2- to 9-year outcome of stemmed total knee arthroplasty

BACKGROUND AND PURPOSE There is an increase in demand for primary and revision total knee joint procedures. We studied implant survival and functional outcome of patients operated with a constrained condylar knee (CCK) or a rotating hinge implant (RH) as a primary or a revision total knee arthoplasty (TKA). PATIENTS AND METHODS We evaluated clinically and radiographically 65 surgical procedures with a mean follow-up time of 5 (2-9) years (40 CCK and 25 RH). There were 24 primary TKAs-due to instability-and 41 revision TKAs, mostly due to aseptic loosening. Mean age at the index operation was 68 (31-88) years. RESULTS Overall, there were 12 failures, including 8 reoperations due to deep infection. The overall 5-year survival rate with reoperation as the endpoint was 82% (95% CI: 72-99). Radiolucent lines on either the femoral or the tibial side were seen in 36 cases. When comparing the cases that were operated as a primary TKA or as a revision TKA, function, health-related quality of life, and survival were similar. However, after primary TKA the patients generally had less pain and a higher proportion of patients were very satisfied or satisfied. INTERPRETATION Although a high rate of severe complications was observed, most patients improved in function after surgery regardless of whether it was a primary or a revision TKA. We found narrow radiolucent lines-mainly on the tibial side-in nearly half of the cases, but none of the implants were loose radiographically. Overall patient satisfaction and health-related quality of life were high, and a minority had problems with persistent pain.