Avulsion Injury to Pelvis Ischial tuberosity

Most commonly, pelvic site. Usually occurs before closure of the apophysis secondary to extreme active hamstring contractions, as in sprinting by runners or sudden and excessive passive lengthening in cheerleaders or dancers. Patients typically present with pain in the buttock region, an antalgic gate, or inability to walk.

Imaging Findings :

Insertion of the hamstring muscle group. During the healing stage, the avulsion can have an aggressive appearance, including lysis and destruction. Chronic avulsions frequently result in prominent bone formation.

Ischial tuberosity. Bilateral chronic avulsions. Note the protuberant bone (closed arrows) and a large, smooth fragment (open arrows).