Bone Morphogenetic Protein Promotes Vascularization and Osteoinduction in Preformed Hydroxyapatite in the Rabbit

Publisher Website
Google Scholar
Abstract
Early reconstruction of large osseous defects in children is often delayed due to limited availability of autogenous bone graft donor sites. With the advent of growth factors, osteoinductive proteins, and delivery matrices, it is possible to fabricate new bone at extraskeletal sites. Due to their own blood supply, adequate bony volume, and decreased resorption, vascularized bone flaps have demonstrated greater success in restoring large bony defects compared with nonvascularized bone grafts. The purpose of this study is to prefabricate a vascularized bone flap in the immatureage rabbit using the auricularis anterior muscle as a muscle pedicle. Sixteen female New Zealand White rabbits, 2.0 to 2.5 kg, were divided into two groups. Group 1 contained 8 animals that had T-shaped, 10 ×6 × 4-mm hydroxyapatite (HA) implants combined with 100-µg bovine-derived bone morphogenetic protein (BMP) placed supraperiosteally and fixed deep to the auricularis anterior muscle. Implants with HA alone were placed in the same animal and secured to the contralateral auricularis anterior muscle. Group 2 contained 8 animals that had HA/BMP placed subperiosteally and fixed deep to the auricularis anterior muscle, while implants with HA alone were secured in the same animal to the contralateral auricularis anterior muscle. In each group, 4 animals were sacrificed at 4 and 8 weeks. The animals underwent randomized bilateral carotid artery Injection with micropaque barium suspension just prior to sacrifice to help maintain vascularity. At harvest the implants and surrounding muscle and cranium were removed en bloc. New bone formation in the HA implants was examined by using routine histology and scanning electron microscopic backscattering image (quantitative) analysis. Microradiographs were performed on representative specimens. At 4 weeks postimplantation, backscattering analysis in the subperiosteal HA/BMP showed a mean 17.1% bone ingrowth vs. 11.3% of HA alone (p

This publication has 0 references indexed in Scilit: