Clinical and magnetic resonance imaging findings associated with Little League elbow.

BACKGROUND: Valgus overload in the skeletally immature elbow can lead to medial epicondyle apophysitis, or Little League elbow. The skeletal manifestations have been well described through radiographic studies. The involvement of surrounding structures, including the ulnar collateral ligament, remains unclear. The purpose of this study is to better characterize the involvement and relationship of medial elbow structures in Little League elbow through magnetic resonance (MR) imaging.

METHODS: Institutional review board approval was obtained. Nine Little Leaguers, 8 to 13 years, with clinical diagnosis of Little League elbow were enrolled. Play history questionnaire (including age, position, pitching history, duration of symptoms, and Kerlan Jobe Orthopedic Clinic shoulder elbow score), clinical examination, radiograph, and MRI of both elbows were obtained for analysis. Evaluation of radiographs and MRIs were performed by 2 radiologists blinded to clinical findings.

RESULTS: A majority of the players reported compliance with pitch count recommendations. Four out of 9 players, however, were throwing breaking pitches at an average age of 11 years. Radiographic abnormalities were present in 4 players. MRI abnormalities were present in 6 players. All patients demonstrated normal ulnar collateral ligament (UCL) on MRI. The distance from UCL origin to the medial epicondyle physis were measured in both injured and healthy elbows. No significant differences were found. This distance ranged from 0 to 4 mm.

CONCLUSIONS: MRI of Little League elbow demonstrated more abnormalities compared with radiographs. The increased number of findings, however, does not change clinical management. MR evaluation of the ulnar collateral ligament demonstrates no role for reconstruction in Little League elbow. In addition, given the close proximity of the ligament to the physis, any surgical procedure involving the UCL origin should be performed with caution.

LEVEL III: Diagnostic study.