Outcomes over 30 years after megaprosthetic reconstruction of the lower limb following tumor resection: a retrospective case series of 10 patients

BACKGROUND: Megaprosthetic reconstruction has become the standard method for resecting bone and soft tissue tumors. However, the long-term functional outcomes and complications have not yet been sufficiently investigated. This study aimed to address a gap in the literature by analyzing patients who underwent tumor prosthesis of the hip or knee and were followed up for over 30 years. METHODS: We retrospectively analyzed 10 patients who underwent megaprosthetic reconstruction of the hip or knee between 1986 and 1995 at two institutions in Japan, with a minimum follow-up of 30 years. Patient characteristics, complications, reoperation, and Musculoskeletal Tumor Society (MSTS) scores were reviewed. The long-term risks of reoperation, major revision, and deep infection were assessed. RESULTS: This study included seven distal femoral, two proximal femoral, and one proximal tibial reconstructions (median age at surgery, 22 years). Histologically, the tumors were predominantly osteosarcomas (n = 7). Eight of the 10 patients (80%) developed complications, with a median of 1.5 reoperations (range, 1-5). Major revisions occurred in five patients, including four with stem fractures and two with deep infections. The median overall reoperation-free survival was 16.2 years (95% confidence interval, 2.4-24.2). At the final follow-up, all patients remained ambulatory, and the median MSTS score was 75.0% (range, 53.3-96.7). CONCLUSION: Despite the occurrence of frequent late complications, considerably long-term survivors following tumor endoprosthetic reconstruction in this small cohort were able to preserve ambulatory function for more than three decades, suggesting the effectiveness of this method while underscoring its lifelong risks and the necessity of long-term follow-up.