Locally applied nerve growth factor enhances bone consolidation in a rabbit model of mandibular distraction osteogenesis

Distraction osteogenesis is widely used in treating deformities, defects, and fractures of both long bones and cramofacial bones. Demands for acceleration of bone consolidation are increased in distraction osteogenesis. Nerve growth factor (NGF) can enhance innervation and bone regeneration in a fracture model and stimulate differentiation of osteoblastic cells. In this study, we tested the ability of locally applied NGF to enhance bone regeneration in a rabbit model of mandibular distraction osteogenesis. Twenty rabbits underwent bilateral distraction osteogenesis with a rate of 0.5 mm per 12 h. Two times 0.04 mg human NGF beta (hNGF beta) in buffer was injected into the callus after distraction. The contralateral side received placebo injections. Rabbits were euthanized at consolidation times of 14 and 28 days. Specimens were subjected to radiography, callus dimensions measurement, mechanical testing, and bone histological and histomorphometric analysis. The maximum load, bone volume/total volume, mineral apposition rate of the 1st to 11th day, and mineralized bone percentage were significantly higher in the hNGF beta side at 14 and 28 days (p < 0.05). The data indicate that locally applied hNGF beta can accelerate callus maturation and may be an option to shorten the consolidation period in distraction osteogenesis. (c) 2006 Orthopaedic Research Society.