[Bone regeneration in Pro Osteon 500 alone and in combination with Colloss in the patellar gliding model of the...

In order to optimize osteoneogenesis, Pro Osteon 500 (coralline hydroxylapatite) was coated with the osteoinductive protein complex Colloss and implanted in distal rabbit femurs for 28, 84, 168, and 365 days. Uncoated material was placed contralaterally and examined for intraindividual control. No impairment of bone formation on the implant granules was noted upon histological examination, as well as after coating with Colloss. Both osteoid and chondroid were sparsely found. After 84 days the original woven bone had been largely transformed into lamellar bone. Formation of new bone increased up to 84 days and from then on ranged from 49.8% to 58.7% up to 365 days. This increase was independent of the lower density of the cancellous bone surrounding the graft. Coating with Colloss promoted osteoneogenesis to a maximum of 15.1%, which, however, was not statistically significant. The implant granules were not subject to resorption.