Zone 2 Flexor Hallucis Longus Tendoscopy: A Cadaveric Study

Background: The purpose of this study was to verify the safety and efficacy of zone 2 flexor hallucis longus tendoscopy with the patient in the prone position. Materials and Methods: The technique was performed in 12 cadaver feet (6 pairs). The endoscopic findings were compared to an anatomic dissection. The locations of the posteromedial and plantar portals were studied. The relationship between the medial plantar nerve and the tract of FHL tendoscopy was also studied. Result: The average distance of the posteromedial portal above the medial malleolar tip was 10.3 mm. The average distance between the posteromedial portal and the posterior tibial nerve was 9.9 mm. The average distance between the plantar portal and the intermalleolar line was 41.5 mm. The average distance between the rod simulating the tenoscope and the nerve was 4.8 mm. The nerve was medial to the rod in 4 specimens and lateral to the rod in 8 specimens. Conclusion: Zone 2 flexor hallucis longus tendoscopy was a feasible approach to the deep portion of the flexor hallucis longus tendon in this cadaveric study. There is potential risk of damage to the medial plantar nerve. Clinical Relevance: These findings can help guide a surgeon who is considering trying this clinically.