Salvage of Monoblock Metal-on-Metal Acetabular Components Using a Dual-Mobility Bearing.

BACKGROUND: Large-diameter, monoblock acetabular components have been used for both hip resurfacing arthroplasty and metal-on-metal (MoM) total hip arthroplasty (THA). If revision is required, one solution is to retain the shell and use a dual-mobility bearing. METHODS: We reviewed the results of 25 revision THAs including 11 hip resurfacing arthroplasty and 14 MoM THAs where a monoblock acetabular component was mated to a dual-mobility bearing. RESULTS: At a mean of 29 months, there was one failure, an intraprosthetic dislocation of the dual-mobility bearing. There was a significant decrease in serum metal ion levels postoperatively. CONCLUSION: Retention of a well-fixed, monoblock MoM acetabular shell and mating it to a dual-mobility bearing in the setting of revision surgery seems to be a reasonable, low-morbidity option at short-term follow-up in appropriately positioned cups.

Sixteen-year follow-up of the cemented spectron femoral stem for hip arthroplasty.

Clinical and radiographic follow-up was performed on a consecutive series of 105 patients who underwent 120 total hip arthroplasties at the authors' institution from 1983 to 1988 with a straight, cobalt-chrome femoral stem implanted using a second-generation cementing technique. The mean age at the time of surgery was 68.5 years, and the mean follow-up was 16 years. At 16 years' follow-up, the prevalence of revision for aseptic loosening of the Spectron femoral component was only 4.2%; 5 stems were revised for aseptic loosening at a mean of 10.2 years after implantation. Sixteen-year survivorship of the component was 93.9% +/- 2.7% when revision for aseptic loosening was taken as the endpoint or 90.3% +/- 4.4% when either revision for aseptic loosening or radiographic evidence of loosening was taken as the endpoint.