Biologic model of bone transport distraction osteogenesis and vascular response.

We developed an experimental model in the rabbit of distraction osteogenesis through bone transport that closely corresponds to the clinical use of bone transport in humans. We also applied injection angiography to study the arterial response of a limb undergoing bone transport. This model includes a proximal osteotomy and bone transport to fill in a segmental tibial diaphyseal defect. Regenerate bone formed well in the gap that was created that trailed the transport segment, and slow healing at the docking site was observed, as seen in humans. The angiographic techniques clearly revealed, by radiography and anatomic dissection, the arterial response to bone transport. The results showed that the transport segment had an arterial supply after osteotomy and after transport. They also demonstrated an extensive increase in vessels in limbs that had undergone distraction osteogenesis, an observation made clinically in humans but not well demonstrated experimentally. Furthermore, angiography showed proximal stretching and distal kinking of the major artery of the leg. This model closely resembles distraction osteogenesis through bone transport in humans and definitively demonstrates that the transport segment can maintain blood supply and remain viable during the transport process. The results of this study provide a basis for further work on factors that enhance and interfere with successful bone transport in humans.