We reported a case of total hip arthroplasty (THA) for an irradiated hip. The patient was 65 years old woman with right coxalgia. At age 60, total hysterectomy surgery, for womb malignant melanoma, was performed at our department. This enforced external radiotherapy at an irradiation level of 48.5Gy. After treatment blood tests did not reveal any complications and tumor markers were negative, but right hip joint mobility was limited. At her first examination before THA, end stage coxarthrosis was diagnosed. Radiography and computerized tomography (CT) revealed protrusio acetabuli. During the five months period to surgery, the patient received conservative treatment without retrogression. Cement THA surgery using a Kerboull cross plate was then performed, because postoperative loosening of acetabular is often observed after cementless and cement THA procedure. Preoperative Japanese Orthopaedic Association (JOA) score was 15 points compared to postoperative score of 85 points. We recommend reinforcement of the acetabulum by a Kerboull cross plate in THA surgery for irradiated hip.
