HA COATED FEMORAL COMPONENTS IN TOTAL KNEE REPLACEMENTS

Abstract

Three hundred and fifty-eight Tri Con 2 total knee replacements were done between 1987 and 1993. There were three versions of the femoral component, smooth for cement, porous coated and HA coated. Fifty-nine died or were lost to follow-up within two years leaving 229 cases with a follow-up of between 2 and 17 years. Eighteen were cemented, 162 porous coated and 51 HA coated. No porous or cemented femoral components were revised. Three (5.9) HA components were. One was revised at 2 years for unexplained pain. Revision did not help. In 2 cases the tibia loosened. The HA femoral component was tight. There was significant femoral osteolysis. It was possible to knock off the femoral component fairly easily. Virtually no HA remained on the components. There was significant 3-body wear of the polyethylene.

The conclusions are that the advantage of an HA coating is that well-fixed femoral component can be knocked off with a simple application of force. This can never be done with a well fixed porous component. The disadvantage is that HA fixation does not seal against osteolysis. The incidence of 3-body wear is possibly increased and HA coating may have a finite life expectancy.