Osteogenesis and angiogenesis in regenerating bone during transverse distraction: quantitative evaluation using a canine model.

Abstract

For some patients with a bone defect, curved deformity, or small diameter bone, transverse distraction might be better indicated than bone transport or lengthening. However, detailed quantitative evaluation of osteogenesis or angiogenesis during transverse distraction by creating a well-controlled animal model has not been done. We established a transverse distraction model of the canine tibia. A rectangular cortex was separated for a distraction fragment. Seven days after the operation, 0.5-mm distraction was applied twice daily for 14 days. After a 28-day consolidation period, the animals were sacrificed. Quantitative evaluations of the rates of mineralization and the increases of bone mineral density indicated faster mineralization and earlier corticalization of the regenerating bone in the initial stage of the consolidation period. The average blood vessel volume ratio in the distraction area was more than three times greater than in the intact contralateral tibiae. We hypothesized that adequate preservation of the marrow arteries and stability of the distraction site throughout an experimental period could induce this faster osteogenesis. Our results indicated that the transverse distraction technique was feasible. The transverse distraction technique could be indicated for patients with small-diameter bones or with massive bone defects.