THE EFFECT OF TITANIUM PLASMA-SPRAYED IMPLANTS ON TRABECULAR BONE HEALING IN THE GOAT

The bone response to different titanium plasma-sprayed implants was ev aluated in a goat model. Therefore, beam-shaped implants were installe d into the trabecular femoral condyles of 10 goats. These implants wer e provided with three different titanium plasma-sprayed coatings (Ti2, Ti3 and Ti4) with a Pa of 16.5, 21.4 and 37.9 mu m, respectively. An Al2O3 grit-blasted implant (Ti-un) with a Pa of 4.7 mu m was used as c ontrol. After an implantation period of 3 months, the implants were ev aluated histologically and histomorphometrically. Only one implant (Ti 3) was not recovered after the evaluation period. Light microscopy sho wed a limited amount of bone for the various implants. Most of the imp lants showed a different degree of fibrous tissue alternating with dir ect bone contact. Complete fibrous encapsulation of the implants was o bserved in some of the sections. No signs of delamination of the plasm a-sprayed coating was visible. No significant difference in bone conta ct were measured between the different types of implants (P > 0.05). H istomorphometrical analysis revealed significantly higher bone mass cl ose to the implant (0-500 mu m) for the Ti3, Ti4 and Ti-un implants pl aced in the medial femoral condyle and the Ti4 implants placed in the lateral condyle. At distance (500-1500 mu m), no difference in bone ma ss measurements between the different implants was observed (P > 0.05) . (C) 1998 Published by Elsevier Science Ltd. All rights reserved.