Implant survival and risk factors for failure after proximal femoral megaprosthetic reconstruction

Abstract

Background: Proximal femoral megaprosthetic reconstruction is a well-established solution for extensive bone loss in the hip region. Despite its utility in limb salvage, it carries notable complication rates, reported between 30% and 40%, along with increased morbidity and mortality. This study evaluated implant and patient survival, failure modes, and associated risk factors. Methods: We retrospectively reviewed 165 patients who underwent proximal femoral megaprosthetic reconstruction between 2003 and 2023. Indications included primary bone tumors (n = 67), metastatic bone disease (n = 60), and non-oncologic conditions (n = 38). A total of 57 METS (Stanmore) and 108 MUTARS (Implantcast) implants were used. Median follow-up was 5 years (range: 0.25–17 years). Results: Mean implant survival was 5.13 years (range: 0.2–17 years), with an overall complication rate of 30.9%. The most common failure modes were type 1 (11.5%) and type 4 (13.3%) per Henderson classification. Five-year implant survival ranged from 60% to 70% across indications. Independent risk factors for type 4 failure included prolonged hospitalization (OR = 1.07, p = 0.020) and longer operative time (OR = 1.01, p = 0.023). Silver-coated implants showed a trend toward reduced infection (OR = 0.18, p = 0.29), though not statistically significant. METS implants were associated with lower type 1 failure risk (OR = 0.09, p = 0.020), with a soft-tissue failure rate of 3.5% versus 15.7% for MUTARS. Conclusion: Proximal femoral megaprostheses remain effective for limb salvage but are linked to a substantial complication burden. Recognition of modifiable and patient-specific risk factors may improve surgical outcomes and reduce failure rates.