Ankle position affects dorsalis pedis artery exposure in anterior ankle arthroscopy

In anterior ankle arthroscopy, the anterior working area (AWA) is restricted by the presence of the dorsalis pedis artery (DPA) and tendons. Pseudoaneurysms caused by iatrogenic damage to the DPA are difficult to identify intraoperatively. In knee arthroscopy, risk of popliteal artery damage is reduced in the flexed position [1]. This study investigates how DPA movement is affected by dorsiflexion and plantarflexion with the aim of identifying the positions providing the greatest AWA.

Twelve cadaveric ankles were dissected to access the DPA. While distracted, ankles were progressively dorsiflexed at 5° intervals from maximum plantarflexion. DPA and tibialis anterior tendon (TA) movement at each 5° interval was measured by their respective distances from the inferior border of the medial malleolus.

Mean ankle dorsiflexion was 24.58±1.30° with all specimens showing anterior DPA and TA movement as dorsiflexion increased. Mean DPA and TA movement at maximum dorsiflexion was 3.58±0.29mm and 2.92±0.34mm respectively. A ratio of 1:1.23 relates TA and DPA movement (inmm), and a ratio of 10:1.46 relates dorsiflexion angle to DPA movement (inmm).

Anterior movement of the dorsalis pedis artery during dorsiflexion increases the AWA for anterior arthroscopy. Increasing the AWA with maximal dorsiflexion may prove to be a valuable method for lowering the risk of iatrogenic DPA damage. Additionally, increased AWA may allow the use of larger diameter surgical instruments allowing greater control and a reduction in operation time.