Fracture or avulsion of the medial epicondylar physis can be a stress fracture or overt fracture due to repeated valgus forces, falling, or repetitive violent forearm flexor muscle contraction in the skeletally immature athlete. Throwing results in a repetitive valgus stress and can result in accelerated growth of the medial epicondylar apophysis, which can be followed by separation and eventual fragmentation if the body does not have the opportunity to recover and heal from the repetitive forces (65,66) (Fig 23-23). Pediatric athletes with medial epicondylar apophysitis complain of pain with throwing while also noting their throwing accuracy, speed, and distance are reduced. On examination, the patient has point tenderness over the medial epicondyle. Frequently, these pediatric athletes have an elbow flexion contracture of more than 15 degrees based on muscular and capsular tightness. Radiographs demonstrate that the medial epicondylar apophysis can be widened and occasionally fragmented. This is as compared with the contralateral elbow, which should always be obtained when evaluating an injured elbow in the skeletally immature patient with elbow pain due to the complexity and various ages of closure of the multiple different physes about the elbow (Fig 23-24). Care should be taken, since this finding may be normal in throwing athletes (34). The treatment of the stress fracture or inflamed apophysis is rest from throwing for 4 to 6 weeks, along with the
application of ice (take care to protect the ulnar nerve from ice injury by placing a wet towel between the ice and the medial elbow). NSAIDs may also be used to reduce pain and the acute inflammation. After the symptoms subside, a rehabilitation program is instituted consisting of stretching to eliminate the flexion contracture, strengthening of the muscles that cross the elbow, and then transitioning to a gradual throwing program.

Continued stress to the elbow with apophysitis may result in progression to a complete fracture or separation of the medial epicondyle. The avulsion fracture of the medial epicondyle, however, may occur without any preceding symptoms of medial elbow pain and is usually due to a single, more severe, valgus force or violent muscle contraction. Medial epicondylar apophyseal fracture can have two distinct patterns, as described by Woods (67) and Woods et al. (68). A Woods Type 1 fracture occurs in the younger child and is characterized radiographically by a large fragment, involving the entire epicondyle that is often displaced and rotated anteriorly and distally, and may even become entrapped in the joint. A Woods Type 2 fracture occurs in the adolescent and is radiographically notable for medial epicondylar fragmentation with a small fracture fragment. In this type of injury, the flexor-pronator muscle is essentially avulsed; however, the anterior oblique ligament of the UCL complex is usually intact. Treatment of this entity, however, depends on elbow stability (Fig 23-18).

The treatment of these injuries where the elbow is stable and epicondyle is nondisplaced is rest for 2 to 3 weeks, with return to throwing by 6 weeks after attaining full motion. Unstable elbows are treated by open reduction and internal fixation, using wires, pins, or screws. If, however, the medial epicondyle is displaced more than 1 cm, then surgery should be performed to anatomically reduce the fragment and internally fix it with pins or screw(s) (69,70) (Fig 23-25). It should be noted that displacement of 1 cm as an indication for surgery is somewhat arbitrary, and it is easy to see how malunion of this fracture could lead to functional medial ligamentous laxity, which would be expected to be symptomatic in a throwing athlete. Therefore, we recommend aggressive management, including open reduction and internal fixation, to obtain adequate fracture reduction. In nonthrowing pediatric athletes or for the nondominant elbow, some authors recommend surgery only if the fragment is displaced 2 cm or more.

Occasionally, elbow dislocation is complicated by avulsion of the medial epicondyle fragment, which may become entrapped within the elbow joint. Closed manipulation of the elbow by applying valgus stress and wrist extension can free the fragment from within the joint, enabling the child to avoid open surgery. As an adjunct, air can be injected into the lateral joint, which may help to move the incarcerated fragment out of the joint, helping to avoid open reduction (69,71). Minimally displaced medial epicondyle avulsion injuries and apophysitis (widening of the growth plate without fracture or displacement) can usually be managed without surgery. If surgery is required to manage this problem, UCL evaluation is also performed and the ligament is repaired as needed.

Abnormal stresses of the triceps attachment on the olecranon apophysis can result in an injury syndrome similar to Osgood-Schlatter disease of the knee. An intrinsic overload from repeated triceps pull can lead to inflammation and separation of the olecranon secondary ossification center (72). This injury may also be due to valgus extension overload and has been reported in a baseball pitcher (73,74). Generally, those afflicted are adolescents. Typical complaints are those of pain on resisted elbow extension and tenderness over the olecranon. Radiographs demonstrate widening of the olecranon apophysis, and should be confirmed by comparison with radiographs of the contralateral elbow.

When the apophysis is widened, but not separated or avulsed, initial treatment is rest from the offending activity, gentle range-of-motion and flexibility exercises, eventually progressing to strengthening exercises. Ice and NSAIDs are useful if acute inflammation is present. If the child is in severe pain, a short period of immobilization in a splint or brace may be beneficial. In the situation where there is separation of the secondary growth center or adolescents have persistent pain despite conservative management due to lack of fusion of the physis, internal fixation is recommended. Surgical intervention to promote fusion of the apophysis may require internal fixation with a screw in addition to bone grafting, due to the high incidence of fibrous union when bone grafting is not used (75,76). Left untreated, apophysitis of the olecranon may result in an incompletely fused olecranon apophysis, which may later fracture as a result of direct trauma when older (73,74,75,77,78). It is generally recommended that unfused olecranon physis fractures in adults be treated with open reduction, internal fixation, and primary bone grafting, though recent case series have been presented calling into question the need for bone grafting (75).

OCD is a focal lesion of the lateral elbow that occurs most frequently in young throwers and gymnasts. Although OCD can occur in throwers and nonthrowers, in the dominant and nondominant elbows, and in the capitellum, radial head, or both, it tends to occur in the capitellum of the dominant arm in throwers and gymnasts 10 to 15 years of age (79,80,81,82,83,84,85). The exact etiology of OCD remains a mystery. A current leading hypothesis of the etiology of OCD is that it is a result of vascular insufficiency due to repetitive trauma or microfracture in a genetically predisposed adolescent. The capitellar blood supply is tenuous, with end-arterioles terminating at the subchondral plate (86). The current leading pathogenesis theory proposes that compression at the radiocapitellar joint produces arterial injury at the subchondral plate resulting in bone death (34). As noted in the section on throwing injuries, the radiocapitellar joint functions as a secondary restraint to the valgus stresses associated with throwing resulting in compression of this joint (Figs 23-26 and 23-27). OCD can be a disabling problem.

There is a debate as to whether OCD is a distinctly different entity from Panner disease; however, it should be clear that these diagnoses have different prognoses and treatments. The difference between the two problems focuses on age and degree of involvement of the capitellar secondary ossification center. Panner disease occurs in the young child, usually 7 to 12 years of age, and is characterized by a focal, localized lesion of the subchondral bone and its overlying articular cartilage (anterior central capitellum) (86). In comparison, OCD occurs in the older child, 13 to 16 years of age, and is characterized as a focal lesion in the capitellum demarcated by a rarefied zone, with or without loose bodies (34).

The skeletally immature athlete often gives a history of insidious onset of lateral elbow pain and reduced throwing effectiveness and distance. The child may have a flexion contracture of more than 15 degrees on examination. A provocative test, which may reproduce symptoms and suggest the diagnosis, known as the “active radiocapitellar compression test,” consists of forearm pronation and supination with the elbow in full extension resulting in pain if OCD is present. Early in the process, radiographs may be normal, although with time, islands of subchondral bone demarcated by a rarified zone can be seen, and with even more time, loose bodies may be generated (Fig 23-28). MRI, computed tomography (CT), and ultrasound have all been found to be helpful in defining the extent of the lesion. The critical factor in determining treatment is the status of the overlying cartilage. The diagnosis is usually made by MRI, MR arthrogram, arthro-CT scan, ultrasound, or arthroscopy if plain films do not show free fragments to help detect early OCD lesions and to assess the integrity of the overlying articular cartilage (87). If the overlying articular cartilage is intact, treatment is relative rest and occasionally splinting, followed by range-of-motion and then strengthening exercises. Some have also advocated an unloading type of elbow brace. Symptoms generally subside with rest alone; however, throwing is contraindicated because the healing process may lag behind symptomology and tends to be slow. The athlete is restricted from throwing and other heavy activities until there is radiographic evidence of healing. Bennett and Tullos (34) have suggested that fragmentation is likely if pain and flexion contracture persist for more than 6 weeks. If the overlying articular cartilage is not intact at the time of surgery, some recommended excising the fragment regardless of size. They note the patient will have a functional elbow; however, the patient should be discouraged from throwing or performing heavy labor. The current recommended management for elbows where the articular cartilage is not intact is to reattach and internally fix large fragments with screws, wires, or biodegradable pins after drilling the bed to enhance vascularity, similar to the procedure described by Indelicato et al. (88). Smaller fragments, on the other hand, are usually just removed. The surgeon usually attempts to fix the larger fragments to help reduce articular surface incongruity and potentially degenerative changes, while smaller fragments, if removed, would have less impact on contact stresses.

If the large fragment has been chronically detached, the fragments may have continued to grow, and/or become incarcerated within the joint, resulting in multiple smaller fragments or in a fragment that is rounded and hypertrophied, and in either scenario, reattachment may not be possible. In these situations, the bony fragment(s) is removed and the crater is cleared of the fibrous tissue and roughened to attempt to stimulate fibrocartilaginous growth. Yamamoto has also recommended filling the defect, particularly if it involves the lateral columnar wall, with an autogenous osteochondral graft from the knee (88a). There have been several reports of excellent short-term results of arthroscopic debridement of loose articular cartilage flaps and loose bodies removal for OCD (89,99). However, studies have also shown that the late sequelae of OCD after removal of loose bodies include deformity of the capitellum and radial head, arthritis, loss of motion, pain, and often residual disability (91,92).

Fracture of the radial neck at the physis may be the result of a fall on an outstretched hand or due to valgus stresses at the elbow with attenuation or insufficiency of the UCL resulting in increased compressive forces to the radiocapitellar joint. This injury tends to be acute due to a sudden force to the radiocapitellar joint in the skeletally immature athlete. These children complain of lateral elbow pain and reduced forearm rotation. On examination, these kids have tenderness over the radial head and concomitant loss of supination and pronation. Radiographs reveal a fat pad sign is present, and the fracture may be identified if displaced or with stress films. The treatment for nondisplaced fractures is rest for 4 to 6 weeks, until the fracture is healed. Displaced fractures
are treated with closed versus open reduction, which is based on the degree of angular displacement.