Early outcomes of limb salvage surgery with mega-prosthesis: A single center experience

Objective: To determine the early outcomes of limb salvage surgery with mega prosthesis. Methods: This retrospective study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH&RC) from 1st January 2017 till 31st January 2020. Data like demographics, histopathology, functional and survival outcomes were retrieved from the Hospital Information System. Musculoskeletal Tumor Society (MSTS) score was used to evaluate the functional outcomes after the surgery. For survival analyses, Kaplan-Meier curve was applied. Prosthesis joint infection, amputation rate, metastasis, mortality rate, and recurrence were also recorded. Results: This study included 43 patients who underwent limb salvage surgery with endoprosthesis reconstruction at SKMCH&RC. The mean age at the time of diagnosis was (26.5±15.8) years. Patients with distal femoral replacement had the highest MSTS scores (81.45±9.70) while those with proximal humerus replacement has the lowest MSTS scores (56.8±11.2). There was a strong association between site of tumor and MSTS (F=3.30, P=0.017). We also found a correlation between surgical site infection and MSTS scores (r=0.484, P=0.001). Patients with recurrence also had significantly lower MSTS scores (P<0.05). The cumulative survival rate at the end of two-year follow-up was (71.4±17.1)% in proximal femur tumor patients, (88.0±7.8)% in distal femur tumor patients, and (50.0±3.5)% in proximal humerus tumor patients. Besides, patients with Ewing sarcoma had the highest survival rate (97.5±11.0)% while patients with chondrosarcoma had the lowest survival rate (77.8±13.9)%. Conclusions: Limb salvage surgery with mega-prosthesis can be performed with satisfactory functional and survival outcomes, but further studies are needed to compare it with other limb salvage methods. This study can be used as a reference for future studies.