Chapter 18: Dislocations of the Elbows, Medial Epicondylar Humerus Fractures

Anthony A. Stans, J. Todd R. Lawrence

Chapter Outline

Introduction to Elbow Dislocations and Medial Epicondyle Fractures

Disruptions of the elbow joint represent a spectrum of injuries involving three separate articulations: The radiocapitellar, the ulnohumeral, and the proximal radioulnar joints. Dislocations of the elbow joint in children are not common. Of all elbow injuries in skeletally immature patients, Henrikson65 found that only about 3% of all were dislocations. The peak incidence of pediatric elbow dislocations typically occurs in the second decade of life, usually between 13 and 14 years of age when the physes begin to close.65,80 Based on the National Electronic Injury Surveillance System database, the calculated incidence of elbow dislocations in adolescents aged 10 to 19 years old was 6.87 dislocations per 100,000 person-years with an almost 2:1 ratio of injuries in males compared to females (incidence 8.91 vs. 4.72 per 100,000 person-years).171 The largest proportion of elbow dislocations (44.5%) occur in conjunction with sports activities; football/rugby, wrestling, and basketball being the most common sports for males and gymnastics and skating being the most common sports for females.171 Almost 60% of medial epicondyle fractures are associated with elbow dislocations in this age group.89,188 As with all joint dislocations, the principles of treatment include promptly obtaining a concentric reduction of the elbow joint while identifying and treating all associated injuries. The ultimate goal is allowing protected motion and rehabilitation with the goal of restoring full elbow motion without recurrent instability. 

Assessment of Elbow Dislocations and Medial Epicondyle Fractures

Because of the location of critical stabilizing factors and surrounding neurovascular structures, elbow dislocations should be considered based on the direction of dislocation and the associated fractures which may be present. As the mechanism of injury, the associated injuries, and imaging differ based on the nature of the injury, these factors should be considered for each dislocation pattern. 

Pathoanatomy and Applied Anatomy Relating to Elbow Dislocations and Medial Epicondyle Fractures

Constraints about the elbow preventing dislocation can be considered as either dynamic or static. Dynamic elbow stabilizers consist of the elbow musculature, over which the patient has conscious control, which change depending on the degree of muscular contraction. Unlike the shoulder, dynamic stabilizers play only a modest role in elbow stability. 
Static constraints are of greater importance and can be divided into osseous and ligamentous restraints (Figs. 18-118-3). The bony geometry of the elbow creates a relatively constrained hinge. The coronoid and olecranon form a semicircle of approximately 180 degrees into which the trochlea of the humerus securely articulates. The concave surface of the radial head matches the convex capitellum and provides stability to the lateral aspect of the elbow joint. The bony configuration of the medial and lateral aspects of the elbow complement each other with the ulnohumeral articulation providing stability against medial–lateral or longitudinal translation, whereas the radiocapitellar joint provides resistance to axial compression. The circular nature of the proximal radius allows for nearly 180 degrees of rotation through the full range of flexion and extension allowing for maintenance of these relationships with forearm rotation. 
Figure 18-1
Anteroposterior view of the elbow illustrates the bone and ligamentous structures which contribute to elbow stability.
 
(A, lateral collateral ligament; B, annular ligament; C, medial collateral ligament.)
(A, lateral collateral ligament; B, annular ligament; C, medial collateral ligament.)
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Figure 18-1
Anteroposterior view of the elbow illustrates the bone and ligamentous structures which contribute to elbow stability.
(A, lateral collateral ligament; B, annular ligament; C, medial collateral ligament.)
(A, lateral collateral ligament; B, annular ligament; C, medial collateral ligament.)
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Figure 18-2
The annular ligament and lateral collateral ligament complex provides stability to the proximal radioulnar joint and radial capitellar articulation.
 
(A, annular ligament; B, lateral collateral ligament insertion on annular ligament; C, lateral collateral ligament insertion on ulna.)
(A, annular ligament; B, lateral collateral ligament insertion on annular ligament; C, lateral collateral ligament insertion on ulna.)
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Figure 18-2
The annular ligament and lateral collateral ligament complex provides stability to the proximal radioulnar joint and radial capitellar articulation.
(A, annular ligament; B, lateral collateral ligament insertion on annular ligament; C, lateral collateral ligament insertion on ulna.)
(A, annular ligament; B, lateral collateral ligament insertion on annular ligament; C, lateral collateral ligament insertion on ulna.)
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Figure 18-3
The medial elbow is stabilized by the hinge articulation between the proximal ulna and the humerus.
 
Three components of the ulnar collateral ligament provide additional elbow stability. (A, coronoid process; B, olecranon process; C, anterior oblique medial collateral ligament; D, posterior oblique medial collateral ligament; E, transverse medial collateral ligament.)
Three components of the ulnar collateral ligament provide additional elbow stability. (A, coronoid process; B, olecranon process; C, anterior oblique medial collateral ligament; D, posterior oblique medial collateral ligament; E, transverse medial collateral ligament.)
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Figure 18-3
The medial elbow is stabilized by the hinge articulation between the proximal ulna and the humerus.
Three components of the ulnar collateral ligament provide additional elbow stability. (A, coronoid process; B, olecranon process; C, anterior oblique medial collateral ligament; D, posterior oblique medial collateral ligament; E, transverse medial collateral ligament.)
Three components of the ulnar collateral ligament provide additional elbow stability. (A, coronoid process; B, olecranon process; C, anterior oblique medial collateral ligament; D, posterior oblique medial collateral ligament; E, transverse medial collateral ligament.)
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Lateral ligamentous constraints include the annular ligament that is attached to proximal ulna and encircles the radial neck and the lateral collateral ligaments that originate from the lateral epicondyle and insert into the annular ligament and the lateral aspect of the proximal ulna. The primary role of the annular ligament and the lateral collateral ligament complex is to provide stability to the radiocapitellar and proximal radioulnar joints by resisting varus stress. 
The medial ulnar collateral ligament is the primary ligamentous restraint to valgus stress, resisting pathologic opening of the medial aspect of the elbow. Having its origin from the inferior aspect of the medial epicondyle, the medial collateral ligament has two primary components that contribute to elbow stability, the anterior and the posterior bands. The band's anterior portion is taut in extension and the posterior fibers are taut in flexion (Fig. 18-4). There is also a fan-shaped posterior oblique ligament that inserts on the olecranon and functions mainly in flexion and a small transverse ligament runs from the olecranon to the coronoid that is thought to have little functional importance. Woods and Tullos191 pointed out that the major stabilizing ligamentous structure in the elbow is the anterior band of the ulnar collateral ligament. 
Figure 18-4
Ligamentous structures.
 
A: The ulnar collateral ligament is divided into anterior, posterior, and oblique bands. B: On extension, the anterior fibers of the anterior band are taut. The posterior fibers of the anterior band and the entire posterior band are loose in this position. C: In flexion, the posterior fibers of the anterior band and the posterior band become taut. The anterior fibers of the anterior band become loose. D: When the epicondyle is rotated anteriorly, the entire anterior band can become loose.
 
(From Woods GW, Tullos HS. Elbow instability and medial epicondyle fractures. Am J Sports Med. 1977; 5(1):23–30, with permission.)
A: The ulnar collateral ligament is divided into anterior, posterior, and oblique bands. B: On extension, the anterior fibers of the anterior band are taut. The posterior fibers of the anterior band and the entire posterior band are loose in this position. C: In flexion, the posterior fibers of the anterior band and the posterior band become taut. The anterior fibers of the anterior band become loose. D: When the epicondyle is rotated anteriorly, the entire anterior band can become loose.
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Figure 18-4
Ligamentous structures.
A: The ulnar collateral ligament is divided into anterior, posterior, and oblique bands. B: On extension, the anterior fibers of the anterior band are taut. The posterior fibers of the anterior band and the entire posterior band are loose in this position. C: In flexion, the posterior fibers of the anterior band and the posterior band become taut. The anterior fibers of the anterior band become loose. D: When the epicondyle is rotated anteriorly, the entire anterior band can become loose.
(From Woods GW, Tullos HS. Elbow instability and medial epicondyle fractures. Am J Sports Med. 1977; 5(1):23–30, with permission.)
A: The ulnar collateral ligament is divided into anterior, posterior, and oblique bands. B: On extension, the anterior fibers of the anterior band are taut. The posterior fibers of the anterior band and the entire posterior band are loose in this position. C: In flexion, the posterior fibers of the anterior band and the posterior band become taut. The anterior fibers of the anterior band become loose. D: When the epicondyle is rotated anteriorly, the entire anterior band can become loose.
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The medial epicondyle represents a traction apophysis because the forces across its physis are in tension rather than the compressive forces present across the other condylar physes of the distal humerus. The medial epicondylar apophysis actually arises from the posterior surface of the medial distal humeral metaphysis. Ossification begins at about 4 to 6 years of age and fuses at about 15 years of age, making it the last secondary ossification center to fuse with the distal humeral metaphysis. The ossification center starts as a small eccentric oval nucleus (Fig. 18-5A). As it matures, parallel sclerotic margins develop along both sides of the physis (Fig. 18-5B). There may be some irregularity of the ossification process, which gives the ossific nucleus a fragmented appearance. This fragmentation may be falsely interpreted as a fracture. 
Figure 18-5
Ossification of the medial epicondyle.
 
A: The concentric oval nucleus of ossification of the medial epicondylar apophysis (arrow). B: As ossification progresses, parallel smooth sclerotic margins develop in each side of the physis. C: Because it is somewhat posterior, on a slightly oblique anteroposterior view the apophysis may be hidden behind the distal metaphysis. D: The posterior location of the apophysis (arrow) is appreciated on this slightly oblique lateral view. E: On the anteroposterior view, the line created by the overlapping of the metaphysis (arrow) can be misinterpreted as a fracture line (pseudofracture).
A: The concentric oval nucleus of ossification of the medial epicondylar apophysis (arrow). B: As ossification progresses, parallel smooth sclerotic margins develop in each side of the physis. C: Because it is somewhat posterior, on a slightly oblique anteroposterior view the apophysis may be hidden behind the distal metaphysis. D: The posterior location of the apophysis (arrow) is appreciated on this slightly oblique lateral view. E: On the anteroposterior view, the line created by the overlapping of the metaphysis (arrow) can be misinterpreted as a fracture line (pseudofracture).
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Figure 18-5
Ossification of the medial epicondyle.
A: The concentric oval nucleus of ossification of the medial epicondylar apophysis (arrow). B: As ossification progresses, parallel smooth sclerotic margins develop in each side of the physis. C: Because it is somewhat posterior, on a slightly oblique anteroposterior view the apophysis may be hidden behind the distal metaphysis. D: The posterior location of the apophysis (arrow) is appreciated on this slightly oblique lateral view. E: On the anteroposterior view, the line created by the overlapping of the metaphysis (arrow) can be misinterpreted as a fracture line (pseudofracture).
A: The concentric oval nucleus of ossification of the medial epicondylar apophysis (arrow). B: As ossification progresses, parallel smooth sclerotic margins develop in each side of the physis. C: Because it is somewhat posterior, on a slightly oblique anteroposterior view the apophysis may be hidden behind the distal metaphysis. D: The posterior location of the apophysis (arrow) is appreciated on this slightly oblique lateral view. E: On the anteroposterior view, the line created by the overlapping of the metaphysis (arrow) can be misinterpreted as a fracture line (pseudofracture).
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Superficially the flexor–pronator mass, which includes the origin of the flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis, palmaris longus, and part of the pronator teres, originates from the anterior aspect of the medial epicondylar apophysis (Fig. 18-6).160 Part of the flexor carpi ulnaris also originates on the posterior aspect of the epicondyle. Deep to these muscular insertions, the medial ulnar collateral ligament originates from the medial epicondyle. In younger children, some of the capsule's origin extends up to the physeal line of the epicondyle. In older children and adolescents, as the epicondyle migrates more proximally, the capsule is attached only to the medial crista of the trochlea.12 Thus, in older children, if there is a pure muscular avulsion force on the epicondyle, the capsule and part of the medial ligamentous complex may remain attached to the trochlea's outer border and relative elbow stability preserved. However if the medial epicondyle is avulsed via the medial ulnar collateral ligament, given the importance of this ligament in elbow stability, relative elbow instability usually results. 
Figure 18-6
Soft tissue attachments.
 
The AP view of the distal humerus demonstrates the relationship of the apophysis to the origins of the medial forearm muscles. The origin of the ulnar collateral ligament lies outside the elbow capsule. The margin of the capsule is outlined by the dotted line.
The AP view of the distal humerus demonstrates the relationship of the apophysis to the origins of the medial forearm muscles. The origin of the ulnar collateral ligament lies outside the elbow capsule. The margin of the capsule is outlined by the dotted line.
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Figure 18-6
Soft tissue attachments.
The AP view of the distal humerus demonstrates the relationship of the apophysis to the origins of the medial forearm muscles. The origin of the ulnar collateral ligament lies outside the elbow capsule. The margin of the capsule is outlined by the dotted line.
The AP view of the distal humerus demonstrates the relationship of the apophysis to the origins of the medial forearm muscles. The origin of the ulnar collateral ligament lies outside the elbow capsule. The margin of the capsule is outlined by the dotted line.
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In general, flexion and supination are usually regarded as positions of stability, whereas extension and pronation are positions of relative instability (Fig. 18-7). 
Figure 18-7
Assessment of elbow stability based on forearm rotation.
 
Following closed reduction of a posterior elbow dislocation in a 15-year old, stability was assessed. With the forearm in mild pronation, note the significant medial joint space opening (arrow) with only mild valgus stress. With the forearm slightly supinated a concentric elbow reduction was maintained through a greater range of motion. Stability should be assessed on an individual case by case basis.
Following closed reduction of a posterior elbow dislocation in a 15-year old, stability was assessed. With the forearm in mild pronation, note the significant medial joint space opening (arrow) with only mild valgus stress. With the forearm slightly supinated a concentric elbow reduction was maintained through a greater range of motion. Stability should be assessed on an individual case by case basis.
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Figure 18-7
Assessment of elbow stability based on forearm rotation.
Following closed reduction of a posterior elbow dislocation in a 15-year old, stability was assessed. With the forearm in mild pronation, note the significant medial joint space opening (arrow) with only mild valgus stress. With the forearm slightly supinated a concentric elbow reduction was maintained through a greater range of motion. Stability should be assessed on an individual case by case basis.
Following closed reduction of a posterior elbow dislocation in a 15-year old, stability was assessed. With the forearm in mild pronation, note the significant medial joint space opening (arrow) with only mild valgus stress. With the forearm slightly supinated a concentric elbow reduction was maintained through a greater range of motion. Stability should be assessed on an individual case by case basis.
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Classification of Elbow Dislocations and Medial Epicondyle Fractures

Elbow dislocations are described by the position of the proximal radioulnar joint relative to the distal humerus: Posterior, anterior, medial, or lateral. Posterior dislocations are typically further subdivided into posterolateral and posteromedial injuries. Occasionally, the proximal radioulnar joint is disrupted. When this happens, the radius and ulna can diverge from each other. Rarely, the radius and ulna translocate, with the radius medial and the ulna lateral. Isolated dislocations of the radial head must be differentiated from congenital dislocations. Isolated dislocations of the proximal ulna are exceedingly rare and have not been reported in children. Included in this chapter is a discussion of the commonly occurring subluxation of the radial head, or “nursemaid's elbow.” This is not a true subluxation but rather a partial entrapment of the annular ligament in the radiocapitellar joint. Monteggia fracture dislocations are discussed in detail in Chapter 14

Posterior Elbow Dislocations
Assessment of Posterior Elbow Dislocations

Mechanisms of Injury for Posterior Elbow Dislocations

O'Driscoll et al.125 have proposed that most posterior elbow dislocations begin with disruption of the lateral ligaments and proceed along the anterior capsular structures to the medial ligaments. Although this is likely the mechanism for the more rarely seen posteromedial elbow dislocation, for the more common posterior and posterolateral elbow dislocations, this notion has been challenged. Clinical and magnetic resonance imaging (MRI)-based studies noting that medial ulnar collateral ligament injuries occur more frequently than lateral ulnar collateral injuries,76,77,79,144 have led to the competing theory144 that most posterior elbow dislocations initiate from a valgus force at the elbow leading to failure of the medial ulnar collateral ligament or the medial epicondyle apophysis, to which it is attached, creating a medial epicondyle fracture. As the proximal radius and ulna displace laterally, the coronoid disengages with the intact biceps tendon acting as the center of rotation for the displaced forearm (Fig. 18-8). Application of both an abduction and an extension force leads to forearm external rotation and, with anterior soft tissue disruption, the result is a posterior or posterolateral elbow dislocation.125,144 
Figure 18-8
Mechanism of injury producing a posterior elbow dislocation.
 
A: The elbow is forced into extension that ruptures the medial collateral ligaments. The normal valgus alignment of the elbow accentuates the valgus force at the elbow. B: The lateral slope of the medial crista of the trochlea forces the proximal ulna posterolaterally (small arrow). The biceps tendon serves as a fulcrum for rotation (medium arrow) leading to valgus hinging (large arrow) of the forearm. C: The proximal ulna and radius are then impacted posteriorly and held against the distal articular surface by the contraction of the biceps and triceps (arrows).
A: The elbow is forced into extension that ruptures the medial collateral ligaments. The normal valgus alignment of the elbow accentuates the valgus force at the elbow. B: The lateral slope of the medial crista of the trochlea forces the proximal ulna posterolaterally (small arrow). The biceps tendon serves as a fulcrum for rotation (medium arrow) leading to valgus hinging (large arrow) of the forearm. C: The proximal ulna and radius are then impacted posteriorly and held against the distal articular surface by the contraction of the biceps and triceps (arrows).
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Figure 18-8
Mechanism of injury producing a posterior elbow dislocation.
A: The elbow is forced into extension that ruptures the medial collateral ligaments. The normal valgus alignment of the elbow accentuates the valgus force at the elbow. B: The lateral slope of the medial crista of the trochlea forces the proximal ulna posterolaterally (small arrow). The biceps tendon serves as a fulcrum for rotation (medium arrow) leading to valgus hinging (large arrow) of the forearm. C: The proximal ulna and radius are then impacted posteriorly and held against the distal articular surface by the contraction of the biceps and triceps (arrows).
A: The elbow is forced into extension that ruptures the medial collateral ligaments. The normal valgus alignment of the elbow accentuates the valgus force at the elbow. B: The lateral slope of the medial crista of the trochlea forces the proximal ulna posterolaterally (small arrow). The biceps tendon serves as a fulcrum for rotation (medium arrow) leading to valgus hinging (large arrow) of the forearm. C: The proximal ulna and radius are then impacted posteriorly and held against the distal articular surface by the contraction of the biceps and triceps (arrows).
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Associated Injuries with Posterior Elbow Dislocations

Fractures Associated with Posterior Elbow Dislocations

Concomitant fractures occur in over one-half of posterior elbow dislocations.90,121,147,150 The most common fractures involve the medial epicondyle, the coronoid process, and the radial head and the neck. Fractures involving the lateral epicondyle, lateral condyle, olecranon, capitellum, and trochlea occur less frequently.25 Given the significant association between fractures of the medial epicondyle, the coronoid process and the proximal radius (especially markedly displaced radial neck fractures), and posterior elbow dislocations, evaluating for elbow stability when these fractures are noted is important. 

Soft Tissue Injuries Associated with Posterior Elbow Dislocations

Posterior dislocations normally produce moderate soft tissue injury and can be associated with neurovascular injuries in addition to concomitant fractures (Fig. 18-9). The anterior capsule fails in tension, opening the joint cavity. Radial head displacement strips the capsule from the posterolateral aspect of the lateral condyle with the adjacent periosteum. Because of the large amount of cartilage on the posterolateral aspect of the lateral condyle, the posterior capsule may not reattach firmly with healing. This lack of a strong reattachment is believed to be a factor in the rare recurrent elbow dislocation.126 In a series of 62 adults and adolescents with elbow dislocations requiring surgical treatment, McKee et al.111 reported that disruption of the lateral collateral ligament complex occurred in all 62 elbows. 
Figure 18-9
Injuries associated with elbow dislocation.
 
(1)The radial head and olecranon are displaced posterolaterally. (2)The brachialis muscle is stretched across the articular surface of the distal humerus. (3)The origins of the medial forearm flexion muscles are either torn or avulsed with the medial epicondyle from the medial condyle. (4)The median nerve and brachial artery are stretched across the medial condyle and held firmly by the lacertus fibrosus. (5)The medial condyle lies in the subcutaneous tissue between the brachialis anteriorly and the pronator teres posteriorly. (6)The lateral (radial) collateral ligaments often avulse a piece of cartilage or bone from the lateral condyle.
(1)The radial head and olecranon are displaced posterolaterally. (2)The brachialis muscle is stretched across the articular surface of the distal humerus. (3)The origins of the medial forearm flexion muscles are either torn or avulsed with the medial epicondyle from the medial condyle. (4)The median nerve and brachial artery are stretched across the medial condyle and held firmly by the lacertus fibrosus. (5)The medial condyle lies in the subcutaneous tissue between the brachialis anteriorly and the pronator teres posteriorly. (6)The lateral (radial) collateral ligaments often avulse a piece of cartilage or bone from the lateral condyle.
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Figure 18-9
Injuries associated with elbow dislocation.
(1)The radial head and olecranon are displaced posterolaterally. (2)The brachialis muscle is stretched across the articular surface of the distal humerus. (3)The origins of the medial forearm flexion muscles are either torn or avulsed with the medial epicondyle from the medial condyle. (4)The median nerve and brachial artery are stretched across the medial condyle and held firmly by the lacertus fibrosus. (5)The medial condyle lies in the subcutaneous tissue between the brachialis anteriorly and the pronator teres posteriorly. (6)The lateral (radial) collateral ligaments often avulse a piece of cartilage or bone from the lateral condyle.
(1)The radial head and olecranon are displaced posterolaterally. (2)The brachialis muscle is stretched across the articular surface of the distal humerus. (3)The origins of the medial forearm flexion muscles are either torn or avulsed with the medial epicondyle from the medial condyle. (4)The median nerve and brachial artery are stretched across the medial condyle and held firmly by the lacertus fibrosus. (5)The medial condyle lies in the subcutaneous tissue between the brachialis anteriorly and the pronator teres posteriorly. (6)The lateral (radial) collateral ligaments often avulse a piece of cartilage or bone from the lateral condyle.
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Medially, the ulnar collateral ligament complex is disrupted either by an avulsion of the medial epicondyle or a direct tear of the ligament.157,165 Cromack30 found that with medial epicondylar fractures, the origins of the ulnar collateral ligaments and the medial forearm flexor muscles remain as a unit, along with most of the pronator teres, which is stripped from its humeral origin proximal to the epicondyle. These structures are then displaced posterior to the medial aspect of the distal humerus. The ulnar collateral ligaments and the muscular origins of the common flexor muscles tear if the epicondyle remains attached to the humerus. With posterolateral displacement of the forearm, the medial aspect of the distal humerus most often passes into the intermuscular space between the pronator teres posteriorly and the brachialis anteriorly. The brachialis, because it has little distal tendon, is easily ruptured. The rent in the anterior capsule usually is in this same area. 
The structure most commonly torn on the lateral aspect of the elbow is the annular ligament.165 On occasion, the lateral collateral ligament either avulses a small osteochondral fragment from the lateral epicondyle or tears completely within its substance. 

Neurovascular Injuries Associated with Posterior Elbow Dislocations

When the elbow is dislocated, the medial aspect of the distal humerus typically protrudes between the pronator teres posteriorly and the brachialis anteriorly. The median nerve and brachial artery lie directly over the distal humerus in the subcutaneous tissues. In a cadaver and clinical study by Louis et al.,94 there was a consistent pattern of disruption of the anastomosis between the inferior ulnar collateral artery and the anterior ulnar recurrent artery. If the main brachial arterial trunk also is compromised, the loss of this collateral system can result in the loss of circulation to the forearm and hand. 
The ulnar nerve is at risk in posterior elbow dislocation because of its position posterior to the medial epicondyle. In clinical cases, the ulnar nerve is the most common neurovascular injury. 

Signs and Symptoms of Posterior Elbow Dislocations

Posterior elbow dislocations must be differentiated from extension-type supracondylar fractures of the distal humerus. With both injuries, the elbow is held semiflexed and swelling may be considerable. Swelling initially is usually less with a dislocation than with a type III supracondylar humeral fracture. Crepitus is usually absent in children with a dislocation and the forearm appears shortened. The prominence produced by the distal humeral articular surface is more distal and is palpable as a blunt articular surface. The tip of the olecranon is displaced posteriorly and proximally so that its triangular relationship with the epicondyles is lost. The skin may have a dimpled appearance over the olecranon fossa. If the dislocation is posterolateral, the radial head also may be prominent and easily palpable in the subcutaneous tissues. 

Imaging and Other Diagnostic Studies for Posterior Elbow Dislocations

Anteroposterior (AP) and lateral x-rays usually are diagnostic of a posterior elbow dislocation. There is a greater superimposition of the distal humerus on the proximal radius and ulna in the AP view. The radial head may be proximally and laterally displaced, or it may be directly behind the middistal humerus, depending on whether the dislocation is posterolateral, posterior, or posteromedial (Fig. 18-10). The normal valgus angulation between the forearm and the arm usually is increased. On the lateral view, the coronoid process lies posterior to the condyles. Prereduction and postreduction x-rays must be examined closely for associated fractures. The medial epicondyle should be identified on the postreduction films. If it should be present based on the patient's age and elbow ossification pattern and it is not visible, the medial epicondyle is likely fractured and may be entrapped in the joint. Additional radiographs may be necessary to further evaluate an associated medial epicondyle fracture. Postreduction radiographs should be carefully scrutinized for a congruent reduction and for subtle osteochondral fracture fragments that can become entrapped in the joint (Fig. 18-11). If anatomic, congruent reduction is in question or not feasible or if osteochondral fragments are visualized, further evaluation with computerized tomography or MRI is utilized. MRI may be used to further define the extent of soft tissue injury in complex injury patterns. 
Figure 18-10
Radiographic findings.
 
A: Anteroposterior radiograph. The radial head is superimposed behind the distal humerus. There is increased cubitus valgus. The medial epicondyle has not been avulsed. B: Lateral radiograph demonstrating that the proximal radius and ulna are both displaced posteriorly to the distal humerus.
A: Anteroposterior radiograph. The radial head is superimposed behind the distal humerus. There is increased cubitus valgus. The medial epicondyle has not been avulsed. B: Lateral radiograph demonstrating that the proximal radius and ulna are both displaced posteriorly to the distal humerus.
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Figure 18-10
Radiographic findings.
A: Anteroposterior radiograph. The radial head is superimposed behind the distal humerus. There is increased cubitus valgus. The medial epicondyle has not been avulsed. B: Lateral radiograph demonstrating that the proximal radius and ulna are both displaced posteriorly to the distal humerus.
A: Anteroposterior radiograph. The radial head is superimposed behind the distal humerus. There is increased cubitus valgus. The medial epicondyle has not been avulsed. B: Lateral radiograph demonstrating that the proximal radius and ulna are both displaced posteriorly to the distal humerus.
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Figure 18-11
Intra-articular entrapment of osteochondral fragments following closed reduction of a posterior elbow dislocation.
 
A: A 15-year-old female presented with a posterior elbow dislocation. B: Following successful closed reduction, fluoroscopic images suggested an entrapped intra-articular osteochondral fragment (arrow). This was confirmed with a CT scan. She subsequently underwent early open removal of these fragments via a medial approach. Significant damage was noted to the brachialis musculature.
A: A 15-year-old female presented with a posterior elbow dislocation. B: Following successful closed reduction, fluoroscopic images suggested an entrapped intra-articular osteochondral fragment (arrow). This was confirmed with a CT scan. She subsequently underwent early open removal of these fragments via a medial approach. Significant damage was noted to the brachialis musculature.
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Figure 18-11
Intra-articular entrapment of osteochondral fragments following closed reduction of a posterior elbow dislocation.
A: A 15-year-old female presented with a posterior elbow dislocation. B: Following successful closed reduction, fluoroscopic images suggested an entrapped intra-articular osteochondral fragment (arrow). This was confirmed with a CT scan. She subsequently underwent early open removal of these fragments via a medial approach. Significant damage was noted to the brachialis musculature.
A: A 15-year-old female presented with a posterior elbow dislocation. B: Following successful closed reduction, fluoroscopic images suggested an entrapped intra-articular osteochondral fragment (arrow). This was confirmed with a CT scan. She subsequently underwent early open removal of these fragments via a medial approach. Significant damage was noted to the brachialis musculature.
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Treatment Options for Posterior Elbow Dislocations

If untreated, elbow dislocation predictably results in dramatic loss of elbow function characterized by loss of motion and eventually pain (Fig. 18-12). In comparison, reduction of the dislocated elbow usually achieves marked improvement of acute pain as well as restoration of long-term function. 
Figure 18-12
Unreduced dislocation.
 
A: Preoperative anteroposterior radiograph. The elbow sustained an injury 3 years before surgery. Elbow motion was extremely limited and painful. The lateral supracondylar ridge had been eroded by the radial head (arrow). B: Lateral radiograph. The posterior position of the olecranon is apparent. C: Anteroposterior radiograph 3 months postoperatively. Total elbow motion was 30 degrees, but there was less pain and more stability.
A: Preoperative anteroposterior radiograph. The elbow sustained an injury 3 years before surgery. Elbow motion was extremely limited and painful. The lateral supracondylar ridge had been eroded by the radial head (arrow). B: Lateral radiograph. The posterior position of the olecranon is apparent. C: Anteroposterior radiograph 3 months postoperatively. Total elbow motion was 30 degrees, but there was less pain and more stability.
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Figure 18-12
Unreduced dislocation.
A: Preoperative anteroposterior radiograph. The elbow sustained an injury 3 years before surgery. Elbow motion was extremely limited and painful. The lateral supracondylar ridge had been eroded by the radial head (arrow). B: Lateral radiograph. The posterior position of the olecranon is apparent. C: Anteroposterior radiograph 3 months postoperatively. Total elbow motion was 30 degrees, but there was less pain and more stability.
A: Preoperative anteroposterior radiograph. The elbow sustained an injury 3 years before surgery. Elbow motion was extremely limited and painful. The lateral supracondylar ridge had been eroded by the radial head (arrow). B: Lateral radiograph. The posterior position of the olecranon is apparent. C: Anteroposterior radiograph 3 months postoperatively. Total elbow motion was 30 degrees, but there was less pain and more stability.
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Nonoperative Treatment of Posterior Elbow Dislocations

Indications/Contraindications

Progressive elbow swelling secondary to the soft tissue injury associated with an elbow dislocation makes it imperative that all acute elbow dislocations be promptly reduced under adequate sedation or anesthesia. Royle150 found that dislocations reduced soon after the injury had better outcomes than those in which reduction was delayed. Immediately after reduction, the surgeon should determine and document the stability of the elbow by examination under anesthesia or sedation. Definitive nonoperative treatment following closed reduction can be considered if the elbow is stable through a functional range of motion, a concentric anatomic reduction can be obtained and maintained, and there is no evidence to suggest a vascular injury, nerve entrapment, or significant intra-articular osteochondral fragments (Table 18-1). 
 
Table 18-1
Posterior Elbow Dislocation
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Table 18-1
Posterior Elbow Dislocation
Nonoperative Treatment Following Successful Closed Reduction
Indications Relative Contraindications
Stable concentric elbow reduction obtained following closed treatment Unable to obtain a concentric and stable elbow reduction
Intra-articular entrapment of fracture fragments
Vascular injury
Change in neurologic status following reduction or other indication of nerve entrapment
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Techniques for Closed Reduction of Posterior Elbow Dislocations

All methods of closed reduction must overcome the deforming muscle forces so that the coronoid process and the radial head can slip past the distal end of the humerus. Adequate sedation or anesthesia is necessary to permit muscle relaxation. Before the primary reduction forces are applied, the forearm is hypersupinated to dislodge the coronoid process and radial head from their position behind the distal humerus and to reduce tension on the biceps tendon.126 The reducing forces are applied in two major directions (Fig. 18-13). The first reducing force must be along the long axis of the humerus to overcome the contractions of the biceps and brachialis anteriorly and the triceps posteriorly. Once these forces are neutralized, the proximal ulna and radius must be passed from posterior to anterior. Combined pusher–puller techniques are also possible.59,183 
Figure 18-13
Forces required to reduce posterior elbow dislocations.
 
A: The forearm is hypersupinated (arrow 1) to unlock the radial head. B: Simultaneous forces are applied to the proximal forearm along the axis of the humerus (arrow 2) and distally along the axis of the forearm (arrow 3). C: The elbow is then flexed (arrow 4) to stabilize the reduction once the coronoid is manipulated distal to the humerus.
A: The forearm is hypersupinated (arrow 1) to unlock the radial head. B: Simultaneous forces are applied to the proximal forearm along the axis of the humerus (arrow 2) and distally along the axis of the forearm (arrow 3). C: The elbow is then flexed (arrow 4) to stabilize the reduction once the coronoid is manipulated distal to the humerus.
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Figure 18-13
Forces required to reduce posterior elbow dislocations.
A: The forearm is hypersupinated (arrow 1) to unlock the radial head. B: Simultaneous forces are applied to the proximal forearm along the axis of the humerus (arrow 2) and distally along the axis of the forearm (arrow 3). C: The elbow is then flexed (arrow 4) to stabilize the reduction once the coronoid is manipulated distal to the humerus.
A: The forearm is hypersupinated (arrow 1) to unlock the radial head. B: Simultaneous forces are applied to the proximal forearm along the axis of the humerus (arrow 2) and distally along the axis of the forearm (arrow 3). C: The elbow is then flexed (arrow 4) to stabilize the reduction once the coronoid is manipulated distal to the humerus.
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Previous authors90,183 have strongly advised against initial hyperextension before reduction forces are applied to the elbow. Loomis91 demonstrated that when the coronoid process is locked against the posterior aspect of the humerus and the elbow is extended, the force applied to the anterior muscles is multiplied by as much as five times because of the increased leverage. This places a marked strain on the injured structures in the antecubital fossa including the anterior capsule, the brachialis muscle, and the neurovascular structures (Fig. 18-14). By contrast, when force is applied to the proximal forearm with the elbow flexed, the force exerted against the muscles across the elbow is equal to the distracting force. For patients with posterolateral dislocations, the lateral displacement of the proximal radius and ulna must first be corrected to prevent the median nerve from being entrapped or injured during reduction.18,22 Hyperextension reduction puts the median nerve more at risk for entrapment. 
Figure 18-14
Hyperextension forces.
 
A: The brachialis is stretched across the distal humerus. B: Hyperextending the elbow before it is reduced greatly increases the arc of motion and leverage placed across the brachialis. This can result in rupture of large portions of the muscle.
 
(Reprinted from Loomis LK. Reduction and after-treatment of posterior dislocation of the elbow. Am J Surg. 1944; 63:56–60, with permission.)
A: The brachialis is stretched across the distal humerus. B: Hyperextending the elbow before it is reduced greatly increases the arc of motion and leverage placed across the brachialis. This can result in rupture of large portions of the muscle.
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Figure 18-14
Hyperextension forces.
A: The brachialis is stretched across the distal humerus. B: Hyperextending the elbow before it is reduced greatly increases the arc of motion and leverage placed across the brachialis. This can result in rupture of large portions of the muscle.
(Reprinted from Loomis LK. Reduction and after-treatment of posterior dislocation of the elbow. Am J Surg. 1944; 63:56–60, with permission.)
A: The brachialis is stretched across the distal humerus. B: Hyperextending the elbow before it is reduced greatly increases the arc of motion and leverage placed across the brachialis. This can result in rupture of large portions of the muscle.
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Closed Reduction of a Posterior Elbow Dislocation by the “Puller” Technique

The puller technique can be performed in various positions including the supine position and the prone position. 
Prereduction Planning
If adequate sedation to achieve full muscular relaxation cannot be achieved in the emergency department, the procedure should be performed in the operating room under general anesthesia. An assistant who can provide adequate stabilizing force is required. Use of fluoroscopy is not usually required to assess the reduction. However, if available, it can help assess elbow stability and provide a more dynamic assessment of reduction congruity that postreduction plain radiographs, especially those obtained following placement of immobilization, cannot provide (Table 18-2). 
Table 18-2
Closed Reduction of a Posterior Elbow Dislocation by the “Puller” Technique
Preprocedure Planning Checklist
  •  
    Location: Emergency room if full muscular relaxation can be obtained. If not, under general anesthesia in the operating room is preferred.
  •  
    Table: Any supportive stretcher or operating room table will suffice
  •  
    Position/positioning aids: For supine technique the patient is placed supine with the shoulder abducted 90 degrees and the elbow over the edge of the bed. For the prone technique the patient is placed prone with the shoulder abducted 90 degrees and the elbow draped over the side of the table. Proper padding of all peripheral pressure points is critical.
  •  
    Fluoroscopy location: The image intensifier is placed alongside the table on the side of elbow dislocation and arranged to assess a lateral x-ray once the elbow is reduced.
  •  
    Equipment: Postreduction immobilization supplies (cast or splint)
X
Positioning
The patient is placed on the table either in the supine or the prone position with the shoulder abducted 90 degrees and the elbow off the side of the table. An assistant is positioned on the opposite side of the patient to provide the counterforce. A sheet can be placed around the patient for stabilization purposes if desired. If this is done an additional assistant may be required to stabilize the upper arm during the reduction. 
Technique
With the elbow flexed to almost 90 degrees, a traction force is applied to the anterior portion of the forearm along the longitudinal axis of the humerus with one hand while the other hand pulls distally along the forearm. If any medial or lateral displacement is present, this should be corrected before the forearm is translated distally to release soft tissue structures from the distal humerus and prevent entrapment of tissue around the distal humerus. Gently “milking” the anterior soft tissue out from around the distal humerus, by gently pinching and pulling the tissues enveloping the distal humerus forward, as the reduction is performed can also help the reduction. During the procedure, a counterforce is applied by an assistant to offset the manipulating forces and stabilize the humerus. The physician performing the procedure usually appreciates a palpable clunk of the reduction. Using fluoroscopic evaluation, if available, the reduction is assessed in multiple projections. The range of stable motion is assessed, noting stability with the forearm in full supination and in neutral rotation (Table 18-3). 
Table 18-3
Closed Reduction of a Posterior Elbow Dislocation by the “Puller” Technique
Technical Steps
  •  
    Ensure adequate sedation with near-complete muscular relaxation
  •  
    Have assistant to stabilize the body and the humerus
  •  
    Flex the elbow to about 90 degrees
  •  
    “Milk” the distal humerus out of anterior soft tissues
  •  
    Apply force on the anterior forearm in line with the humeral shaft
  •  
    Correct any medial or lateral displacement
  •  
    Apply a distally directed force in line with the forearm to reduce the elbow joint
  •  
    Check the elbow reduction with static and dynamic fluoroscopic evaluation
  •  
    Assess elbow stability
  •  
    Immobilize elbow in about 90 degrees of flexion
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Closed Reduction of a Posterior Elbow Dislocation by the “Pusher” Technique

Like the puller technique, the pusher technique can be performed in various positions. 
Prereduction Planning
Again, like the pusher technique, adequate sedation is required and fluoroscopy can be helpful for postreduction evaluation (Table 18-4). 
Table 18-4
Closed Reduction of a Posterior Elbow Dislocation by the “Pusher” Technique
Preprocedure Planning Checklist
  •  
    Location: Emergency room if full muscular relaxation can be obtained. If not, under general anesthesia in the operating room is preferred.
  •  
    Table: Any supportive stretcher or operating room table will suffice. The patient can even be supported in the arms of a parent or an assistant.
  •  
    Position/positioning aids: For Lavine's method (Fig. 18-18A
     
    ), the child is held by the parent while the elbow is draped over the edge of the chair. The back of the chair must be well padded. For Meyn's technique (Fig. 18-18B
     
    ), the patient is placed prone with the shoulder abducted 90 degrees and the elbow draped over the side of the table. Proper padding of all peripheral pressure points is critical.
  •  
    Fluoroscopy location: The image intensifier is placed alongside the table on the side of elbow dislocation and arranged to assess a lateral x-ray once the elbow is reduced.
  •  
    Equipment: Post reduction immobilization supplies (cast or splint)
X
Positioning
The patient is positioned with the distal humerus over a fixed surface, either the back of a chair or the edge of the bed. 
Technique
With the elbow flexed to almost 90 degrees, the thumb is used to push the olecranon distally past the humerus. The other arm then pulls distally along the axis of the forearm affecting the reduction. Again, if any medial or lateral displacement is present, this should be corrected before the forearm is translated distally. Fluoroscopic evaluation, if available, can then be performed as with the puller technique. Elbow stability should be assessed and the elbow then immobilized in a position of stability (Table 18-5). 
Table 18-5
Closed Reduction of a Posterior Elbow Dislocation by the “Pusher” Technique
Technical Steps
  •  
    Ensure adequate sedation with near-complete muscular relaxation
  •  
    Have assistant to stabilize the body and the humerus over the edge of a fixed surface
  •  
    Flex the elbow to about 90 degrees
  •  
    “Milk” the distal humerus out of anterior soft tissues
  •  
    Using the thumb, apply force on the prominent olecranon translating it distally in line with the humeral shaft
  •  
    Correct any medial or lateral displacement
  •  
    Apply a distally directed force in line with the forearm with the other hand to reduce the elbow joint
  •  
    Check the elbow reduction with static and dynamic fluoroscopic evaluation
  •  
    Assess elbow stability
  •  
    Immobilize elbow in about 90 degrees of flexion
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Postreduction Care Following Closed Reduction of a Posterior Elbow Dislocation

Some type of immobilization, usually a posterior splint, is advocated by most investigators. A frequently recommended period of immobilization is 3 weeks,90,91,130,158 although some have advocated early motion.149,150,191 In a recent study of 42 adult patients comparing 2 weeks of cast immobilization with the use of a simple arm sling and early motion, Maripuri et al.106 demonstrated improved early and final functional outcomes in the early mobilization group compared to the group placed in a cast following reduction. O'Driscoll et al.125 suggested that if the elbow was stable in response to valgus stress with the forearm pronated then the anterior portion of the medial collateral ligament was intact and the patient could begin early motion. Ninety degrees of elbow flexion appears to be the standard position of immobilization. Hinged elbow braces with adjustable blocks to motion are very useful for obtaining progressive, protected motion. 

Posterior Elbow Dislocation Outcomes

Closed reduction of posterior elbow dislocations is successful in most cases. In the combined series of 317 dislocations,90,121,147,150 only two cases90 could not be reduced by closed methods. In the Carlioz and Abols25 series, two dislocations reduced spontaneously and closed reduction was successful in 50 cases, but failed in six cases (10%). Josefsson et al.78 reported that all 25 dislocations without associated fractures were successfully reduced. 

Operative Treatment of Posterior Elbow Dislocations

Indications/Contraindications

Indications for primary open reduction include an inability to obtain or maintain a concentric closed reduction, an open dislocation, a displaced osteochondral fracture with entrapment in the joint, a vascular injury, or a neurologic injury for which there is any indication that there may be entrapment of the nerve. 
Primary ligament repair is not routinely indicated. Adults with posterior elbow dislocations without concomitant fracture have no better function or stability following a primary ligamentous repair than those treated nonoperatively.76,77 All fractures preventing concentric reduction need to be repaired with an open reduction of an elbow dislocation. Beware of elbow dislocations in children less than age 10 as they often have associated osteochondral fractures blocking reduction or preventing stability postreduction (Table 18-6). 
 
Table 18-6
Posterior Elbow Dislocation
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Table 18-6
Posterior Elbow Dislocation
Operative Treatment
Indications Contraindications
Unable to obtain a concentric and stable elbow reduction Stable concentric elbow reduction obtained following closed treatment
Intra-articular entrapment of fracture fragments
Vascular injury
Change in neurologic status following reduction or other indication of nerve entrapment
X
Open Posterior Elbow Dislocations
Open dislocations have a high incidence of associated arterial injury.63,82,90,94 Operative intervention is necessary in open posterior dislocations to irrigate and debride the open wound and elbow and to evaluate the brachial artery. If there is vascular disruption, most advocate vascular repair or reconstruction with a vein graft even in the presence of adequate capillary refill. This may lessen the risk of late cold intolerance, dysesthesias, or dysvascularity. 
Fractures Associated with Posterior Elbow Dislocations
Children with an elbow dislocation can have an associated fracture of the coronoid, lateral condyle, olecranon (Fig. 18-15), radial neck, or medial epicondyle (Fig. 18-16). Fractures of the anteromedial facet of the coronoid have been recognized as an important injury associated with elbow dislocations in adolescents and adults.35,36 The presence of a concomitant displaced fracture is a common indication for surgical intervention.25,46,185 Surgery for associated fractures produced better results than nonoperative treatment in the series of Carlioz and Abols,25 and similar results were reported by Wheeler and Linscheid.185 Repair of an associated medial epicondylar fracture may also improve elbow stability in throwing athletes when the injury is in the dominant arm.157,191 Entrapment of any fracture fragments within the joint is an absolute indication for surgical treatment. Displaced medial epicondyle fractures can be entrapped within the joint after reduction and are often overlooked on the radiographs (Fig. 18-20). Because of the high association of this fracture with elbow dislocations, the location of the medial epicondyle should be confirmed in every case. Ultimately, the surgical treatment for fractures associated with an elbow dislocation is based on the circumstances surrounding each individual patient. Factors favoring operative treatment include older patient age, instability of the elbow during examination under sedation at the time of reduction, the presence of a displaced intra-articular fracture, injury to multiple elbow stabilizers, injury to the patient's dominant arm, and anticipated high-demand sports, especially overhead sports, or activities on the elbow. 
Figure 18-15
Lateral radiograph of a 4-year-old child who sustained an elbow dislocation with a concomitant olecranon fracture (large arrow) and a coronoid fracture (small arrow).
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Figure 18-16
 
A: Anteroposterior and lateral radiograph of a 14-year-old male who sustained an elbow dislocation with an ipsilateral medial epicondyle fracture. B: Anteroposterior radiographs after a closed reduction. Note the entrapment of the medial epicondyle in the joint. C: This patient was treated with an open reduction to extract the medial epicondyle from the joint and an internal fixation using a cannulated screw that allowed rapid mobilization of his elbow.
A: Anteroposterior and lateral radiograph of a 14-year-old male who sustained an elbow dislocation with an ipsilateral medial epicondyle fracture. B: Anteroposterior radiographs after a closed reduction. Note the entrapment of the medial epicondyle in the joint. C: This patient was treated with an open reduction to extract the medial epicondyle from the joint and an internal fixation using a cannulated screw that allowed rapid mobilization of his elbow.
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Figure 18-16
A: Anteroposterior and lateral radiograph of a 14-year-old male who sustained an elbow dislocation with an ipsilateral medial epicondyle fracture. B: Anteroposterior radiographs after a closed reduction. Note the entrapment of the medial epicondyle in the joint. C: This patient was treated with an open reduction to extract the medial epicondyle from the joint and an internal fixation using a cannulated screw that allowed rapid mobilization of his elbow.
A: Anteroposterior and lateral radiograph of a 14-year-old male who sustained an elbow dislocation with an ipsilateral medial epicondyle fracture. B: Anteroposterior radiographs after a closed reduction. Note the entrapment of the medial epicondyle in the joint. C: This patient was treated with an open reduction to extract the medial epicondyle from the joint and an internal fixation using a cannulated screw that allowed rapid mobilization of his elbow.
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Figure 18-20
Closed reduction.
 
A: Anteroposterior radiograph of a 9-year-old girl with a posterior dislocation of the right elbow. B: Lateral radiograph shows the proximal radius and ulna posterior to the distal humerus. C: There is a concentric reduction following closed reduction using a puller technique. D: Lateral radiograph.
A: Anteroposterior radiograph of a 9-year-old girl with a posterior dislocation of the right elbow. B: Lateral radiograph shows the proximal radius and ulna posterior to the distal humerus. C: There is a concentric reduction following closed reduction using a puller technique. D: Lateral radiograph.
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A: Anteroposterior radiograph of a 9-year-old girl with a posterior dislocation of the right elbow. B: Lateral radiograph shows the proximal radius and ulna posterior to the distal humerus. C: There is a concentric reduction following closed reduction using a puller technique. D: Lateral radiograph.
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Figure 18-20
Closed reduction.
A: Anteroposterior radiograph of a 9-year-old girl with a posterior dislocation of the right elbow. B: Lateral radiograph shows the proximal radius and ulna posterior to the distal humerus. C: There is a concentric reduction following closed reduction using a puller technique. D: Lateral radiograph.
A: Anteroposterior radiograph of a 9-year-old girl with a posterior dislocation of the right elbow. B: Lateral radiograph shows the proximal radius and ulna posterior to the distal humerus. C: There is a concentric reduction following closed reduction using a puller technique. D: Lateral radiograph.
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A: Anteroposterior radiograph of a 9-year-old girl with a posterior dislocation of the right elbow. B: Lateral radiograph shows the proximal radius and ulna posterior to the distal humerus. C: There is a concentric reduction following closed reduction using a puller technique. D: Lateral radiograph.
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Vascular Injuries Associated with Posterior Elbow Dislocations
With initial evidence of vascular compromise, treatment should consist of urgent reduction of the elbow dislocation which usually returns the displaced brachial vessels to their normal position64,187 followed by reassessment of the vascular status. With prompt normalization of the vascular status, serial observation is still recommended to evaluate for evolving circulatory compromise. If there is evidence of persistent vascular compromise after reduction, vascular exploration followed by operative repair of those structures that are ruptured or severely damaged should be pursued emergently. Even though collateral vessels may provide adequate vascular flow to give a warm hand with good capillary refill, if there has been a significant vascular injury, failure to repair the injury may predispose the patient to late ischemic changes such as claudication, cold sensitivity, or even late amputation. 
Neurologic Injuries Associated with Posterior Elbow Dislocations
As with vascular injuries, initial evidence of neurologic compromise should prompt urgent reduction. A significant negative change in the neurologic status following closed reduction may indicate nerve entrapment and should prompt exploration. 

Open Reduction of an Irreducible Posterior Elbow Reduction

Preoperative Planning
The surgical approach will be dictated by the goals of the procedure and based on an estimation of the structures that may be blocking the reduction. The most common structures preventing reduction via closed means include the distal humerus being buttonholed through the brachialis musculature, the radial head being buttonholed through the capsule and lateral collateral ligament, and entrapment of fracture fragments, especially the medial epicondyle, with their attached ligamentous or muscular structures wedging them in place. If the distal humerus or the radial head is easily palpable in the subcutaneous tissues and not able to be milked out of these tissues through closed means, an operative approach to perform this will be necessary. For the distal humerus in the brachialis a medial approach should be performed. For the radial head block, a lateral approach has been described.55,84 If a fracture fragment, especially the medial epicondyle, can be visualized and is thought to be responsible for the block, the medial approach should be employed to facilitate fracture fixation (Table 18-7). Loose osteochondral fracture fragments can block a congruent reduction and computed tomography (CT) and/or MRI scanning may be required to visualize the fragments and determine operative approach. 
Table 18-7
Open Reduction of an Irreducible Posterior Elbow Dislocation
Preprocedure Planning Checklist
  •  
    Approach: Lateral approach if radial head noted to be subcutaneous indicating possible block to reduction because of buttonholing through the lateral capsule and around the lateral collateral ligaments. Medial approach if the distal humerus is noted to be subcutaneous indicating a block to reduction because of buttonholing through the brachialis or if an associated medial epicondyle fracture is present and surgical fixation is planned.
  •  
    OR Table: Any supportive operating room table will suffice
  •  
    Position/positioning aids: Supine positioning with a hand table will usually suffice. However, lateral position or even prone positioning as for fixation of a medial epicondyle fracture may be helpful.
  •  
    Fluoroscopy location: The image intensifier is placed alongside the table on the side of elbow dislocation, on the side opposite the anticipated surgical approach.
  •  
    Equipment: Loup magnification may facilitate identification of neurovascular structures in the surgical field. Bipolar electrocautery is preferred around neurovascular structures for hemostasis. A headlamp greatly facilitates visualization. Suture anchors may be employed to resecure ligamentous avulsions and should be available.
X
Positioning
Supine positioning with a hand table will usually suffice. With an associated medial epicondyle fracture, the lateral position or the prone position may be employed as well. (See the section on medial epicondyle fractures.) 
Technique for Open Reduction
For a medial approach, an incision is made just anterior to the predicted mid humeral line and curved distally just anterior the medial epicondyle. With gentle spreading of the subcutaneous tissues the significant soft tissue trauma is evident. The buttonholed distal humerus, the median and ulnar nerves, and the brachial artery should be identified. Any intervening tissue or osteochondral fragments are removed from the interval between the joint surfaces. The joint is then reduced through a similar set of distraction and translational forces as described for the closed reduction techniques. Once reduced, joint stability is evaluated and a thorough assessment of the capsular and ligamentous structures is performed. Primary repair or reattachment of the medial collateral ligament complex with small suture anchors or transosseous drill holes may be performed to improve stability. The elbow is stabilized in a posterior splint or hinged elbow brace in a position of stability (Table 18-8). 
Table 18-8
Open Reduction of an Irreducible Posterior Elbow Dislocation
Technical Steps
  •  
    Make a medially based incision just anterior to the humerus curving distally at the elbow (note that the neurovascular structures may be very subcutaneous because of the injury)
  •  
    Identify the median and ulnar nerves and the brachial artery. Protect medial antebrachial cutaneous nerves
  •  
    Remove any tissue or any other intervening structures
  •  
    Visually inspect the joint surfaces and remove any loose osteochondral fragments
  •  
    Flex the elbow to about 90 degrees
  •  
    Apply force on the forearm in line with the humerus translating it distally in line with the humeral shaft and opening the joint surface
  •  
    Correct any medial or lateral displacement
  •  
    Apply a distally directed force in line with the forearm, or directly posteriorly translate the distal humerus to reduce the elbow joint
  •  
    Check the elbow reduction with visual evaluation as well as dynamic fluoroscopic evaluation
  •  
    Assess elbow stability through range of motion
  •  
    Assess the extent of capsular and ligamentous damage and repair critical elements such as the medial ulnar collateral ligament and/or the medial epicondyle (see below separate medial epicondyle section)
  •  
    Reassess elbow stability through range of motion if repairs are performed
  •  
    Immobilize elbow in about 90 degrees of flexion
X

Postoperative Care

Immobilization after surgery depends on the procedure performed. After open reduction, management is similar to that after satisfactory closed reduction. The length of immobilization for fractures is 5 to 10 days up to 3 to 4 weeks. Protected arc of motion with a hinged brace or intermittent splinting is utilized frequently to lessen the risk of posttraumatic contracture. 

Author's Preferred Method of Treatment for Posterior Elbow Dislocations (Fig. 18-17)

Figure 18-17
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Figure 18-17
Algorithm.
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The “pusher” technique of reduction of an elbow dislocation is preferred in children 9 years of age or younger. In this age group, the child often can be seated comfortably in the parent's lap (Fig. 18-18). Hanging the arm over the back of a well-padded chair may provide some stabilization. 
Figure 18-18
Reduction by “pusher” techniques.
 
A: Lavine's method. The child is held by the parent while the elbow is draped over the edge of the chair. The olecranon is pushed distally past the humerus by the thumb of the physician while the other arm pulls distally along the axis of the forearm. B: Meyn's technique with patient lying prone on the table.
 
(Redrawn from Meyn MA, Quigley TB. Reduction of posterior dislocation of the elbow by traction on the dangling arm. Clin Orthop. 1974; 103:106–107, with permission.)
A: Lavine's method. The child is held by the parent while the elbow is draped over the edge of the chair. The olecranon is pushed distally past the humerus by the thumb of the physician while the other arm pulls distally along the axis of the forearm. B: Meyn's technique with patient lying prone on the table.
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Figure 18-18
Reduction by “pusher” techniques.
A: Lavine's method. The child is held by the parent while the elbow is draped over the edge of the chair. The olecranon is pushed distally past the humerus by the thumb of the physician while the other arm pulls distally along the axis of the forearm. B: Meyn's technique with patient lying prone on the table.
(Redrawn from Meyn MA, Quigley TB. Reduction of posterior dislocation of the elbow by traction on the dangling arm. Clin Orthop. 1974; 103:106–107, with permission.)
A: Lavine's method. The child is held by the parent while the elbow is draped over the edge of the chair. The olecranon is pushed distally past the humerus by the thumb of the physician while the other arm pulls distally along the axis of the forearm. B: Meyn's technique with patient lying prone on the table.
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For a child 9 years of age and older, the puller technique advocated by Parvin130 is used (Figs. 18-13 and 18-19). The forearm must remain supinated during the process of reduction. Occasionally, it is necessary to hypersupinate the forearm to unlock the coronoid process and the radial head before reduction. Closed reduction is done with either heavy sedation or general anesthesia. The range of stable elbow motion is assessed. Fluoroscopy can be helpful during and after the reduction to assess stability as well. Formal x-rays are obtained after the manipulation to assess the adequacy of the reduction (Fig. 18-20), to be certain the joint is congruently reduced and to assess for the presence of any intra-articular fragments. If the elbow is stable through a functional range of motion, the elbow is immobilized in a posterior splint, hinged brace, or a split cast with the elbow flexed 90 degrees. If there is a question of persistent relative instability, the forearm is held in full supination. If the elbow is absolutely stable following reduction, the forearm can be immobilized in midpronation to allow the patient to be more functional with early progressive motion. 
Figure 18-19
Reduction by “puller” techniques in a supine position.
 
A: With the elbow flexed to almost 90 degrees, a force is applied to the anterior portion of the forearm with one hand while the other hand pulls distally along the forearm. A counterforce is applied to offset the manipulating forces by direct stabilization of the patient by a second medical person. B: The counterforce is applied with a sheet around the chest in the ipsilateral axilla.
 
(Redrawn from Parvin RW. Closed reduction of common shoulder and elbow dislocations without anesthesia. Arch Surg. 1957; 75(6):972–975, with permission. Copyright 1957, American Medical Association.)
A: With the elbow flexed to almost 90 degrees, a force is applied to the anterior portion of the forearm with one hand while the other hand pulls distally along the forearm. A counterforce is applied to offset the manipulating forces by direct stabilization of the patient by a second medical person. B: The counterforce is applied with a sheet around the chest in the ipsilateral axilla.
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Figure 18-19
Reduction by “puller” techniques in a supine position.
A: With the elbow flexed to almost 90 degrees, a force is applied to the anterior portion of the forearm with one hand while the other hand pulls distally along the forearm. A counterforce is applied to offset the manipulating forces by direct stabilization of the patient by a second medical person. B: The counterforce is applied with a sheet around the chest in the ipsilateral axilla.
(Redrawn from Parvin RW. Closed reduction of common shoulder and elbow dislocations without anesthesia. Arch Surg. 1957; 75(6):972–975, with permission. Copyright 1957, American Medical Association.)
A: With the elbow flexed to almost 90 degrees, a force is applied to the anterior portion of the forearm with one hand while the other hand pulls distally along the forearm. A counterforce is applied to offset the manipulating forces by direct stabilization of the patient by a second medical person. B: The counterforce is applied with a sheet around the chest in the ipsilateral axilla.
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Entrapped intra-articular fragments should be removed before mobilizing the elbow (Fig. 18-16). With the capsule disrupted and the joint full of blood clot, early arthroscopic removal of loose bodies is not recommended. Thus, we prefer to perform loose body removal with an open arthrotomy in the early postreduction period. Given the extensive medial soft tissue disruption, a medial approach with visualization of the joint through the windows created by the injury allows for easy access to all aspects of the joint. Be certain to locate the ulnar nerve and medial antebrachial cutaneous nerves with operative exposure. 
Persistent significant elbow instability should prompt a thorough investigation for associated fractures or incongruity of the reduction suggesting incarceration of soft tissue or chondral fragments in the joint. In the postreduction examination an estimation of the direction of instability should be performed: Valgus, varus, or posterolateral rotatory instability. In these circumstances, evaluation with a postreduction MRI to assess the extent of the soft tissue injury may help direct treatment. 
Fractures associated with elbow dislocations may necessitate reduction and fixation as dictated by the guiding principles for the individual fracture. Failure to reduce and fix fractures associated with an elbow dislocation may lead to persistent instability. As is discussed at length in the second half of this chapter, we prefer to reduce and fix medial epicondyle fractures associated with elbow dislocations. 

Postreduction Care

Because the major complication of elbow dislocations is stiffness, the initial full-time immobilization is removed after approximately 1 week and the patient transitioned to a removable splint or the hinged brace is unlocked for progressive motion. The patient begins intermittent protected active elbow motion out of the splint multiple times a day as limited by pain. In a reliable patient with minimal risk of additional trauma, the patient can usually dispense with the splint after 10 to 14 days and use a sling. If there are times at high risk for another fall, the splint can be continued up till about 5 to 6 weeks post injury during these times (i.e., during school), but should be removed at other times of the day when there is minimal risk (i.e., meal time) to promote range of motion. The emphasis is on early active motion in a safe environment to prevent stiffness that often occurs after this injury. Before reduction, it is important to emphasize to the parents that there may be some loss of motion, especially extension, regardless of the treatment. This is usually less than 30 degrees and not of functional or aesthetic significance. 

Potential Pitfalls and Preventative Measures

Closed reduction of pediatric elbow dislocations should always be done with adequate analgesia, sedation, or anesthesia. In addition to making the experience much less frightening and traumatic for the child, adequate analgesia, sedation, or anesthesia will achieve sufficient muscle relaxation for the reduction to be obtained more effectively with less force, thereby reducing the risk of creating an iatrogenic fracture (such as fracture of the radial neck) during reduction. 
A careful neurologic examination must be done before and after the reduction with special attention to the median nerve in terms of entrapment. This same careful examination must be made at all follow-up evaluations. Persistent median nerve motor–sensory loss associated with severe pain and resistance with elbow flexion–extension arc of motion may be indicative of entrapment. Of note, ulnar neuropathy is not uncommon and usually resolves spontaneously (Table 18-9). 
 
Table 18-9
Posterior Elbow Dislocation
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Table 18-9
Posterior Elbow Dislocation
Potential Pitfalls and Preventions
Pitfall Preventions
Stiffness Early mobilization
Inadequate analgesia Perform the reduction in the OR if adequate analgesia for muscular relaxation is not available in the emergency setting
Median nerve entrapment Correct lateral displacement before translating anteriorly
Coronoid fracture during reduction Attempt reduction with the elbow in flexion
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Outcomes Following Closed Reduction of Posterior Elbow Dislocations

Outcomes following closed reduction of a posterior elbow dislocation are generally excellent despite some overall loss of range of motion. 

Management of Expected Adverse Outcomes and Unexpected Complications Related to Posterior Elbow Dislocations

Complications associated with posterior elbow dislocations can be divided into those occurring early and those occurring later. Early complications include neurologic and vascular injuries. Late complications include loss of motion, myositis ossificans, recurrent dislocations, radioulnar synostosis, and cubitus recurvatum. The special problems of chronic, unreduced dislocations are not considered complications of treatment (Table 18-10). 
 
Table 18-10
Posterior Elbow Dislocations
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Table 18-10
Posterior Elbow Dislocations
Common Adverse Outcomes and Complications
Neurologic injuries: Ulnar and median nerve are injured most commonly
Vascular injuries: Injury to the brachial artery is most common
Loss of elbow range of motion
Heterotopic bone formation
Radioulnar synostosis
Cubitus recurvatum
Recurrent posterior dislocations
Unreduced posterior elbow dislocations
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Associated Neurologic Injuries with Posterior Elbow Dislocations

Ulnar Nerve Lesions

In a combined series of 317 patients,90,121,147,150 the most commonly injured nerve was the ulnar nerve. Of the 32 patients (10%) who had nerve symptoms after reduction, 21 had isolated ulnar nerve injuries, seven had isolated median nerve injuries, and in four patients both the median and ulnar nerves were involved. Linscheid and Wheeler90 recommended ulnar nerve transposition if ulnar nerve symptoms were present in a patient undergoing open reduction and internal fixation of a displaced medial epicondylar fracture. Except for the one patient described by Linscheid and Wheeler,90 the reported ulnar nerve injuries were transient and resolved completely. 

Radial Nerve Lesions

Radial nerve injury with posterior elbow dislocation is very rare. Watson-Jones183 reported two radial nerve injuries associated with elbow dislocation; in both the symptoms rapidly resolved after reduction. Rasool142 reported a third case. 

Median Nerve Lesions

The most serious neurologic injury involves the median nerve, which can be damaged directly by the dislocation or can be entrapped within the joint. Median nerve injuries occur most commonly in children 5 to 12 years of age. These injuries, either isolated median nerve (7 out of 317 total dislocations) or combined median and ulnar nerve injuries (4 out of 317 total dislocations), were present in only 3% of dislocations.90,121,147,150 
Types of Median Nerve Entrapment
Fourrier et al.,43 in 1977, delineated three types of medial nerve entrapment (Fig. 18-21). 
Figure 18-21
Median nerve entrapment.
 
A: Type 1. Entrapment within the elbow joint with the median nerve coursing posterior to the distal humerus. B: Type 2. Entrapment of the nerve between the fracture surfaces of the medial epicondyle and the medial condyle. C: Type 3. Simple kinking of the nerve into the anterior portion of the elbow joint.
 
(Redrawn from Hallett J. Entrapment of the median nerve after dislocation of the elbow. J Bone Joint Surg Br. 1981; 63-B(3):408–412, with permission.)
A: Type 1. Entrapment within the elbow joint with the median nerve coursing posterior to the distal humerus. B: Type 2. Entrapment of the nerve between the fracture surfaces of the medial epicondyle and the medial condyle. C: Type 3. Simple kinking of the nerve into the anterior portion of the elbow joint.
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Figure 18-21
Median nerve entrapment.
A: Type 1. Entrapment within the elbow joint with the median nerve coursing posterior to the distal humerus. B: Type 2. Entrapment of the nerve between the fracture surfaces of the medial epicondyle and the medial condyle. C: Type 3. Simple kinking of the nerve into the anterior portion of the elbow joint.
(Redrawn from Hallett J. Entrapment of the median nerve after dislocation of the elbow. J Bone Joint Surg Br. 1981; 63-B(3):408–412, with permission.)
A: Type 1. Entrapment within the elbow joint with the median nerve coursing posterior to the distal humerus. B: Type 2. Entrapment of the nerve between the fracture surfaces of the medial epicondyle and the medial condyle. C: Type 3. Simple kinking of the nerve into the anterior portion of the elbow joint.
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Type 1. The child has an avulsion fracture of the medial epicondyle or has a rupture of the flexor–pronator muscle origin and the ulnar collateral ligament (Fig. 18-21A). This allows the median nerve, with or without the brachial artery, to displace posteriorly, essentially wrapping posteriorly around the medial aspect of the humerus and then coursing distally around the articular surface of the distal humerus. With the deep groove of the trochlea acting like a hook for the nerve and catching it out of the anterior soft tissues, if the lateral displacement of the proximal radius and ulna is not corrected before reduction, the nerve may become entrapped in the joint, wrapped around the distal humerus alongside or even in the ulnotrochlear articulation during the process of reduction. Hallett58 demonstrated in cadavers that pronation of the forearm while the elbow is hyperextended forces the median nerve posteriorly during the process of reduction making it vulnerable to entrapment. This type of entrapment also has been reported by other authors.13,18,22,43,54,138,141,169 If median nerve dysfunction is present prior to reduction, it is often difficult to identify nerve entrapment postreduction. Certainly any significant decrease in median nerve function following a closed reduction or incongruity in the reduction should prompt evaluation for this injury pattern. In some patients with an associated medial epicondyle fracture, the nerve can be so severely damaged after being entrapped that neuroma resection, nerve transposition, and direct repair or grafting is necessary.18,54 Good recovery of nerve function has been reported after operative decompression and repair. 
If the nerve has been entrapped for a considerable period, the Matev sign may be present on the x-rays. This represents a depression on the posterior surface of the medial epicondylar ridge where the nerve has been pressed against the bone.13,31,54,58,138,141,169 This groove is seen on x-ray as two sclerotic lines parallel to the nerve (Fig. 18-22). This sign disappears when the nerve has been decompressed. 
Figure 18-22
The Matev sign suggesting entrapment of the median nerve in the elbow joint and impingement of the nerve against the posterior surface of the medial condyle.
 
This produces a depression with sclerotic margins.
 
(Redrawn from Matev I. A radiographic sign of entrapment of the median nerve in the elbow joint after posterior dislocation. J Bone Joint Surg Br. 1976; 58(3):353–355, with permission.)
This produces a depression with sclerotic margins.
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Figure 18-22
The Matev sign suggesting entrapment of the median nerve in the elbow joint and impingement of the nerve against the posterior surface of the medial condyle.
This produces a depression with sclerotic margins.
(Redrawn from Matev I. A radiographic sign of entrapment of the median nerve in the elbow joint after posterior dislocation. J Bone Joint Surg Br. 1976; 58(3):353–355, with permission.)
This produces a depression with sclerotic margins.
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Type 2. The nerve is entrapped between the fracture surfaces of the medial epicondyle and the distal humerus (Fig. 18-21B). The fracture heals and the nerve is surrounded by bone, forming a neuroforamen.138,145,169 This may or may not be visible on x-ray. The medial epicondyle is osteomized to free the nerve. Again, decompression alone may be an adequate treatment, although neuroma resection and repair or reconstruction with nerve grafts may be necessary. 
Type 3. The nerve is kinked and entrapped between the distal humerus and the olecranon (Fig. 18-21C). Only three injuries of this type have been reported.13,137,140 Decompression, neuroma resection, and repair resulted in return of good function over 6 to 24 months. 
Al-Qattan et al.6 described a fourth type of median nerve entrapment in a 14-year-old boy who had a posterior elbow dislocation with a medial epicondylar fracture. The median nerve was found entrapped in a healed medial epicondylar fracture (type 2) in an anterior to posterior direction 18 months after injury. The nerve then passed through the elbow joint in a posterior to anterior direction (type 1). The nerve was so severely damaged that it had to be resected and repaired with sural nerve grafts. A second type 4 median nerve entrapment also requiring nerve segment resection and grafting was reported by Ozkoc et al.127 
The combination of an associated fracture of the medial epicondyle and significant median nerve dysfunction was cited by Rao and Crawford141 as an absolute indication for surgical exploration of the nerve because of the frequency of median nerve entrapment with fractures of the medial epicondyle. MRI may be helpful in defining the course of the median nerve if entrapment is suspected.3 Electromyography and nerve conduction studies have been utilized to assist in operative decision making. Painful dysesthesias with arc of motion is usually indicative of entrapment. Once the entrapped nerve is removed from the joint, neurologic function typically improves. Resection and repair or nerve grafting may be necessary. 

Associated Arterial Injuries with Posterior Elbow Dislocations

Arterial injuries are uncommon with posterior elbow dislocations in children and adolescents with only eight vascular injuries (3%) reported in the combined series of 317 patients.90,121,147,150 However, Carlioz and Abols25 reported four patients with diminished radial pulses that resolved after reduction. Arterial injuries have been associated with open dislocations in which collateral circulation is disrupted.63,82,94,151 In these situations, usually the brachial artery is ruptured,57,63,68,82,94,151 but it can also be thrombosed187 as well as entrapped in the elbow joint.64,133,187 Pearce133 reported an entrapped radial artery in which there was a high bifurcation of the brachial artery. When there is a complete rupture, there usually is evidence of ischemia distally. However, the presence of good capillary circulation to the hand or a Doppler pulse at the wrist does not always mean the artery is intact.57,68 Arteriograms usually are not necessary because the arterial injury is at the site of the dislocation. If imaging is indicated to evaluate possible arterial injury, its minimal risk and invasiveness make vascular ultrasound an attractive initial imaging choice. 
For surgical treatment of vascular injuries about the elbow, simple ligation of the ends has been done in the past with adults, especially if there was good capillary circulation distally.63,82 However, this may predispose to late ischemic changes such as claudication, cold sensitivity, or even late amputation. Most investigators recommend direct arterial repair or a vein graft.57,68,94,102,151 Louis et al.94 recommended arterial repair because their cadaver studies demonstrated that a posterior elbow dislocation usually disrupted the collateral circulation necessary to maintain distal blood flow. 

Loss of Motion Associated with Posterior Elbow Dislocations

Almost all patients with elbow dislocations lose some range of elbow motion.25,46,7678, This loss is less in children than in adults78 and usually is no more than 10 degrees of extension. This rarely is of functional or aesthetic significance. However, the potential for loss of motion must be explained to the parents before reduction and may be an indication for a supervised rehabilitation program. If there is a displaced medial epicondylar fracture, because of the loss of isometry in the medial ligaments, the loss of major range of motion can be severe and limiting. Similarly, an incongruent elbow joint will have marked limitations of motion. In situations where the loss of motion is greater than 45 to 60 degrees, late operative release may be indicated. 

Myositis Ossificans Versus Heterotopic Calcification

True myositis ossificans should be differentiated from heterotopic calcification, which is a dystrophic process. Myositis ossificans involves ossification within the muscle sheath that can lead to a significant loss of range of motion of the elbow. Disruption of the brachialis muscle is believed to be a contributory factor.91 Fortunately, myositis ossificans is rare in children.78,176 Although heterotopic calcification in the ligaments and capsule of the elbow is common,78,147 it rarely results in loss of elbow function (Fig. 18-23). 
Figure 18-23
 
A: Heterotopic calcification of the ulnar collateral ligaments in an elbow that had been dislocated for 2 months (arrow). B: Lateral view of the same elbow. Some myositis ossification has occurred where the brachialis inserts into the coronoid process (arrow).
A: Heterotopic calcification of the ulnar collateral ligaments in an elbow that had been dislocated for 2 months (arrow). B: Lateral view of the same elbow. Some myositis ossification has occurred where the brachialis inserts into the coronoid process (arrow).
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Figure 18-23
A: Heterotopic calcification of the ulnar collateral ligaments in an elbow that had been dislocated for 2 months (arrow). B: Lateral view of the same elbow. Some myositis ossification has occurred where the brachialis inserts into the coronoid process (arrow).
A: Heterotopic calcification of the ulnar collateral ligaments in an elbow that had been dislocated for 2 months (arrow). B: Lateral view of the same elbow. Some myositis ossification has occurred where the brachialis inserts into the coronoid process (arrow).
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In Neviaser and Wickstrom's121 series of 115 patients, 10 had x-ray evidence of myositis ossificans; all, however, were asymptomatic. Roberts147 differentiated true myositis ossificans from heterotopic calcification in his series of 60 elbow dislocations, and noted that only three patients had true myositis ossificans. Linscheid and Wheeler90 reported that the incidence of some type of heterotopic calcification was 28%, which was most common around the condyles. Only in five patients was it anterior to the capsule (which probably represented true myositis ossificans in the brachialis muscle). Four of these patients had some decrease in elbow function. Josefsson et al.78 reported that 61% of 28 children with posterior dislocations had periarticular calcification, but this did not appear to be functionally significant. 

Radioulnar Synostosis

In dislocations with an associated fracture of the radial neck, the incidence of a secondary proximal radioulnar synostosis is increased (Fig. 18-24). This can occur regardless of whether the radial neck fracture is treated operatively or nonoperatively22,25,125 and likely occurs because of the extensive periosteal stripping that occurs along the anterior aspect of the forearm between the proximal radius and ulna. Carlioz and Abols25 reported a synostosis in one of three patients with posterior elbow dislocations associated with radial neck fractures. 
Figure 18-24
Radioulnar synostosis.
 
An 11-year-old male fell injuring his nondominant left elbow. An elbow dislocation was reduced by emergency personnel prior to arrival at the hospital. A: Initial radiographs demonstrated a significantly displaced radial neck fracture. This was reduced using percutaneous techniques. B: Five months later radiographs and (C) a CT scan noted a complete radioulnar synostosis.
An 11-year-old male fell injuring his nondominant left elbow. An elbow dislocation was reduced by emergency personnel prior to arrival at the hospital. A: Initial radiographs demonstrated a significantly displaced radial neck fracture. This was reduced using percutaneous techniques. B: Five months later radiographs and (C) a CT scan noted a complete radioulnar synostosis.
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Figure 18-24
Radioulnar synostosis.
An 11-year-old male fell injuring his nondominant left elbow. An elbow dislocation was reduced by emergency personnel prior to arrival at the hospital. A: Initial radiographs demonstrated a significantly displaced radial neck fracture. This was reduced using percutaneous techniques. B: Five months later radiographs and (C) a CT scan noted a complete radioulnar synostosis.
An 11-year-old male fell injuring his nondominant left elbow. An elbow dislocation was reduced by emergency personnel prior to arrival at the hospital. A: Initial radiographs demonstrated a significantly displaced radial neck fracture. This was reduced using percutaneous techniques. B: Five months later radiographs and (C) a CT scan noted a complete radioulnar synostosis.
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Cubitus Recurvatum

Occasionally, a severe elbow dislocation results in significant tearing of the anterior capsule. As a result, after reduction, when all the stiffness created by the dislocation has subsided, the patient may have some hyperextension (cubitus recurvatum) of the elbow. This is usually minimally symptomatic but if asymmetric, may be aesthetically disturbing to the parents and adolescent. 

Recurrent Posterior Dislocations

Recurrent posterior elbow dislocation is rare. In the combined series of dislocations, only 2 of 317 patients (0.6%) experienced recurrent dislocations.90,121,147,150 Approximately 80% of recurrent dislocations are in males. Three investigators have reported bilateral cases.81,116,143 The pathology of recurrent dislocation involves any or all of a combination of collateral ligament instability, capsular laxity, and bone and articular cartilage defects. 

Pathology Contributing to Recurrent Posterior Dislocations

Osborne and Cotterill126 suggested that articular changes are secondary and that the primary defect is a failure of the posterolateral ligamentous and capsular structures to become reattached after reduction (Fig. 18-25). Osborne and Cotterill126 proposed that the extensive articular cartilage covering the surface of the distal humerus leaves little surface area for soft tissue reattachment and the presence of synovial fluid further inhibits soft tissue healing. With recurrent dislocations, the radial head impinges against the posterolateral margin of the capitellum, creating an osteochondral defect (Fig. 18-26). In addition to the defect in the capitellar articular surface, a similar defect develops in the anterior articular margin of the radial head. When these two defects oppose each other, recurrence of the dislocation is more likely. Subsequent studies have confirmed these findings in almost all recurrent dislocations, especially in children.37,62,124,172,178,190 
Figure 18-25
Pathology associated with recurrent elbow dislocations.
 
The three components that allow the elbow to dislocate: A lax ulnar collateral ligament, a “pocket” in the radial collateral ligament, and a defect in the lateral condyle.
 
(Adapted from Osborne G, Cotterill P. Recurrent dislocation of the elbow. J Bone Joint Surg Br. 1966; 48(2):340–346.)
The three components that allow the elbow to dislocate: A lax ulnar collateral ligament, a “pocket” in the radial collateral ligament, and a defect in the lateral condyle.
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Figure 18-25
Pathology associated with recurrent elbow dislocations.
The three components that allow the elbow to dislocate: A lax ulnar collateral ligament, a “pocket” in the radial collateral ligament, and a defect in the lateral condyle.
(Adapted from Osborne G, Cotterill P. Recurrent dislocation of the elbow. J Bone Joint Surg Br. 1966; 48(2):340–346.)
The three components that allow the elbow to dislocate: A lax ulnar collateral ligament, a “pocket” in the radial collateral ligament, and a defect in the lateral condyle.
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Figure 18-26
Radiographic changes associated with recurrent elbow dislocation.
 
A: Anteroposterior radiograph of a 13-year old who had recurrent dislocations. An osteochondral fragment (arrow) is attached to the lateral ligament. B: An oblique radiograph shows the defect (arrow) in the posterolateral condylar surface. C: Radiographs of an 11-year old after his first dislocation. D: One year later, after recurrent dislocation and subluxations, blunting of the radial head has developed (arrow).
 
(Courtesy of Marvin E. Mumme, MD.)
A: Anteroposterior radiograph of a 13-year old who had recurrent dislocations. An osteochondral fragment (arrow) is attached to the lateral ligament. B: An oblique radiograph shows the defect (arrow) in the posterolateral condylar surface. C: Radiographs of an 11-year old after his first dislocation. D: One year later, after recurrent dislocation and subluxations, blunting of the radial head has developed (arrow).
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Figure 18-26
Radiographic changes associated with recurrent elbow dislocation.
A: Anteroposterior radiograph of a 13-year old who had recurrent dislocations. An osteochondral fragment (arrow) is attached to the lateral ligament. B: An oblique radiograph shows the defect (arrow) in the posterolateral condylar surface. C: Radiographs of an 11-year old after his first dislocation. D: One year later, after recurrent dislocation and subluxations, blunting of the radial head has developed (arrow).
(Courtesy of Marvin E. Mumme, MD.)
A: Anteroposterior radiograph of a 13-year old who had recurrent dislocations. An osteochondral fragment (arrow) is attached to the lateral ligament. B: An oblique radiograph shows the defect (arrow) in the posterolateral condylar surface. C: Radiographs of an 11-year old after his first dislocation. D: One year later, after recurrent dislocation and subluxations, blunting of the radial head has developed (arrow).
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O'Driscoll et al.124 described posterolateral instability in five patients, including two children, in whom laxity of the ulnar part of the radial collateral ligament allowed a transitory rotary subluxation of the ulnohumeral joint and a secondary dislocation of the radiohumeral joint. Patients with posterolateral instability often complain of a feeling of apprehension with certain activities or describe a history of recurrent temporary dislocation of the elbow but, when examined, exhibit no unusual clinical findings. The instability is diagnosed with a posterolateral rotary instability test, which is done by holding the patient's arm over the head while applying proximal axial compression plus a valgus and supination force to the forearm (Fig. 18-27). As the elbow is slowly flexed from an extended position, the radial head, which is initially posteriorly subluxated, reduces producing the appreciation of a “clunk” or “shift.” In some cases the only positive finding is that of apprehension with the examination and in others, posterolateral rotary instability can be detected only with the patient completely relaxed under general anesthesia. The prone push-up test (performed with the forearms maximally supinated) or the chair push-up test (also performed with the arms maximally supinated) can often reproduce the patient's symptoms of pain or a feeling of subluxation or apprehension in the office setting, and thus can often help establish the diagnosis. O'Driscoll et al.124 reported that surgical repair of the lax ulnar portion of the radial collateral ligament eliminated the posterolateral rotary instability. In children and adolescents, the same instability can occur from cartilage nonunion of the origin of the radial collateral ligament. 
Figure 18-27
Posterolateral rotary instability.
 
Posterolateral rotational instability is best demonstrated with the upper extremity over the head with the patient supine. The radial head can be subluxated or dislocated by applying a valgus and supination force to the forearm at the same time proximal axial compression is applied along the forearm.
 
(Reprinted from O'Driscoll SW, Bell DF, Morrey BF. Posterolateral rotary instability of the elbow. J Bone Joint Surg Am. 1991; 73:441, with permission.)
Posterolateral rotational instability is best demonstrated with the upper extremity over the head with the patient supine. The radial head can be subluxated or dislocated by applying a valgus and supination force to the forearm at the same time proximal axial compression is applied along the forearm.
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Figure 18-27
Posterolateral rotary instability.
Posterolateral rotational instability is best demonstrated with the upper extremity over the head with the patient supine. The radial head can be subluxated or dislocated by applying a valgus and supination force to the forearm at the same time proximal axial compression is applied along the forearm.
(Reprinted from O'Driscoll SW, Bell DF, Morrey BF. Posterolateral rotary instability of the elbow. J Bone Joint Surg Am. 1991; 73:441, with permission.)
Posterolateral rotational instability is best demonstrated with the upper extremity over the head with the patient supine. The radial head can be subluxated or dislocated by applying a valgus and supination force to the forearm at the same time proximal axial compression is applied along the forearm.
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In addition to the osteochondral defects in the capitellum and radial head, bone defects may include a shallow semilunar notch resulting from a coronoid fossa process fracture or multiple recurrent dislocations. 

Treatment Options for Recurrent Posterior Dislocations

There is only one report of successful nonsurgical management of recurrent elbow dislocations. Herring and Sullivan66 used an orthosis that blocked the last 15 degrees of extension. After his patient wore this orthosis constantly for 2 years and with vigorous activities for another 6 months, there were no further dislocations, but the follow-up period was only 1 year. Beaty and Donati14 emphasized that physical therapy and the use of an orthosis should be tried before surgery is considered. 
Because nonsurgical management is so often unsuccessful, the treatment of recurrent posterior elbow dislocations is predominately surgical. Various surgical procedures have been described to correct bone and soft tissue abnormalities (Fig. 18-28). 
Figure 18-28
Surgical procedures for recurrent dislocation.
 
A: Simple coronoid bone block. B: Open wedge coronoid osteotomy. C: Biceps tendon transfer to coronoid process. D: Cruciate ligament reconstruction. E: Lateral capsular reattachment of Osborne and Cotterill.
 
(Adapted from Osborne G, Cotterill P. Recurrent dislocation of the elbow. J Bone Joint Surg Br. 1966; 48(2):340–346.)
A: Simple coronoid bone block. B: Open wedge coronoid osteotomy. C: Biceps tendon transfer to coronoid process. D: Cruciate ligament reconstruction. E: Lateral capsular reattachment of Osborne and Cotterill.
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Figure 18-28
Surgical procedures for recurrent dislocation.
A: Simple coronoid bone block. B: Open wedge coronoid osteotomy. C: Biceps tendon transfer to coronoid process. D: Cruciate ligament reconstruction. E: Lateral capsular reattachment of Osborne and Cotterill.
(Adapted from Osborne G, Cotterill P. Recurrent dislocation of the elbow. J Bone Joint Surg Br. 1966; 48(2):340–346.)
A: Simple coronoid bone block. B: Open wedge coronoid osteotomy. C: Biceps tendon transfer to coronoid process. D: Cruciate ligament reconstruction. E: Lateral capsular reattachment of Osborne and Cotterill.
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Bone Procedures
These are directed toward correcting dysplasia of the semilunar notch of the olecranon. Milch116 inserted a boomerang-shaped bone block. Others52,112,181 found that a simple bone block was all that was necessary (Fig. 18-28A). Mantle103 increased the slope of the semilunar notch in two patients with an opening wedge osteotomy of the coronoid process (Fig. 18-28B). 
Soft Tissue Procedures
Reichenheim143 and King85 transferred the biceps tendon just distal to the coronoid process to reinforce it (Fig. 18-28C). Kapel81 developed a cruciate ligament-type reconstruction in which distally based strips of the biceps and triceps tendon were passed through the distal humerus (Fig. 18-28D). Beaty and Donati14 modified this technique by transferring a central slip of the triceps through the humerus posterior to anterior and attaching it to the proximal ulna. 
The most widely accepted technique is that described by Osborne and Cotterill,126 in which the lateral capsule is reattached to the posterolateral aspect of the capitellum with sutures passing through holes drilled in the bone (Fig. 18-28E). The joint should be inspected at surgery because osteocartilaginous loose bodies may be present.62,101,172 Since Osborne and Cotterill's126 initial report of eight patients, successful use of this technique has been reported in numerous others.37,62,101,124,172,178,190 Zeier194 and O'Driscoll et al.124 reinforced the lateral repair with strips of fascia lata, triceps fascia, or palmaris longus tendon. 
Postoperative Care
Postoperatively, especially after the repair described by Osborne and Cotterill,126 the arm is immobilized in a long arm cast with the elbow flexed 90 degrees for 4 to 6 weeks. Protected active range-of-motion exercises are performed for an additional 4 to 6 weeks. Strenuous activities are avoided for 12 weeks' postoperative. 
Complications
Major complications after correction of recurrent dislocations include loose osteocartilaginous fragments and destruction of the articular surface of the joint (Fig. 18-29), elbow stiffness, or recurrent instability. 
Figure 18-29
Effects of recurrent dislocation.
 
This girl began to have recurrent dislocations of her elbow at age 9. A: The ease at which the elbow redislocates is shown in this radiograph. B, C: Radiographs taken at the beginning of episodes of dislocation. Her dislocation continued. D, E: Four years later, the elbow demonstrated marked changes in its architecture.
 
(Courtesy of David J. Mallams, MD.)
This girl began to have recurrent dislocations of her elbow at age 9. A: The ease at which the elbow redislocates is shown in this radiograph. B, C: Radiographs taken at the beginning of episodes of dislocation. Her dislocation continued. D, E: Four years later, the elbow demonstrated marked changes in its architecture.
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Figure 18-29
Effects of recurrent dislocation.
This girl began to have recurrent dislocations of her elbow at age 9. A: The ease at which the elbow redislocates is shown in this radiograph. B, C: Radiographs taken at the beginning of episodes of dislocation. Her dislocation continued. D, E: Four years later, the elbow demonstrated marked changes in its architecture.
(Courtesy of David J. Mallams, MD.)
This girl began to have recurrent dislocations of her elbow at age 9. A: The ease at which the elbow redislocates is shown in this radiograph. B, C: Radiographs taken at the beginning of episodes of dislocation. Her dislocation continued. D, E: Four years later, the elbow demonstrated marked changes in its architecture.
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Unreduced Posterior Elbow Dislocations

Untreated posterior dislocations of the elbow in children are extremely rare in North America. Most reported series are from other countries.44 

Diagnosis

Children with untreated dislocations typically have pain and limited midrange of motion (Fig. 18-12). Pathologically, there is usually subperiosteal new bone formation that produces a radiohumeral horn, myositis ossificans of the brachialis muscle, capsular contractures, shortening of the triceps muscle, contractures of the medial and lateral collateral ligaments, and compression of the ulnar nerve.43,44 These factors have to be considered when planning treatment. 

Treatment Options

Closed Reduction of an Unreduced Posterior Elbow Dislocation
Closed reduction of dislocations recognized within 3 weeks of injury may be possible.5,44 If this fails or if the dislocation is of longer duration, open reduction is necessary. 
Operative Treatment for an Unreduced Posterior Elbow Dislocation
Open reduction through a posterior approach, as described by Speed,168 involves lengthening of the triceps muscle and release or transposition of the ulnar nerve.44 Satisfactory results usually can be obtained if a stable concentric reduction is achieved within 3 months of the initial dislocation.5 Results after surgical reconstruction decline thereafter but still may produce some improvement in function.33,44,99,115,118 Fixation of the elbow joint to maintain reduction with one or two large smooth pins for 2 to 4 weeks followed by vigorous but protected physical therapy has been recommended.44,118 Consideration may be given to hinged external fixation instead of transarticular pins. 
Mahaisavariya et al.100 reported improved extension and better functional results 1 to 3 months after injury in 34 patients with chronic elbow dislocation reconstruction in whom the triceps tendon was not lengthened compared with 38 patients who had the triceps lengthened at surgery. 

Congenital Elbow Dislocations

Chronic elbow dislocation may be congenital in origin. Altered anatomy and limited motion predispose these patients to injury. The key to differentiating a congenital from an acute traumatic elbow dislocation is examination of the x-ray architecture of the articulating surfaces. In a congenitally dislocated elbow, there is atrophy of the humeral condyles and the semilunar notch of the olecranon. The radial head and neck may be hypoplastic, and the articular surface of the radial head may be dome shaped instead of concave. Unfortunately, these same changes can result from chronic recurrent dislocation after trauma, making the differentiation between congenital and chronic traumatic dislocation difficult. If other congenital anomalies are present or the child has an underlying syndrome, such as Ehlers–Danlos or Larsen syndrome, the dislocation is likely to be nontraumatic. Obtaining comparison x-rays of the asymptomatic, contralateral elbow often reveals identical anatomy, confirming the etiology of the dislocation as congenital or nontraumatic acquired. 

Anterior Elbow Dislocations

Anterior elbow dislocations are rare. Of the 317 elbows in the combined series,90,121,147,150 only 5 were anterior, for an incidence of slightly over 1%. They are associated with an increased incidence of complications, such as brachial artery disruption and associated fractures, compared with posterior dislocations.73,186 

Assessment of Anterior Elbow Dislocations

Mechanisms of Injury for Anterior Elbow Dislocations

Anterior elbow dislocations usually are caused by a direct blow to the posterior aspect of the flexed elbow.71 Hyperextension of the elbow also has been implicated in one study.186 

Associated Injuries with Anterior Elbow Dislocations

Associated fractures are common. In children, the triceps insertion may be avulsed from the olecranon with a small piece of cortical bone.189 This fragment usually reduces to the olecranon after reduction. Wilkerson186 reported an anterior dislocation associated with a displaced olecranon fracture in a 7-year-old boy. Inoue and Horii71 reported an 11-year-old girl with an anterior elbow dislocation with displaced fractures of the trochlea, capitellum, and lateral epicondyle. These were repaired with open reduction and internal fixation using Herbert bone screws. 

Signs and Symptoms of Anterior Elbow Dislocations

The elbow is held in extension upon presentation. There is a fullness in the antecubital fossa. Swelling usually is marked because of the soft tissue disruption associated with this type of dislocation. There is severe pain with attempted motion. A careful neurovascular examination is mandatory. 

Imaging and Other Diagnostic Studies for Anterior Elbow Dislocations

Routine AP and lateral x-rays are diagnostic. In most cases, the proximal radius and ulna dislocate in an anteromedial direction (Fig. 18-30). As with posterior dislocations, postreduction radiographs should be carefully scrutinized for a congruent reduction and for subtle osteochondral fracture fragments. Evaluation with computerized tomography or MRI may be utilized to further define the extent of soft tissue injury in complex injury patterns. 
Figure 18-30
Anterior dislocation of the elbow.
 
A: Initial anteroposterior radiograph. The olecranon lies anterior to the distal humerus. B: Initial lateral radiograph. The proximal ulna and radial head lie anteromedial, and the elbow carrying angle is in varus.
 
(Courtesy of Hilario Trevino, MD.)
A: Initial anteroposterior radiograph. The olecranon lies anterior to the distal humerus. B: Initial lateral radiograph. The proximal ulna and radial head lie anteromedial, and the elbow carrying angle is in varus.
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Figure 18-30
Anterior dislocation of the elbow.
A: Initial anteroposterior radiograph. The olecranon lies anterior to the distal humerus. B: Initial lateral radiograph. The proximal ulna and radial head lie anteromedial, and the elbow carrying angle is in varus.
(Courtesy of Hilario Trevino, MD.)
A: Initial anteroposterior radiograph. The olecranon lies anterior to the distal humerus. B: Initial lateral radiograph. The proximal ulna and radial head lie anteromedial, and the elbow carrying angle is in varus.
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Treatment Options for Anterior Elbow Dislocations

Nonoperative Treatment of Anterior Elbow Dislocations

Indications/Contraindications

As with posterior elbow dislocations, because of the significant amount of soft tissue swelling and potential for neurovascular compromise, all anterior elbow dislocations should be reduced with adequate analgesia and relaxation as soon as possible. Consideration for nonoperative treatment following closed reduction can only be considered if the elbow is stable through close to a functional range of motion, a concentric anatomic reduction can be obtained and maintained, and there is no evidence to suggest a vascular injury, nerve entrapment, or significant intra-articular osteochondral fragments. 
Surgery usually is not required unless the dislocation is open, there is a brachial artery injury, or there is an associated fracture that does not realign satisfactorily after closed reduction. Open reduction and internal fixation of the fracture may then be necessary.71,186 

Techniques for Closed Reduction of Anterior Elbow Dislocations

Reduction usually is accomplished by flexing the elbow and pushing the forearm proximally and downward at the same time.189 As with posterior dislocations, a force must first be applied longitudinally along the axis of the humerus with the elbow semiflexed to overcome the forces of the biceps and triceps. The longitudinal force along the axis of the forearm is directed toward the elbow (Fig. 18-31). To make reduction easier, the distal humerus can be forced in an anterior direction by pushing on the posterior aspect of the distal arm. 
Figure 18-31
Reduction of anterior dislocation.
 
A: With the elbow semiflexed, a longitudinal force is applied along the long axis of the humerus (arrow 1). Pulling distally on the forearm may be necessary to initially dislodge the olecranon. B: Once the olecranon is distal to the humerus, the distal humerus is pushed anteriorly (arrow 2) whereas a proximally directed force is applied along the long axis of the forearm (arrow 3). C: Finally, the elbow is immobilized in some extension (arrow 4).
A: With the elbow semiflexed, a longitudinal force is applied along the long axis of the humerus (arrow 1). Pulling distally on the forearm may be necessary to initially dislodge the olecranon. B: Once the olecranon is distal to the humerus, the distal humerus is pushed anteriorly (arrow 2) whereas a proximally directed force is applied along the long axis of the forearm (arrow 3). C: Finally, the elbow is immobilized in some extension (arrow 4).
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Figure 18-31
Reduction of anterior dislocation.
A: With the elbow semiflexed, a longitudinal force is applied along the long axis of the humerus (arrow 1). Pulling distally on the forearm may be necessary to initially dislodge the olecranon. B: Once the olecranon is distal to the humerus, the distal humerus is pushed anteriorly (arrow 2) whereas a proximally directed force is applied along the long axis of the forearm (arrow 3). C: Finally, the elbow is immobilized in some extension (arrow 4).
A: With the elbow semiflexed, a longitudinal force is applied along the long axis of the humerus (arrow 1). Pulling distally on the forearm may be necessary to initially dislodge the olecranon. B: Once the olecranon is distal to the humerus, the distal humerus is pushed anteriorly (arrow 2) whereas a proximally directed force is applied along the long axis of the forearm (arrow 3). C: Finally, the elbow is immobilized in some extension (arrow 4).
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Because most anterior dislocations occur in flexion, the elbow should be immobilized in some extension for 1 to 3 weeks, followed by protected active range-of-motion exercises. Early motion after open reduction and internal fixation of an associated olecranon fracture usually can be allowed.71,186 

Author's Preferred Method of Treatment for Anterior Elbow Dislocations

Closed reduction (Fig. 18-31) is the initial procedure of choice. A distal force must be applied in line with and parallel to the long axis of the humerus first. Once the length has been reestablished, a posteriorly directed force along the axis of the forearm is applied until the elbow is reduced. The same principles that were discussed for posterior elbow dislocations apply to anterior elbow dislocations as well. There should be a thorough and systematic evaluation of the elbow stability following reduction, postreduction radiographs should be carefully scrutinized for a concentric reduction and associated fractures or entrapped loose bodies, if appropriate a brief period of immobilization followed by an early protected motion program should be employed. Stable fixation of associated fractures is also necessary as dictated by the treatment principles for those fractures. 

Management of Expected Adverse Outcomes and Unexpected Complications for Anterior Elbow Dislocations

There appears to be an increased incidence of brachial artery rupture or thrombosis associated with anterior elbow dislocations.73,167 As discussed with posterior elbow dislocations, early and persistent vigilance for circulatory issues should be exercised. When compromised, as discussed above in more detail with posterior elbow dislocations, a prompt evaluation with consideration for arterial repair or reconstruction with vein grafting may be necessary. 

Medial and Lateral Elbow Dislocations

These are rare dislocations. Lateral dislocations, either incomplete or complete, are more common than medial dislocations in adults. There are no recent reports of medial dislocations in children. 

Assessment of Medial and Lateral Elbow Dislocations

Signs and Symptoms of Medial and Lateral Elbow Dislocations

In an incomplete lateral dislocation, the semilunar notch articulates with the capitulotrochlear groove, and the radial head appears more prominent laterally. There is often good flexion and extension of the elbow, increasing the likelihood that a lateral dislocation will be overlooked. In a complete lateral dislocation, the olecranon is displaced lateral to the capitellum. This gives the elbow a markedly widened appearance. 

X-Ray and Other Imaging Studies for Medial and Lateral Elbow Dislocations

AP x-rays of the elbow usually are diagnostic. On the lateral view, the elbow may appear reduced. 

Treatment Options for Medial and Lateral Elbow Dislocations

These rare dislocations can be treated by closed reduction in virtually all patients.192 A longitudinal force is applied along the axis of the humerus to distract the elbow, and then direct medial or lateral pressure (opposite the direction of the dislocation) is applied over the proximal forearm (Fig. 18-32). 
Figure 18-32
Lateral elbow dislocation.
 
A: Initial anteroposterior radiograph in this 6-year old with a lateral dislocation and displaced medial epicondyle fracture. B: Lateral radiograph shows slight posterior dislocation. C, D: Postreduction radiographs demonstrate anatomic reduction of the dislocation. The medial epicondyle is satisfactorily aligned.
A: Initial anteroposterior radiograph in this 6-year old with a lateral dislocation and displaced medial epicondyle fracture. B: Lateral radiograph shows slight posterior dislocation. C, D: Postreduction radiographs demonstrate anatomic reduction of the dislocation. The medial epicondyle is satisfactorily aligned.
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Figure 18-32
Lateral elbow dislocation.
A: Initial anteroposterior radiograph in this 6-year old with a lateral dislocation and displaced medial epicondyle fracture. B: Lateral radiograph shows slight posterior dislocation. C, D: Postreduction radiographs demonstrate anatomic reduction of the dislocation. The medial epicondyle is satisfactorily aligned.
A: Initial anteroposterior radiograph in this 6-year old with a lateral dislocation and displaced medial epicondyle fracture. B: Lateral radiograph shows slight posterior dislocation. C, D: Postreduction radiographs demonstrate anatomic reduction of the dislocation. The medial epicondyle is satisfactorily aligned.
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Divergent Elbow Dislocation

Divergent dislocation represents a posterior elbow dislocation with disruption of the interosseous membrane between the proximal radius and ulna with the radial head displaced laterally and the proximal ulna medially (Fig. 18-33). These dislocations are extremely rare.10,23,32,49,69,70,110,119,158,166,180 
Figure 18-33
Medial–lateral divergent dislocation.
 
A: Anteroposterior view demonstrating disruption of the proximal radioulnar joint with the radius lateral and the ulna medial. B: Lateral radiograph confirms that the radius and ulna are both posterior to the distal humerus. C: A radiograph taken 4 weeks after injury shows periosteal new bone formation (arrows), indicating where the soft tissues were extensively torn away from the proximal ulna.
A: Anteroposterior view demonstrating disruption of the proximal radioulnar joint with the radius lateral and the ulna medial. B: Lateral radiograph confirms that the radius and ulna are both posterior to the distal humerus. C: A radiograph taken 4 weeks after injury shows periosteal new bone formation (arrows), indicating where the soft tissues were extensively torn away from the proximal ulna.
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Figure 18-33
Medial–lateral divergent dislocation.
A: Anteroposterior view demonstrating disruption of the proximal radioulnar joint with the radius lateral and the ulna medial. B: Lateral radiograph confirms that the radius and ulna are both posterior to the distal humerus. C: A radiograph taken 4 weeks after injury shows periosteal new bone formation (arrows), indicating where the soft tissues were extensively torn away from the proximal ulna.
A: Anteroposterior view demonstrating disruption of the proximal radioulnar joint with the radius lateral and the ulna medial. B: Lateral radiograph confirms that the radius and ulna are both posterior to the distal humerus. C: A radiograph taken 4 weeks after injury shows periosteal new bone formation (arrows), indicating where the soft tissues were extensively torn away from the proximal ulna.
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Divergent dislocations are often caused by high-energy trauma. Associated fractures of the radial neck, proximal ulna, and coronoid process are common.2,23,40,180 It has been speculated that, in addition to the hyperextension of the elbow that produces the dislocation, a strong proximally directed force is applied parallel to the long axis of the forearm, disrupting the annular ligament and interosseous membrane and allowing the divergence of the proximal radius and ulna. In a cadaveric study, Altuntas et al.7 confirmed that only after release of all the ligamentous stabilizers of the elbow and release of the intraosseous membrane from the elbow to the distal third of the forearm could a divergent dislocation be replicated. 

Treatment Options for Divergent Elbow Dislocations

Closed Reduction in Divergent Elbow Dislocations

Divergent dislocations are typically easily reduced using closed reduction under general anesthesia. Reduction is achieved by applying longitudinal traction with the elbow semiextended and at the same time compressing the proximal radius and ulna together. 

Open Reduction in Divergent Elbow Dislocations

Very few divergent dislocations reported in the literature have required open reduction.40,110,120 Failure of closed reduction110,120 and displaced associated fracture40 are indications for open reduction. After failed attempted closed reduction was unsuccessful, Nanno et al.120 performed surgical exploration and identified the avulsed anterior band of the medial collateral ligament complex of the elbow interposed between the medial condyle of the humerus and the olecranon. After removing and repairing the interposed ligament, stable reduction was achieved. van Wagenberg et al.179 describes a patient with divergent elbow dislocation with associated distal radius and coronoid fractures. After anatomic reduction of the fractures a stable reduction of the divergent elbow dislocation was achieved. 

Postreduction Care in Divergent Elbow Dislocations

After successful closed reduction, the elbow is immobilized in 90 degrees of flexion and the forearm in neutral for approximately 2 to 3 weeks. Active range-of-motion exercises are then begun. Most patients regain full elbow motion, including forearm pronation and supination. 

Management of Expected Adverse Outcomes and Unexpected Complications Related to Divergent Elbow Dislocations

A case of symptomatic radiocapitellar instability 7 years following a transverse, mediolateral divergent dislocation has been reported.193 No discussion of treatment for this complication was provided, but knowledge of the difficulty treating chronic elbow instability emphasizes the importance of obtaining a stable, congruent reduction during the time of acute injury management. 

Proximal Radioulnar Translocations

Translocation of the proximal radius and ulna is an extremely rare injury with very few cases having been reported in the English literature.11,23,24,28,39,51,61,72,97 Radioulnar translocation is commonly missed on the AP x-ray unless the proximal radius and ulna are noted to be completely reversed in relation to the distal humerus. Translocations are believed to be caused by a fall onto the pronated hand with the elbow in full or nearly full extension, producing an axial force on the proximal radius. The anterior radial head dislocation occurs first, followed by the posterior dislocation of the olecranon. Combourieu et al.28 suggests that avulsion of the brachialis insertion is necessary for the radial head to translate medially. The radial head, depending on the degree of pronation, can be lodged in the coronoid fossa or dislocated posteriorly. As a consequence, fractures of the radial head, radial neck, or coronoid process may occur.23,24,39,97 Harvey and Tchelebi61 reported a case in which the cause of radioulnar translocation may have been iatrogenic: The result of inappropriate technique used to reduce a posterior elbow dislocation. 

Assessment of Proximal Radioulnar Translocations

Swelling and pain may obscure the initial examination, and minimal deformity may be apparent. Once pain has been adequately managed with analgesics, the most consistent finding on clinical examination is limited elbow range of motion, especially in supination. 

Associated Injuries with Proximal Radioulnar Translocations

Radial neck fracture is the most common fracture associated with proximal radioulnar translocation.24,39,72,97 Eklof et al.39 also reported one patient who sustained a fracture of the tip of the coronoid. Proposed soft tissue injuries include radial collateral ligament, medial collateral ligament, annular ligament, interosseous ligament, and avulsion of the brachialis.28,39,72 Transient ulnar nerve paresthesia that resolved after reduction of the translocation has been reported in several patients.28,72 Osteonecrosis of the radial head was noted in one patient after open reduction of a proximal radioulnar translocation and premature closure of the proximal radial physis has been reported.28,61 

Treatment Options for Proximal Radioulnar Translocations

Closed Reduction in Proximal Radioulnar Translocations

Successful closed reduction of proximal radioulnar translocation has been reported.28,72,97 The patient must be completely relaxed under general anesthesia, as sedation or regional anesthesia is unlikely to provide sufficient relaxation. With the elbow flexed approximately 90 degrees, longitudinal traction is applied to the elbow while the forearm is supinated (Fig. 18-34). If the radial head can be palpated, gentle anterior-directed pressure may help slide the radial head and neck over the coronoid process, allowing the proximal radius and ulna to resume their normal configuration. As always, just the right amount of force should be used; excessive force risks iatrogenic fracture to the proximal radius. Successful closed reduction should be confirmed on x-ray, and the elbow should be immobilized for approximately 3 to 4 weeks with the forearm supinated and the elbow flexed 90 to 100 degrees. 
Figure 18-34
Proximal radioulnar translocation.
 
A: Position of the proximal radius and ulna with a proximal radioulnar translocation. B: Closed reduction is rarely successful, but may be attempted under general anesthesia using gentle longitudinal traction while supinating the forearm.
 
(Redrawn from Harvey S, Tchelebi H. Proximal radioulnar translocation. A case report. J Bone Joint Surg Am. 1979; 61(3):447–449, with permission.)
A: Position of the proximal radius and ulna with a proximal radioulnar translocation. B: Closed reduction is rarely successful, but may be attempted under general anesthesia using gentle longitudinal traction while supinating the forearm.
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Figure 18-34
Proximal radioulnar translocation.
A: Position of the proximal radius and ulna with a proximal radioulnar translocation. B: Closed reduction is rarely successful, but may be attempted under general anesthesia using gentle longitudinal traction while supinating the forearm.
(Redrawn from Harvey S, Tchelebi H. Proximal radioulnar translocation. A case report. J Bone Joint Surg Am. 1979; 61(3):447–449, with permission.)
A: Position of the proximal radius and ulna with a proximal radioulnar translocation. B: Closed reduction is rarely successful, but may be attempted under general anesthesia using gentle longitudinal traction while supinating the forearm.
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Open Reduction in Proximal Radioulnar Translocations

Radioulnar translocations may require open reduction.23,24,39,51,61,72 A lateral approach provides adequate exposure to the translocation and radial neck fracture if present. At surgery, the radial head and neck are typically found trapped beneath the trochlea of the distal humerus. Elbow extension tightens the biceps tendon, making reduction more difficult. With the elbow flexed, a freer or joker elevator can be placed beneath the radial head and neck facilitating delivery over the coronoid process as the forearm is supinated. If present, a radial neck fracture may now be treated in standard fashion. Internal fixation also may be necessary for an unstable displaced fracture. 
Harvey and Tchelebi61 used an osteotomy of the proximal ulna to expose and reduce the radius that was complicated by a postoperative ulnar nerve paralysis that recovered completely over 2 months. 
After successful closed or open reduction, the forearm is immobilized for approximately 3 to 4 weeks with the forearm supinated and the elbow flexed 90 to 100 degrees, followed by active elbow range-of-motion exercises. 

Medial Epicondyle Apophysis Fractures

In the early 1900s, it was recognized that the medial epicondyle fracture was often associated with elbow dislocation and the apophyseal fragment could become entrapped within the joint.182 The reported incidence of medial epicondyle fracture associated with dislocation of the elbow in children and adolescents has varied from as low as 30% to as high as 55% in many of the reported series.15,188 Two bilateral injuries associated with bilateral elbow dislocations have been reported,17,42 both patients having sustained their injuries while participating in gymnastics (Table 18-11). Fractures involving the medial epicondylar apophysis constitute approximately 14% of fractures involving the distal humerus and 11% of all fractures in the elbow region.15,17,26 Fractures involving the epicondylar apophysis have a peak age in preadolescence, similar to fractures involving the medial condylar physis. The youngest reported patient with this injury was 3.9 years.26 In the large series of fractures of the medial epicondylar apophysis, most occurred between ages 9 and 14, and the peak age incidence was 11 to 12 years.15,46,67,83,117,128,161,188 Fractures of the epicondylar apophysis preferentially affect males by a ratio of almost 4 to 1 over females. In six large series in the literature, boys constituted 79% of the patients.46,47,105,148,182,188 
 
Table 18-11
Fractures of the Medial Epicondylar Apophysis: Incidence
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Table 18-11
Fractures of the Medial Epicondylar Apophysis: Incidence
Overall incidence: Fractures of the elbow region, 11.5%
Age: peak, 11–12 y
Sex: males, 79% (4:1, male:female)
Association with elbow dislocation: Approximately 50% (15–18% of these involve incarceration of the epicondylar apophysis)
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Mechanisms of Injury for Medial Epicondyle Apophysis Fractures

Injuries to the medial epicondylar apophysis most commonly occur as acute injuries in which a distinct event produces a partial or a complete separation of the apophyseal fragment. Three theories have been proposed about the mechanism of acute medial epicondylar apophyseal injuries: A direct blow, avulsion mechanisms, and association with elbow dislocation. 

Direct Blow

Stimson170 speculated that this type of injury could occur as a result of a direct blow on the posterior aspect of the epicondyle. Among more recent investigators, however, only Watson-Jones183 described this injury as being associated with a direct blow to the posterior medial aspect of the elbow. In rare patients in whom the fragment is produced by a direct blow to the medial aspect of the joint, the medial epicondylar fragment is often fragmented (Fig. 18-35). In these injuries, there may also be more superficial ecchymosis in the skin. 
Figure 18-35
Direct fragmentation.
 
The fragmented appearance of the medial epicondyle (arrows) in a 13-year old who sustained a direct blow to the medial aspect of the elbow.
 
(From Wilkins KE. Fractures of the medial epicondyle in children. Instr Course Lect. 1991; 40:1–8, with permission.)
The fragmented appearance of the medial epicondyle (arrows) in a 13-year old who sustained a direct blow to the medial aspect of the elbow.
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Figure 18-35
Direct fragmentation.
The fragmented appearance of the medial epicondyle (arrows) in a 13-year old who sustained a direct blow to the medial aspect of the elbow.
(From Wilkins KE. Fractures of the medial epicondyle in children. Instr Course Lect. 1991; 40:1–8, with permission.)
The fragmented appearance of the medial epicondyle (arrows) in a 13-year old who sustained a direct blow to the medial aspect of the elbow.
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Avulsion Mechanisms

Various investigators have suggested that some of these injuries are due to a pure avulsion of the epicondyle by the flexor–pronator muscles of the forearm.83,132 This muscle avulsion force can occur in combination with a valgus stress in which the elbow is locked in extension, or as a pure musculature contraction that may occur with the elbow partially flexed. 
Smith161 proposed that when a child falls on his outstretched upper extremity with the elbow in extension, the wrist and fingers are often hyperextended as well, placing an added tension force on the epicondyle by the forearm flexor muscles (Fig. 18-36). The normal valgus carrying angle tends to accentuate these avulsion forces when the elbow is in extension. Many proponents of this theory point to the other associated elbow fractures that have been seen with this injury as evidence to confirm that a valgus force is applied across the elbow at the time of the injury. These associated injuries include radial neck fractures with valgus angulation and greenstick valgus fractures of the olecranon.83 
Figure 18-36
Hyperextension forces.
 
When a person falls on the outstretched upper extremity, the wrist and fingers are forced into hyperextension (solid arrow), which places tension on the forearm flexor muscles. This sudden tension along with the normal valgus carrying angle tends to place a strong avulsion force on the medial epicondyle (open arrow).
When a person falls on the outstretched upper extremity, the wrist and fingers are forced into hyperextension (solid arrow), which places tension on the forearm flexor muscles. This sudden tension along with the normal valgus carrying angle tends to place a strong avulsion force on the medial epicondyle (open arrow).
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Figure 18-36
Hyperextension forces.
When a person falls on the outstretched upper extremity, the wrist and fingers are forced into hyperextension (solid arrow), which places tension on the forearm flexor muscles. This sudden tension along with the normal valgus carrying angle tends to place a strong avulsion force on the medial epicondyle (open arrow).
When a person falls on the outstretched upper extremity, the wrist and fingers are forced into hyperextension (solid arrow), which places tension on the forearm flexor muscles. This sudden tension along with the normal valgus carrying angle tends to place a strong avulsion force on the medial epicondyle (open arrow).
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Isolated avulsion can also occur in adolescents with the simple act of throwing a baseball. In this instance, the sudden contracture of the forearm flexor muscles may be sufficient to cause the epicondyle to fail (Fig. 18-37). The literature has reflected a high incidence of medial epicondylar apophyseal avulsions occurring with arm wrestling in patients near skeletal maturity.95,123 The largest series, reported by Nyska et al.123 from Israel, involved eight boys of 13 to 15 years of age, all of whom were treated conservatively with good results. 
Figure 18-37
Muscle avulsion.
 
Isolated avulsion of the medial epicondyle occurred suddenly in this 14-year-old Little League pitcher after throwing a curve ball.
 
(From Wilkins KE. Fracture of the medial epicondyle in children. Instr Course Lect. 1991; 40:1–8, with permission.)
Isolated avulsion of the medial epicondyle occurred suddenly in this 14-year-old Little League pitcher after throwing a curve ball.
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Figure 18-37
Muscle avulsion.
Isolated avulsion of the medial epicondyle occurred suddenly in this 14-year-old Little League pitcher after throwing a curve ball.
(From Wilkins KE. Fracture of the medial epicondyle in children. Instr Course Lect. 1991; 40:1–8, with permission.)
Isolated avulsion of the medial epicondyle occurred suddenly in this 14-year-old Little League pitcher after throwing a curve ball.
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Associated Injuries with Medial Epicondyle Avulsion Fractures

Avulsion fractures of the medial epicondyle may be associated with elbow dislocation in which the ulnar collateral ligament provides the avulsion force. If the patient presents with the elbow dislocated, there is no doubt that the dislocation is the major factor causing this fracture. If the patient presents with the elbow located, it is less clear as to whether the medial epicondyle fracture may have been caused by an occult or partial elbow dislocation that has reduced spontaneously. Some investigators15,17,46 have noticed calcification development in the lateral collateral ligaments and adjacent lateral periosteum after fracture. They believed this calcification was evidence that the ligament had been stretched during the process of elbow dislocation. Marion and Faysse105 found that most elbow dislocations associated with medial epicondyle fractures were posterolateral, but some pure lateral, posterior, and posteromedial dislocations were also observed. A question has also arisen as to whether incarceration of the epicondylar fragment into the joint can occur without a dislocation. Patrick132 believed that when an extreme valgus stress was applied to the joint, a vacuum was created within the joint that “sucked in” the avulsed epicondylar fragment. 
It appears that any of these mechanisms can produce an acute apophyseal injury of the distal humerus. The direct blow mechanism appears to occur only rarely. Many of these injuries may be associated with an elbow dislocation that may or may not have reduced spontaneously. 

Assessment of Medial Epicondyle Avulsion Fractures

Clinical Examination of Medial Epicondyle Avulsion Fractures

Medial epicondyle fractures associated with elbow dislocation are associated with gross deformity of the elbow, swelling, and distracting injuries so that the medial epicondyle fracture can be easily overlooked. A careful and focused evaluation looking specifically at the medial epicondyle is necessary to avoid missing this injury. If a fracture of the medial epicondyle has occurred, then tenderness to palpation will be present. 
Because the anterior oblique band of the ulnar collateral ligament may be attached to the medial epicondylar apophysis, the elbow may exhibit some instability after injury. To evaluate the medial stability of the elbow, Woods and Tullos191 and Schwab et al.157 advocated a simple valgus stress test. This test is performed with the patient supine and the arm abducted 90 degrees. The shoulder and arm are externally rotated 90 degrees. The elbow must be flexed at least 15 degrees to eliminate the stabilizing force of the olecranon. If the elbow is unstable, simple gravity forces will open the medial side. A small additional weight or sedation may be necessary to acquire an accurate assessment of the medial stability with this test. 
Ulnar nerve function must be carefully tested before initiating treatment and documented in the medical record. 

Imaging Studies of Medial Epicondyle Avulsion Fractures

Good quality AP and lateral radiographs are essential. Oblique radiographs as well as comparison radiographs of the opposite elbow are often helpful when the interpretation of initial images is not conclusive. Widening or irregularity of the apophyseal line may be the only clue in fractures that are slightly displaced or nondisplaced. If the fragment is significantly displaced, the radiographic diagnosis is usually obvious. If the fragment is totally incarcerated in the joint, however, it may be hidden by the overlying ulnar or distal humerus. The clue here is the total absence of the epicondyle from its normal position just medial and posterior to the medial metaphysis. Knowledge of the order and approximate age of appearance of elbow ossification centers is necessary to appreciate the absence of the epicondyle when it should be present. CT scans can be diagnostic in confusing situations. 
Potter136 suggested that properly performed MRI might disclose acute or chronic injury to the medial epicondylar apophysis, recommending pulse sequences for evaluating the apophysis include fat-suppressed gradient-echo imaging. On MRI, increased signal intensity and abnormal widening of the medial epicondylar physis are seen, typically with surrounding soft tissue edema. 
Fractures of the medial epicondyle, even if displaced, may not produce positive fat pad signs.60,160 If the fracture is only minimally displaced and if it is the result of an avulsion injury, there may be no effusion because all the injured tissues remain extra-articular. In fractures associated with elbow dislocation, there is rupture of the capsule, so its ability to confine the hemarthrosis is lost. In minimally displaced fractures of the medial epicondyle with significant hemarthrosis, the evaluation must be especially thorough to ensure that an unrecognized fracture involving the medial condylar physis is not present. 
The ability to accurately measure medial epicondyle fracture displacement has recently been questioned by several authors who have published work regarding this concern. In a study of medial epicondyle fracture radiographs in 38 patients, Pappas et al.129 reported poor intraobserver and interobserver agreement with regard to fracture displacement measurement, and questioned the value of perceived fracture displacement as a criterion for choosing surgical versus nonsurgical treatment.In a separate publication, a series of 11 patients judged to have nondisplaced or minimally displaced medial epicondyle fractures had their fractures imaged by both standard radiography and CT.38 Medial and anterior displacement were then measured on standard radiographs and CT images and compared. Edmonds reported statistically significant differences between standard radiographs and CT images in all measurements with marked increased displacement appreciated on CT scan including six fractures with greater than 10 mm of displacement. To improve our ability to accurately measure fracture displacement on standard radiographs, Klatt and Aoki86 performed a review of 171 normal AP and lateral elbow radiographs describing the relationship between the medial epicondyle center and reproducible local anatomic landmarks. On the AP radiographs the medial epicondyle center was located 0.5 mm inferior to a line based on the inferior olecranon fossa and on the lateral radiograph the medial epicondyle center was located 1.2 mm anterior to the posterior humeral line. 

Differential Diagnosis of Medial Epicondyle Avulsion Fractures

The major injuries to differentiate from isolated medial epicondyle fractures are those fractures involving the medial condylar physis. This is especially true if secondary ossification centers are not present (see Chapter 20 “Fractures Involving the Medial Condylar Physis”). If there is a significant hemarthrosis or a significant piece of metaphyseal bone accompanying the medial epicondylar fragment, arthrography or MRI may be indicated to determine if there is an intra-articular component to the fracture (Fig. 18-38). Other elbow fractures that can be associated with this injury include fracture of the radial neck, olecranon, or coronoid process. 
Figure 18-38
Intra-articular extension.
 
A: Injury film in a 7-year-old girl who was initially suspected of having only a fracture of the medial epicondyle. In addition to moderate displacement, there was a significant metaphyseal fragment (arrow). B: An arthrogram revealed intra-articular components (arrow), which defined this injury instead as a fracture involving the medial condylar physis.
 
(Courtesy of Carl McGarey, MD.)
A: Injury film in a 7-year-old girl who was initially suspected of having only a fracture of the medial epicondyle. In addition to moderate displacement, there was a significant metaphyseal fragment (arrow). B: An arthrogram revealed intra-articular components (arrow), which defined this injury instead as a fracture involving the medial condylar physis.
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Figure 18-38
Intra-articular extension.
A: Injury film in a 7-year-old girl who was initially suspected of having only a fracture of the medial epicondyle. In addition to moderate displacement, there was a significant metaphyseal fragment (arrow). B: An arthrogram revealed intra-articular components (arrow), which defined this injury instead as a fracture involving the medial condylar physis.
(Courtesy of Carl McGarey, MD.)
A: Injury film in a 7-year-old girl who was initially suspected of having only a fracture of the medial epicondyle. In addition to moderate displacement, there was a significant metaphyseal fragment (arrow). B: An arthrogram revealed intra-articular components (arrow), which defined this injury instead as a fracture involving the medial condylar physis.
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Treatment Options for Medial Epicondyle Apophysis Fractures

Better implants, improved surgical technique, greater appreciation of the importance of the ulnar collateral ligament inserting on the medial epicondyle, and increased understanding of the degree of displacement in fractures previously thought to be nondisplaced all contribute to a general trend toward more frequent surgical treatment of medial epicondyle fractures.53 In a 2012 article titled “Medial Epicondyle Fractures In Children: Clinical Decision Making In The Face Of Uncertainty,” Mehlman and Howard114 acknowledge the dearth of high-level evidence in the published literature on this topic but reports that meta-analysis of clinical research with a particular focus on harm supports surgical treatment for most patients. Independent of whether a nonoperative or operative approach is chosen for the management of a particular medial epicondyle fracture, treatment goals remain to obtain fracture healing and to promote the return of motion, strength, and stability to the elbow.131 
Even though our ability to measure fracture displacement may be less accurate than we believed in the past, displacement remains an important fracture to consider when making treatment decisions. Additional concerns include intra-articular fragment entrapment, ulnar nerve symptoms, and patient activity level (Fig. 18-39). 
Figure 18-39
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Figure 18-39
Algorithm.
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Undisplaced or Minimally Displaced Fractures

The apophyseal line remains intact in undisplaced medial epicondyle fractures. The clinical manifestations usually consist only of swelling and local tenderness over the medial epicondyle. Crepitus and motion of the epicondyle are usually not present. On radiographs, the smoothness of the edge of the apophyseal line remains intact. Although there may be some loss of soft tissue planes medially on the radiograph, displacement of the elbow fat pads may not be present because the pathology is extra-articular.60 
Fractures with displacement usually result from a stronger avulsion force, so there is often more soft tissue swelling. Palpating the fragment may elicit crepitus because the increased displacement allows motion of the fragment. On radiographs, there is a loss of parallelism of the smooth sclerotic margins of the physis (Fig. 18-40).160 The radiolucency in the area of the apophyseal line is usually increased in width. 
Figure 18-40
AP radiograph shows loss of normal smooth margins of the physis.
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Significantly Displaced Fractures

In significantly displaced fractures the fragment may be palpable and freely movable. When displaced a considerable distance from the distal humerus, crepitus between the fragments may not be present. Significantly displaced fractures may be associated with an elbow dislocation that reduced spontaneously and there may be no documentation of the original dislocation. On radiograph, the long axis of the epicondylar apophysis is typically rotated medially (Fig. 18-41). The displacement often exceeds 5 mm, but the fragment remains proximal to the true joint surface. 
Figure 18-41
Displaced medial epicondylar fracture.
 
AP view of an elbow in which the epicondyle (arrow) is significantly displaced both distally and medially. In addition, the fragment is rotated medially.
AP view of an elbow in which the epicondyle (arrow) is significantly displaced both distally and medially. In addition, the fragment is rotated medially.
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Figure 18-41
Displaced medial epicondylar fracture.
AP view of an elbow in which the epicondyle (arrow) is significantly displaced both distally and medially. In addition, the fragment is rotated medially.
AP view of an elbow in which the epicondyle (arrow) is significantly displaced both distally and medially. In addition, the fragment is rotated medially.
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Entrapment of the Epicondylar Fragment into the Joint

Without Elbow Dislocation

In many instances, the elbow appears reduced. The key clinical finding is a block to motion, especially extension. The epicondylar fragment is usually between the joint surfaces of the trochlea and the semilunar notch of the olecranon. On radiograph, any time the fragment appears at the level of the joint, it must be considered to be totally or partially within the elbow joint until proven otherwise.132 If the radiograph is examined carefully, the elbow is usually found to be incompletely reduced. Because of an impingement of the fragment within the joint, a good AP view may be difficult to obtain because of the inability to extend the elbow fully. If the fracture is old the fragment may be fused to the coronoid process, and widening of the medial joint space may be the only clue that the fragment is lying in the joint. The epicondylar ossification center may become fragmented and mistaken for the fragmented appearance of the medial crista of the trochlea.26,148 Absence of the apophyseal center on the radiograph may be further confirmatory evidence that the fragment is within the joint. Comparison radiographs of the opposite elbow may be necessary to delineate the true pathology. 

With Elbow Dislocation

If the elbow is dislocated, the fragment will occasionally lie within the joint and prevent reduction. Recognition of this fragment as being within the joint before a manipulation should alert the physician to the possible need for open reduction. There should be adequate relaxation during the manipulative process. An initial manipulation to extract the fragment from the elbow joint may need to be accomplished before a satisfactory closed reduction of the elbow joint can be obtained (Fig. 18-42). 
Figure 18-42
Dislocation with incarceration.
 
A: AP view showing a posterolateral elbow dislocation. The presence of the medial epicondyle within the elbow joint (arrow) prevented a closed reduction. B: The lateral view of the same elbow demonstrates the fragment (arrow) between the humerus and olecranon.
A: AP view showing a posterolateral elbow dislocation. The presence of the medial epicondyle within the elbow joint (arrow) prevented a closed reduction. B: The lateral view of the same elbow demonstrates the fragment (arrow) between the humerus and olecranon.
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Figure 18-42
Dislocation with incarceration.
A: AP view showing a posterolateral elbow dislocation. The presence of the medial epicondyle within the elbow joint (arrow) prevented a closed reduction. B: The lateral view of the same elbow demonstrates the fragment (arrow) between the humerus and olecranon.
A: AP view showing a posterolateral elbow dislocation. The presence of the medial epicondyle within the elbow joint (arrow) prevented a closed reduction. B: The lateral view of the same elbow demonstrates the fragment (arrow) between the humerus and olecranon.
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Fractures Through the Epicondylar Apophysis

Fractures through the body of the epicondyle can result from either a direct blow or avulsion of only part of the apophysis. In either case, the fragments may or may not be displaced. The normal lucent line formed by the overlying metaphyseal border should not be confused with this injury. Although described by Silberstein et al.,160 this intrafragment fracture is a rare presentation usually seen with throwing athletes. 

Treatment Options for Medial Epicondyle Avulsion Fractures

There appears to be consensus that fractures which are undisplaced or minimally displaced less than 2 mm should be treated nonoperatively. Minimally displaced fractures may be treated using simple immobilization for comfort or cast immobilization for 2 to 3 weeks. Some investigators have recommended initiation of motion early to prevent stiffness, which is the most common complication of this injury.17,161 Likewise, there is agreement that if the medial epicondyle fragment is irreducible and is incarcerated within the elbow joint, then the accepted treatment is surgical extraction and stable internal fixation. 
However, controversy remains as to the optimal treatment method for patients with displacement more than 2 mm. 

Nonoperative Treatment of Medial Epicondyle Avulsion Fractures

Josefsson and Danielsson75 reported 35-year follow-up results in 56 isolated fractures treated nonoperatively. Although more than 60% of their patients demonstrated nonunion on radiograph, these investigators reported a high percentage of good and excellent results. Other reports in the literature4,128,188 also demonstrated overall good results with nonoperative management. 
Results of fractures associated with a documented elbow dislocation are less favorable15,46 for patients treated nonoperatively and operatively (Table 18-12). 
 
Table 18-12
Medial Epicondyle Fractures
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Table 18-12
Medial Epicondyle Fractures
Nonoperative Treatment
Indications Relative Contraindications
Displacement less than 2 mm Incarcerated fragment within joint
Low-to-moderate activity demands Displacement greater than 10 mm
Displaced fracture involving the dominant arm in a throwing athlete; either arm in gymnast or wrestler
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Operative Treatment of Medial Epicondyle Avulsion Fractures

Early studies comparing nonoperative and operative treatment often reported superior results in the nonsurgical group.15,17,188 These three studies were published in the 1970s and 1980s reporting patients treated in the decades prior, before the availability of high-quality fluoroscopic imaging and cannulated small-diameter screws. More recent literature describes excellent results obtained with surgical treatment. Louahem et al.93 from Montpellier, France, report excellent results in 130 and good results in 9 of 139 displaced medial epicondyle fractures treated surgically. Hines et al.,67 whose practice was to surgically repair all fractures displaced more than 2 mm, found that 96% of their patients had good-to-excellent results. Poor results were attributed mainly to technical errors. 

Indications for Operative Intervention in Medial Epicondyle Avulsion Fractures

Indications for operative intervention in acute injuries are divided into two categories: Absolute and relative. The single absolute indication is incarceration of the epicondylar fragment within the joint. The relative indications include ulnar nerve dysfunction, a need for elbow stability, and a desire to avoid symptomatic nonunion. 

Incarceration in the Joint—Absolute

If the fragment is found in the joint acutely, it must be removed. There are proponents of nonsurgical and surgical techniques for extraction. 
Nonoperative Extraction
Various methods of extracting the fragment by nonoperative methods have been proposed. The success rate of extracting the fragment successfully from the joint by manipulation alone at best has been reported at approximately 40%.132 All the nonoperative methods require either heavy sedation or light general anesthesia. 
Roberts Manipulative Technique
The manipulative technique most commonly used is the method popularized by Roberts.41,146 It involves placing a valgus stress on the elbow while supinating the forearm and simultaneously dorsiflexing the wrist and fingers to place the forearm muscles on stretch; theoretically, this maneuver should extract the fragment from the joint. To be effective, this procedure should be carried out within the first 24 hours after injury. 
Operative Extraction
Failure to extract the fragment by manipulative techniques is an indication to proceed with open surgical extraction. Once open extraction and reduction have been performed, many methods have been advocated to stabilize the fragment, including screw fixation or suture fixation in comminuted fractures. Excision has also been advocated, especially if the fragment is comminuted. 

Ulnar Nerve Dysfunction—Relative

Ulnar nerve dysfunction is a relative indication for operative intervention. If there are mild-to-moderate ulnar nerve symptoms at the time of the injury, there is usually no need to explore the nerve, because most of these mild symptoms resolve spontaneously.17,34 If the dysfunction is complete, then the ulnar nerve may be directly impinged upon by the fracture or entrapped within the fracture site and should be explored surgically. One of the original fears was that the raw surface of the fracture fragment would create scar tissue around or adjacent to the nerve and cause continued dysfunction. Thus, it was originally recommended that the ulnar nerve should be transposed at the time of open reduction.184 Subsequent reports have not found this step to be necessary.174 
There has been some question as to whether delayed ulnar nerve symptoms can occur after fractures of the epicondyle that are not associated with elbow dislocation. However, in a review of more than 100 patients with uncomplicated fractures involving the medial epicondylar apophysis, Patrick132 could not find any instance in which a delayed ulnar neuritis developed. 

Joint Stability—Relative

Woods and Tullos191 suggested that even minor forms of valgus instability after elbow injuries involving the medial epicondylar apophysis can cause significant disability in athletes. This condition is especially true in athletes who must have a stable upper extremity, such as baseball pitchers, gymnasts, or wrestlers. In younger adolescents (younger than 14 years of age), the anterior band of the ulnar collateral ligament often displaces with the apophyseal fragment. In older individuals (15 years or older), large fragments may be avulsed without a ligamentous injury. Rather than depending on arbitrary measurements of fracture displacement, Woods and Tullos191 recommended using the gravity valgus stress test to determine the presence or absence of valgus instability. They believed that demonstration of a significant valgus instability, using this simple gravity test, was an indication for surgical intervention in patients who require a stable elbow for their athletic activities (Table 18-13). 
 
Table 18-13
ORIF of Medial Epicondyle Fractures
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Table 18-13
ORIF of Medial Epicondyle Fractures
Preoperative Planning Checklist
  •  
    OR Table: Spine table or flat radiolucent table
  •  
    Position: Prone, “sloppy lateral,” or supine position
  •  
    Fluoroscopy location: C-arm and monitor are positioned on the side of the table opposite the surgeon
  •  
    Equipment: 4- or 4.5-mm diameter cannulated or solid screws
  •  
    Tourniquet: Nonsterile tourniquet high on the affected arm
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Author's Preferred Treatment for Medial Epicondyle Fractures

Determining the appropriate treatment for each patient involves a process of shared decision making in which the benefits and risks of each treatment alternative are discussed with the family. We use the general treatment guidelines outlined in Table 18-14 as a starting point for discussion with the patient and family. We strongly consider the expected activity of the patient and extremity in deciding with the patient and family on nonoperative or operative treatment. 
 
Table 18-14
Author's Preferred Treatment for Medial Epicondyle Fractures
Nonoperative Treatment Indications
Nondisplaced or minimally displaced
Displaced in patients with low-demand upper-extremity function
Operative Treatment Indications
Absolute: Irreducible incarcerated fragment in the elbow joint
Relative: Ulnar nerve dysfunction
Relative: Patient with high-demand upper-extremity function
X
For uncomplicated fractures of less than 2 mm of displacement we recommend nonoperative treatment. The parents are warned that no matter which type of treatment is provided, some loss of elbow extension may occur. They should be reassured, however, that this loss of motion, if it does occur, is not usually of any functional or cosmetic significance. The elbow is immobilized initially with a posterior splint or hinged elbow brace, used mainly for comfort and some support. 
Because stiffness is the most common complication of this injury, we promote early active motion. Five to 10 days following the injury, the initial splint is exchanged for a removable splint and the patient is instructed on range-of-motion exercises. The patient uses the splint at school and outside the home, but within the home the splint is exchanged for a sling as soon as the patient feels he or she no longer needs the splint for support. Redislocation or instability is rare but elbow stiffness is common, so it is more important to initiate motion early. Physical therapy should be used only if voluntary active motion is difficult to obtain. The therapist should emphasize modalities designed to decrease swelling and pain and reestablish strength. Range of motion should be achieved only by active means, not by passive stretching. 

Operative Indications

Our indications for operative intervention are twofold. First and foremost are fractures in which the fragments cannot be extracted by manipulative means from within the elbow joint. Second, we stabilize the epicondyles operatively in patients whose expected physical activity level requires a stable elbow. We realize that it is difficult to predict the athletic potential of a young child but most parents do see great possibilities for their offspring. 

Acute Incarceration in the Joint

If the elbow is reduced and if the ulnar nerve is intact, we use Roberts' manipulative technique146 to attempt to extract the fragment. If this technique fails to remove the fragment or if there is any ulnar nerve dysfunction, we proceed directly with an open procedure, extracting the fragment under direct vision. We usually stabilize these fractures with a single cannulated screw and washer, which allows almost immediate motion, rather than wires or pins (Fig. 18-43). Follow-up care is essentially the same as after closed treatment. Active motion is initiated 5 to 10 days postoperatively. 
Figure 18-43
A 13-year-old boy is referred for treatment following posterolateral elbow dislocation.
 
A, B: Notice on the AP and lateral radiographs that a medial epicondyle fracture cannot be easily seen but the medial epicondyle ossification center is absent from its normal anatomic position at the distal medial posterior humerus. C, D: A prereduction CT scan was obtained at the outside facility clearly demonstrating the medial epicondyle fragment within the elbow joint. E, F: Four months following surgical removal of the incarcerated medial epicondyle fragment and internal fixation of the fracture, a follow-up CT scan demonstrates anatomic reduction and excellent position of the single screw (with washer) within the medial column of bone, engaging subcortical bone for maximum fixation. The fracture is completely healed and the patient has returned to virtually all activities.
A, B: Notice on the AP and lateral radiographs that a medial epicondyle fracture cannot be easily seen but the medial epicondyle ossification center is absent from its normal anatomic position at the distal medial posterior humerus. C, D: A prereduction CT scan was obtained at the outside facility clearly demonstrating the medial epicondyle fragment within the elbow joint. E, F: Four months following surgical removal of the incarcerated medial epicondyle fragment and internal fixation of the fracture, a follow-up CT scan demonstrates anatomic reduction and excellent position of the single screw (with washer) within the medial column of bone, engaging subcortical bone for maximum fixation. The fracture is completely healed and the patient has returned to virtually all activities.
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Figure 18-43
A 13-year-old boy is referred for treatment following posterolateral elbow dislocation.
A, B: Notice on the AP and lateral radiographs that a medial epicondyle fracture cannot be easily seen but the medial epicondyle ossification center is absent from its normal anatomic position at the distal medial posterior humerus. C, D: A prereduction CT scan was obtained at the outside facility clearly demonstrating the medial epicondyle fragment within the elbow joint. E, F: Four months following surgical removal of the incarcerated medial epicondyle fragment and internal fixation of the fracture, a follow-up CT scan demonstrates anatomic reduction and excellent position of the single screw (with washer) within the medial column of bone, engaging subcortical bone for maximum fixation. The fracture is completely healed and the patient has returned to virtually all activities.
A, B: Notice on the AP and lateral radiographs that a medial epicondyle fracture cannot be easily seen but the medial epicondyle ossification center is absent from its normal anatomic position at the distal medial posterior humerus. C, D: A prereduction CT scan was obtained at the outside facility clearly demonstrating the medial epicondyle fragment within the elbow joint. E, F: Four months following surgical removal of the incarcerated medial epicondyle fragment and internal fixation of the fracture, a follow-up CT scan demonstrates anatomic reduction and excellent position of the single screw (with washer) within the medial column of bone, engaging subcortical bone for maximum fixation. The fracture is completely healed and the patient has returned to virtually all activities.
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Prevention of Valgus Instability

Currently, our most common indication for operative intervention is to ensure a stable elbow in patients participating in activities which may require stability to valgus stress (Fig. 18-44). This usually involves the dominant extremity of baseball pitchers, tennis players, or football quarterbacks. In wrestlers and gymnasts, the stability of the nondominant extremity also must be considered, which is best achieved with operative fixation. 
Figure 18-44
Operative stabilization.
 
A: Injury film in a 12-year-old gymnast. Although this was a nondominant extremity, it was thought that both elbows needed stability. B: Radiographs taken 4 weeks postoperatively show stabilization of the fragment with a single screw. There was also calcification of the lateral ligaments (arrows), confirming that the elbow was probably originally dislocated as well.
 
(From Wilkins KE. Fractures of the medial epicondyle in children. Instr Course Lect. 1991; 40:1–8, with permission.)
A: Injury film in a 12-year-old gymnast. Although this was a nondominant extremity, it was thought that both elbows needed stability. B: Radiographs taken 4 weeks postoperatively show stabilization of the fragment with a single screw. There was also calcification of the lateral ligaments (arrows), confirming that the elbow was probably originally dislocated as well.
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Figure 18-44
Operative stabilization.
A: Injury film in a 12-year-old gymnast. Although this was a nondominant extremity, it was thought that both elbows needed stability. B: Radiographs taken 4 weeks postoperatively show stabilization of the fragment with a single screw. There was also calcification of the lateral ligaments (arrows), confirming that the elbow was probably originally dislocated as well.
(From Wilkins KE. Fractures of the medial epicondyle in children. Instr Course Lect. 1991; 40:1–8, with permission.)
A: Injury film in a 12-year-old gymnast. Although this was a nondominant extremity, it was thought that both elbows needed stability. B: Radiographs taken 4 weeks postoperatively show stabilization of the fragment with a single screw. There was also calcification of the lateral ligaments (arrows), confirming that the elbow was probably originally dislocated as well.
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We have not found the valgus stress test to be helpful in deciding on the need for operative stabilization of an athlete's medial epicondyle. Almost all of these patients with any significant displacement have a positive valgus stress test. Our decision is based primarily on the patient's need to have a very stable elbow for his or her athletic or work activity. 
Fixation must be stable enough to allow early motion. Pins provide stability but do not allow early motion. Fortunately, most patients are mature enough so that the fragment can be secured with a solid or cannulated screw (Table 18-15). 
 
Table 18-15
ORIF of Medial Epicondyle Fractures
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Table 18-15
ORIF of Medial Epicondyle Fractures
Surgical Steps
  •  
    Position patient prone or “sloppy lateral” allowing the arm to be positioned in a “figure 4” configuration with the forearm resting behind the patient's back (Fig. 18-45). This applies a varus force to the elbow and facilitates fracture reduction.
  •  
    A longitudinal 5-cm incision is made just posterior to the anatomic location of the medial epicondyle.
  •  
    Expose the ulnar nerve and ensure that it is not trapped within the fracture. Transposition of the nerve is not necessary. If not already torn by the injury, release the fascia overlying the ulnar nerve as the nerve travels in its groove behind the medial epicondyle. This allows mobilization of the nerve and gentle retraction.
  •  
    Exposure of the ulnar nerve will also expose the fracture site. The medial epicondyle fragment will typically be displaced distally and rotated anteriorly.
  •  
    Preserve soft tissue attachments to the medial epicondyle and elevate just enough soft tissue at the fracture site to allow adequate visualization to achieve an anatomic reduction.
  •  
    Using a penetrating towel clamp, grasp the flexor–pronator group fascia where it attaches to the medial epicondyle. This will prevent fragmentation of the medial epicondyle.
  •  
    Using the towel clamp to manipulate the fragment, anatomically reduce the medial epicondyle to the distal humeral metaphysis. Consider provisionally fixing the fragment in place with a small-diameter K-wire.
  •  
    Under fluoroscopic guidance place a cannulated guide pin or solid drill through the center of the medial epicondyle fragment into the center of the medial column of bone in the distal humerus and confirm anatomic reduction of the fracture.
  •  
    Drill and tap into the medial column of the distal humeral metaphysis.
  •  
    Place a single screw within the dense cancellous bone of the medial column. Do not use a screw so long that it ends within the central intramedullary canal where screw purchase is poor (Figs. 18-43 and 18-44).
  •  
    Confirm anatomic reduction of the fracture and position of the implant with fluoroscopy before wound closure.
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Figure 18-45
 
A: The patient is positioned prone on a radiolucent table with the shoulder internally rotated and the arm resting on the patient's back. B: The medial aspect of the elbow is immediately accessible to the surgeon. The prone position results in application of a gentle varus stress to the elbow which facilitates maintenance of reduction while stable internal fixation is achieved.
A: The patient is positioned prone on a radiolucent table with the shoulder internally rotated and the arm resting on the patient's back. B: The medial aspect of the elbow is immediately accessible to the surgeon. The prone position results in application of a gentle varus stress to the elbow which facilitates maintenance of reduction while stable internal fixation is achieved.
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Figure 18-45
A: The patient is positioned prone on a radiolucent table with the shoulder internally rotated and the arm resting on the patient's back. B: The medial aspect of the elbow is immediately accessible to the surgeon. The prone position results in application of a gentle varus stress to the elbow which facilitates maintenance of reduction while stable internal fixation is achieved.
A: The patient is positioned prone on a radiolucent table with the shoulder internally rotated and the arm resting on the patient's back. B: The medial aspect of the elbow is immediately accessible to the surgeon. The prone position results in application of a gentle varus stress to the elbow which facilitates maintenance of reduction while stable internal fixation is achieved.
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Operative Technique

Our preferred operative technique involves positioning the patient prone or in a “sloppy lateral” position on a radiolucent table (Table 18-13) (Fig. 18-45). The arm is placed in a “figure 4” position with the forearm resting across the patient's back. This position places a varus stress on the elbow which facilitates fracture reduction while allowing a direct medial approach to the fracture site. The fragment is usually displaced distally and anteriorly. Interposed periosteum and soft tissue are removed from the fracture site, and the clot is extracted by irrigation. It is important to identify and protect the ulnar nerve along with medial antebrachial cutaneous nerves. If not already disrupted by the fracture, we typically release the cubital tunnel retinaculum, but a complete dissection of the nerve is usually unnecessary. A small towel clip or clamp is used to grasp the fascia and tendinous origin of the flexor–pronator group, avoiding fragmentation of the medial epicondyle, and the fracture is reduced while the elbow is flexed and the forearm is pronated. The medial epicondyle is reduced under direct vision to its anatomic position on the posterior aspect of the distal medial humerus. Temporarily stabilization with one or two small K-wires, or the guide pin for a cannulated screw, is performed. Final fixation is achieved using a partially threaded screw to compress the medial epicondyle fragment against the humeral metaphysic. In large male patients a 4.5-mm diameter screw is used, and a 4-mm diameter screw is appropriate for smaller elbows. Because cannulation increases the core diameter of the screw shaft, small-diameter cannulated screws have less coarse threads and potentially less fixation. For this reason we will often use a noncannulated 4-mm diameter screw. All fixations depend on a single screw which must be strong enough to allow early motion. Therefore every effort should be made to optimize its strength. Bicortical fixation has been used but injury to the radial nerve when penetrating the opposite cortex with a cannulated screw has been reported.104 Dense cancellous bone of the medial condyle provides excellent fixation but care should be taken to avoid using a longer screw with threads solely within the hollow central intramedullary canal proximal to the olecranon fossa where fixation is less secure (Figs. 18-43 and 18-44). 
A washer may be added to increase fixation surface area and reduce the risk of fragmenting the medial epicondyle with compression but this does make the implant slightly more prominent. After removal of the guide pin or K-wires, the elbow is assessed to ensure valgus stability and reestablishment of a full range of motion. After the surgical incision is closed, the extremity is placed in a well-padded posterior splint which is removed 5 to 10 days postoperatively and replaced with a removable splint or hinged brace, allowing initiation of early active range-of-motion exercise. 
If the epicondyle is fragmented and if there is a need to achieve elbow stability, an American Society for Internal Fixation spiked washer can be used to secure the multiple pieces to the metaphysis. If the washer is used, a second procedure may be necessary to remove the spike washer once the epicondyle is securely united to the metaphysis. If internal fixation is impossible, we simply excise the fragments and reattach the ligament to the bone and periosteum at the base of the epicondylar defect (Table 18-16). 
 
Table 18-16
Medial Epicondyle Fractures
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Table 18-16
Medial Epicondyle Fractures
Potential Pitfalls and Preventions
Pitfalls Preventions
Pitfall #1 Failure to recognize a medial epicondyle fragment entrapped within the joint following elbow dislocation Prevention 1: All children older than age 5 years should have a medial epicondyle ossification center which must be visualized in its normal anatomic location following elbow dislocation reduction.
Pitfall #2 Fragmentation of the medial epicondyle during ORIF Prevention 2a: Instead of grasping the medial epicondyle bone with a clamp, grasp the flexor–pronator fascia where it attaches to the medial epicondyle.
Prevention 2b: Avoid overtightening the screw which is fixing the medial epicondyle in place.
Prevention 2c: Consider using a washer to distribute pressure over greater surface area
Pitfall #3 Injury to the radial nerve Prevention 3a: Do not obtain bicortical fixation in the lateral cortex of the distal humerus with the medial epicondyle screw
X

Management of Expected Adverse Outcomes and Unexpected Complications Related to Medial Epicondyle Fractures

Although much has been written about fractures involving the medial epicondylar apophysis, few complications are attributed to the fracture itself. The major complications that result in loss of function are failure to recognize incarceration in the joint and ulnar or medial nerve dysfunction. Most of the other complications are minor and result in only minimal functional or cosmetic sequelae (Table 18-17). 
 
Table 18-17
Fractures of the Medial Epicondylar Apophysis: Complications
Major
Failure to recognize incarceration in the elbow
Ulnar nerve dysfunction
Minor
Myositis ossificans
Calcification of the collateral ligaments
Loss of motion
Cosmetic effects
Nonunion in the high-performance athlete
X

Major Complications in Medial Epicondyle Fractures

Failure to Recognize Fragment Incarceration

Failure to recognize incarceration of the epicondylar fragment into the joint can result in significant loss of elbow motion, especially if it remains incarcerated for any length of time. Fowles et al.45 challenged the opinion that surgery is detrimental in patients with late incarceration, and the idea remains controversial. In their patients in whom the fragment was surgically extracted an average of 14 weeks after injury, 80% more elbow motion was regained. In addition, the patients' preoperative pain was relieved, and the ulnar nerve dysfunction resolved. Lopez et al.92 described a case report of an incarcerated fragment treated 12 weeks following injury by excision of the fragment. Twelve months following surgery the ulnar neuropathy had resolved, the patient had minimal symptoms and excellent motion. 
The long-term outcome following intra-articular retention of the medial epicondyle fragment is unpredictable. Rosendahl148 reported an 8-year follow-up of a fragment retained within the joint. The epicondyle had fused to the semilunar surface of the ulna, producing a large bony prominence clinically. There was only minor loss of elbow motion, with little functional disability. Potenza et al.135 described a case report of a neglected intra-articular medial epicondyle fracture with 48-year follow-up resulting in minimal symptoms. Similar to the case reported by Rosendahl, the fragment had fused to the olecranon where it caused minimal problems. 

Ulnar Nerve Dysfunction

The other major complication associated with this injury is the development of ulnar nerve dysfunction. The incidence of ulnar nerve dysfunction varies from 10% to 16%.15,105 If the fragment is entrapped in the joint, the incidence of ulnar nerve dysfunction may be as high as 50%.15,42 More profound ulnar nerve injury has been reported after manipulative procedures.132 Thus, in patients with fragments incarcerated in the joint, manipulation may not be the procedure of choice if a primary ulnar nerve dysfunction is present. Patients in whom the fragment was left incarcerated in the joint for a significant time have experienced poor recovery of the primary ulnar nerve injury.105 A consistent finding noted by surgeons when exploring the ulnar nerve and removing the incarcerated fragment from the joint has been a thick fascial band binding the ulnar nerve to the underlying muscle.12,132 Constriction by this band has been noted to cause immediate or late dysfunction of the ulnar nerve. 
Delayed ulnar nerve palsy has also been reported following surgical treatment. Anakwe et al.9 described two cases in which open reduction of a medial epicondyle was performed. Patients presented at 1- and 2-week follow-up with complete ulnar nerve palsy despite normal neurologic examination immediately postoperatively. In both patients, on re-exploration the ulnar nerve was found to be compressed by scar tissue between two heads of the flexor carpi ulnaris just distal to the medial epicondyle. Both patients experienced a complete recovery following ulnar nerve decompression. 

Symptomatic Nonunion

Nonunion of the medial epicondyle fragment with the distal metaphysis occurs in up to 50% of fractures with significant displacement.15 Although the majority of the nonunions cause minimal problems, symptomatic nonunions do occur (Fig. 18-46). Smith et al.162 from Boston Children's Hospital reviewed 137 patients treated for medial epicondyle fracture at their institution. Of the 42 fractures which were treated nonoperatively, nonunion occurred in 19 fractures and 8 of those fracture nonunion patients experienced symptoms significant enough to warrant surgical treatment at a mean of 12 months following their initial injury. All patients were treated with open reduction and internal fixation of the ununited fragment, three of whom underwent grafting of the nonunion site. Successful fracture union was achieved in seven of the eight fractures and all patients experienced significant symptomatic improvement. Shukla and Cohen159 described the treatment results of five patients with chronic medial epicondyle nonunion using a tension band construct At a mean follow-up of 31 months all fractures were healed, patients reported being satisfied with their surgery and measurable outcome measures were significantly improved. 
Figure 18-46
Nonunion in an athlete.
 
This 15-year-old baseball pitcher had an untreated medial epicondyle fracture 1 year before this radiograph. He developed a fibrous union, but the epicondyle was shifted distally (arrow). His elbow was unstable enough to prevent him from pitching.
This 15-year-old baseball pitcher had an untreated medial epicondyle fracture 1 year before this radiograph. He developed a fibrous union, but the epicondyle was shifted distally (arrow). His elbow was unstable enough to prevent him from pitching.
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Figure 18-46
Nonunion in an athlete.
This 15-year-old baseball pitcher had an untreated medial epicondyle fracture 1 year before this radiograph. He developed a fibrous union, but the epicondyle was shifted distally (arrow). His elbow was unstable enough to prevent him from pitching.
This 15-year-old baseball pitcher had an untreated medial epicondyle fracture 1 year before this radiograph. He developed a fibrous union, but the epicondyle was shifted distally (arrow). His elbow was unstable enough to prevent him from pitching.
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Valgus Instability

Valgus instability following displaced medial epicondyle fracture nonunion is a very challenging problem and has been used as an argument for surgical treatment. Gilcrist and McKee50 reported good and excellent treatment results following excision of the ununited fragment and advancement of the medial collateral ligament complex with fixation to the distal humerus with suture anchors in five patients with symptomatic valgus elbow instability. Mayo Elbow Performance Score improved from 66 preoperatively to 91 postoperatively, and all patients were satisfied with the result. 

Radial Nerve Injury

When fixing a medial epicondyle fragment the operating surgeon must decide whether to accept fixation within the cancellous bone of the medial column or achieve bicortical fixation by gaining purchase in the lateral cortex of the proximal humeral metaphysis. Unfortunately the radial nerve travels on the surface of the humerus at the location where a bicortical screw penetrates the cortex. Marcu et al.104 have reported two cases of radial nerve injury with cannulated screw fixation. 

Minor Complications in Medial Epicondyle Fractures

The most common minor complication is loss of the final degrees of elbow extension. A loss of 5% to 10% can be expected to develop in about 20% of these fractures. Little functional deficit is attributed to this loss of elbow motion. Prolonged immobilization seems to be the key factor in loss of elbow extension. Again, it is important to emphasize before treatment is begun that loss of motion is common after this injury, regardless of the treatment method used. Sufficient fracture stability to allow for early motion is paramount to lessening the risk of functional loss of motion. 
Myositis ossificans is a rare occurrence following vigorous and repeated manipulation to extract the fragment from the joint. As with many other elbow injuries, myositis may be a result of the treatment rather than the injury itself. Myositis ossificans must be differentiated from ectopic calcification of the collateral ligaments, which involves only the ligamentous structures. This condition may occur after repeated injuries to the epicondyle and ligamentous structures (Fig. 18-47). Often, this calcified ligament is asymptomatic and does not seem to create functional disability. The cosmetic effects are minimal. In some patients, an accentuation of the medial prominence of the epicondyle creates a false appearance of an increased carrying angle of the elbow. In his extensive review, Smith161 recognized a slight decrease in the carrying angle in only two patients (Table 18-18). 
Figure 18-47
Heterotopic calcification.
 
A: Injury to an 11-year old who had moderate displacement of the medial epicondyle (arrow). B: One year later, she had considerable calcification of the ulnar collateral ligament (arrows). Other than mild instability with valgus stress, the patient had full range of motion and was asymptomatic.
 
(Courtesy of Mark R. Christofersen, MD.)
A: Injury to an 11-year old who had moderate displacement of the medial epicondyle (arrow). B: One year later, she had considerable calcification of the ulnar collateral ligament (arrows). Other than mild instability with valgus stress, the patient had full range of motion and was asymptomatic.
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Figure 18-47
Heterotopic calcification.
A: Injury to an 11-year old who had moderate displacement of the medial epicondyle (arrow). B: One year later, she had considerable calcification of the ulnar collateral ligament (arrows). Other than mild instability with valgus stress, the patient had full range of motion and was asymptomatic.
(Courtesy of Mark R. Christofersen, MD.)
A: Injury to an 11-year old who had moderate displacement of the medial epicondyle (arrow). B: One year later, she had considerable calcification of the ulnar collateral ligament (arrows). Other than mild instability with valgus stress, the patient had full range of motion and was asymptomatic.
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Table 18-18
Medial Epicondyle Fractures
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Table 18-18
Medial Epicondyle Fractures
Common Adverse Outcomes and Complications
Failure to recognize fragment incarceration
Ulnar nerve dysfunction
Symptomatic nonunion
Valgus instability
Radial nerve injury
Elbow stiffness
X

Chronic Tension Stress Injuries (Little League Elbow) in Medial Epicondyle Fractures

This chronic injury is related to overuse in skeletally immature baseball pitchers. Brogdon and Crow21 described the original radiographic findings in 1960. Later, Adams1 demonstrated that the radiographic changes were due to excessive throwing and emphasized the need for preventive programs. This injury is thought to be due to excessive tension on the medial epicondyle with secondary tendinitis. There can also be a repeated compression on the lateral condyle, producing an osteochondritis. 
Studies have shown that as long as the rules outlined by the Little League are followed (i.e., pitch counts of 50 to 75 pitches per game depending on age), the incidence of these chronic tension stress injuries is fairly low.47 Most of the problems arise when overzealous parents and coaches require excessive pitching preseason, at home between practices and/or participation on multiple teams. Albright et al.4 found a greater incidence in pitchers who had improper pitching techniques. The spectrum of these chronic injuries is outlined in Table 18-19
Table 18-19
Spectrum of Chronic Tension Stress Injuries of Medial Elbow Epicondylar Apophysis
Stress fracture of the epicondylar physis
Calcification of the ulnar collateral ligaments
Hypertrophy of the medial epicondyle
Acceleration of growth maturity with generalized synovitis and stiffness
Osteochondritis of the lateral condyle
X
In chronic tension stress injuries (Little League Elbow Syndrome), the history is usually quite characteristic. It is found in young baseball pitchers who are throwing an excessive number of pitches or who are just starting to throw curve pitches.47 Clinically, this syndrome is manifested by a decrease in elbow extension. Medial epicondylar pain is accentuated by a valgus stress to the elbow in extension. There is usually significant local tenderness and swelling over the medial epicondyle. 
On radiographs, the density of the bone of the distal humerus is increased because of the chronicity of the stress. The physeal line is irregular and widened. If the stress has been going on for a prolonged period, there may be hypertrophy of the distal humerus with accelerated bone growth. 
We use a multifaceted approach that involves educating the parents, coaches, and player. Once symptoms develop, all pitching activities must cease until the epicondyle and adjacent flexor muscle origins become nontender. In addition, local and systemic measures to decrease the inflammatory response are used. Once the initial pain and inflammation have decreased, a program of forearm and arm muscle strengthening is initiated. The pitching technique is also examined to see if any corrections need to be made. Once strength has been reestablished in the muscles in the upper extremity and motion has been fully reestablished, the patient is gradually returned to pitching with careful monitoring of the number of innings and pitches within a specified time period. 
In cases of chronic nonunion due to a chronic medial epicondylar stress fracture in older pitchers, open reduction with a compression screw and washer may be necessary to achieve union, stop pain, and allow return to full function. 

Pulled Elbow Syndrome (Nursemaid's Elbow)

Subluxation of the annular ligament, or pulled elbow syndrome, is a common elbow injury in young children.8,27,70,74,163 The term “nursemaid's elbow” and other synonyms have been used to describe this condition. The demographics associated with subluxation of the radial head have been well described.8,27,70,74,163 The mean age at injury is 2 to 3 years, with the youngest reported patient 2 months of age. It rarely occurs after 7 years of age; 60% to 65% of the children affected are girls, and the left elbow is involved in approximately 70%. It is difficult to determine the actual incidence because many subluxations are treated in primary care physician's offices, by parents, or resolve spontaneously before being seen by a physician. 

Mechanisms of Injury for Pulled Elbow Syndrome

Longitudinal traction on the extended elbow is the usual mechanism of injury (Fig. 18-48). Cadaver studies have shown that longitudinal traction on the extended elbow can produce a partial slippage of the annular ligament over the head of the radius and into the radiocapitellar joint, sometimes tearing the subannular membrane.108,115,154 Displacement of the annular ligament occurs most easily with the forearm in pronation. In this position, the lateral edge of the radial head, which opposes the main portion of the annular ligament, is narrow and round at its margin.98,108 In supination, the lateral edge of the radial head is wider and more square at its margin, thereby restricting slippage of the annular ligament. McRae and Freeman113 demonstrated that forearm pronation maintained the displacement of the annular ligament. 
Figure 18-48
The injury most commonly occurs when a longitudinal pull is applied to the upper extremity.
 
Usually the forearm is pronated. There may be a partial tear in the subannular membrane, allowing the annular ligament to subluxate into the radiocapitellar joint.
Usually the forearm is pronated. There may be a partial tear in the subannular membrane, allowing the annular ligament to subluxate into the radiocapitellar joint.
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Figure 18-48
The injury most commonly occurs when a longitudinal pull is applied to the upper extremity.
Usually the forearm is pronated. There may be a partial tear in the subannular membrane, allowing the annular ligament to subluxate into the radiocapitellar joint.
Usually the forearm is pronated. There may be a partial tear in the subannular membrane, allowing the annular ligament to subluxate into the radiocapitellar joint.
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X
After 5 years of age, the distal attachments of the subannular membrane and annular ligament to the neck of the radius have strengthened sufficiently to prevent its tearing and subsequent displacement.154 Previously, the theory was proposed that the radial head diameter was less in children than in adults and this contributed to subluxation of the annular ligament. However, cadaver studies of infants, children, and adults have shown that the ratio of the head and neck diameters is essentially the same.152,154 Griffin56 suggested that the lack of ossification of the proximal radial epiphysis in children less than 5 years of age made it more pliable, thereby facilitating slippage of the annular ligament. 
Amir et al.8 performed a controlled study comparing 30 normal children with 100 who had pulled elbow syndrome. They found an increased frequency of hypermobility or ligamentous laxity among children with pulled elbows. Also, there was an increased frequency of hypermobility in one or both parents of the involved children compared with noninvolved children, suggesting that hypermobility could be a factor predisposing children to this condition. 
Thus, the most widely accepted mechanism is that the injury occurs when the forearm is pronated, the elbow extended, and longitudinal traction is applied to the patient's wrist or hand (Fig. 18-48).109,113,156 Such an injury typically occurs when a young child is lifted or swung by the forearm or when the child suddenly steps down from a step or off a curb while one of the parents is holding the hand or wrist. 

Unusual Mechanisms

Newman122 reported that five of six infants under 6 months of age with a pulled elbow sustained the injury when rolling over in bed with the extended elbow trapped under the body. It was believed that this maneuver, especially if the infant was given a quick push to turn over by an older sibling or a parent, provided enough longitudinal traction to displace the annular ligament proximally. 

Associated Injuries with Pulled Elbow Syndrome

No other associated injuries have consistently been linked with pulled elbow syndrome. 

Assessment of Patients with Pulled Elbow Syndrome

History and Physical Examination

The history is usually that of an episode of a longitudinal pull on the elbow of the young child. The initial pain usually subsides rapidly, and the child does not appear to be in distress except that he or she is reluctant to use the involved extremity. The upper extremity is typically held at the side with the forearm pronated. A limited painless arc of flexion and extension may be present; however, any attempt to supinate the forearm produces pain and is met with resistance. Although there is no evidence of an elbow effusion, local tenderness may be present over the radial head and annular ligament. In some patients, the pain may be referred proximally to the shoulder but most complain of pain distally toward the wrist.8,70 
Unfortunately, the classic history is not always present.27,134,139,153,156 In some studies 33% to 49% of patients had no clear history of longitudinal traction to the elbow.153,156 In patients without a witnessed longitudinal traction injury, other causes, such as occult fracture or early septic arthritis, must be carefully ruled out. 

Imaging Studies for Pulled Elbow Syndrome

Standard Radiographs

Should x-rays be taken of every child before manipulation is attempted? If there is a reliable history of traction to the elbow, the child is 5 years of age or younger, and the clinical findings strongly support the diagnosis, x-rays are not necessary.8,27,139,154,177 If, however, there is an atypical history or clinical examination, x-rays should be obtained to be certain that there is not a fracture before manipulation is attempted. 
AP and lateral x-rays usually are normal,20,27,56,139,154,156,164 but subtle abnormalities may be present. Normally, the line down the center of the proximal radial shaft should pass through the center of the ossification center of the capitellum (radiocapitellar line).48,164 Careful review of x-rays may demonstrate the radial capitellar line to be lateral to the center of the capitellum in up to 25% of patients.48,164 Determination of this subtle change requires a direct measurement on the x-ray. Interestingly, the pulled elbow can be reduced by the radiology technician because the elbow x-rays are usually taken with the forearm supinated. The subluxation is reduced inadvertently when the technician places the forearm into supination to position it for the x-ray. Bretland19 suggested that if the best x-ray that can be obtained is an oblique view with the forearm in pronation, pulled elbow syndrome is the likely diagnosis. 

Ultrasonography

When the diagnosis is not evident, ultrasonography may be helpful,88,98 although not always reliable.155 The diagnosis is made by demonstrating an increase in the echo-negative area between the articular surfaces of the capitellum and the radial head and increased radial capitellar distance. Kosuwon et al.88 found that this distance is normally about 3.8 mm with forearm pronated. With a subluxated radial head, this measured 7.2 mm. A difference of 3 mm between the normal and affected sides, therefore, suggests radial head subluxation. 

Treatment Options for Pulled Elbow Syndrome

Nonoperative Treatment: Closed Reduction

Virtually all annular ligament subluxations are successfully treated by closed reduction. The traditional reduction maneuver has been to supinate the forearm.27,56,70,139,156,163 Some authors have recommended that supination be done with the elbow flexed, and others have found that supination alone with the elbow extended can affect a reduction. In many patients, a snapping sensation can be both heard and palpated when the annular ligament reduces (Fig. 18-49). More recently there has been significant interest in forearm hyperpronation as a reduction maneuver. More than one prospective randomized study has reported that hyperpronation is more successful than supination.16,96 Macias reported that reduction was successful in 40 of 41 patients (98%) in the hyperpronation group compared with 38 of 44 patients (86%) in the supination group. They concluded that the hyperpronation technique was more successful, required fewer attempts, and was often successful when supination failed. Generally, a full arc of supination to pronation of the forearm, with elbow flexion and extension, will reduce all pulled elbows. 
Figure 18-49
Reduction technique for nursemaid's elbow.
 
Left: The forearm is first supinated. Right: The elbow is then hyperflexed. The surgeon's thumb is placed laterally over the radial head to feel the characteristic snapping as the ligament is reduced.
Left: The forearm is first supinated. Right: The elbow is then hyperflexed. The surgeon's thumb is placed laterally over the radial head to feel the characteristic snapping as the ligament is reduced.
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Figure 18-49
Reduction technique for nursemaid's elbow.
Left: The forearm is first supinated. Right: The elbow is then hyperflexed. The surgeon's thumb is placed laterally over the radial head to feel the characteristic snapping as the ligament is reduced.
Left: The forearm is first supinated. Right: The elbow is then hyperflexed. The surgeon's thumb is placed laterally over the radial head to feel the characteristic snapping as the ligament is reduced.
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X
The value of immobilizing the elbow following reduction has been debated. Taha173 reported a decreased rate of recurrence during the 10 days following reduction if the elbow was splinted in a flexed supinated position for 2 days following reduction. Salter and Zaltz154 recommended the use of a sling, mainly to prevent the elbow from being pulled a second time. Kohlhaas and Roeder87 recommended a T-shirt technique for flexed elbow stabilization in very young children. This provided adequate immobilization without the use of a sling by pinning the sleeve of the long sleeve T-shirt to the opposite chest. In general, after a successful closed reduction of a first-time annular ligament subluxation, immobilization of the extremity is not necessary if the child is comfortable and using the arm normally. After the reduction, it is important to explain to the parents the mechanism of injury and to emphasize the need to prevent longitudinal pulling on the upper extremities. Picking the child up under the axillae and avoiding games such as “ring around the roses” and involve longitudinal traction to the arm are stressed. However, recurrence rate is high even with the most diligent parents. Therefore, instruction in home reduction of the pulled elbow is very useful and lessens visits to the emergency room and primary care physician. 

Surgical Treatment

Even if untreated, most annular ligament subluxations reduce spontaneously. There are no reported cases of negative long-term sequelae following untreated annular ligament subluxation. Therefore, open reduction is rarely, if ever, indicated for annular ligament subluxation. An indication for surgery might be the chronic, symptomatic, irreducible subluxation.29,177 In such a circumstance, the annular ligament may need to be partially transected to achieve reduction. 

Author's Preferred Treatment: Pulled Elbow Syndrome—Closed Reduction

It is important to elicit a reliable history as to whether or not the child had a traction force applied across the extended elbow. The entire extremity is then carefully examined. Focal tenderness should be present directly over the radiocapitellar joint. If the history or physical examination is not entirely consistent with annular ligament subluxation, then x-rays of the upper extremity are obtained to assess for other injuries before manipulating the elbow. 
Once the diagnosis of annular ligament subluxation is clearly established, manipulation is performed. It is first explained to the parents that there will be a brief episode of pain followed by relief of the symptoms. The patient usually is seated on the parent's lap. The patient's forearm is grasped with the elbow semiflexed while the thumb of the surgeon's opposite hand is placed over the lateral aspect of the elbow. The forearm is first supinated. If this fails to produce the characteristic snap of reduction, then the elbow is gently flexed maximally until the snap occurs (Fig. 18-31). Just before reaching maximal flexion, there often is an increase in the resistance to flexion. At this point, a little extra pressure toward flexion is applied, which usually produces the characteristic snap as the annular ligament suddenly returns to its normal position. If this fails, then the hyperpronation technique of Macias et al.96 is used. Full flexion–extension elbow motion and forearm pronation–supination motion is performed to the extremes, and this usually resolves the “outliers” which do not reduce with the usual mechanisms. 
What should be done if a definite snap or pop is not felt or if the patient fails to use the extremity after manipulation? In a subgroup of patients, discomfort may persist despite successful annular ligament reduction. If the subluxation has occurred more than 12 to 24 hours before the child is seen, there often is a mild secondary synovitis, and recovery may not be immediate and dramatic. One must confirm that the initial diagnosis was correct. If not taken before the manipulation, x-rays should be obtained and the entire extremity carefully reexamined. If the x-ray results are normal and the elbow can be fully flexed with free supination and pronation, the physician can be assured that the subluxated annular ligament has been reduced. In this circumstance, the patient's arm may be placed in a splint or sling for a few days to 1 week and reexamined clinically and by x-ray if needed (Table 18-20). 
 
Table 18-20
Pulled Elbow Syndrome
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Table 18-20
Pulled Elbow Syndrome
Potential Pitfalls and Preventions
Pitfalls Preventions
Never assume that an unwitnessed fall has resulted in annular ligament subluxation Obtain radiographs on all patients whose elbow injury was unwitnessed or occurred with a mechanism other than longitudinal traction
Persistent pain following apparent successful reduction maneuver Place the child in an elbow sling, allow the child to use the elbow and reevaluate in 2–7 days with radiographs if necessary
X

Management of Expected Adverse Outcomes and Unexpected Complications Related to Pulled Elbow Syndrome

There are no reports of long-term sequelae from unrecognized and unreduced subluxations. Almost all subluxations reduce spontaneously. The only problem seems to be discomfort to the patient until the annular ligament reduces. 

Recurrent Subluxations in Pulled Elbow Syndrome

The reported incidence of recurrent subluxation has varied from 5% to 39%.27,56,70,139,156,163,175 Children 2 years of age or younger appear to be at greatest risk for recurrence.156,177 Recurrent subluxations usually respond to the same manipulative procedure as the initial injury. They eventually cease after 4 to 5 years when the annular ligament strengthens and ligament laxity lessens. Recurrences do not lead to any long-term sequelae. If recurrent annular ligament subluxation significantly impacts a patient's quality of life because of pain or limited activity, immobilization in an above-elbow cast with the forearm in supination or neutral position for 2 to 3 weeks is usually effective at preventing recurrence. 

Summary, Controversies, and Future Directions Related to Elbow Dislocations and Medial Epicondyle Fractures

The vast majority of dislocation about the elbow in children and adolescents can be successfully managed nonoperatively. Recurrent dislocation and instability appear to be very rare complications with stiffness being a much more common potential occurrence. Following elbow dislocation reduction patients may be successfully managed in a well-padded posterior splint for 5 to 10 days at which time a removable splint may be applied and early elbow range of motion initiated. Medial epicondyle fractures commonly occur in association with elbow dislocation and the treating physician must have a high index of suspicion for this injury. Careful physical examination and thoughtful use of imaging studies will allow the treating physician to detect medial epicondyle fractures in all patients. The most common cause of a missed medial epicondyle fracture is that the treating physician did not think to specifically look for this injury. There is general agreement that medial epicondyle fractures displaced less than 2 mm can be effectively treated with immediate splint immobilization and initiation of active elbow range of motion 5 to 10 days following the injury. Medial epicondyle fractures entrapped within the elbow joint must be extracted, with open reduction and stable internal fixation allowing early elbow range of motion indicated in most patients. Controversy remains regarding treatment of medial epicondyle fractures displaced more than 2 mm. Shared decision making with patient and family, considering activity demands, dominant extremity, and displacement allow formulation of an optimal treatment strategy for each patient. Better implants, improved surgical technique, greater appreciation of the importance of the ulnar collateral ligament function, and increased understanding of the degree of displacement in fractures previously thought to be nondisplaced all contribute to a general trend toward more frequent surgical treatment of medial epicondyle fractures. 

Acknowledgments

We thank James H. Beaty, James R Kasser, Stephen D. Heinrich, Kaye Wilkins, and George Thompson for their contributions to this chapter. The information presented in this chapter is based on their efforts in previous editions. 

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