Bone marrow stromal cells and their use in regenerating bone tissue

We have used autologous BMSC/bioceramic composites to treat full-thickness gaps of long bones, first in a large animal model (tibia diaphysis in adult sheep) and than in few selected patients. A complete integration of ceramic with bone was observed by X-ray, histology, microradiography and SEM studies. In addition a good functional recovery was obtained. The healing process involved four main steps: 1) bone formation on the outer surface of the implant; 2) bone formation in the inner cylinder canal; 3) formation of fissures and cracks in the implant body (integration and disintegration mechanisms); 4) bone formation in the bioceramics pores. The results obtained are very promising and could represent a real and significant improvement in the repair of critical size long bone defects.