Histological evaluation of free revascularized iliac crest bone after transplantation for mandibular reconstruction

Differing views on the nutritional status of revascularized bone in animal studies and in human transfer have been expressed. Normal viability is reported as well as single cell necrosis and devitalized areas and, finally, necrosis of the complete graft. From 19 patients with revascularized bone transfer into injured recipient tissues, we obtained 32 drill biopsies out of the centre of the graft and near the mandibular stump during the removal of the osteosynthesis plates. The histological preparations were examined for bone viability. In 58% of all patients, there occurred partial necroses in the grafted bone and in 26% single cell necroses; 16% of the transplants maintained normal viability. The areas with disturbed nutrition were found more frequently in peripheral areas than in central regions of the graft (p < 0.05, chi 2 test). The overall graft failure rate was 6.8%. The results of this clinical study are discussed with particular reference to the technical procedure, the recipient tissue quality, and the design of the graft. The indication for using revascularized bone transfer in difficult local conditions of the recipient tissues has been confirmed. The viability of the grafts cannot always be maintained entirely. The particular risk to the viability of the graft in the peripheral regions requires careful technical procedures.