How Many Operations Does it Take? Incidence and Risk Factors for Secondary Surgery and Amputation after Lower Extremity Limb Salvage

Background: Traumatic defects of the lower extremity (LE) require robust soft tissue to cover critical structures and facilitate healing. Free tissue transfer (FTT) is often necessary when local tissue is inadequate. While much of the literature emphasizes free flap viability in successful limb salvage, there is limited understanding regarding the need for additional surgeries or eventual amputation. We investigated a single institutions limb salvage efforts to better understand the need for additional procedures. Methods: All patients that underwent LE limb salvage were retrospectively reviewed from 2014-2022 at a single level-1 Trauma center. Our primary clinical outcome was the incidence and indication of secondary surgeries following FTT. Results: 92 LE free flaps were performed during the study period. The mean age was 45 and majority were male. 72% of flaps were fasciocutaneous while 28% were muscle flaps. 72% of patients required a secondary surgery following FTT, with a mean of 7 total surgeries per salvage attempt. 10% of patients proceeded to amputation. BMI >30, higher frailty scores, flap type, and masquelet technique were significantly associated with subsequent amputation (p= 0.017, p=.024, p=0.005, p=0.04 respectively. Conclusion: FTT is an important component of limb salvage. Patients undergoing limb salvage should be counseled on the need for secondary surgeries, as the process is often not complete following FTT. Furthermore, risk factors identified in this study may increase the likelihood of subsequent amputation. Thorough preoperative counseling is necessary to optimize the post-operative course and expectations in this population.