The Origin of the Anterior Lateral Malleolar Artery From the Anterior Tibial Artery: A Fresh Cadaveric Study.

The anterior lateral malleolar artery (ALMA), which usually originates from the anterior tibial artery (ATA), courses transversely and laterally, passing under the extensor digitorum longus and peroneus tertius tendons. Variations in the origin of the ALMA from the ATA can occur. Branches of the ATA, such as the ALMA, are prone to pseudoaneurysm. This study reviewed the origin of the ALMA from the ATA and aimed to identify problems in anterior ankle arthroscopy that might cause injury to the ALMA. Enhanced computed tomography scans of 24 feet of 24 fresh cadavers (13 males, 11 females; average age 78.1 years) were assessed. The limb was injected with barium sulfate suspension through the external iliac artery; the origin of the ALMA from the ATA on the sagittal plane was recorded. The origin was at the ankle joint level in 4 specimens and below the ankle joint in 17 specimens. The distance from the ankle joint to the branching point of the ALMA on the sagittal plane was 5.2 mm distal to the joint. The level of origin of the ALMA from the ATA was established. Instruments should not be inserted from the distal direction when placing anterolateral portals. Levels of Evidence: Level IV, cadaveric study.