Fabrication of vascularized bone grafts using ceramic chambers

The present study was designed to create a vascularized bone graft combining the osteogenetic potential of bone marrow cells, and vascular bundle implantation in a hydroxyapatite chamber, using New Zealand white rabbits. A hydroxyapatite chamber was molded into a cylindrical shape, and hydroxyapatite fillers were soaked in an autogenous bone-marrow-cell suspension at a concentration of 1.6 x 10(8)/ml. In one group, the implant was packed with allogenic demineralized bone matrix powder (DBM) and implanted in the mid-thigh subcutaneously, with the epigastric vessels running through the chamber. In a second group, the chamber with bone marrow cells and DBM was implanted subcutaneously, without vascular bundle implantation. The control group consisted of a chamber without DBM, soaked in venous blood and implanted in the opposite thigh, with the epigastric vessels running through the chamber. Cross-sectional bone area and mineral apposition rate were measured, in addition to newly-formed vessels. After 3 weeks, chambers implanted with bone marrow cells and DBM demonstrated consistent bone formation in the pores of the chamber walls and within the chambers. No evidence of bone formation was noted in the chambers soaked with venous blood. The results indicated that vascular-bundle implantation promoted earlier bone formation with neovascularization in the chambers with bone-marrow cells and DBM. Microangiograms revealed vascular connections between the vascular bundle and soft tissue surrounding the chamber through newly-formed vessels in the chamber wall. These findings support the concept of creating a preformed vascularized bone graft, to reconstruct segmental bone defects.