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 11.3cm² in neutral and 10.2 cm² in dorsiflexion. The average talus exposed was 2.0 cm² in neutral and 2.4 cm² in dorsiflexion. Using an Achilles tendon-splitting approach, the average exposed distal tibia was 33% more (15.0 cm²) in neutral and 43% more (14.6 cm²) in dorsiflexion. The average talus exposed was 47% more (3.0 cm²) in neutral and 76% more (4.2 cm²) 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.