Association of Surgical Service Line and Frailty with Outcomes after Major Lower Extremity Amputation

Background Major lower extremity amputations (LEA) are frequently performed by vascular, trauma, and orthopedic surgeons, yet comparative outcomes across services and the role of frailty remain unclear. Materials and Methods We conducted a single-center retrospective review of adults undergoing major LEA (above-knee, through-knee, and below-knee) from 2015-2022. Frailty was assessed using the 5-factor modified Frailty Index (mFI-5). Outcomes included complications, length of stay (LOS), readmission, re-amputation, mortality, and prosthetic ambulation. We evaluated 30-day return to the operating room (RTOR) overall and separated planned staged open guillotine amputation (OGA)-to-closure returns from unplanned RTOR. Results Among 684 patients (689 LEAs), vascular surgery (VS) performed 44% of procedures, trauma surgery (TS) 37%, and orthopedic surgery (OS) 19%. Median LOS was 14 days and 30-day mortality was 10.8%; 36% achieved prosthetic ambulation. OS had higher ambulation than VS and TS in both non-frail and frail subgroups. Overall, 30-day RTOR differed by service and was highest after TS; however, these differences were largely attributable to planned staged OGA-to-closure returns, while unplanned RTOR did not significantly differ by service. On multivariable analysis, both VS and TS had lower odds of prosthetic ambulation than OS (adjusted OR ≈0.34). Discussion Surgical service line and frailty are associated with outcomes after major LEA. Differences in ambulation, particularly among non-frail patients, suggest that service-specific pathways and perioperative processes may influence functional recovery and represent targets for standardized LEA pathways.