Bone healing after implantation of hydroxyapatite granules and blocks (Interpore 200) combined with autolyzed antigen-extracted allogeneic bone and fibrin glue. Experimental studies on adult rabbits.

Bone healing around hydroxyapatite granules and blocks (Interpore 200), implanted in mandibular and tibial bone cavities with or without autolyzed, antigen-extracted, allogeneic (AAA) bone, was studied in young adult rabbits. The study was done in two series. In series I, standardized bone cavities were filled with implants in granular form mixed with a fibrin glue, Tisseel, for half of the cavities. The animals were followed for 5 and 8 weeks. In all cavities implanted with AAA bone, regardless of the combination with hydroxyapatite or the fibrin glue, bone had formed in excess of the cavities, resembling exostosis formation. AAA bone significantly increased (P < 0.005 or 0.01) bone formation. In series II, a 6 x 3-mm cavity was created in the medial aspect of the proximal part of each tibia. This was filled with a hydroxyapatite block--its cross section measuring 6 x 3 mm--such that 2 mm of the block extended outside the bone surface. In alternation between left and right sides, half of the blocks were covered with a paste of AAA bone and Tisseel, and half with Tisseel with the fibrin glue alone. The observation time was 8 weeks. The area of newly formed bone within and around the hydroxyapatite blocks was significantly increased (P < 0.001) when AAA bone was used. Thus, hydroxyapatite, both as granules and blocks for supporting structures, can be successfully combined with AAA bone, the bone-inductive capacity of AAA bone being utilized.