Characterization of an injectable chitosan-demineralized bone matrix hybrid for healing critical-size long-bone defects in a rabbit model.

BACKGROUND: The effect of injectable demineralized bone matrix (DBM) on bone repair is not known. Here, we tested the hypothesis that injectable DBM can heal a critical-size diaphyseal radius defect in a rabbit model. MATERIALS AND METHODS: The bone defect was filled with DBM powder, injectable DBM or powdered, freeze-dried powdered allografts. Radiological determination, gross evaluation, histology, and micro-computer tomography was carried out 4, 8, and 12 weeks after the surgery, respectively. RESULTS: The injectable DBM group yielded better when compared with the freeze-dried powder group (p < 0.05). Moreover, biomechanical functionality was restored comparable to normal levels in the injectable DBM group. CONCLUSIONS: The injectable DBM was as effective in structurally and functionally repairing bone defects as the DBM powder and more effective than the freeze-dried bone powder. Thus, our study supports the use of injectable DBM for bone healing.