USE OF DEMINERALIZED BONE AS AN OSTEOINDUCTIVE ORBITAL ENUCLEATION IMPLANT IN THE RABBIT

Implanted allogeneic demineralized bone particles (DBP) may be transfo rmed into endochondral bone by inductive or conductive new bone format ion. Using a rabbit model, enucleation or evisceration was performed, and DBP was implanted into the socket. Histology confirmed endochondra l bone formation in both groups. A morphologic difference existed betw een enucleation and evisceration: compact bone was produced following evisceration, and cancellous bony spheres were formed following enucle ation. Serial quantitative computed tomography (qCT) was performed to monitor mineral density and proved to be an ideal technique to monitor bone mineralization noninvasively in the postoperative orbit. Bone mi neral density (BMD, mg/ml) increased approximately 300% in DBP implant ed orbits when compared to controls at 6 weeks. The ideal mass/volume ratio of DBP to socket volume was 400 mg/ml. The rapidly formed bone i s well vascularized and creates a stable integrated orbital implant, f ollowing enucleation and evisceration surgery. DBP implantation into t he central orbit results in inductive bone formation with interesting potential in socket and orbit reconstruction.