Medial and lateral malleolar arteries in ankle arthroscopy: a cadaver study.

Neurovascular injury may occur during ankle arthroscopy. The majority of complications are neurological injuries; however, vascular injuries do exist. Neurovascular structures are especially vulnerable during portal placement and debridement of anterior structures. Routine anteromedial and anterolateral portals are generally accepted to be safe; this is different from the anterocentral portal, which is associated with a higher risk of injury. However, injuries may occur in these relatively safe portals. The purpose of this cadaver study was to examine other relatively minor neurovascular structures such as medial and lateral malleolar arteries and to determine how these portals can be more safely placed. The distance between standard anteromedial, anterolateral portals and the medial and lateral malleolar arteries was measured in 18 ankles from 9 cadavers. These distances varied with the position of the ankle during portals placement, and measurements were obtained in both flexion and extension. The average distance in flexion and extension was 6.41 to 2.47 mm on the lateral side and 4.73 to 1.58 mm on the medial side. The distances significantly increased with ankle flexion and decreased with extension (P < .005). The current study demonstrated that there were other minor vascular structures at risk other than tibialis anterior artery and proper positioning of the ankle during portal placement, and that injury risk may be associated with ankle position. Ankle flexion may decrease the risk of damage to malleolar arteries and decrease minor vascular complications such as postoperative bleeding and hematoma.