Total hip arthroplasty for fused hips; planning and techniques.

Conversion of an arthrodesed or fused hip to total hip arthroplasty (THA) is a challenging orthopedic problem due to the effects of previous operations, the altered anatomy, atrophy of the muscles, arthritis of neighboring joints, and limb length discrepancy. This prospective work included conversion of 19 arthrodesed hips to THA. The failure rate was 5% after an average follow-up period of 7 years. Specific preoperative planning and refined techniques have been elucidated to achieve a success rate nearly similar to that of primary THA.