This fracture type is classified by the AO/OTA as 13A1.2.
These fractures represent avulsion of the humeral origin of the medial collateral ligament and common flexor origin, resulting from a valgus force to the elbow.
Medial epicondyle fractures are more common in skeletally immature patients.
Take note to exclude an associated compression fracture of the radial head or the capitellum.
X-ray of avulsion of medial epicondyle
In rare cases, the fragment is incarcerated in the ulnohumeral joint.
AP view of an avulsion of medial epicondyle in an adult with the fragment incarcerated in the ulnohumeral joint
Lateral view of a similar case in a pediatric patient