Cadaveric Anatomical Study of Sural Nerve: Where is The Safe Area for Endoscopic Gastrocnemius Recession?

PURPOSE: To ascertain in cadavers where the sural nerve crosses the gastro-soleus complex and where the gastrocnemius tendon merges with the Achilles tendon in relation to the calcaneal tuberosities. METHODS: Twelve cadaveric lower limbs (6 right and 6 left) were dissected. The distances between the calcaneal tuberosities and the lateral border of the Achilles tendon where the sural nerve crosses from medial to lateral, as well as to the gastrocnemius tendon insertion into the Achilles tendon, were measured. RESULTS: The mean and median longitudinal distances from the calcaneal tuberosity to where the sural nerve crosses the lateral border of the Achilles tendon are 9.9cm and 10cm respectively (range 7cm to 14cm). The mean and median longitudinal distances from the calcaneal tuberosity to where the gastrocnemius tendon inserts into the Achilles tendon are 19.9cm and 18.5cm (range 17cm to 25cm) respectively. CONCLUSION: It is generally safe to place the posterolateral incision more than 14cm above the calcaneal tuberosity to avoid the sural nerve if surgeons plan to use a posterolateral incision for endoscopic recession. The distance between the calcaneal tuberosity to the gastrocnemius tendon insertion into the Achilles tendon is too highly variable to be used as a landmark for locating the gastrocnemius insertion.