Peroneus Longus Tendoscopy at the Sole: A Cadaveric Study

PURPOSE: The aim of this study was to investigate the safety of tendoscopy of the peroneus longus (PL) at the sole in a cadaveric model. METHODS: Twelve fresh-frozen foot and ankle specimens were used. The locations of the plantar medial and plantar lateral portals were studied. The relationships of the medial and lateral plantar nerves to the tendon sheath of the PL at the sole were also studied. RESULTS: The plantar lateral portal was located on average 11 mm (6 to 16 mm) proximal and 9 mm (6 to 15 mm) plantar to the fifth metatarsal styloid. The plantar medial portal was located on average 1 mm (12 mm proximal to the joint to 7 mm distal to the joint) proximal to the first tarsometatarsal joint. The lateral plantar nerve touched the PLT sheath in 8 specimens. The nerve was separated from the tendon sheath by a thin layer of muscle in 4 specimens. The medial plantar nerve was separated from the tendon sheath of the PL by the flexor digitorum longus and flexor hallucis longus tendons in all specimens. CONCLUSIONS: Tendoscopy of the PL at the sole of the foot is described; however, the lateral plantar nerve can be at risk and the tendoscopy should be performed with caution. CLINICAL RELEVANCE: This cadaveric study provides the anatomic basis of the PL tendoscopy of the sole.