Evaluation of Clinical Results and Complications of Structural Allograft Reconstruction after Bone Tumor Surgery.

BACKGROUND: Massive bone allograft is an option in cases of limb preservation and reconstruction after massive benign and malignant bone tumor resection. The purpose of this study was to analyze the outcome of these procedures at Imam Reza Hospital, Mashhad University of Medical Sciences.
METHODS: In this study, 113 cases have been presented. Eleven cases were excluded (patients has a traumatic defect or they passed away before the completion of the study's two-year follow up period). Each patient completed a questionnaire, went through a physical examination and, if indicated, X-ray information was collected. The patients were divided into three groups: chemotherapy, chemotherapy plus radiation therapy, and no-adjuvant-therapy.
RESULTS: Fifty-four cases were male and the mean age was 24.5±5.39. The number of cases and indications for surgery were: 33 cases of aggressive benign tumors or low grade malignant bone tumors (large bone defects) including 16 germ cell tumors, eight aneurysmal bone cysts, five low grade osteosarcomas, and four chondrosarcomas. Another 69 cases were high-grade malignant bone tumors including 42 osteosarcomas, 21 Ewing's sarcoma, and six other high grade osteosarcomas. Patients were divided into three groups: the first group received no adjuvant therapy, the second group received chemotherapy, and the third group received chemotherapy plus radiotherapy. The location of tumors were as follows: eight cases in the pelvic bone, 12 in the proximal femur, 18 in the femoral shaft, 36 in the distal femur, 12 in the proximal tibia, and 16 in the humeral bone. The 12 cases of proximal femoral defects were reconstructed by allograft composite prosthesis, 18 diaphyseal defects with intercalary allograft, and 36 distal femoral defects were reconstructed using osteoarticular allograft. The rate of deep infection was 7:8% (eight patients) and in this regard, we found a significant difference among the three groups, such that most cases of infection occurred in the adjuvant chemotherapy plus radiation therapy group. Allograft fracture occurred in six patients and prevalence was the same in all groups. Only in six cases of radio-chemotherapy nonunion occurred, so we used autogenous bone graft for union. Local recurrence was observed in six patients: three belonged to the adjuvant chemotherapy group and the other three were in the chemo-radiotherapy group; no significant difference was observed between these two groups. However, there was a significant difference between these two and the group that received no adjuvant therapy. Also, there were 11 cases of metastases and Restriction of knee joint motion occurred in 48 cases of osteo-cartilaginous grafts of the distal femur and proximal tibia.
CONCLUSION: Although structural allograft is an appropriate choice in limb reconstruction after massive resection of involved tissues in malignant and invasive bone tumors, the risk of complications such as nonunion and infection in massive allograft increases in cases of adjuvant (chemotherapy and radiotherapy) modalities of treatment. Whereas the rate of tumor recurrence, metastasis, and restrictions in range of motion during a short term follow up after implantation showed no significant difference among the evaluated groups. Consequently, further attention and constant periodic visits of the patients and checking for local recurrence and distant metastasis should be done after surgery.