Medial Approaches to the Posterior Malleolus: A Comparative Cadaveric Study

CATEGORY: Ankle; Trauma INTRODUCTION/PURPOSE: Ankle fractures are the most common fractures of the lower extremity. In spite of that, there is still no consensus regarding the best way to approach posterior malleolus (PM) fractures. The aim of this study is to compare the degree of PM exposure, tension of the flap containing the medial neurovascular bundle (NVB) and distance between the surgical incision and the NVB using three different posteromedial ankle approaches. METHODS: Three different posteromedial approaches were compared: direct medial (DM) modified posteromedial (MPM) and posterior paramedian (PPM). Each approach was performed four times using a standardized technique. With a digital tensiometer, the minimal tension of the flap containing the NVB that allowed proper exposure of the PM was measured. In a second stage, an axial cut 1cm proximal to the tibiotalar joint was performed in nine frozen pieces and PM exposure degree and distance between the incision and the NVB was measured. RESULTS: The median minimal tension was DM: 14,78 N, MPM: 8N and PPM: 5,75N. The median distance between the incision and the NVB was DM: 17mm, MPM: 6mm and PPM: 28mm. The median degree of exposure was DM: 51%, MPM: 58% and PPM: 72%. CONCLUSION: The PPM approach achieved the highest degree of PM exposure, with the lowest tension applied to the NVB and allowing the greatest distance between the incision and the NBV. Thus, we believe it should be considered the approach of choice for large fractures compromising the posteromedial and posterolateral aspect of the PM.