Avulsion of the Hamstring Muscles from the Ischial Tuberosity

In two rare cases with avulsion of the hamstring muscles from the ischial tuberosity without fracture of the ischium, the clinical features were: (1) sudden onset of pain in the buttock; (2) difficulty on standing after trauma; (3) a palpable defect and tenderness on the area distal from the ischial tuberosity; and (4) weakness of flexion of the knee with a loss of normal outline of the hamstring muscles on the dorsal aspect of the knee. There was no roentgenologic evidence of fracture of the ischium. Surgical repair with reattachment of avulsed muscles to the ischium and proximal tendinous sheaths of the muscles restored function or corrected deformity.