Coronal T2-weighted FS MR image through the elbow demonstrates the insertion of the UCL on the sublime tubercle.
Images A show 11 year old baseball pitcher with elbow pain. Findings show increased bone marrow edema within the medial epicondyle with widening of the physics. Findings compatible with medial epicondyle epiphysis. Also known as little leaguer’s elbow.
Images B show 14 year old baseball pitcher with elbow pain. He has increased edema within the medial epicondyle with edema surrounding the medial epicondyle. Findings compatible with medial apophysitis. There is bone bruise and contusion within the olecranon. Also there is chronic thickening of the ulnar collateral ligament without evidence of a discrete tear.
Images C show 13 year old baseball pitcher who presents with elbow pain. Findings are bone marrow edema within the medial epicondyle with fracture and avulsion with widening of the medial epicondylar apophysis. Findings compatible with medial epicondylar apophysitis. In addition, there is avulsion tear of the ulnar collateral ligament at its proximal attachment to the medial epicondyle.
In the skeletally immature athlete, valgus stress results in fracture of the medial epicondyle. This injury is usually seen in young baseball players resulting in fragmentation and displacement of the apophysis with widening of the apophysis. Patients might also have fragmentation and avulsion of the medial epicondyle. There may be associated tear of the ulnar collateral ligament.
The treatment is usually guided by MRI findings. If there is just a stress reaction this is managed by conservative management by cessation of throwing activities, use of anti-inflammatory medication, application of ice, and physical therapy. If there is apophyseal avulsion greater than 4 mm, surgical reattachment is indicated. If there is tear of the ulnar collateral ligament this requires surgical intervention with a procedure called Tommy John procedure.
Radiology 2016 279:1, 12-28