The safety of the posterior ankle arthroscopy in management of posterior ankle impingement: A cadaveric study

BackgroundArthroscopic management of the posterior ankle impingement with the patient in supine position has the advantage of dealing with anterior ankle pathology at the same time without the need to change position of the patient. This study aims at evaluation of the safety of portal establishment and instrumentation of this technique.MethodsSixteen fresh-frozen cadaver specimens were used. The relationships of the posteromedial and posterolateral portals to the adjacent tendons and nerves and the relationship of the coaxial portal tract with the posterior ankle capsule and the flexor hallucis longus tendon were studied.ResultAngle θ₁ between the intermalleolar line and the posterior ankle coaxial portal tract averaged 1° (−10° to 22°). Angle θ₂ between the intermalleolar line and the metal rod where the neurovascular bundle started to move averaged 19° (10° to 30°). Angle θ₃ between the intermalleolar line and the metal rod where it reached the lateral border of the Achilles tendon was larger than angle θ₂ in all specimens. The angle of safety (θ_s) averaged 18° (−1° to 26°).ConclusionsInjury to the tendon, nerves or vessels is possible during establishment of the portals and resection of the os trigonum.