Posterior ankle arthroscopy portal safety regarding proximity to the tibial and sural nerves

The aim of this cadaveric study was to assess the relative safety of posterior ankle arthroscopy portal sites regarding their distance from the tibial and sural nerves. We dissected 20 embalmed cadaveric lower limbs, carefully exposed the nerves, preserving their original position, and established the entry points of five posterior ankle portals using pins. We measured distances with a digital calliper and used Friedman test and Wilcoxon Signed Ranks tests for statistical analyses. There was unequal safety between the five portals (p = 0.00001). There was no statistically significant difference between the two posterolateral or two posteromedial portals. The trans-Achilles tendon portal as expected was significantly further away from either nerve (p = 0.00001). In conclusion, the trans-Achilles portal is the safest portal in terms of its distance from the nerves but has the disadvantage of surgical injury to the Achilles tendon. The two medial and two lateral posterior portals are equivalent in terms of safety.