Cadaveric Analysis of Exposure of the Talar Articular Surface Through the Posteromedial Approach

The purpose of this cadaveric study is to assess the talar articular surface visible through a modified posterior medial approach to the ankle joint for talar osteochondral defects. Ten fresh frozen cadaveric specimens were included. The talar surface area was outlined utilizing a marker. The talus was removed to measure the medial to lateral length and posterior to anterior length using a flexible ruler. A skin incision was made posterior to the medial malleolus. The incision was deepened through the flexor retinaculum. Dissection was carried between the posterior tibial and flexor digitorum longus tendons through the posterior tibial tendon sheath in order to access the posteromedial ankle joint. The posterior tibiofibular ligament should remain intact. A Hintermann distractor was then inserted to distract the ankle joint. The average articular cartilage visible from medial to lateral was 1.90 (68.6%) centimeters, while from posterior to anterior was 2.00 (43.6%) centimeters. Medial malleolar osteotomy is often required to visualize posteromedial talar osteochondral defects that are difficult to visualize with standard anterior ankle arthroscopy. Our study suggests that the modified posteromedial approach between the posterior tibial and flexor digitorum longus tendons and utilizing a Hintermann distractor allows for visualization of common posterior and central-medial lesions. When considering the anatomic 9-zone grid scheme proposed by Raikin et al, zone 4, 7, and 8 lesions can be assessed with this approach. A clinical study should be undertaken to evaluate the morbidity of this approach.