Comparison of hydroxyapatite- and porous-coated stems in total hip replacement.

24 patients underwent bilateral hip replacement, using the SROM modular system (Depuy Johnson & Johnson, MA, USA) with the porous-coated sleeve in one hip and an HA-coated sleeve in the other. 20 patients were followed for at least 4 years with clinical and radiographic evaluations. We found no difference between the two sides as regards the time of disappearance of thigh pain and hip scores. Radiographs showed a buttress sign in 18 HA-coated and 15 porous coated stems. There were no differences in the serial bone-remodeling pattern around the proximal sleeve and measurement of wear volume between the two groups. In the short- to medium-term, our findings support the view that the hydroxyapatite-coated femoral stem has no advantages over those with porous coating.