Portal safety and efficacy of anterior subtalar arthroscopy: a cadaveric study

Anterior subtalar arthroscopy was performed in 14 feet of 7 cadaveric bodies using the primary visualization and working portals. The cartilage of the anterior/middle calcaneal facet that can be reached was marked. The feet were dissected and the distances between the portals and surrounding cutaneous nerves were measured. Any damage to the ligaments of the sinus tarsi was noted. The percentage area of the articular cartilage that was marked was measured. In all specimens, the primary visualization portal tract passed through the lateral root of the inferior extensor retinaculum. The primary working portal tract passed through the lateral root in nine specimens (64%). Cervical ligament was intact in all specimens. In three specimens (21%), the primary visualization portal tract passed through the posterior edge of the intermediate root of the inferior extensor retinaculum. The interosseous talocalcaneal ligament was intact in all specimens. The primary visualization portal tract passed through the medial root of the inferior extensor retinaculum in eight specimens (57%). The primary working portal tract passed through the medial root of the inferior extensor retinaculum in one specimen. The average working area on the calcaneal facet was 95% +/- 4% of the total articular surface. There was no case of nerve injury in all specimens. In conclusion, anterior subtalar arthroscopy is a minimally invasive approach to deal with pathologies of this joint without the need of extensive resection of the ligamentous structures of the sinus tarsi.