SLR - January 2022 - Alexander F. Standiford

The Coverage of Soft-Tissue Defects Around the Foot and Ankle Using Free or Local Flaps: A Comparative Cohort Study

Reference: Yuan K, Zhang F, Lineaweaver W, Chen X, Li Z, Yan H. The Coverage of Soft-Tissue Defects Around the Foot and Ankle Using Free or Local Flaps; A Comparative Cohort Study. Annals of Plastic Surgery. 2021 June; 86(6), 668-673.

Level of Evidence: III

Scientific Literature Review

Reviewed By: Alexander F. Standiford, DPM
Residency Program: Inova Fairfax Medical Campus – Falls Church, VA

Podiatric Relevance: Foot and Ankle surgeons are routinely faced with deep soft tissue defects in the lower extremity. Whether from trauma, infection, diabetes, or tumor resection, these defects often require complex soft tissue reconstruction with local or free flaps. These defects necessitate timely coverage and wound healing to prevent infection and ultimately reduce loss of limbs. Both local flaps and free tissue transfers are available to treat these defects with potential variation in the outcomes depending on procedure selection. This article aimed to compare the outcomes of defects treated with each technique.

Methods: The study was performed as a retrospective comparative cohort review of patients with a unilateral foot or ankle injury with associated soft tissue defect between 2010 and 2018. 130 patients were included in the study: 47 of which were treated with free tissue transfers and 83 patients underwent local flaps for soft tissue deficits. The patients were followed for a minimum of six months postoperatively. Primary outcome measure was defined as flap survival rate and secondary outcome measures included complications, aesthetic outcomes, and donor-site morbidity.

Results: Demographics of patients included in the study had a mean age of 45 years and underwent on average 1.74 debridement (1-5) prior to the flap reconstruction. The average soft tissue deficit was 60.29 cm^2 for both groups. There was no difference in age, sex, and number of debridement before wound coverage (P > 0.05). No significant difference was identified in complete or partial necrosis between the free flap group and the local flap group (P > 0.05). However, the local flap group demonstrated a significantly higher rate of donor site infection and need for revision surgery including skin grafting with 4 infections of the free flap donor site and 0 issues with necrosis compared  to 10 infections and 7 cases of donor necrosis in the local flap group ( P < 0.05). Additionally, 61.7 percent of patients rated the free flap as having a good aesthetic outcome as compared with 27.7 symptoms of the local flap group (P < 0.05).

Conclusions: While both local and free flap soft tissue reconstructions are routinely indicated for foot and ankle soft tissue defects depending on wound size, location and vascular status, the authors conclude that complex wounds may achieve better aesthetic outcomes and decreased donor-site compromise with comparable flap survival rate when treated with free tissue transfer compared to local flaps, Ultimately the authors make a valid argument for more frequent use of free tissue transfer for severe lower extremity wounds when feasible, though local pedicle flaps are still useful for small wounds. It is important to identify what wounds will respond appropriately to local tissue transfer and which require consultation of reconstructive plastic surgery for additional treatment options. The results of this article demonstrate the importance of aggressive soft tissue coverage of severe foot and ankle wounds, though additional research is needed to identify risk factors and specific indications for local versus free tissue transfers.

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