RESUMEN
BACKGROUND:A newly developed calcium phosphate/β-tricalcium phosphate composite bone cement with a negative surface charge (genex?) has been reported to possess osteoinductivity properties. However, to our knowledge, no previous literatures have reported genex? for vertebroplasty in the osteoporotic spine. OBJECTIVE:To evaluate the biomechanical properties and osteogenesis of vertebral bodies injected with genex? cement in a rabbit vertebroplasty defect model. METHODS:Thirty New Zealand rabbits were used to establish osteoporosis models. Four weeks after modeling, model rabbits had an iatrogenical y created cavitary lesion at L 3 and L 5 and were injected with either genex? cement (experimental group) or polymethyl methacrylate bone cement (control group). The L 1 vertebral body served as model group without treatment. After 3 and 6 months, 15 rats from each group were executed respectively, and three vertebral samples were taken for Micro-CT analysis and biomechanical tests. RESULTS AND CONCLUSION:(1) The Micro-CT showed better three-dimensional structure parameters of the trabecular bone in the experimental group than the control group (P0.05). After 6 months, the structure parameters in the experimental group were superior to those in the control and model groups (P0.05), but stil higher than that of the model group (P0.05). These findings indicate that genex? cement can rapidly repair osteoporotic vertebral defects and improve the bone strength. Verterbroplasty with genex? cement has adequate osteoinductivity, biocompatibility, and adequate compressive strength.