A difficult conversion of heterotopic ossification to total hip replacement.

Heterotopic ossification (HO) is abnormal bone formation in soft tissues, commonly between muscle and joint capsule, often following stroke, traumatic brain injury or spinal cord injury. The hip is the most frequently affected site, with management ranging from analgesics to surgical excision and, rarely, total hip replacement (THR).We report a case of a man in his early 30s with Brooker grade 4 HO of the left hip, presenting with severe restriction of motion. The heterotopic bone involving the acetabulum and proximal femur was excised, followed by THR using a dual mobility prosthesis. At 6 months and 1 year of follow-up, the patient demonstrated a significant improvement in pain, range of motion and function.