BONE RESPONSE TO HYDROXYAPATITE-COATED AND COMMERCIALLY PURE TITANIUMIMPLANTS IN THE HUMAN ARTHRITIC KNEE

Rough and smooth commercially pure (c.p.) titanium implants and hydrox y-apatite-coated (HA-C) implants were inserted in arthritic human knee s and left in situ in order to compare the response of bone to these t hree implants. Radiographic examination alone could not determine if b one apposition had occurred. After 3 and 6 months, histomorphometric a nalyses of undecalcified sections, 10 mu m thick, revealed a statistic al significance in the amount of bone apposition to rough-surfaced and HA-C implants as compared with smooth uncoated implants. Most of the rough-surfaced c.p. titanium implants and the HA-C implants had achiev ed bone apposition on the order of 50%. No statistically significant d ifferences in apposition were seen between the rough-surfaced and HA-C implants. The smooth c.p. titanium implants were mostly encapsulated in fibrous tissue.