Megaprosthesis for Metastatic Bone Disease-A Comparative Analysis

Background: Megaprosthetic reconstruction is sometimes indicated in advanced metastatic bone disease (MBD) of the appendicular skeleton with large degrees of bone loss or need for oncological segmental resection. Outcome after megaprosthetic reconstruction was studied in the setting of primary bone sarcoma with high levels of complications, but it is not known if this applies to MBD. Method: We performed a comparative analysis of complications and revision surgery for MBD and bone sarcoma surgery in an institutional cohort from 2005-2019. Presented are the descriptive data of the cohort, with Kaplan-Meier (K-M) rates of revision at 1, 2 and 5 years together with a competing risk analysis by indication type. Results: Rates of revision surgery are significantly lower for MBD (8% at 1 year, 12% at 2 years), in the intermediate term, compared to that of sarcoma (18% at 1 year, 24% at 2 years) (p = 0.04). At 5 years this is not significant by K-M analysis (25% for MBD, and 33% for sarcoma), but remains significant in a competing risk model (8% for MBD, and 20% for sarcoma) (p = 0.03), accounting for death as a competing event. Conclusion: Rates of revision surgery after megaprosthetic reconstruction of MBD are significantly lower than that for primary bone sarcoma in this cohort.