Experiment Studies Of Autologous BMSCs And Bio-derived Bone Materials Combined With RhBMP-2 For Osteonecrosis Of Femoral Head Defect Repair

Objective To evaluate the effectiveness of autologous bone marrow mesenchymal stem cells(BMSCs)and bio-derived bone materials(BBM) combined with recombinant human bone morphogenetic protein-2(rhBMP-2)in osteonecrosis of the femoral head(ONFH)defect repair,and search a new therapy for ONFH by tissue engineering technology.Methods Left hip early-stage osteonecrosis was induced in adult New Zealand rabbits after core decompression and delivery of liquid nitrogen into the femoral head.Animals were devided into 3 groups(n=12 per group).Group A did not implant anything as control,Group B were implanted BBM combined with rhBMP-2,Group C were implanted BMSCs-seeded BBM combined with rhBMP-2. At 4,8,12 weeks after surgery,X-ray was taken imageing with rabbits,four of which were killed at the same time each group.Femoral heads were investigated by general observation,Hematoxylin and Eosin staining,the Lane-Sandhu scores of X-ray and the rate of new bone trabecular area growth.Results At 4,8,12 weeks after surgery,there were no significant osteogenesis in femoral head defect area of A group,where only little of fibrous bony callus generate and two femoral heads collapse,for 12 week's Lane-Sandhu scores of X-ray were 2.02±0.32,the rate of new bone trabecular area growth was 10.2±0.32%.At the same time,degradation of rhBMP-2/BBM was observed gradually in femoral head defect area of B groups,and little of new bone formation were found,for 12 week's Lane-Sandhu scores of X-ray were 4.31±0.24,the rate of new trabecular bone area growth was 31.1±1.31%.Especially more obviously bone trabecularism formation was in C group,rhBMP-2/BBM degraded at equal pace,and defect repair was so validness.Femoral heads found no collapse,for 12 week's Lane-Sandhu scores of X-ray were 9.44±0.32,the rate of new trabecular bone area growth was 63.2±2.36%.Lane-Sandhu scores of X-ray and rate of new bone trabecular area growth in group C were higher,which was statistically significant compared with group A and group B.Conclusions Our findings indicate that BBM combined with rhBMP-2 has a good ability of biocompatibility and degradation,a stong activity of osteoconduction and osteogenesis.It is a superior choice of repairing the experimental defect of ONFH with BMSCs seeded BBM combined with rhBMP-2.