Comparison of Neurovascular Structures at Risk During Ankle Arthroscopy: A Cadaveric Study.

Background: Arthroscopy has become increasingly common for diagnosis and treatment of ankle joint pathology. The four most common portals used for ankle arthroscopy are the anteromedial, anterolateral, posteromedial, and posterolateral. Anatomy of neurovascular structures along the ankle can significantly vary.

Methods: The distance of neurovascular structures was compared with anatomical landmarks of ankle arthroscopic portals to verify safe zones for scope insertion. Twenty-six fresh frozen cadavers were used, with dissection of standard anatomical landmarks and neurovascular structures. Portals were made and verified with a 2.7-mm arthroscope.

Results: Significant differences were found in mean distances between anatomical landmarks except for the peroneus tertius tendon to the intermediate dorsal cutaneous nerve (P = .181; all others, P < .0001). In quantifying a scope space, the anteromedial and anterolateral portals had the largest margin of error at 0.82 cm and 1.04 cm, respectively. The saphenous nerve and vein were an average of 1.39 cm and 1.23 cm, respectively, from the anteromedial portal. The peroneus tertius tendon was an average of 0.23 cm from the intermediate dorsal cutaneous nerve. The tibialis anterior tendon was an average of 1.10 cm lateral to the medial gutter; the peroneus tertius tendon, 1.31 cm medial to the lateral gutter; and the Achilles tendon, 0.94 and 0.73 cm from the medial and lateral gutters, respectively.

Conclusions: Among common ankle arthroscopic approaches, the anterolateral portal features the highest anatomic variability. These data support the standard protocol of beginning with the anteromedial portal to facilitate visualization of lateral-sided anatomy before anterolateral portal placement.