The effect of multidrug chemotherapy on bone graft augmented prosthesis fixation.

Use of combination adjuvant chemotherapies have improved the disease free survival rate of tumor patients significantly. However, studies have shown that chemotherapeutic agents have negative effects on bone graft incorporation and fixation of porous-coated prostheses needed for reconstruction of bone defects after wide resection of malignant tumors. Unilateral resection of a 6-cm segment of the femoral diaphysis and reconstruction with a porous-coated segmental prosthesis was performed in eight mixed-breed dogs under perioperative chemotherapy with doxorubicin, cisplatin, and ifosfamide. Eight strips of autogenous cortical bone were evenly placed around the junctions between the femur and the prosthetic surface. Autogenous cancellous bone was placed under and between the strips of cortical bone. Two cycles of the chemotherapy were given preoperatively, and three cycles postoperatively. The animals were followed for 12 weeks, with sequential assessments of weight-bearing and radiographic evaluation. Biomechanical, histological, and microradiographic analyses of the retrieved specimens were performed. Doxorubicin, cisplatin, and ifosfamide combination chemotherapy showed a significant effect on new bone formation as seen in reduced callus size and lower ultimate strength of extracortical fixation. However, the onlay corticocancellous grafting method provided better biologic fixation of the prosthesis compared with fixation without any bone grafting under non-chemotherapy condition in a previous study. Extracortical bone grafting is an effective modality for implant fixation even under intensive chemotherapy.