Effect of Function-Based Approach to Nontraumatic Major Lower Extremity Amputation on 5-Year Mortality

Five-year mortality rates after lower extremity amputation in the chronic wound population have long been regarded as high and inevitable. We theorize that function-based surgical technique and multidisciplinary care improve mortality and assess our institution's mortality rates after major lower extremity amputation (MLEA).

We performed a retrospective review of patients who underwent primary nontraumatic MLEA at our institution from 2010 to 2013. Major amputations included below knee amputation, through knee amputation, and above knee amputation. Our function-based surgical approach to MLEA is guided by 4 tenets: (1) optimization of limb biomechanics, (2) maximal soft tissue preservation, (3) multidisciplinary team approach, and (4) addressing nerves during primary amputation to prevent postamputation pain. Kaplan-Meier analysis and Cox regression were performed to estimate cumulative 5-year mortality and to identify predictors of 5-year mortality, respectively.

A total of 188 patients underwent MLEA. Median Charlson Comorbidity Index was 4. Estimated 5-year mortality was 40% overall and 43% for diabetic patients. When stratified by amputation level, 5-year mortalities were 36.3% for below knee amputation, 60.9% for through knee amputation, and 44.0% for above knee amputation. Charlson Comorbidity Index (hazard ratio 1.24, p < 0.001) and end-stage renal disease (hazard ratio 3.38, p < 0.001) were the strongest predictors of 5-year mortality.

We demonstrate the lowest mortality rate reported for MLEA. Improved functional and mortality outcomes can be achieved with a function-based surgical approach to MLEA and close follow-up by a multidisciplinary team. Future studies, using standardized reporting of mortality data and incorporating patient-reported outcomes, are warranted to correlate return to function and mortality.