A Partial Posterior Bundle Ulnar Collateral Ligament Tear in a 10-year old Boy.

Medial-sided elbow pain is becoming more common among pediatric overhead sport athletes. One potential cause of this is a partial or complete tear of the ulnar collateral ligament (UCL). Because the growth plate remains open in many of these athletes, the most common injury experienced is an avulsion at the medial epicondyle. However, although rare, there is a potential to tear the UCL, with the most common tears occurring at the anterior bundle. However, tears to the posterior bundle are quite rare in pediatric patients. We aim to describe the case of a 10-year old boy who was diagnosed with a partial posterior bundle UCL tear and was successfully treated by cessation of throwing activities and physical therapy. He was able to return to baseball 10 months after his diagnosis.