Imaging description

Little Leaguer’s elbow was initially described to specifically indicate an injury to the medial epicondylar apophysis. More recently the term has been erroneously used to describe osteochondral injuries to the capitellum or tendinopathy of the common flexor tendon in the pediatric population. The radiographic appearance of Little Leaguer’s elbow manifests in two ways. The first is separation of the medial epicondyle apophysis from the underlying humerus. The second appearance is fragmentation of this apophysis on the symptomatic side with the asymptomatic elbow not having any apophyseal fragmentation. Apophyseal separation is diagnosed when the subjacent physis is widened by more than 1 mm relative to the asymptomatic contralateral elbow (Figure 28.1). Additional associated abnormalities that can be seen on MRI include bone marrow-like edema in the apophysis/subjacent humerus, tendinopathy of the common flexor tendon, and a normal ulnar collateral ligament (UCL). Research suggests that injury to the UCL is not present in the pediatric patient with Little Leaguer’s elbow.

Importance

It is important to know that this entity is usually diagnosed clinically. The imaging work-up, if indicated, consists of AP and lateral elbow radiographs. At present, research indicates that further evaluation with MRI is not warranted in patients with the classic clinical findings of Little Leaguer’s elbow. This disease is usually treated conservatively, especially if the clinical findings are classic and the radiograph is normal or has minimal separation. MRI may be warranted if the patient does not respond to initial therapy and the radiographs are normal.