SLR - October 2020 - Tyler A. Gloschat

Lateral Malleolar Defect Coverage Using Abductor Digiti Minimi Muscle Flap 

Reference: Elfeki, B., & Eun, S. (2019). Lateral Malleolar Defect Coverage Using Abductor Digiti Minimi Muscle Flap. Annals of Plastic Surgery, 83(6). doi:10.1097/sap.0000000000002044Scientific Literature Review

Scientific Literature Review

Reviewed By: Tyler A. Gloschat, DPM
Residency Program: Northwest Medical Center - Margate, FL

Podiatric Relevance: The lateral malleolus is particularly susceptible to chronic and nonhealing wounds. There is minimal soft tissue coverage, the malleolus is prominent, and injuries to the area, which require surgery, are common. In the event of a persistent wound, the risk of osteomyelitis is high. Quick closure of the wound is paramount. Within the scope of podiatry there are relatively few available rotational flaps. A peroneus brevis flap can be utilized to cover large defects of the lateral lower leg. The flap size, however could be excessive for a small to moderate wound, and it is accompanied with functional morbidity. Due to differing scopes of practice, some podiatrists would not have access to the peroneus brevis flap. The abductor digiti minimi muscle flap, provides a viable option for coverage of small to moderate sized lateral malleolus wounds. The flap leaves little to no donor site morbidity, is relatively less technically difficult, and is available to most podiatric surgeons.

Methods: A level IV case series was used to demonstrate the reliability of closing deep, small to moderate defects of the lateral malleolar region. The flap used is the abductor digiti minimi muscle flap. A total of eight patients were included in the study, six of which were male and two were female. All patients had a chronic nonhealing wound in the area of the lateral malleolus with exposed bone, joint, or tendon. Exclusion criteria included previous surgery to the lateral foot and patients with vascular insufficiency to the ipsilateral limb. The study was conducted between 2013 and 2016 and patients had a mean follow up of 22 months.

Results: Eight patients underwent the procedure. The mechanisms of injury to the lateral malleolus were traffic accident, pressure sore, and uncontrolled diabetes. Wounds  ranged  from no infection to chronic osteomyelitis. Patients had an average hospital stay of 13 days. No revisions were required, and no recurrence of ulceration was observed during the follow up period. The patients did not report or experience any donor site morbidity. All patients were able to ambulate with full weight bearing by postoperative week four.

Conclusions: There are few options when attempting to cover a small to moderate sized defect of the lateral malleolus. Free flaps require long OR time, have high cost, and often are not acceptable to patients. The peroneus brevis muscle flap may be considered; however, it comes with functional morbidity and the large size of the flap may dwindle a small to moderate size wound. This study shows that the abductor digit minimi muscle flap is a viable option that has little to no functional morbidity and can be more aesthetically acceptable to patients.

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