Impact of weight-bearing status on design and outcomes of free anterolateral thigh flaps in foot and ankle reconstruction

Reconstruction of foot and ankle soft-tissue defects remains challenging due to distinct anatomical and biomechanical demands between weight-bearing and non-weight-bearing regions. The anterolateral thigh (ALT) flap offers versatile reconstructive options; however, its application based on functional subunits has not been fully defined. A multicenter retrospective study of 161 patients examined free ALT flap reconstructions for foot and ankle defects, classified as weight-bearing or non-weight-bearing. It analyzed flap design, components, thickness, complications, and outcomes, with functional results assessed using AOFAS scores, range of motion, and patient-reported outcomes, and aesthetic results using a modified Hollander Scale. A total of 176 flap components were used, including fasciocutaneous, adipofascial, fascia-only, and chimeric types. Flap sizes were similar across regions but thicker in weight-bearing areas, reflecting conservative thinning. Flap survival was 93.8%, with low total (1.9%) and partial necrosis (4.3%). Complications were more common in weight-bearing regions and were associated with vascular compromise and flap design factors. Functional outcomes were favorable, with a mean AOFAS score of 82.3 and no significant between-group differences. Most patients achieved satisfactory gait and were able to wear standard shoes. Cosmetic outcomes were favorable, with over 88% rated as good. ALT flap reconstruction of foot and ankle defects should be tailored to biomechanical demands. Weight-bearing regions require thicker, more durable flaps, whereas non-weight-bearing areas allow for thinner designs to optimize contour and mobility. The versatility of the ALT flap enables region-specific adaptation, supporting reliable functional and aesthetic outcomes.