Reconstruction for protrusio acetabuli deformity. A, Protrusio deformity in 52-year-old woman with lupus. B, After total hip arthroplasty. Hip center was restored to more lateral and inferior position. Large acetabular component allowed rim fixation without need for screws, and medial deficits were grafted with cancellous autograft from femoral head with excellent incorporation. Low neck resection and high-offset stem design helped avoid overlengthening of limb.