OBJECTIVE To evaluate the efficacy of transposition of the gastracnemius muscle in the limb-salvage operation of the proximal tibial tumor. METHODS From 1995, transposition of the gastrocnemius muscle was applied to cover the devitalized bone, bone cement or autologous bone graft in 15 cases with tumors of the proximal tibia (transposition of medial heads of gastrocnemius muscle in 12 cases, and lateral heads of gastrocnemius muscle in 3 cases respectively). Among them, there were 7 osteosarcomas, 5 giant cell tumors, 1 malignant fibrous histocytoma, 1 chondrosarcoma and 1 osteoblastoma. The operations included segmental devitalization with 95% alcohol in 7 cases, knee reconstruction of the unilateral tibial plateau with iliac graft in 5 cases, segmental devitalization with microwave in 2 cases, local resection and bone graft in 1 cases. RESULTS Apart from 2 cases whose wounds needed suturing again due to the liquefaction of the subcutaneous fat around the incision, no wound complications were occured in other 13 patients. No significant loss in the function of the leg and ankle was observed after transposition of the gastrocnemius muscle. There was no local recurrence, but 3 patients died due to lung metastases. CONCLUSION Transposition of the gastrocnemius muscle after resection of promixal tibial tumors can improve the local blood supply, cover the deep structures and prevent from the failure of limb-salvage operation due to wound complications.
OBJECTIVE To investigate the feasibility of osteoid callus allograft as a kind of bone healing promoting materials. METHODS The osteoid callus was obtained at one week after bilateral femoral fracture of a SD rat, then was kept at -196 C for 2 weeks. The bone defect model which bone repair was in intra-membranous osteogenesis was made at bilateral tibial shaft in 5 rats, and filled with the osteoid callus in the left defect area, the right side was filled with allogenous cancellous as control group. The specimen were processed with undecalcified technique and the sections were staining with light blue and sofranin T. RESULTS After 2 weeks, there were cartilage and bone formation in the defect area of osteoid callus graft group(3/4), medullary cavity formation in bone tissue with cartilage arround it, fibrous tissues between new bone and host bone. While there were no cartilage or bone formation in the control group. CONCLUSION The allograft osteoid callus is not absorbed by immunological rejection, but changed into bone tissue through endochondral osteogenesis. It is inspiring to develop osteoid callus allograft as a kind of material for bone healing.