Press fit condylar Sigma total knee arthroplasty: 7-9 years results

This study reports the first clinical and radiological results at 7-9 years for the DePuy Pressed Fit Condylar Sigma total knee arthroplasty (TKA). A total of 318 consecutive Sigma TKAs were performed in 275 patients between October 1998 and March 2000. Of 318 knees, 225 (193 patients) were alive at final review. Six knees (five patients) were lost to follow up. Seven knees (2.2%) were revised, six for infection within 2 years and one at 59 months who underwent isolated change of polyethylene insert. The 9-year survival was 97.7% with revision for any reason and 99.6% with endpoint revision for aseptic failure. The mean American Knee Society Knee Score was 84 +/- A 16 at 7-9 years compared with 33/100 pre-operatively. Of 140 radiographs, 48 knees had non-progressive radiolucent lines but none showed radiological evidence of loosening. These results suggest that the Sigma TKA gives excellent clinical results up to 9 years.