# Constancy of the anterior lateral malleolar artery anastomosis in retrograde lateral supramalleolar flaps: Anatomical basis and clinical relevance

## TL;DR

This study confirms the reliability of a specific blood vessel connection for a surgical flap used in foot reconstruction, showing consistent anatomy and good clinical results.

## Contribution

The study provides a detailed anatomical and clinical validation of the retrograde ALMA-based LSM flap for dorsal forefoot reconstruction.

## Key findings

- Anastomoses between the ALMA and peroneal artery were consistently found with reproducible anatomical landmarks.
- Clinical use of the retrograde LSM flap achieved a 92% complete survival rate in 38 patients.
- Radiography confirmed reliable perfusion extending to the midline of the leg.

## Abstract

The lateral supramalleolar (LSM) flap is traditionally based on peroneal perforators, but its retrograde vascularization via the anterior lateral malleolar artery (ALMA) remains insufficiently defined. Clarifying this pathway may expand reconstructive options for dorsal forefoot defects.

Anatomical dissections were performed on 31 fresh above-knee amputated limbs, focusing on the retrograde anastomosis between the ALMA and the descending branch of the peroneal artery. Distances, diameters, and perfusion were documented by direct measurements and contrast radiography. Surface landmarks were established: landmark 1 (ALMA origin at the anterior tibial artery–malleolar line intersection) and landmark 2 (fourth metatarsal axis–malleolar line intersection). Clinical validation was conducted in 38 patients with dorsal forefoot defects reconstructed using retrograde LSM flaps.

Anastomoses between the ALMA and peroneal artery were consistently identified. The mean distance from landmark 2 to the anastomosis was 13.1 mm, with a mean arterial diameter of 0.8 mm; the ALMA origin was 12.2 mm from landmark 1 with a diameter of 1.0 mm. Flap length averaged 19.8 cm from the anastomosis. Radiography confirmed perfusion extending to the midline of the leg. Clinically, the mean wound size was 7.9 × 4.8 cm, reconstructed with flaps averaging 9.4 × 5.3 cm and 17.4 cm in length. Complete survival was achieved in 35 of 38 cases (92%); three had partial necrosis managed with grafting.

The retrograde ALMA consistently supports the LSM flap, with reproducible anatomical landmarks and reliable perfusion. Clinical outcomes confirm its value as a practical option for dorsal forefoot reconstruction, combining anatomical predictability with high survival rates.