The outcome of cemented vs. cementless fixation of a femoral component in total knee replacement (TKR) with the identification of radiological signs for the prediction of failure.

A survival analysis and radiological review were performed on a series of femoral total knee arthroplasty (TKA) prostheses either cemented (150 cases) or cementless, press-fit (201 cases). The internal surface of the femoral components were shot-blast CoCr alloy. The incidence of loosening of the femoral component at 6 years was 9.8% with cementless fixation and 0.6% with cement (P<0.05) at 6 years. Amongst uncemented prostheses, there was no difference in the survival or radiological outcome with the use of a stem as against two condylar pegs. The clinical need for revision may be predicted radiologically 3 years after operation in symptomless patients by noting a change in component position combined with progressive radiolucent lines and osteolysis. Thus, radiological follow-up should be continued for a minimum of 3 years after knee replacement. The use of a stem enabled the detection of radiolucent lines which we believe were missed around prostheses with condylar pegs. Thus, the use of a stem improves the prediction of failure (but does not improve fixation).