Metal-on-metal dysplasia cup total hip arthroplasty for hip osteoarthritis secondary to developmental dysplasia of the hip

Objectives: this study aims to evaluate the clinical and radiological results of metal-on-metal dysplasia cup total hip arthroplasty (tha) for hip osteoarthritis secondary to developmental dysplasia of the hip (ddh). patients and methods: between may 2009 and october 2011,tha was performed on 27 hips (7 crowe type ii,9 crowe type iii,11 crowe type iv) of 22 patients (2 males,20 females; mean age 43 years; range 25 to 63 years) with hip osteoarthritis secondary to ddh. all patients were evaluated clinically and radiographically. results: average follow-up period was 34.2 months (range 24-53 months). while mean harris hip score (hhs) was 43 (range 30 to 72 points) preoperatively,it was 92 (range 87 to 98 points) at final follow-up. two patients developed sciatic nerve palsy postoperatively. recurrent dislocation occurred in one patient one year after the operation. mean cup inclination was 45.6° (range 42°-51°). heterotopic ossification developed in eight patients. no patient's acetabular and femoral component migrated or subsided significantly. none of the implants was revised. conclusion: early clinical and radiological results of metalon-metal dysplasia cup tha in ddh are satisfactory.