Experimental research on the repair of massive bone defects by using vascular-attached ulna autograft combined with bone allografts

Objeetive To investgate the therapeutic effect of the treatment of vascular-attached autograft combining with allograft for repairing massive bone defects after bone tumor resection.Methods Twelve 6-month old goats were chosen as the experimental animals.A 6.0 cm bone defect of diaphysis and periosteum was made at the shaft of the ulna and the radius.The defects of the experimental group were frepaired with ipsilateral vascular-attached ulna combining with allograft bone.In the control group,the defects were filled with allografts only.External fixation and plaster were used tostabilize the grafts.X-ray,micro-CT and histological observations were taken after operation or 12, 24 weeks post-operatively.Results In week 12,plenty of new bones were found in the group of experimental group and the defects were completely repaired by the grafts in week 24.The healing rate of the bone defects was 100%.On the contrary,no evidence of bone repairing was found in the control group.After the Micro-CT reconstruction,the proximal and distal end of the defects were repaired completely and many new bones were formed between the implanted allograft and vascularized autografts in the experimental group.Moreover,the defects of allografts were filled with new bone and medullary cavity were formed.The density of bone mineral of the allografts bone in the control group declined, and obvious bone absorption were found.The bone formation of experimental group was obviously higher than that of the control group.Creep substitutions occured in the proximal and distal end or the middle of the bone defects in the experimental group according to histological investigation.Conclusions The treatment of vascular-attached autograft combining with allograft for repairing massive bone defects was very effective.The vascularized autograft was found to accelerate the healing and promote the creep substitution of allograft which was useful to the healing.The method used in the experiment may be carried out to repair massive bone defect after the resection of bone tumor.