Fixation of the NexGen HA-TCP-coated cementless, screwless total knee arthroplasty: comparison with conventional cementless total knee arthroplasty of the same type.

We performed a 12-month prospective study on 59 patients (92 knees) who underwent NexGen (Zimmer Inc, Warsaw, IN) cruciate-retaining total knee arthroplasty. In the control group, uncoated components were fixed using screws, whereas the hydroxyapatite-tricalcium phosphate (HA-TCP) group underwent screwless fixation of coated components. At 12 months postoperatively, there was a radiographic clear zone around the femoral and tibial components of 56.5% and 32.6% of the knees in the control group. The HA-TCP group showed a clear zone at the medial aspect of the tibial component in only 1 knee. These results suggested that HA-TCP-coated articular components show good initial fixation without using screws. The NexGen coated knee arthroplasty may be useful for solving the problems of cementless fixation. Copyright 2002, Elsevier Science (USA).