Denervation impairs bone regeneration during distraction osteogenesis in rabbit tibia lengthening

Background and purposes The nervous system plays an important role in bone metabolism. However, the effect of denervation on bone formation during distraction osteogenesis (DO) remains unclear. We studied neural influence on bone regeneration during DO in a rabbit model. Methods 24 New Zealand male white rabbits underwent left tibial osteodistraction. Before distraction, the animals were randomly divided into group R (resected left sciatic nerve) and group I (intact left sciatic nerve). 8 weeks after completion of distraction, the animals were killed and the lengthened tibias were harvested for radiography, micro-CT, histological evaluation, and mechanical testing. Results New regenerated bone was present in the distraction gaps of all animals at the end of the study, as revealed by radiography, micro-CT, and histology. However, less new bone formation and a lower degree of mineralization were observed in group R. The mechanical strength of the distraction gap in group I was 1.3-fold greater than that in group R when measured using the 3-point bending test. Interpretation The results suggest that the nervous system plays an essential role during DO: the denervation appears to have an inhibitory effect on bone formation.