Abstract: [Objective]To investigate the feasibility of repairing bone defects associated with open fractures by vascularization of canine free long segmental radius via fostering in the blood-rich saphenous vein.[Method] A total of 12 healthy dogs were randomly divided into experimental group and control group.For both of the groups,a bone segment with length of 15 mm in middle part of radius of right forelimb was amputated.Under the simulated traffic accident condition,the amputated long radial segment was kept in soil outside for 1 h.Subsequently,the retrieved bone segment was subjected to a series of treatments,including washing with plenty of physiological saline,immersing in 10% povidone-iodine for 5 min,flushing using physiological saline for 1 min,and draining off for further use.For experimental group,the radial segment was embedded in the blood-rich saphenous vein,and for control group,it was preserved at -80 ℃ in a sterile condition.After 8 weeks,the bones were removed and implanted back to repair the canine radial defect.Gross morphology of the bones was observed at 6 and 12 weeks after replantation.The repair effect was evaluated by X-ray at weeks of 4,8,and 12,respectively,and was scored using the Lane-Sandhu X-ray scoring standard.[Result] In the same period of time,the better repair effect of radial defect was observed in the experimental group compared to the control group.[Conclusion] The canine radial defect can be repaired by fostering the vascularized long bone segment or cryopreserving the long bone segment.Compared with the bone segment preserved at -80 ℃,the vascularized one has the advantages of shorter healing time and less bone resorption.