Case Identification. Cases were identified from our arthroplasty registry over a 10-year period. THA = total hip arthroplasty, DDH =developmental dysplasia of the hip, AVN = avascular necrosis, OA = osteoarthritis, SCFE = slipped capital femoral epiphysis, LCPD = Legg–Calvé–Perthes disease, JRA = Juvenile rheumatoid arthritis, SLE= Systemic Lupus Erythematosus, FAI= Femoroacetabular impingement