Experimental animal investigation of bone regeneration with collagen-apatite.

Multicentric osteoregeneration is a new principle of osteoinduction [31a] which can be realized with the combination of collagen and fine dispersed hydroxyapatite ceramic particles (Collapat). This was histomorphometrically proved in the present study involving 14 rabbits with 28 6-mm-wide bore holes in the distal femoral condyles. With Collapat, an average of 5 times more new bone was regenerated than in the control defects without implant. The Wilcoxon matched-pairs signed-ranks test proved the positive effect of the implant Collapat on osteoregeneration with a significance of P less than 0.0001. At sites of Collapat insertion bone regeneration begins in the 2nd week, reaches its climax in the 3rd week, and is completed after the 4th week. in the course of development the histological picture is typified by a lively bone remodeling. Bone formation can be recognized in direct contact to the apatite granules. Foreign body or allergic reactions are not observed. Remodeling of the bone is not hindered by the slowly resorbable apatite granules. About 250 human implantations have been performed in our hospital since 1979, with good results and no negative effects.