Survival, Failure Modes, and Risk Factors After Limb Salvage Surgery with Modular Megaprosthetic Reconstruction

Modular megaprosthetic reconstruction is a central limb-salvage strategy after major skeletal resection, but long-term outcomes remain limited. This study aimed to evaluate patient and implant survival, complication burden, Henderson failure modes, and associated risk factors.

We retrospectively analyzed 340 consecutive patients undergoing modular megaprosthetic reconstruction at a tertiary referral center from 2003 to 2024 for primary malignant bone tumors, metastatic disease, or complex revision- or trauma-related indications. Kaplan-Meier methods estimated patient, implant, and complication-free survival. Implant failure and first recorded Henderson failure modes were additionally assessed using competing-risk methods. Cox regression evaluated risk factors, with multivariable modelling focused on Type IV infection.

Median follow-up was 5 years. Patient survival was 71.4% at 5 years and 61.3% at 10 years and was poorer in metastatic disease (p < 0.001). Implant survival was 78.0% and 70.3%, respectively. Complications occurred in 133 patients (39.1%). Type IV infection was the most frequent first failure mode (49, 14.4%), followed by Type I soft-tissue failure (40, 11.8%). The cumulative incidence of infection was 14.6% at 5 years and 15.3% at 10 years. Previous surgeries at the operative site (hazard ratio [HR] 2.30 per additional surgery, 95% confidence interval [CI] 1.90-2.80), operative time (HR 1.005/min, 95% CI 1.002-1.008), and diabetes mellitus (HR 2.30, 95% CI 1.25-4.25) were independently associated with infection and remained significant after expanded adjustment.

Implant survival remained 70.3% at 10 years, but complications were frequent. Infection was the dominant first failure mode, and prior local surgery, longer operative time, and diabetes identified higher-risk patients. These findings support individualized risk assessment, preventive planning, and long-term surveillance.