Ten-year evaluation of geometric total knee arthroplasty.

One hundred ninety-three geometric total knee arthroplasties (TKA) were performed between 1972 and 1975 in 129 patients (66 women, 63 men; mean age, 69 years) with osteoarthritis. Of these, 102 knees were followed for a mean of 11 years. Eighty-three percent of the patients had mild or no pain. The revision rate was 20%, and the surgical complication rate was 12%. By actuarial analysis, the probability of retaining a geometric prosthesis at 10 years was 78%. With revision or moderate to severe pain as the end point, the predicted implant survival was 69% at 10 years. Lucent lines greater than 1 mm were present in 38% of the knees and progressed in 34%; they were more frequent in knees with greater than or equal to 3 degrees of varus axial alignment (p less than 0.05) or greater than or equal to 4 degrees of varus placement of the tibial component (p less than 0.05). The geometric prosthesis has provided a functional result in 69% of knees at 10 years, despite being the first two-part component knee replacement retaining the cruciate ligaments and using early surgical instrumentation and implant design.