Long-term results of metasul metal-on-metal total hip arthroplasty.

Abstract

We assessed 90 total hip arthroplasties (THAs) performed with the Metasul metal-on-metal hip system (Zimmer, Warsaw, Indiana); the patients were monitored for >10 years. The average Harris Hip Score of the patients was 40.5 points preoperatively and 85.8 points at final follow-up. No adverse reactions to the metal debris were observed in patients presenting with symptoms or phenomena such as unexplained pain, joint effusion, bursitis, or pseudotumor. Radiographically, the acetabular component fixation was stable in 86 hips, possibly unstable in 3 hips, and unstable in 1 hip. The unstable hip required revision of the acetabular component. The femoral component was bone-ingrown in 81 hips and stable-fibrous in 9 hips. Distal femoral cortical hypertrophy was seen in 34.4% of hips.Postoperatively, 6 hips dislocated, of which 2 developed recurrent dislocation and required revision of the acetabular component. Dissociation of the polyethylene liner occurred in 2 hips 6 and 12 years postoperatively, respectively, and required revision of the polyethylene liner and the articular head. The survival rate with the endpoint defined as revision surgery and radiologic loosening was 94.4% at mean follow-up (12.3 years). This study found that the Metasul metal-on-metal THA produces excellent long-term results.