear fracture involving the lateral or medial (“Hoffa fracture”) condyle is not uncommon and is usually seen with other bony or ligamentous injuries around the knee (Fig. 53-24).63 This fracture pattern is often missed on injury plain films as occurred in the case presented, but is easily visualized on CT scans. The posterior condyle fragment is mostly articular and fixation may be problematic. In isolated fractures a limited arthrotomy can be performed and screw fixation applied. If any displacement of Hoffa fracture is present or other parts of the distal femur are to be addressed, then an extensive approach is necessary. Fixation is with two or more carefully measured and placed 2.7-, 3.5-, or 4-mm lag screws inserted anteriorly to posteriorly and countersunk beneath the anterior articular surface. Occasionally, a nonarticular fracture spike extends superiorly from the posterior fragment that is useful for assessing reduction and application of an antiglide plate. 
Figure 53-24
 
Illustrative case of combined open reduction of intercondylar fracture (at time of open fracture debridement and external fixator placement) and staged minimally invasive plating for articular (33C) distal femur fracture. A: Injury radiographs. B: Postoperative x-rays after open fracture wound was debrided and condyles were repaired at initial OR visit. C, D: Second operative visit included serial debridement and minimally invasive plating of the fracture. E: Seven-month follow-up radiographs show healed fractures.
Illustrative case of combined open reduction of intercondylar fracture (at time of open fracture debridement and external fixator placement) and staged minimally invasive plating for articular (33C) distal femur fracture. A: Injury radiographs. B: Postoperative x-rays after open fracture wound was debrided and condyles were repaired at initial OR visit. C, D: Second operative visit included serial debridement and minimally invasive plating of the fracture. E: Seven-month follow-up radiographs show healed fractures.
View Original | Slide (.ppt)
Figure 53-24
Illustrative case of combined open reduction of intercondylar fracture (at time of open fracture debridement and external fixator placement) and staged minimally invasive plating for articular (33C) distal femur fracture. A: Injury radiographs. B: Postoperative x-rays after open fracture wound was debrided and condyles were repaired at initial OR visit. C, D: Second operative visit included serial debridement and minimally invasive plating of the fracture. E: Seven-month follow-up radiographs show healed fractures.
Illustrative case of combined open reduction of intercondylar fracture (at time of open fracture debridement and external fixator placement) and staged minimally invasive plating for articular (33C) distal femur fracture. A: Injury radiographs. B: Postoperative x-rays after open fracture wound was debrided and condyles were repaired at initial OR visit. C, D: Second operative visit included serial debridement and minimally invasive plating of the fracture. E: Seven-month follow-up radiographs show healed fractures.
View Original | Slide (.ppt)
X

ORIF of OTA Type C Distal Femur Fractures

For type C injuries, the principles and goals of treatment are precise anatomic reduction and fixation of the articular surface as well as stabilization of the metadiaphyseal component (Table 53-3). The authors currently use both locked plates and intramedullary nails for these difficult fractures. Using either fixation method, the initial step is anatomic reduction and stabilization of the articular surface. With nondisplaced or minimally displaced simple articular splits in OTA type C1 injuries, the condyles can often be anatomically held or reduced with a large clamp and stabilized through an open or minimally invasive lateral approach using long 3.5-, 4.5-, or 6.5-mm lag screws applied outside the footprint of the plate on the lateral femoral condyle or path of the nail. Sometimes inserting lag screws from the medial side simplifies their placement. For type C2 and C3 injuries, the authors strongly recommend ORIF through an open arthrotomy (usually anterolateral, see above). This usually provides excellent exposure for efficient quality articular reduction and fixation as well as application of the definitive implant (Fig. 53-14). Two cases treated with open reduction and plate fixation are presented in Figures 53-25 and 53-26, a simple articular injury with metaphyseal comminution (C1.3) and a complex articular injury (C3.3), respectively. 
Figure 53-25
Illustrative case of comminuted articular distal femur fracture (33C.3) treated with dual plating.
 
Injury radiographs (A) and CT (B). Fluoroscopic sequence (C) of reduction and fixation: from left to right, the medial side was reduced and dual plated via sub-VMO approach followed by minimally invasive plating of lateral side. An intraoperative photograph shows plate insertion through limited approach (D). Postoperative (E) and 6-month follow-up (F) radiographs.
Injury radiographs (A) and CT (B). Fluoroscopic sequence (C) of reduction and fixation: from left to right, the medial side was reduced and dual plated via sub-VMO approach followed by minimally invasive plating of lateral side. An intraoperative photograph shows plate insertion through limited approach (D). Postoperative (E) and 6-month follow-up (F) radiographs.
View Original | Slide (.ppt)
Injury radiographs (A) and CT (B). Fluoroscopic sequence (C) of reduction and fixation: from left to right, the medial side was reduced and dual plated via sub-VMO approach followed by minimally invasive plating of lateral side. An intraoperative photograph shows plate insertion through limited approach (D). Postoperative (E) and 6-month follow-up (F) radiographs.
View Original | Slide (.ppt)
Figure 53-25
Illustrative case of comminuted articular distal femur fracture (33C.3) treated with dual plating.
Injury radiographs (A) and CT (B). Fluoroscopic sequence (C) of reduction and fixation: from left to right, the medial side was reduced and dual plated via sub-VMO approach followed by minimally invasive plating of lateral side. An intraoperative photograph shows plate insertion through limited approach (D). Postoperative (E) and 6-month follow-up (F) radiographs.
Injury radiographs (A) and CT (B). Fluoroscopic sequence (C) of reduction and fixation: from left to right, the medial side was reduced and dual plated via sub-VMO approach followed by minimally invasive plating of lateral side. An intraoperative photograph shows plate insertion through limited approach (D). Postoperative (E) and 6-month follow-up (F) radiographs.
View Original | Slide (.ppt)
Injury radiographs (A) and CT (B). Fluoroscopic sequence (C) of reduction and fixation: from left to right, the medial side was reduced and dual plated via sub-VMO approach followed by minimally invasive plating of lateral side. An intraoperative photograph shows plate insertion through limited approach (D). Postoperative (E) and 6-month follow-up (F) radiographs.
View Original | Slide (.ppt)
X
Figure 53-26
Shown is the author’s preferred “mini-open” approach for retrograde nailing of non- or minimally articular distal femur fractures that is 3- to 4-cm long incision medial (or rarely lateral) to the patellar ligament.
 
This allows for protection of the patella and proximal tibia (or tibial component) knee arthroplasty while optimizing the nail’s starting point. This can be extended into an extensile parapatellar approach if necessary for articular reduction of more complex articular injuries.
This allows for protection of the patella and proximal tibia (or tibial component) knee arthroplasty while optimizing the nail’s starting point. This can be extended into an extensile parapatellar approach if necessary for articular reduction of more complex articular injuries.
View Original | Slide (.ppt)
Figure 53-26
Shown is the author’s preferred “mini-open” approach for retrograde nailing of non- or minimally articular distal femur fractures that is 3- to 4-cm long incision medial (or rarely lateral) to the patellar ligament.
This allows for protection of the patella and proximal tibia (or tibial component) knee arthroplasty while optimizing the nail’s starting point. This can be extended into an extensile parapatellar approach if necessary for articular reduction of more complex articular injuries.
This allows for protection of the patella and proximal tibia (or tibial component) knee arthroplasty while optimizing the nail’s starting point. This can be extended into an extensile parapatellar approach if necessary for articular reduction of more complex articular injuries.
View Original | Slide (.ppt)
X
 
Table 53-3
ORIF of Distal Femur Fractures (A- and C-Types)
View Large
Table 53-3
ORIF of Distal Femur Fractures (A- and C-Types)
Surgical Steps
  •  
    Preoperative plan: All cases (few of these are “simple”)
  •  
    Surgical approach: Open lateral, MIPO lateral, or extensile lateral arthrotomy
  •  
    Reduce and repair intercondylar split or other intra-articular injury, if present: Clamps, K-wires provisionally for reduction, and lag screws definitively. Visualize and palpate reduction in all but nondisplaced articular fractures.
  •  
    Gain gross metaphyseal alignment: Usually with femoral distractor and towel roll. The plate, if well applied, can be used as a reduction tool. Schantz pin “joysticks” or clamps, are also useful.
  •  
    Apply lateral plate: Ensure that plate positioning is appropriate (use radiographic cues from plate/ instrumentation). Plate may be used as a reduction tool.
  •  
    Coronal plane (varus-valgus) alignment: Place first pin/screw through distal plate hole parallel to articular surface
  •  
    Stabilize the construct if doing MIPO surgery with proximal pinning of the plate: “Rectangularize” the construct
  •  
    Reconfirm reduction and instrumentation regularly: C-arm
  •  
    Apply appropriate mechanics: For example, compression in simple fracture patterns for absolute stability or create bridging construct for comminuted fractures (according to the preoperative plan)
  •  
    Apply nonlocking and/or locking screws according to preoperative plan
X
Postoperative Care After ORIF of Distal Femur Fractures.
Early knee motion is initiated postoperatively. In conscious patients motion is started on the first or second postoperative day with physical therapy. If the patient is reticent to move the knee, a continuous passive motion (CPM) machine is ordered as well as in intubated patients or those in the intensive care unit. Early isometric muscle-strengthening exercises and active-assisted range of motion are encouraged. In patients with stable internal fixation in an A-type fracture, partial weight bearing (i.e., up to 20 lb [9.07 kg] of body weight with crutches or a walker) at 3 to 6 weeks is allowed, whereas in patients with less stable fixation progressive weight bearing is usually delayed until signs of fracture healing (callus) appear on the x-rays. For an intra-articular injury (B- or C-type), weight bearing is delayed until the articular injury is healed, usually around 10 to 12 weeks. By 12 weeks, most patients should tolerate substantial weight bearing, although many still require an assist device. 
Potential Pitfalls and Preventative Measures After ORIF of Distal Femur Fractures.
The distal thigh and knee area include a bony, articular, and soft tissue complex where erroneous plate and/or screw placement may cause a number of problems with considerable consequences. Plate application has not only become more complex with the evolution of better implants, but also potentially more effective with options for screws to be standard or locked, cannulated or noncannulated screws, bi- or unicortical screws, uniaxial and polyaxial screws, plates to be inserted via open or minimally invasive insertion and anatomically contoured to be used to aid in fracture reduction (Table 53-4). 
 
Table 53-4
ORIF of Distal Femur Fractures
View Large
Table 53-4
ORIF of Distal Femur Fractures
Potential Pitfalls and Preventions
Pitfalls Preventions
Missed coronal plane (“Hoffa”) or other intra-articular fracture Preoperative CT
Malalignment
Varus–valgus (usually valgus)
Flexion–extension
Rotational (usually external)
Axial (usually shortening)
Careful surgical technique with intraoperative radiographic assessment and clinical evaluation with comparison to uninjured side
Flexion–extension malalignment Careful radiographic assessment
Well-placed bump
Use of joysticks (Schantz pins) and/or clamps
Rotational malalignment (usually external) Careful radiographic assessment. Accurate use of the plate for reduction. Cortical reads
Length malalignment (usually short) Careful radiographic and physical evaluation
Use of femoral distractor (or ex-fix)
Intra-articular hardware Careful radiographic assessment, including roll-over and notch views. Knowledge of the femur’s radiographic anatomy is critical.
Appropriate plate application
Irritable implants Apply plate flush with lateral condyle. Intraoperative assessment of plate positioning. Roll over AP view to assess long screws through trapezoidal condyles
Knee stiffness Early mobility, range of motion. Continuous passive motion machine, in rare cases.
Arthritis Anatomic reduction of articular surface and restoration of optimal limb alignment
X
Preoperative planning by understanding the injury and the goal for the injured anatomy during reconstruction is critical. As with all periarticular fractures, the goals of surgery are anatomic reduction of the articular surface, restoration of the joint anatomy relative to the bony shaft, stable fixation that will allow for early mobility, and respectful soft tissue handling to preserve biology and allow for optimized healing. 
Plate application is previously described in the “ORIF distal femur” procedure section; using these strategies is critical to optimizing alignment and preventing iatrogenic problems for most cases. Modern plating systems are designed to aid in this process and a number of technical tricks are outlined in this chapter and elsewhere. If the typical plate is placed too distal or proximal, anterior or posterior, or relatively rotated to one major segment or another, deformity is likely to be imparted. Implant issues, including prominence or intra-articular, are also an issue for these fracture treated with ORIF, especially if not applied well. 
Prevention of poor implant placement in this area can likely be prevented by following the following steps. First, preoperatively plan to allow for quality fluoroscopy, including positioning and allowing for comfortable unobstructed views. Check details of reduction frequently and carefully, including obtaining true AP and lateral images, radiographic alignment of the fracture, and appropriate provisional and definitive plate position. Exchange or move parts until the desired result is obtained. Spending a few extra minutes on these details may be invaluable in avoiding revising fixation that is recognized too late or missing a problem altogether. 
Outcomes of Distal Femur Fractures after Osteosynthesis with Plates and Screws.
Open anatomic reduction and internal fixation with traditional nonlocked plates has been associated with relatively high rates of delayed union, nonunion and infection, and the need for supplemental bone graft has been reported to be as high as 90% in comminuted fractures treated this way.59,61,62,64,91,92 These problems may be reflective of the wide dissection required for the fracture fixation and the lack of stability in early nonlocking implants. Dramatically improved results have been achieved using biologic approaches and improved angle stable implants such as the 95-degree blade plate and DCS. Reports by Bolhofner et al.9 and Ostrum and Geel65 in treating distal femur fractures with techniques of indirect fracture reduction and internal fixation using 95-degree fixed angle devices showed markedly improved results compared with previous methods. These authors found union in 93% to 100% of fractures and infections in only 0% to 2% of cases, respectively. 
Multiple reports on distal femur fractures treated with minimally invasive locked plating using the LISS system have shown promising early results. Schutz et al.88 described their early results from multiple European centers, where they found early healing in 37 of 40 patients (93%) treated for fractures with indirect reduction and plating with the LISS system. Kregor et al.48 reported early union in 58 of 61 patients (95%) with distal femur fractures treated similarly. The authors attributed successful early healing to vigilant maintenance of the fracture biology and strict adherence to modern fixation principles, but early in these series, malalignment was recognized as a significant potential problem with this method. Subsequently, Ricci et al.73 treated 26 distal femur fractures in multiply injured patients using the LISS plate. There were no nonunions or infections and no patient required a bone graft. Most patients had excellent range of motion and alignment. Finally, Weight and Collinge103 reported excellent fracture alignment and healing in a cohort of 27 high-energy, mechanically unstable fractures (OTA 33 A2, A3, C2, and C3) treated with a LISS plate. Recently, Streubel et al.96 evaluated far distal periprosthetic supracondylar fractures of the femur and concluded they are not a contraindication to lateral locked plating. Patients with a mean age of 72 years were divided into fractures located proximally (28) and those with fractures that extended distal to the proximal border of the femoral component (33). Delayed healing and nonunion occurred in five (18%) and three (11%) of more proximal fractures, and in two (6%) and five (15%) of the fractures with distal extension (p = 0.23 for delayed healing; p = 0.72 for nonunion). Four construct failures (14%) occurred in more proximal fractures, and three (9%) in fractures with distal extension (p = 0.51). 
Recently, Vallier and Immler102 retrospectively compared patients with distal femoral fractures treated with the 95-degree ABPs (n = 32) and the locking condylar plate (LCP) (n = 39). Although the groups were not perfectly matched, complications were more frequent in LCP patients (35%) versus ABP patients (10%, p = 0.001) after a mean of 26-month follow-up. Malunions occurred in 11% of LCP patients and one ABP patient (3.4%, p = 0.14) and secondary procedures were more common after LCP (43%) versus ABP (6.9%, p = 0.0008) patients. Complications were not related to fracture pattern, periprosthetic fracture, or open fracture. Mean age of patients with complications was 64 years (vs. 53 years, p = 0.01), and they were more likely to have lower-energy mechanisms (p = 0.017). 

Retrograde Femoral Nailing of Distal Femur Fractures

Retrograde nailing of femur fractures is a viable option for treating distal femur fractures as implant technology and techniques have improved over the past decade. Similar to current plates, full length retrograde femoral nails are usually inserted and offer multiple locking screw options including the ability to become a fixed angled construct. The main potential advantage of retrograde nailing over plating is that they may be inserted through smaller, potentially less invasive surgical approaches than plates, and the devices are centrally placed so that bending forces may be better resisted. Keys to successful nailing in the distal femur as well as elsewhere are (1) optimizing the starting point and initial reamer pass and (2) obtaining and maintaining a quality reduction during the procedure. 
Relative Indications for Retrograde Nailing of Distal Femur Fractures.
Retrograde intramedullary nails have also been used to treat selected distal femur fractures. There are several potential advantages with this method of treatment: the intramedullary nail is a load-sharing device compared with a plate and has the potential to stabilize complex fractures with less soft tissue dissection. Modern nailing systems allow multiple distal screws in different planes and rigid locking capability to improve stabilization of the condylar block (Fig. 53-27). Although there are short and long retrograde nails, most surgeons favor full-length nails inserted beyond the isthmus of the femur to the level or just above the lesser trochanter to prevent residual instability or fractures above short nails. Finally, in patients with ipsilateral hip and distal femoral fractures, both fractures can be independently stabilized with screws in the hip and a retrograde nail for the femur. Antegrade nailing has been advocated for some distal femur fractures and may be especially useful in segmental fractures, although retrograde femoral nailing is more effective than antegrade nailing for obtaining and maintaining alignment of a distal fracture. 
Figure 53-27
Illustrative case of retrograde intramedullary nailing for nonarticular (OTA type 33A) distal femur fracture.
 
A: Injury radiographs. B: Intraoperative fluoroscopy showing proper preparation of distal segment with guidepin and step reamer. Proper starting point and reamer trajectory are critical to successful nailing. C: Intraoperative picture showing operative setup and instrumentation. D: Postoperative radiographs. E: Nine-month follow-up radiographs showing healed fracture. F: Arthroscopic photograph at 9.5 months postoperatively shows that reparative cartilage may fill in the nail insertion channel after retrograde femoral nailing.
A: Injury radiographs. B: Intraoperative fluoroscopy showing proper preparation of distal segment with guidepin and step reamer. Proper starting point and reamer trajectory are critical to successful nailing. C: Intraoperative picture showing operative setup and instrumentation. D: Postoperative radiographs. E: Nine-month follow-up radiographs showing healed fracture. F: Arthroscopic photograph at 9.5 months postoperatively shows that reparative cartilage may fill in the nail insertion channel after retrograde femoral nailing.
View Original | Slide (.ppt)
Figure 53-27
Illustrative case of retrograde intramedullary nailing for nonarticular (OTA type 33A) distal femur fracture.
A: Injury radiographs. B: Intraoperative fluoroscopy showing proper preparation of distal segment with guidepin and step reamer. Proper starting point and reamer trajectory are critical to successful nailing. C: Intraoperative picture showing operative setup and instrumentation. D: Postoperative radiographs. E: Nine-month follow-up radiographs showing healed fracture. F: Arthroscopic photograph at 9.5 months postoperatively shows that reparative cartilage may fill in the nail insertion channel after retrograde femoral nailing.
A: Injury radiographs. B: Intraoperative fluoroscopy showing proper preparation of distal segment with guidepin and step reamer. Proper starting point and reamer trajectory are critical to successful nailing. C: Intraoperative picture showing operative setup and instrumentation. D: Postoperative radiographs. E: Nine-month follow-up radiographs showing healed fracture. F: Arthroscopic photograph at 9.5 months postoperatively shows that reparative cartilage may fill in the nail insertion channel after retrograde femoral nailing.
View Original | Slide (.ppt)
X
Potential disadvantages of retrograde nailing include knee sepsis, stiffness, patellofemoral pain, and synovial metallosis resulting from nail or screw fretting or breakage. Although no long-term studies have been done to assess effects of retrograde nailing on the knee, it seems clear that poor operative technique may cause injury. Although the authors have seen no deleterious effects in technically well-done retrograde nailings, leaving the nail proud or inadvertently reaming the patella places the patellofemoral joint at risk for degenerative changes. Furthermore, with complex intra-articular C3 injuries, the condylar segment, especially if comminuted, may not be optimally stabilized with a nail. Two cases of distal femur fractures treated with nailing are presented, an A- and C-type fracture (Fig. 53-28). 
Figure 53-28
Illustrative case showing treatment of open intra-articular (33C.3) distal femur fracture with retrograde femoral nailing.
 
A: Injury radiographs. B: Anterolateral approach using extension of open fracture wound allows for optimal debridement of open fracture, direct anatomic reduction of the condyles. This was followed by temporizing knee-spanning external fixation. C: Definitive fixation has been applied with lag screw anterior to nail path and retrograde femoral nailing. In this case, the wounds were also used for nailing of the patient’s tibia fracture. D: 8-month follow-up Xrays.
A: Injury radiographs. B: Anterolateral approach using extension of open fracture wound allows for optimal debridement of open fracture, direct anatomic reduction of the condyles. This was followed by temporizing knee-spanning external fixation. C: Definitive fixation has been applied with lag screw anterior to nail path and retrograde femoral nailing. In this case, the wounds were also used for nailing of the patient’s tibia fracture. D: 8-month follow-up Xrays.
View Original | Slide (.ppt)
Figure 53-28
Illustrative case showing treatment of open intra-articular (33C.3) distal femur fracture with retrograde femoral nailing.
A: Injury radiographs. B: Anterolateral approach using extension of open fracture wound allows for optimal debridement of open fracture, direct anatomic reduction of the condyles. This was followed by temporizing knee-spanning external fixation. C: Definitive fixation has been applied with lag screw anterior to nail path and retrograde femoral nailing. In this case, the wounds were also used for nailing of the patient’s tibia fracture. D: 8-month follow-up Xrays.
A: Injury radiographs. B: Anterolateral approach using extension of open fracture wound allows for optimal debridement of open fracture, direct anatomic reduction of the condyles. This was followed by temporizing knee-spanning external fixation. C: Definitive fixation has been applied with lag screw anterior to nail path and retrograde femoral nailing. In this case, the wounds were also used for nailing of the patient’s tibia fracture. D: 8-month follow-up Xrays.
View Original | Slide (.ppt)
X
Preoperative Planning for Retrograde Nailing of Distal Femur Fractures.
The concept of preoperative planning is no less important for intramedullary nailing than it is for osteosynthesis with plates and screws (Table 53-5). Limitations of nails used for distal femur fractures make planning very important, such as the size of the condylar segment, the insertional depth of the nail, the number and distances of locking screws from the nail’s end, and others. Nonetheless, the goals of surgery remain the same as for plating: anatomic reduction of the articular surface, restoration of axial alignment and length, fracture stabilization, and maintenance of a biologic environment conducive to healing with avoidance of infection. Many of the same surgical tactics and reduction methods are useful for intramedullary nailing distal femur fractures. Surgery is done on a radiolucent table with the aid of an image intensifier. 
 
Table 53-5
Retrograde Nailing of Distal Femur Fractures
View Large
Table 53-5
Retrograde Nailing of Distal Femur Fractures
Preoperative Planning Checklist
  •  
    OR Table: Radiolucent “flat top” table
  •  
    Position/positioning aids: Radiolucent triangle or large bump
  •  
    Antibiotics: Broad spectrum prophylaxis
  •  
    Anesthesia: Pharmacologic muscle paralysis
  •  
    Draping: Wide draping to allow for ease of proximal locking (proximal to lesser trochanter). Consider draping in opposite leg (allows for clinical and radiographic “control” and mobilizing it out of the way as needed.
  •  
    Fluoroscopy location: From contralateral side
  •  
    Equipment: Universal distractor (or external fixator), long retrograde nails, large bone clamps
  •  
    Tourniquet (sterile/nonsterile): Sterile—most effective for articular portion of surgery, may aid in metaphyseal reduction
  •  
    Reduction: Similar as for ORIF. Critical evaluation of radiographic alignment intraoperatively, including (1) bony axial alignment, length, and rotation, and (2) appropriate positioning of implants
  •  
    Surgical approaches: Lateral (or medial) parapatellar arthrotomy for reduction and nailing of fractures with an intercondylar split. Small lateral arthrotomy for nailing. Protection of the patella from iatrogenic injury is vital.
  •  
    Intra-articular injury, if present: Displaced intra-articular injury should be anatomically reduced and carefully assessed. Clamps, K-wires provisionally for reduction, and lag screws definitively.
  •  
    Reduction: Traction is critical. A universal distractor (or external fixator, if present) is still helpful and may be placed away from the path of the nail. Sagittal plane alignment with a well placed large bump or towel roll. Coronal plane alignment can be corrected with Schanz pin joysticks, bone clamps, or plate application itself.
X
Positioning for Retrograde Nailing of Distal Femur Fractures.
The patient is positioned supine and the affected limb supported on a radiolucent triangle or a large bump to a 20- or 30-degree angle (Figs. 53-12 and 53-28C). The C-arm unit should come in from the opposite side of the table, and the underside of the table should be clear to move the C-arm from the hip to knee without obstruction in both the AP and lateral projection. When possible the fracture should be reduced before nailing. Many of the indirect reduction methods described in femoral plating are useful for nailing. Schantz pins applied unicortically (or bicortically if carefully placed) can be used with the femoral distractor or as joysticks. 
Approaches for Retrograde Nailing of Distal Femur Fractures.
Intramedullary nailing is usually performed through a medial parapatellar incision, but if an intra-articular split or more complex articular injury is present, an open medial or lateral arthrotomy can be performed for reduction and stabilization of the femoral condyles prior to nail insertion. For retrograde nailing of extra-articular fractures (OTA type A), a 4- to 5-cm incision is made along the medial (or lateral) border of the patellar tendon between the inferior border of the patella and the tibial tubercle (Fig. 53-27). Most displaced intra-articular fractures (displaced OTA types C1, C2, and C3) must be exposed, reduced, and stabilized using an open medial or lateral parapatellar arthrotomy based on the fracture pattern (Figs. 53-14 and 53-28B). The intramedullary nail can then be inserted through the open incision. It is important to leave 5 to 6 mm of capsular tissue for a stable side-to-side repair during closure. The patella and local soft tissues should be protected from reamers and other instrumentation during nailing. A working “soft tissue” cannula is available in most nailing sets or carefully placed right-angle retractors are effective. 
Surgical Technique for Retrograde Nailing of Distal Femur Fractures.
Metaphyseal fracture reduction is performed manually or using the femoral distractor with pins placed eccentrically or unicortically in the shaft, a well-placed sterile towel roll, and Schanz pins attached to a T-handle chuck (joysticks) in the femoral shaft or condyles, to reduce the major fragments. 
The portal of entry for the nail is in the intercondylar notch just anterior to the femoral attachment of the posterior cruciate ligament (Fig. 53-28B). A threaded tipped guidepin and cannulated drill are used to open the distal femur before nailing. The pin is carefully inserted in line with the femoral shaft to ensure restoration of coronal plane alignment (on the AP image). This pin is started at the apex of the intercondylar notch and aimed centrally through the supracondylar region. On the lateral image the starting point is just anterior to the Blumensaat’s line. Once the guidepin placement is confirmed with AP and lateral radiographs, the step reamer is advanced through the working channel soft tissue sleeve over the entry wire to prepare the insertion site. 
For intra-articular (C-type) fractures, screws used for the fixation of condylar fractures must not block the path of the intramedullary nail (Fig. 53-28B). As such, interfragmentary screws must be carefully placed anteriorly or posteriorly so as not to impede eventual nail passage. Screws placed through the articular surface (e.g., for a Hoffa fracture) should be countersunk and carefully measured before insertion, and carefully scrutinized radiographically to avoid articular injury. 
A beaded tip guidewire is inserted into the intramedullary canal and advanced past the fracture site into the proximal femur under fluoroscopic control. With the fracture reduced, the position of the guidewire should be center–center in both the AP and lateral views in both the proximal and distal fragments. An intramedullary fracture reducer or “finger” is available in most nailing sets and can be used to facilitate reduction and guidewire passage across the fracture site. Nail length is determined using the manufacturer’s guides. Blocking screws are sometimes used to narrow the effective canal diameter of distal femur to improve alignment and prevent deformity.49 When necessary, blocking screws should be applied in the short condylar segment. A rule of thumb is to apply the screws on the concave side of the existing deformity. This technique is discussed in more detail in the section on nailing proximal tibia fractures (Chapter 57). 
The fracture should be held reduced and out to length during reaming and insertion of the nail. Excessive reaming should be avoided. The guidewire is removed after nail insertion. The nail must be countersunk several millimeters to prevent cartilage damage to the patellofemoral articulation. Final nail positioning should be checked in both the AP and lateral radiographs to ensure nail depth and proper alignment. 
Distal locking bolts are placed through cannulated sleeves using a radiolucent guide. Proximal locking is usually accomplished in the AP plane using a freehand technique. The C-arm is aligned with the desired locking hole in the nail, so that the hole appears to be a perfect circle. A knife blade is placed on the skin, with the incision point verified with radiographic image and a 1-cm incision is made over the hole in the nail. The tip of the drill bit appears as a solid circle in the center of the screw hole and both cortices are drilled. The pilot hole is measured, or alternatively, a 30- or 35-mm screw may be preselected and inserted. Placing the screw using a screwdriver with the ability to “capture” the screw or a suture lasso may aid in screw recovery if the screw disengages. In simple or stable fracture patterns one proximal locked screw is usually adequate. However, in comminuted fractures and those with diaphyseal extension two proximal screws are recommended. The knee joint is thoroughly lavaged and suctioned to remove reamings or other debris that may cause mechanical problems or heterotopic bone formation. The arthrotomy is anatomically repaired and the skin closed in standard fashion (Table 53-6). 
Table 53-6
Retrograde Nailing of Distal Femur Fractures (A- and C-Types)
Surgical Steps
  •  
    Preoperative plan all cases (none of these are “simple”)
  •  
    Surgical approach: Medial (or lateral) arthrotomy, extensile lateral arthrotomy
  •  
    Repair intercondylar split or other intra-articular injury if present
  •  
    Visualize and palpate reduction in all but nondisplaced articular fractures. Clamps, K-wires provisionally, and lag screws definitively out of way of nail path.
  •  
    Gain gross metaphyseal alignment: Usually with femoral distractor or manual forces with or without adjunctive aids such as a bump or towel roll
  •  
    Instrument femur and insert nail: Optimize starting point. Ensure that reduction is maintained in all planes during instrumentation across the fracture with guidewires, reamers, and nail insertion.
  •  
    Nail position: Should be central in condylar segment, buried at least a few mm below chondral surface in intercondylar notch, and extend proximal to the lesser trochanter proximally
  •  
    Locking: Use multiple screws in the condylar segment (2 or more) and always lock both ends
  •  
    Reconfirm reduction and instrumentation regularly
  •  
    Blocking screws: Useful for obtaining and maintaining reduction in condylar segment
  •  
    Compare alignment and length of injured leg to contralateral leg radiographically and clinically if it is not injured.
X
Postoperative Care for Retrograde Nailing of Distal Femur Fractures.
Postoperatively, knee motion is initiated on day 1 or 2 in cooperative patients with a physical therapist or with a CPM in bedridden patients. Weight bearing is encouraged once there is radiographic evidence of callus formation, typically 6 to 8 weeks postoperatively. Clinical and radiographic examinations are performed at 4- to 6-week intervals until the fracture is healed and patients are able to ambulate without discomfort. 
Potential Pitfalls and Preventative Measures for Retrograde Nailing of Distal Femur Fractures.
The potential pitfalls of retrograde nailing of distal femur fractures are fairly similar as those for “ORIF”: lack of reduction or improper use of the implants during application will result in surgical malreduction. As with all nailings, reduction and starting point are critical factors in a successful surgery. With a well-reduced fracture and a good starting point an optimal reamer path is predictable, facilitating the remainder of the procedure. For complex cases, preoperative planning is as essential for nailing as it is for plating. Quality and frequent use of radiography is critical to this procedure, as it is with plating. Finally, nail depth and screw length are important to avoid implant prominence (Table 53-7). 
 
Table 53-7
Retrograde Nailing of Distal Femur Fractures
View Large
Table 53-7
Retrograde Nailing of Distal Femur Fractures
Potential Pitfalls and Preventions
Pitfalls Preventions
Missed coronal plane (“Hoffa”) or other intra-articular fracture Preoperative CT
Malalignment
  •  
    Starting trajectory colinear with long axis of distal fragment. (on both AP and lateral x-ray views)
  •  
    Use of femoral distractor and/or blocking screws to obtain and maintain alignment
Intra-articular hardware Ensure that nail is inserted so that it is recessed beneath the chondral surface in the notch with direct vision and/or with true lateral radiographs of the knee
Irritable implants Roll over AP view to assess distal screw length through trapezoidal condyles
Knee stiffness Early mobility, range of motion
Arthritis Anatomic reduction of articular surface and restoration of optimal limb alignment
X
Relative Results for Retrograde Nailing of Distal Femur Fractures.
Previous studies using short first generation nails are less relevant today as implant technology and techniques have improved. Published reports over the last decade using long retrograde nails for distal femur fractures have reported mostly good results with relatively few complications. To our knowledge there are no large randomized studies comparing retrograde nailing with plating for these injuries. Nevertheless, three small series have been published comparing the two implants. Hartin et al.37 reported on 23 supracondylar femur fractures randomized to a retrograde intramedullary nail fixation (n = 12) or a fixed angle blade plate fixation (n = 11). Both fixation methods gave generally good outcomes, but there was a trend in patients treated with a retrograde nail to require revision surgery for removal of implants (three vs. zero) and to experience more pain on SF-36 outcome measures. Christodoulou et al.17 reported management of distal femur fractures (OTA types A and C) in mostly elderly patients with the use of a DCS or a retrograde nail. Seventy-two patients were randomized to nailing (n = 35) or plating (n = 37). Mean operative time and estimated blood loss were lower in the nailing group (p < 0.001). Healing times were comparable and clinical results as assessed by Schatzker and Lambert’s criteria were similar with good to excellent results in greater than or equal to 80% of patients. Recently, Thomson et al.100 evaluated outcomes at an average of 6.7 years for 11 patients with traditional ORIF versus 11 others treated with limited open reduction with retrograde intramedullary nailing for OTA type C distal femur fractures. The rate of subsequent bone-grafting procedures (67% vs. 9%) and malunion (42% vs. 0%) were significantly higher in ORIF compared with the less invasive retrograde intramedullary nailing treatment. A nonsignificant trend was noted for increased infection (25% vs. 0%) and nonunion (33% vs. 9%) in the group treated with open plating. The physical function component of the SF-36 was approximately two standard deviations below the United States population mean, and 50% of patients demonstrated radiographic changes of posttraumatic arthritis for all patients. There was no significant difference in any domain of the SF-36 or SMFA, or the Iowa Knee Score between the two treatment groups. Finally, Garnavos et al.29 found that 17 patients with OTA type C distal femur fractures treated with compression bolt fixation of the condyles followed by retrograde intramedullary nailing healed early (average 15 weeks) with no incidences of malunion, nonunion, or infections. No secondary failure of fixation occurred. The mean new Oxford Knee Score was 42. 

Other Operative Methods for Treatment of Distal Femur Fractures

The treatment of distal femur fractures using flexible intramedullary nails or with external fixation are very limited but have been used in the past with some measure of success. Each has its own risk to benefit profile; details of their rationale for use and clinical results are described here. 

Intramedullary Nailing of Distal Femur Fractures with Flexible and Semirigid Nails

Relative Indications for Intramedullary Nailing of Distal Femur Fractures with Flexible and Semirigid Nails.
Intramedullary nailing with flexible nails has been advocated for some distal femur fractures, especially in adolescents or in patients with a fracture above a total knee implant.46,90 The benefit of this method is that it may be applied through small incisions after closed fracture reduction. Dynamic “controlled” motion at the fracture site occurs that may encourage early healing with callus. The problem with this method of treatment is its inability to predictably maintain length and alignment, particularly in comminuted fractures. These limitations restrict its use to a few cases in which a locked plate or standard locked intramedullary nail are contraindicated. 
Relative Results for Intramedullary Nailing of Distal Femur Fractures with Flexible and Semirigid Nails.
Shelbourne and Brueckmann90 reported the use of closed Rush pinning in 98 patients with supracondylar femoral fractures. Excellent and good results were obtained in 84% of patients, with only two nonunions and one deep infection. The nails provided enough stability at the fracture site to allow early knee motion. Several authors, however, have reported complications after Rush pin fixation of supracondylar femoral fractures, including pin migration, knee irritation, loss of reduction, and malunion. Kolmert et al.46 described the use of Ender nails connected to cancellous screws by a coupling device. This technique allows anatomic reduction of the femoral condyles with screws as well as semirigid connection of the condyles to the femoral shaft. Most patients, however, require a cast or cast brace for 8 weeks after surgery. The routine use of flexible nails is not recommended. 

External Fixation of Distal Femur Fractures

Relative Indications for External Fixation of Distal Femur Fractures.
External fixation is used infrequently as definitive treatment for supracondylar femoral fractures. Unlike with tibial plateau fractures, ring fixators have a limited role in the acute management of supracondylar femur fractures. Circular femoral frames tend to be large and bulky and frequently impede soft tissue access in open fractures. In addition, they require considerable time and expertise in application. The major indications for definitive external fixation of distal femur fractures is active infection that has been recalcitrant to aggressive treatment or severe open fractures, particularly type IIIB open injuries.41,84 In complex fracture patterns, supplemental lag screws are often necessary to fix intra-articular extensions. Depending on the location of the wounds and degree of fracture comminution, fixation across the knee is often necessary. 
There has been a resurgence of interest in external fixation for temporary stabilization of severely injured patients or when a delay to surgical repair of more than 24 to 36 hours is anticipated, the so called damage control orthopedics. The advantages of external fixation include rapid application, minimal soft tissue dissection, and the ability to maintain length, wound access, and mobilization of the patient. Once the patient and the soft tissues have improved, definitive internal fixation should be undertaken. Therefore, initial fixator pin placement should avoid areas of planned surgical incisions and implant placement whenever possible (Fig. 53-28). As a general rule, 5-mm half pins are inserted anteriorly or laterally above and below the fracture usually in the mid- to proximal shaft of the femur and proximal tibia, and connected to a unilateral half frame. If instability remains, a second plane of fixation can be added. 
Relative Results for External Fixation of Distal Femur Fractures.
A few relatively small case series have been reported on the use of external fixation as definitive treatment for distal femur fractures, mostly after high-energy open fractures.41,84 The literature describing the use of temporizing external fixation for severe injuries is compelling.35 Damage control orthopedics is described in Chapter 9

Management of Expected Adverse Outcomes and Unexpected Complications in Distal Femur Fractures

Although the use of biologic approaches and state-of-the-art implants have improved results, their use does not guarantee a favorable outcome. The surgeon must have a thorough understanding of the local anatomy, mechanics of fracture fixation, and patterns of fracture healing after internal fixation if consistently good results are to be achieved. Common problems associated with operative treatment are described in the following sections. 

Malalignment/Malunion of Distal Femur Fractures

Malalignment of greater than 5 to 10 degrees is likely to affect knee mechanics and gait. Increased varus or valgus may lead to overloading of the joint and subsequent arthrosis of the medial or lateral compartment, respectively. Flexion–extension, rotational deformity, or shortening may affect gait and comfort during activities of daily living. In early series using traditional plates and screws, problems with fixation failure, varus collapse, and malalignment for unstable injuries occurred commonly. Button et al.16 reported four patients whose fixation failed because of proximal screw pullout following internal fixation with a locking plate. Caution is necessary in applying unicortical locking screws (i.e., LISS) to the femoral shaft if a mini-open approach is not used proximally. Quality lateral radiographs must demonstrate that the plate is centered on the bone to ensure optimal screw purchase. Multiple studies using locked plates or retrograde nails have shown improved fixation in the relatively osteopenic distal or condylar segment. With minimally invasive reduction and fixation techniques, alignment has become more problematic, as indirect reduction methods do not allow for direct assessment of the fracture. Vigilant attention to detail is necessary in the operating room to ensure correct alignment. 

Nonunion in Distal Femur Fractures

Historically, open anatomic reduction and rigid internal fixation with traditional plates in distal femur fractures was associated with delayed or nonunion in 29% to 38% of fractures and infection rates of 7% to 20%.23,59,61,62,64,92 These problems likely reflect the effects of further trauma to the surrounding soft tissues during the wide dissection required for the technique. Dramatically improved results have been reported in similar injuries using more biologic approaches and improved implants. Bolhofner et al.9 and Ostrum and Geel65 reported improved results treating distal femur fractures with indirect fracture reduction and internal fixation using 95-degree fixed angle devices. The authors found union in 93% to 100% of fractures and infections in only 2% of cases. Complications after internal fixation using LISS have shown relatively lower complication rates for “biologic problems” such as nonunion, need for bone graft, and infection. For example, Schutz et al.89 described the results for operative treatment of distal femur fractures from multiple European centers using LISS. They found healing in 37 of 40 patients (93%). Kregor et al.48 reported union in 58 of 61 patients (95%) treated with the femoral LISS device. Weight and Collinge103 used similar methods in a small, but selected high-energy cohort of patients with mechanically unstable distal femur fractures treated with LISS and found a 100% union rate without bone grafting. Two recent studies that reported results of distal femur fractures treated with stainless steel distal femur locking plates have indicated that associated host problems (e.g., diabetes mellitus) are risk factors for nonunion.78,102 
Treatment of distal femur nonunions may be difficult owing to pre-existing or disuse osteopenia, proximity to the knee joint, and prior surgical procedures. Aseptic nonunions in patients with reasonable bone stock should be treated by revision osteosynthesis and bone grafting. Hypertrophic nonunions usually respond to stable internal fixation of the nonunion site. The 95-degree condylar blade plate remains an excellent tool for treating nonunions (and malunions); excellent compression can be applied with this device to increase stability. In patients with atrophic nonunions or bone loss, supplemental autologous bone or bone morphogenetic protein is required. In rare instances, methyl methacrylate or resorbable tricalcium phosphate cements can be used to augment screw fixation in the short osteopenic condylar segment. 

Infection After Operative Treatment of Distal Femur Fractures

One of the major drawbacks with operative fixation of supracondylar femoral fractures is the risk of infection. In major trauma centers with experienced fracture surgeons, infection rates should not exceed 3% or 5% in operatively treated closed fracture cases, although an individual’s fracture risk depends on a number of factors. If deep infection develops postoperatively, aggressive irrigation and debridement are indicated. A deep infection with abscess formation should be packed open or temporarily treated with a wound VAC or antibiotic beads. The wound is closed secondarily when it appears “clean” and the signs of infection have resolved. Type-specific antibiotics are given intravenously for 3 to 6 weeks. The duration of the antibiotic therapy must be correlated with the clinical appearance of the wound, laboratory assessment of infection (i.e., erythrocyte sedimentation rate, C-reactive protein, and white blood cell studies), and bacteriologic reports. In the presence of infection, implants that provide stability should be retained to maintain stability. Nonetheless, if the implant is loose or the infection recalcitrant, implants should be removed and the fracture treated temporarily with external fixation. The use of hardware after sepsis requires careful judgment and should only be replanted when signs of infection have abated. The fracture should be followed carefully and bone grafting may be necessary to prevent nonunion. The role of antibiotic-impregnated beads and Ilizarov external fixator remains controversial. 

Knee Stiffness After Distal Femur Fracture

A common complication following distal femur fractures is loss of knee motion. This untoward complication invariably results from damage to the quadriceps mechanism and joint surface as a consequence of the initial trauma or surgical exposure for fixation or both. Quadriceps scarring with or without arthrofibrosis of the knee or patellofemoral joint are thought to restrict knee movement. These effects are greatly magnified by immobilization after fracture or internal fixation. Immobilization of the knee for periods of more than 3 weeks usually results in some degree of permanent stiffness. 
Early stable internal fixation of the fracture with meticulous soft tissue handling and immediate immobilization of the knee joint maximize the chance for an optimal outcome after a distal femur fracture. Most patients should have 90 degrees of knee flexion 4 weeks postoperatively. Patients who fail to regain knee motion during the first month are best treated with aggressive range-of-motion exercises under the direction of a physician and a physical therapist. Failure to regain at least 90 degrees of knee flexion between 8 and 10 weeks postoperatively is worrisome and usually warrants additional treatment in physiologically young patients. One approach is to combine arthroscopic lysis of adhesions with gentle manipulation of the knee in an effort to regain functional knee motion. Forceful manipulation should be avoided and immediate mobilization of the knee is essential to maintain knee motion. In open distal femur fractures, some component of knee stiffness is common. Patients with significant loss of motion after injury may be candidates for quadricepsplasty as a late reconstructive procedure. 

Implant-Related Problems After Surgical Treatment of Distal Femur Fractures

The relatively bulky nature of the implants used for fracture fixation often leads to local symptoms. This is particularly true for older implants such as the DCS, in which the “shoulder” between the compression screw and barrel of the side plate is prominent and a subset of patients may develop irritation over the implants laterally with symptoms of activity-related pain and crepitance. There are no firmly established criteria for hardware removal after supracondylar femur fracture fixation, but the most common indication for metal removal is local discomfort over the implant with activity in a physiologically young patient with a healed fracture. 
Two areas are particularly at risk for implant irritation problems after modern locked plating.19 First, patients sometimes complain of pain over the plate on the lateral femoral condyle where the iliotibial band may rub and become irritated as the tendon moves anteriorly and posteriorly with knee motion. Positioning of the plate flush with the lateral cortex appears important to avoid this problem. Second, surgeons who are unfamiliar with the trapezoidal shape of the distal femur (Fig. 53-3) may insert screws that penetrate the medial cortex and irritate the medial soft tissues of the distal thigh and knee. To avoid this problem, surgeons must carefully measure length for condylar screws, especially those placed anteriorly, and a 20- to 25-degree rollover C-arm view may be used to confirm length. Postoperatively, when long screws are bothersome, they can usually be removed as an outpatient procedure with minimal technical difficulty. 
In cases where stable internal fixation of distal femur fractures is achieved, primary bone healing results. With this pattern of fracture healing there is little or no external callus if bone graft is not used. Because most supracondylar fractures involve both the metaphysis and lower diaphysis, internal remodeling is slow. Therefore, it seems prudent to defer hardware removal for 18 to 24 months in most patients to avoid refracture. In cases in which flexible fixation was used and callus is abundant, it may be safe to remove implants earlier, although this has not been proved clinically. 
Not all patients require implant removal. In most elderly patients, the risk of anesthesia and surgery probably exceeds the benefits to justify routine hardware removal. Nonetheless, if an elderly patient has persistent local pain and the fracture is healed, the implant can be removed if there are no medical contraindications. In physiologically young patients with little or no symptoms related to the implant, routine metal removal is not justified. 
After implant removal, the patient should be protected from full weight bearing with the use of crutches for 4 to 6 weeks. Return to vigorous activities and sports can be individualized, but probably should be deferred for 3 to 6 months. 

Posttraumatic Arthritis After Distal Femur Fracture

The incidence of posttraumatic arthritis after supracondylar femoral fractures is unknown because no long-term outcome studies have been published. Nonetheless, incongruity of the joint surfaces is likely to be the leading cause of early arthritis. For many patients with fractures involving a weight-bearing joint, the injury often affects the normal function of the joint. Unfortunately, many patients with degenerative arthritis of the knee occurring after fracture are young adults and are not ideal candidates for knee arthroplasty. If the arthritis is limited to the medial or lateral compartment, a corrective osteotomy may be appropriate. In patients with severe disabling bicompartmental or tricompartmental arthritis, a total knee replacement may be indicated. Factors such as age, range of knee motion, presence or absence of flexion contractures, and infections play a major role in surgical decision making (Table 53-8). 
 
Table 53-8
Distal Femur Fractures
View Large
Table 53-8
Distal Femur Fractures
Common Adverse Outcomes and Complications
Malalignment/malunion
Nonunion
Knee stiffness
Infection
Hardware-related problems
Posttraumatic arthritis
X

Author’s Preferred Method of Treatment for Distal Femur Fractures

 
 

The vast majority of displaced distal femur fractures in adults are best treated with internal fixation. We recommend locked plating or closed retrograde intramedullary nailing for these fractures (Table 53-9). We still use the 95-degree ABP in the management of selected nonunions or after corrective osteotomies in the distal femur. Regardless of which implant is used, the goal is anatomic reduction of the joint surface and stable internal fixation to allow early range of knee motion. In isolated closed fractures, internal fixation should be performed within the first 24 to 48 hours. If surgery must be delayed for more than 24 to 36 hours, a temporary external fixator or tibial pin traction should be considered.

 
Table 53-9
General Surgical Tactics for Bony Reconstruction of Distal Femur Fractures
OTA Type A
Open locked plating (or 95-degree blade plate or DCS) using lateral approach
Minimally invasive locked plating
Locked retrograde nailing
OTA Type B
Buttress plating for lateral or medial condyle fracture (or lag screws alone in rare, nondisplaced cases)
Countersunk anterior to posterior screws for most coronally oriented fractures (e.g., Hoffa). Occasionally, the posterior fragment with have a nonarticular apex than can be repaired with a small or mini-fragment buttress plate.
OTA type C: Strong consideration for lateral parapatellar arthrotomy for open reduction and internal fixation of articular fracture(s), followed by:
Open locked plating (or 95-degree blade plate or DCS) using lateral approach
Minimally invasive locked plating
Locked retrograde nailing
X
 

Because the spectrum of injuries to the distal femur is so great, no single implant or approach will be optimal for every case. Careful assessment of the patient and critical review of the x-rays and the “personality” of the fracture are essential. Some factors to be considered in the surgical decision-making process include (1) patient age, (2) ambulatory status, (3) degree of osteopenia, (4) degree of comminution, (5) condition of the soft tissues, (6) presence or absence of open wounds, (7) involvement of the joint surfaces, and (8) whether the fracture is an isolated injury or part of a multiply injured patient.

 

In younger patients, restoration of length and axial alignment with stable fixation and early functional rehabilitation remain the goal of surgery. In elderly osteoporotic patients, impaction of metaphyseal fragments with small amounts of shortening may be a reasonable trade-off for rapid fracture union, and occasionally, with a highly comminuted fracture in incompetent bone with or without a knee, a pre-existing knee prosthesis, knee replacement using a tumor prosthesis may be indicated. With the widespread use of periarticular locked plates, these techniques are not widely indicated.

 

With open distal femur fractures, the literature supports immediate or early internal fixation after debridement in type I, II, and IIIA fractures in stable patients in whom the wounds can be made “clean.” However, in type IIIB and IIIC open fractures with massive wounds and gross contamination, external fixation with delayed internal fixation is preferred. Temporizing knee spanning external fixation is a valuable tool to treat this subset of patients. A variety of frame configurations are possible, but typically two pins are placed anteriorly in the proximal tibia and two anteriorly or laterally in the midproximal femur superior to the anticipated proximal extent of plate fixation (Fig. 53-5). When the soft tissues have recovered and the patient’s condition has improved, internal fixation can be performed. Repeat debridement at 48-hour intervals until all devitalized tissue is removed from the wound is necessary to reduce the risk of infection. A wound VAC or antibiotic beads may be a useful adjunct to stabilize the zone of injury, prevent infection, and promote soft tissue healing. Once a clean wound has been achieved and the patient is stable, internal fixation is carried out.

 

The sequential steps in the surgical management of supracondylar femoral fractures include (1) restoration of the articular surface, if needed, (2) stable internal fixation, (3) grafting of bone loss, if necessary, (4) impaction of the fracture in osteoporotic elderly patients, (5) repair of associated ligament injuries and patellar fractures, as indicated, (6) early range of motion of the knee, and (7) delayed protected weight bearing. Nonarticular injuries can be treated using a variety of implants. The method of fixation should be based on a preoperative plan that incorporates the fracture pattern, soft tissue injury, patient factors, surgeon’s preference/familiarity, and hospital resources. In patients with more complex intra-articular involvement (the vast majority of C2 and C3 fractures), the authors prefer the modified lateral (or medial) parapatellar approach to allow access to the joint. In these cases our preference is to use small fragment fixation for the condylar injuries in conjunction with distal femoral locked plates. Temporarily, secure articular fragments using K-wires and/or reduction forceps. Provisional and/or definitive fixation using 3.5- and 4.5-mm cortical screws must be strategically placed to avoid interference with the plate. If a posterior coronal or Hoffa fracture is present, fixation can be obtained by placing countersunk 2.7- or 3.5-mm cortical, or 4-mm cancellous screws through the articular surface from anterior to posterior. After adequate surgical exposure, the femoral condyles are reduced and provisionally fixed with K-wires. Once reduction is confirmed clinically and/or radiographically, the condyles are definitively fixed with long screws anterior and/or posterior in the condyles, allowing sufficient room for the plate. The condylar block can then be reattached to the shaft segment using whichever fixation method the surgeon prefers, plate or nail.

 

Knowledge of fracture biomechanics is vital to maximizing a patient’s chances for union. The use of direct reduction requires a thorough understanding of Perren’s strain theory, and residual gapping at the fracture site should be avoided because it increases the incidence of nonunion and hardware failure. Eight cortices of fixation above and below the fracture site are recommended to provide adequate stability to prevent early torsional and axial failure. A common technical error encountered during indirect reduction and bridge plating is the placement of an overly stiff implant. The use of longer plates with well-spaced cortical screws limits implant stiffness and encourages secondary bone healing. If a locking construct is chosen, a plate of sufficient length to allow no more than 50% of screw holes to be filled is important to prevent stress concentration and premature implant breakage. Newer techniques to modulate locking plate stiffness have recently been reported. Far cortical locking, slotting of near cortical holes, and threaded screw head inserts are all new methods designed to give surgeons control of implant stiffness and direct modulation of the healing environment at the fracture site.

Comparative Outcomes of Distal Femur Fracture Treatments

Level 1 Evidence (One Study)

A recent prospective, randomized multicenter study compared locked plating versus retrograde nailing for distal femur fractures.101 Eighty patients treated with locked plating and 76 patients treated with nailing were assessed for radiographic, functional, and physical outcomes. Malalignment greater than 5 degrees in any plane was present in 22% of nails and 32% of plates (p = 0.4), with valgus present in 87% of plate deformities. There was significant disability seen in both groups through 1 year follow-up, with results trending toward better outcomes in nails compared to plates for all measures, although not to a level of statistical significance. 

Level 2 Evidence (Two Studies)

Butt et al.14 reported a randomized controlled trial comparing 17 patients treated with a DCS for distal femur fracture with 19 patients treated nonoperatively (traction for 3 to 6 weeks followed by cast bracing). There were good or excellent results in 53% of the patients treated operatively compared with 31% treated nonoperatively using Schatzker criteria. There were no nonunions or deep infections in both groups, and only one fixation failure (6%) in the DCS group. Significant complications such as DVT, UTI, pneumonia, pressure sores, malunion, and delayed union were commonly seen in the nonoperative group compared with the operatively treated group. Markmiller et al.53 reported a prospective cohort study comparing 20 patients treated with internal locked fixation using the LISS and 19 patients treated with locked retrograde femoral nailing. They found no significant differences with regard to rates of nonunion (both 10%), fixation failure (both 0%), infection (locked plating 0% vs. nailing 6%), and secondary surgical procedures (both 10%) at 1-year follow-up. 

Level 4 Evidence

Zlowodski’s meta-analysis of operatively treated distal femur fractures104 included 45 case series reporting 1,614 patients treated with (1) compression plating, (2) antegrade nailing, (3) retrograde nailing, and (4) internal (locked) or external fixation. In all treatment options, additional internal screw and/or plate fixation was performed first if the articular surface was fractured. All operatively treated cases were summarized. The average follow-up was 2.5 years. The articular surface was fractured in 58% of the cases (OTA type C); in 22% severely (C3). Twenty-seven percent of all fractures were open, with type III open fractures in 10% of cases. Overall, there were 6% nonunions, 3.3% fixation failures, 2.7% deep infections, and 16.8% required a secondary surgical procedure. The injury/fracture spectrum was different for the four fixation techniques; therefore, a comparison of outcome parameters was limited. 

Summary, Controversies, and Future Directions for Treatment of Distal Femur Fractures

Major advances in the treatment of distal femur fractures have been achieved over the past decade. Improved biology and fixation have improved outcomes to good or excellent in 80% of cases. Current problems with distal femur fractures, such as the optimal implant, management of bone loss, injury to the extensor mechanism, as well as postoperative knee stiffness, require further investigation. 

References

1.
Aaron RK, Scott. Supracondylar fracture of the femur after total knee arthroplasty. Clin Orthop Relat Res. 1987;(219):136–139.
2.
Amorosa LF, Jayaram PR, Wellman DS, et al. The use of the 95-degree-angled blade plate in femoral nonunion surgery. Eur J Orthop Surg Traumatol. e-pub ahead of print July 6, 2013.
3.
Ayers ME, Iorio R, Healy WL. In: Scott R, Bono J, eds. Periprosthetic Fractures After Total Knee Arthroplasty in Revision Total Knee Arthroplasty. New York: Springer, 2005.
4.
Barei DP. Current utilization, interpretation, and recommendations: The musculoskeletal function assessments (MFA/SMFA). J Orthop Trauma. 2007;21:738–742.
5.
Barei DP, Beingessner DM. Open distal femur fractures treated with lateral locked implants: Union, secondary bone grafting, and predictive parameters. Orthopedics. 2012;35(6):e843–e846.
6.
Bellamy N. Validation study of WOMAC: A health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol. 1988;15:1833–1840.
7.
Bengtsson J, Möllborg J, Werner S. A study for testing the sensitivity and reliability of the Lysholm knee scoring scale. Knee Surg Sports Traumatol Arthrosc. 1996;4:27–31.
8.
Bezwada HP, Neubauer P, Baker J, et al. Periprosthetic supracondylar femur fractures following total knee arthroplasty. J Arthroplasty. 2004;19(4):453–458.
9.
Bolhofner BR, Carmen B, Clifford P. The results of open reduction and Internal fixation of distal femur fractures using a biologic (indirect) reduction technique. J Orthop Trauma. 1996;10(6):372–377.
10.
Bong MR, Egol KA, Koval KJ, et al. Comparison of the LISS and a retrograde-inserted supracondylar intramedullary nail for fixation of a periprosthetic distal femur fracture proximal to a total knee arthroplasty. J Arthroplasty. 2002;17(7):876–881.
11.
Bottlang M, Fitzpatrick DC, Sheerin D, et al. Dynamic fixation of distal femur fractures using far cortical locking screws: A prospective observational study. J Orthop Trauma. 2014;28(4):181–188.
12.
Browner BD, Kenzora JE, Edwards CC. The use of modified Neufeld traction in the management of femoral fractures in polytrauma. J Trauma. 1981;21(9):779–787.
13.
Busse JW. Use of both Short Musculoskeletal Function Assessment questionnaire and Short Form-36 among tibial-fracture patients was redundant. J Clin Epidemiol. 2009;62:1210–1217
14.
Butt MS, Krikler SJ, Ali MS. Displaced fractures of the distal femur in elderly patients. Operative versus non-operative treatment. J Bone Joint Surg Br. 1996;78(1):110–114.
15.
Butt WP, Samuel E. Radiologic anatomy of the proximal end of the femur. J Can Assoc Radiol. 1966;17(2):103–106.
16.
Button G, Wolinsky P, Hak D. Failure of less invasive stabilization system plates in the distal femur: A report of four cases. J Orthop Trauma. 2004;18(8):565–570
17.
Christodoulou A, Terzidis I, Ploumis A, et al. Supracondylar femoral fractures in elderly patients treated with the dynamic condylar screw and the retrograde intramedullary nail: A comparative study of the two methods. Arch Orthop Trauma Surg. 2005;125(2):73–79.
18.
Collinge C, Kennedy J, Schmidt A. Temporizing external fixation of the lower extremity: A survey of the Orthopaedic Trauma Association Membership. Orthopedics. 2010;33(4).
19.
Collinge CA, Gardner MJ, Crist BD. Pitfalls in the application of distal femur plates for fractures. J Orthop Trauma. 2011;25(11):695–706.
20.
Collinge CA, Sanders RW. Percutaneous plating in the lower extremity. J Am Acad Orthop Surg. 2000;8(4):211–216.
21.
Connolly JF. Closed management of distal femoral fractures. Instr Course Lect. 1987;36:428–437.
22.
Connolly JF. Closed treatment of pelvic and lower extremity fractures. Clin Orthop Relat Res. 1989;(240):115–128.
23.
Davison BL. Varus collapse of comminuted distal femur fractures after open reduction and internal fixation with a lateral condylar buttress plate. Am J Orthop. 2003;32(1):27–30.
24.
Dugan TR, Hubert MG, Siska PA, et al. Open supracondylar femur fractures with bone loss in the polytraumatized patient—Timing is everything! Injury. 2013;44(12):1826–1831.
25.
Endres NK, Minas T. Medial subvastus approach: surgical technique. Harvard Orthopaedic Journal. 2010;10:62–65.
26.
Frigg R. The development of the distal femur Less Invasive Stabilization System (LISS). Injury. 2001:32(suppl 3):SC24–SC31.
27.
Fulkerson E, Tejwani N, Stuchin S, et al. Management of periprosthetic femur fractures with a first generation locking plate. Injury. 2007;38(8):965–972.
28.
Gardner MJ, Toro-Arbelaez JB, Harrison M, et al. Open reduction and internal fixation of distal femoral nonunions: Long-term functional outcomes following a treatment protocol. J Trauma. 2008;64(2):434–438.
29.
Garnavos C, Lygdas P, Lasanianos NG. Retrograde nailing and compression bolts in the treatment of type C distal femoral fractures. Injury. 2012;43(7):1170–1175.
30.
Gates DJ, Alms M, Cruz MM. Hinged cast and roller traction for fractured femur. A system of treatment for the Third World. J Bone Joint Surg Br. 1985;67(5):750–756.
31.
Gliatis J. Periprosthetic distal femur fracture: Plate versus nail fixation. Opinion: Intramedullary nail. J Orthop Trauma. 2007;21(3):220–221.
32.
Goesling T, Frenk A, Appenzeller A, et al. LISS PLT: Design, mechanical and biomechanical characteristics. Injury. 2003;34(suppl 1):A11–A15.
33.
Goyal T, Nag HL, Tripathy SK. Dynamization of locked plating on distal femur fracture. Arch Orthop Trauma Surg. 2011;131(10):1331–1332.
34.
Haidukewych G, Sems SA, Huebner D, et al. Results of polyaxial locked-plate fixation of periarticular fractures of the knee. J Bone Joint Surg Am. 2007;89(3):614–620.
35.
Haidukewych GT. Temporary external fixation for the management of complex intra- and periarticular fractures of the lower extremity. J Orthop Trauma. 2002;16:678–685.
36.
Harris WH, Heaney. Skeletal renewal and metabolic bone disease. N Engl J Med. 1969;280:193–202.
37.
Hartin NL, Harris I, Hazratwala K. Retrograde nailing versus fixed-angle blade plating for supracondylar femoral fractures: A randomized controlled trial. ANZ J Surg. 2006;76(5):290–294.
38.
Herrera DA, Kregor PJ, Cole PA, et al. Treatment of acute distal femur fractures above a total knee arthroplasty: Systematic review of 415 cases (1981-2006). Acta Orthop. 2008;79(1):22–27.
39.
Hoppenfeld S, deBoer P, Buckley R. Surgical Exposures in Orthopaedics: The Anatomic Approach. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2009.
40.
Horneff JG 3rd, Scolaro JA, Jafari SM, et al. Intramedullary nailing versus locked plate for treating supracondylar periprosthetic femur fractures. Orthopedics. 2013;36(5):e561–e566.
41.
Hutson JJ Jr, Zych GA. Treatment of comminuted intraarticular distal femur fractures with limited internal and external tensioned wire fixation. J Orthop Trauma. 2000;14(6):405–413.
42.
Jain VK, Sinha S, Kumar S. Supracondylar femur fracture complicating epileptic insult: A specific and under diagnosed complication? Acta Neurol Belg. 2009;109(1):59.
43.
Jassim SS, McNamara I, Hopgood P. Distal femoral replacement in periprosthetic fracture around total knee arthroplasty.Injury. 2014;45:550–553.
44.
Kammerlander C. Functional outcome and mortality in geriatric distal femoral fractures. Injury. 2012:43:1096–1101.
45.
Kolb W, Guhlmann H, Windisch C, et al. Fixation of distal femoral fractures with the Less Invasive Stabilization System: A minimally invasive treatment with locked fixed-angle screws. J Trauma. 2008;65(6):1425–1434.
46.
Kolmert L, Persson BM. Supracondylar femoral fractures as a complication to Ender nailing of trochanteric fractures. A new device for osteosynthesis. Arch Orthop Trauma Surg. 1980;97(1):51–55.
47.
Kregor PJ, Stannard J, Zlowodzki M, et al. Distal femoral fracture fixation utilizing the Less Invasive Stabilization System (L.I.S.S.): The technique and early results. Injury. 2001;32(suppl 3):SC32–SC47.
48.
Kregor PJ, Stannard JA, Zlowodzki M, et al. Treatment of distal femur fractures using the less invasive stabilization system: Surgical experience and early clinical results in 103 fractures. J Orthop Trauma. 2004;18(8):509–520.
49.
Krettek C, Miclau T, Schandelmaier P, et al. The mechanical effect of blocking screws (“Poller screws”) in stabilizing tibia fractures with short proximal or distal fragments after insertion of small-diameter intramedullary nails. J Orthop Trauma. 1999;13(8):550–553
50.
Krettek C, Muller M, Miclau T. Evolution of minimally invasive plate osteosynthesis (MIPO) in the femur. Injury. 2001;32(suppl 3):SC14–SC23.
51.
Krettek C, Schandelmaier P, Miclau T, et al. Transarticular joint reconstruction and indirect plate osteosynthesis for complex distal supracondylar femoral fractures. Injury. 1997;28(suppl 1):A31–A41.
52.
Leung KS. Interlocking intramedullary nailing for supracondylar and intercondylar fractures of the distal part of the femur. J Bone Joint Surg Am. 1991;73:332–340.
53.
Markmiller M, Konrad G, Sudkamp N. Femur-LISS and distal femoral nail for fixation of distal femoral fractures: Are there differences in outcome and complications? Clin Orthop Relat Res. 2004;(426):252–257.
54.
Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium—2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma. 2007;21:S1–S133.
55.
Marti A, Fankhauser C, Frenk A, et al. Biomechanical evaluation of the less invasive stabilization system for the internal fixation of distal femur fractures. J Orthop Trauma. 2001;15(7):482–487.
56.
Martin DP. Comparison of the Musculoskeletal Function Assessment questionnaire with the Short Form-36, the Western Ontario and McMaster Universities Osteoarthritis Index, and the Sickness Impact Profile health-status measures. J Bone Joint Surg Am. 1997:79:1323–1335.
57.
Mast J, Jakob R, Ganz R. Planning and Reduction Technique in Fracture Surgery. Berlin: Springer-Verlag; 1989.
58.
Mills WJ, Barei DP, McNair P. The value of the ankle-brachial index for diagnosing arterial injury after knee dislocation: A prospective study. J Trauma. 2004;56:1261–1265.
59.
Mooney V. Fractures of the distal femur. Instr Course Lect. 1987;36:427.
60.
Mooney V, Nickel VL, Harvey JP Jr, et al. Cast-brace treatment for fractures of the distal part of the femur. A prospective controlled study of one hundred and fifty patients. J Bone Joint Surg Am. 1970;52(8):1563–1578.
61.
Moore TJ, Watson T, Green SA, et al. Complications of surgically treated supracondylar fractures of the femur. J Trauma. 1987;27(4):402–406.
62.
Neer CS 2nd, Grantham SA, Shelton ML. Supracondylar fracture of the adult femur. A study of one hundred and ten cases. J Bone Joint Surg Am. 1967;49(4):591–613.
63.
Nork SE, Segina DN, Aflatoon K, et al. The association between supracondylar-intercondylar distal femoral fractures and coronal plane fractures. J Bone Joint Surg Am. 2005;87:564–569.
64.
Olerud S. Supracondylar, intraarticular fracture of the femur. Results of operative reconstruction. Acta Orthop Scand. 1971;42(5):435–437.
65.
Ostrum RF, Geel C. Indirect reduction and internal fixation of supracondylar femur fractures without bone graft. J Orthop Trauma. 1995;9(4):278–284.
66.
Ostrum RF, Maurer JP. Distal third femur fractures treated with retrograde femoral nailing and blocking screws. J Orthop Trauma. 2009;23(9):681–684.
67.
Otto RJ, Moed BR, Bledsoe JG. Biomechanical comparison of polyaxial-type locking plates and a fixed-angle locking plate for internal fixation of distal femur fractures. J Orthop Trauma. 2009;23(9):645–652.
68.
Parekh AA, Smith WR, Silva S, et al. Treatment of distal femur and proximal tibia fractures with external fixation followed by planned conversion to internal fixation. J Trauma. 2008;64(3):736–739.
69.
Patzakis MJ. Management of open fractures and complications. Instr Course Lect. 1982;31:62–64.
70.
Patzakis MJ. Management of open fracture wounds. Instr Course Lect. 1987;36:367–369.
71.
Patzakis MJ, Wilkins J. Factors influencing infection rate in open fracture wounds. Clin Orthop Relat Res. 1989;(243):36–40.
72.
Rademakers MV, Kerkhoffs GM, Sierevelt IN, et al. Intra-articular fractures of the distal femur: A long-term follow-up study of surgically treated patients. J Orthop Trauma. 2004;18(4):213–219
73.
Ricci AR, Yue JJ, Taffet R, et al. Less invasive stabilization system for treatment of distal femur fractures. Am J Orthop. 2004;33(5):250–255.
74.
Ricci WM, Bolhofner BR, Loftus T, et al. Indirect reduction and plate fixation, without grafting, for periprosthetic femoral shaft fractures about a stable intramedullary implant surgical technique. J Bone Joint Surg Am. 2006;88(suppl 1 Pt 2):275–282.
75.
Ricci WM, Borrelli J Jr. Operative management of periprosthetic femur fractures in the elderly using biological fracture reduction and fixation techniques. Injury. 2007;38(suppl 3):S53–S58.
76.
Ricci WM, Loftus T, Cox C, et al. Locked plates combined with minimally invasive insertion technique for the treatment of periprosthetic supracondylar femur fractures above a total knee arthroplasty. J Orthop Trauma. 2006;20(3):190–196.
77.
Ricci WM, Collinge C, Struebel PN, et al. A comparison of more and less aggressive debridement protocols for the treatment of open supracondylar femur fractures. J Orthop Trauma. 2013;27(12):722–725.
78.
Ricci WM, Streubel PN, Morshed S, et al. Risk factors for failure of locked plate fixation of distal femur fractures: an analysis of 335 cases. J Orthop Trauma. 2014;28:83–89.
79.
Ries MD. Prophylactic intramedullary femoral rodding during total knee arthroplasty with simultaneous femoral plate removal. J Arthroplasty. 1998;13(6):718–721.
80.
Ritter MA. The effect of femoral notching during total knee arthroplasty on the prevalence of postoperative femoral fractures and on clinical outcome. J Bone Joint Surg Am. 2005;87:2411–2414.
81.
Rodriguez EK, Boulton C, Weaver MJ, et al. Predictive factors of distal femoral fracture nonunion after lateral locked plating: A retrospective multicenter case-control study of 283 fractures. Injury. 2014;45:554–559.
82.
Sanders R. Double-plating of comminuted, unstable fractures of the distal part of the femur. J Bone Joint Surg Am. 1991;73:341–346.
83.
Sanders R, Regazzoni P, Ruedi TP. Treatment of supracondylar-intracondylar fractures of the femur using the dynamic condylar screw. J Orthop Trauma. 1989;3(3):214–222.
84.
Saridis A, Panagiotopoulos E, Tyllianakis M, et al. The use of the Ilizarov method as a salvage procedure in infected nonunion of the distal femur with bone loss. J Bone Joint Surg Br. 2006;88(2):232–237.
85.
Schandelmaier P, Partenheimer A, Koenemann B, et al. Distal femoral fractures and LISS stabilization. Injury. 2001;32(suppl 3):SC55–SC63.
86.
Schatzker J, Horne G, Waddell J. The Toronto experience with the supracondylar fracture of the femur 1966-1972. Injury. 1974;6:113–128.
87.
Schutz M, Muller M, Kaab M, et al. Less invasive stabilization system (LISS) in the treatment of distal femoral fractures. Acta Chir Orthop Traumatol Czech. 2003;70(2):74–82.
88.
Schutz M, Muller M, Krettek C, et al. Minimally invasive fracture stabilization of distal femoral fractures with the LISS: A prospective multicenter study. Results of a clinical study with special emphasis on difficult cases. Injury. 2001;32(suppl 3):SC48–SC54.
89.
Schutz M, Muller M, Regazzoni P, et al. Use of the less invasive stabilization system (LISS) in patients with distal femoral (AO33) fractures: A prospective multicenter study. Arch Orthop Trauma Surg. 2005;125(2):102–108.
90.
Shelbourne KD, Brueckmann FR. Rush-pin fixation of supracondylar and intercondylar fractures of the femur. J Bone Joint Surg Am. 1982;64(2):161–169.
91.
Siliski JM, Mahring M, Hofer HP. Supracondylar-intercondylar fractures of the femur. Treatment by internal fixation. J Bone Joint Surg Am. 1989;71(1):95–104.
92.
Slätis P, Ryöppy S, Huittinen VM. AOI osteosynthesis of fractures of the distal third of the femur. Acta Orthop Scand. 1971;42(2):162–172.
93.
Smith TO, Hedges C, MacNair R, et al. The clinical and radiological outcomes of the LISS plate for distal femoral fractures: A systematic review. Injury. 2009;40(10):1049–1063.
94.
Starr AJ, Jones AL, Reinert CM. The “swashbuckler”: A modified anterior approach for fractures of the distal femur. J Orthop Trauma. 1999;13(2):138–140.
95.
Streubel PN. Mortality after periprosthetic femur fractures. J Knee Surg. 2013;26:27–30.
96.
Streubel PN, Gardner MJ, Morshed S, et al. Are extreme distal periprosthetic supracondylar fractures of the femur too distal to fix using a lateral locked plate? J Bone Joint Surg Br. 2010;92(4):527–534.
97.
Streubel PN, Ricci WM, Wong A, et al. Mortality after distal femur fractures in elderly patients. Clin Orthop Relat Res. 2011;469(4):1188–1196.
98.
Struhl S, Szporn MN, Cobelli NJ, et al. Cemented internal fixation for supracondylar femur fractures in osteoporotic patients. J Orthop Trauma. 1990;4(2):151–157.
99.
Syed AA. Distal femoral fractures: Long-term outcome following stabilisation with the LISS. Injury. 2004;35:599–607.
100.
Thomson AB, Driver R, Kregor PJ, et al. Long-term functional outcomes after intraarticular distal femur fractures: ORIF versus retrograde intramedullary nailing. Orthopedics. 2008;31(8):748–750.
101.
Tornetta P III, Egol KA, Jones CB, et al. Presented at annual meeting of the Orthopedic Trauma Association; 2013; Phoenix, AZ.
102.
Vallier HA, Immler W. Comparison of the 95-degree angled blade plate and the locking condylar plate for the treatment of distal femoral fractures. J Orthop Trauma. 2012;26(6):327–332.
103.
Weight M, Collinge C. Early results of the less invasive stabilization system for mechanically unstable fractures of the distal femur (AO/OTA types A2, A3, C2, and C3). J Orthop Trauma. 2004;18:503–508.
104.
Zlowodzki M, Bhandari M, Marek DJ, et al. Operative treatment of acute distal femur fractures: Systematic review of 2 comparative studies and 45 case series (1989 to 2005). J Orthop Trauma. 2006;20(5):366–371.
105.
Zlowodzki M, Williamson S, Cole PA, et al. Biomechanical evaluation of the less invasive stabilization system, angled blade plate, and retrograde intramedullary nail for the internal fixation of distal femur fractures. J Orthop Trauma. 2004;18(8):494–502.