The Posteromedial Neurovascular Bundle of the Ankle: An Anatomic Study Using Plastinated Cross Sections

Purpose: The aim of this study was to evaluate the topography of the posteromedial neurovascular bundle of the ankle. The anatomic relation of the posteromedial neurovascular bundle at different levels of the ankle was studied as an aid in planning minimally invasive surgery. A thorough knowledge of the local anatomy is a prerequisite before attempting release of the tibial nerve or when using the posteromedial portal for ankle arthroscopy. Methods: A slice anatomy study was performed on 12 intact right male cadaveric lower limbs. The distal third of each limb was cut and the foot positioned in the neutral position. The measurements were performed at the level of the tibiotalar joint, at the tip of the medial malleolus, and at the sustentaculum tali. Results: The tibial nerve is predicted to be 11.8 ± 2.4 mm and the posterior tibial artery 16.7 ± 3.8 mm anterior from the calcaneal tendon at the level of the tibiotalar joint. At the tip of the malleolus medialis, the tibial nerve is 14.3 ± 2.5 mm and the posterior tibial artery 22.1 ± 4.1 mm anterior to the Achilles tendon. The medial plantar nerve is situated at the sustentaculum tali level 8.4 ± 3.4 mm and the lateral plantar nerve 16.1 ± 3.1 mm posterior to the sustentaculum. Conclusions: On the basis of our anatomic data, a posteromedial portal made at the level of the tip of the medial malleolus seems to be safe, effective, and reproducible. Therefore a portal at this level would be advantageous for an endoscopic tarsal tunnel release or when using the posteromedial portal for ankle arthroscopy. Anatomic characteristics should be kept in mind when ankle surgery is performed, thereby reducing the risk of injury to the medial neurovascular bundle and offering easy access inside the posterior compartment of the ankle. Clinical Relevance: This cadaveric study suggests that, by placing the posteromedial ankle portal at the tip of the medial malleolus, the risk of neurovascular injuries could be reduced.