Contemporary Outcomes of Staged Versus Primary Major Amputation for Severe Foot Infection

Lower extremity amputation is a necessary, life-saving intervention for patients with severe foot infection. Previous studies have suggested that a staged amputation (SA) approach to severe foot infections may be associated with higher technical success and lower mortality rates, when compared with primary amputations (PAs). In this study, we examined our single-center experience comparing outcomes between SA and PA in patients presenting with unsalvageable severe foot infection.

Institutional medical records were retrospectively reviewed for all lower extremity amputations performed for severe foot infection at a single academic medical center, from January 2020 to December 2023. Per institutional practice, patients presenting with systemic illness and requiring urgent infectious source control were typically managed with a staged approach. Patients undergoing PA were compared with those managed with a staged approach. The primary outcome was postamputation survival, analyzed using Kaplan-Meier survival curves. Secondary outcomes included stump-related complications, 30-day hospital readmission, and unplanned reoperation rates.

A total of 228 patients undergoing major amputation were included in the final cohort. Of these, 169 (74.1%) patients underwent SA and 59 (25.9%) underwent PA. The median follow-up was 1.3 years. Baseline demographics and comorbidity profiles were comparable between the 2 groups. Rates of amputation stump infection (8.9% vs. 13.6%, P = 0.30) and wound necrosis (8.3% vs. 5.1%, P = 0.42) were comparable between SA and PA cohorts. There were no differences in median postoperative hospital length of stay (9 days [interquartile range {IQR} 6-19] vs. 8 days [IQR 5-14], P = 0.141), 30-day hospital readmission (20.7% vs. 20.3%, P = 0.95), unplanned reoperation (20.7% vs. 22.0%, P = 0.83), or nonhome discharge rates (64.5% vs. 59.3%, P = 0.60). One-year and 3-year survival rates were 71.8% (±3.7%) and 50.9% (±4.9%) after SA, and 73.8% (±6.1%) and 41.6% (±9.5%) after PA, respectively (log-rank P = 0.48). On multivariable analysis, factors associated with postamputation mortality included advanced age (hazard ratio [HR] 1.03 per year, 95% confidence interval [CI]: 1.01-1.05, P < 0.001), chronic kidney disease (HR: 1.74, 95% CI: 1.06-2.84, P = 0.03), and end-stage renal disease (HR: 1.86, 95% CI: 1.09-3.17, P = 0.02). Notably, SA strategy was not associated with increased mortality risk compared to PA (HR: 0.81, 95% CI: 0.50-1.29, P = 0.37).

Patients undergoing major lower extremity amputation for severe, unsalvageable foot infection face poor long-term survival. In our experience, both staged and selective PA strategies yielded comparable postoperative outcomes and survival rates. These findings support an individualized, patient-centered approach to amputation strategy selection.