Overgrowth of the ischial tuberosity complicating femoral bone and muscle atrophy: implications for a delayed complication of malunited apophyseal avulsion fracture.

Delayed complications occurring several years after the fused avulsion of ischial tuberosity have rarely been reported. We present a patient with overgrowth of the ischial tuberosity who complained of knee pain associated with significant bone and muscle atrophy in the thigh, which occurred 10 years after the ischial injury. Reinforcement exercise of the hamstrings relieved the knee pain. Here, we emphasize that avulsion fractures of the ischial tuberosity can cause persistent disability and that patients with avulsion fracture of the ischial apophysis in the adolescent period should actively maintain the strength of the hamstrings, even after more than 1 decade.