Displaced ischial stress fracture following revision total hip arthroplasty.

Stress fractures of the ischium are uncommon and are most likely caused by excessive stretching or contracture of the hamstring muscles. In addition, revision total hip arthroplasty (THA) may weaken the ilium, and metabolic bone disease may also contribute to a fracture. Treatment is usually conservative and prognosis is favorable. We present a rare case of spontaneous displaced fracture of the entire ischium following revision THA that healed without requiring operative intervention.