Quantification of posterior ankle exposure through an achilles tendon-splitting versus posterolateral approach.

BACKGROUND The optimal surgical exposure to the posterior ankle for trauma and reconstruction is a source of debate. We hypothesized that the Achilles tendon-splitting approach would provide greater exposure to the posterior ankle than the posterolateral approach. METHODS Forty surgical approaches were performed from twenty fresh-frozen cadavers. Achilles tendon-splitting and posterolateral approaches were performed using a randomized crossover design for surgical sequence. Six landmarks (medial malleolus, ankle joint, subtalar joint, incisura fibularis, lateral malleolus and medial gutter) were identified by direct visualization or palpation. A calibrated digital photograph was taken and Image J (http://rsb.info.nih.gov/ij/) was used to calculate the surface area of the distal tibia and talus exposed in neutral and dorsiflexion. RESULTS Using a posterolateral approach, the average distal tibia exposed was 11.3cm(2) in neutral and 10.2 cm(2) in dorsiflexion. The average talus exposed was 2.0 cm(2) in neutral and 2.4 cm(2) in dorsiflexion. Using an Achilles tendon-splitting approach, the average exposed distal tibia was 33% more (15.0 cm(2)) in neutral and 43% more (14.6 cm(2)) in dorsiflexion. The average talus exposed was 47% more (3.0 cm(2)) in neutral and 76% more (4.2 cm(2)) in dorsiflexion. All increases in exposure were statistically significant. The medial malleolus was visualized in 19 tendon-splitting and six posterolateral approaches. The medial gutter was visualized in 20 tendon-splitting and 13 posterolateral approaches. These differences were statistically significant. All other landmarks could be visualized through both approaches. CONCLUSION The Achilles tendon-splitting approach provided significantly greater exposure of the posterior distal tibia and talus compared to the posterolateral approach. CLINICAL RELEVANCE Prospective studies will help determine if the tendon-splitting approach is a safe and clinically useful approach for surgeries in which direct access to the entire posterior ankle and subtalar joint are required.