TRANSPLANTATION OF THE CANINE DISTAL ULNA AS A FREE VASCULARIZED BONE-GRAFT

An autogenous free vascular bone graft of the canine distal ulna was e valuated. The vascularity of the graft was based on a musculoperiostea l sheath supplied solely by the caudal interosseous artery and vein. F our autogenous heterotopic (ulna to tibia) vascular transfers were per formed. Two avascular transfers were performed to provide baseline cri teria from which the success of vascularized transfers could be assess ed. Clinical lameness evaluation, serial radiographs, bone scintigraph y, and sequential fluorochrome bone labeling were performed after surg ery in both vascular and avascular transfers. All dogs were free of la meness in the donor limb by the 26th postoperative day. Serial radiogr aphs revealed rapid graft incorporation and hypertrophy in all vascula rized grafts and severe bone resorption in nonvascularized grafts. His tology, microangiography, and evaluation of fluorochrome bone labels w ere performed 90 days after surgery to determine graft viability, inco rporation and temporal remodeling patterns. Microangiography and fluor ochrome assessment complemented the histological findings. Based on th ese findings the distal ulnar bone graft was determined to be both via ble and structurally adequate for selected cases of long bone reconstr uction. (C)Copyright 1995 by The American College of Veterinary Surgeo ns