Little league elbow: valgus overload injury in the paediatric athlete.

This article describes a variety of elbow injuries often seen in young, throwing athletes. Understandings of normal skeletal development, as well as the biomechanics of throwing, provide a basis on which to evaluate, diagnose and manage "little league elbow". With emphasis on an anatomically-based differential diagnosis, the pathologic forces placed upon the young thrower's elbow, and the subsequent injury patterns, are reviewed. Medial side injuries are the most common and relate to chronic forces of valgus overload produced during the early and late cocking phases of throwing. The majority of this force is placed on the medial epicondyle and produces age-dependent injury patterns, such as apophysitis in childhood and epicondylar avulsion fractures in the more mature athlete. With repetitive valgus overload, lateral side injuries such as Panner's disease and osteochondritis dissecans of the capitellum and radial head become more apparent. These injuries relate to the compressive forces produced by the late cocking and early acceleration phases of throwing. Finally, posterior injury patterns consistent with olecranon apophysitis and posteromedial impingement, as well as flexion and capsular contracture, can be seen. The key in the treatment of "little league elbow" is prevention and this responsibility lies not only with the evaluating or team physician, but also with the coach, trainer, parents and officials. Proper throwing mechanics must be emphasised at an early age, and the determinants of elbow injury among young pitchers better understood. Early recognition and proper treatment of such injuries will then prevent later sequelae or functional disability.