Risk Factors Associated with Adverse Functional Outcomes in Free Flap Reconstructions of the Lower Extremity.

[BACKGROUND] Lower limb reconstruction remains a significant challenge, often requiring free flap transfers. However, the goal is not only flap survival and limb salvage but, ultimately, restoration of independent ambulation. Therefore, this study aimed to identify risk factors associated with adverse functional outcomes in lower extremity reconstruction despite initial microsurgical success.

[METHODS] A retrospective review of all free flaps performed for lower extremity reconstructions in our unit between 2006 and 2022 was undertaken. Apart from demographic details, data collection focused on long-term results regarding weight-bearing, ambulatory status, secondary amputation, and overall function using the lower extremity functional scale (LEFS). Multivariate regression analysis was used to identify risk factors for adverse functional outcomes.

[RESULTS] A total of 466 consecutive patients undergoing 516 free flap procedures were included. The mean follow-up was 46 months. In most cases, preoperative ambulatory status was restored postoperatively, resulting in 86.4% unassisted ambulation (12.9% assisted, 0.5% wheelchair). Evaluation of 251 LEFS scores (average follow-up 7.8 y) showed a mean value of 55.4 points. Of the patients, 3.77% underwent secondary amputation. The most significant risk factors associated with secondary amputation were flap failure and postoperative infections, whereas lower LEFS scores significantly correlated with secondary amputation and obesity.

[CONCLUSIONS] Lower extremity reconstruction remains a challenging endeavor for reconstructive surgeons, where flap survival should not be regarded as the endpoint. Functional restoration and independent ambulation should constitute the main goals, and patient-specific factors should be considered in an individualized approach.