The Medial Malleolar Tip as a Landmark for Medial Clamp Placement in Syndesmotic Reduction: A Cadaveric Study

Research Type: Level 2 - Prospective comparative study, Meta-analysis of Level 2 studies or Level 1 studies with inconsistent results Introduction/Purpose: Iatrogenic syndesmosis malreduction remains a significant concern in ankle surgery, emphasizing the need for precise reduction and fixation techniques. Accurate placement of reduction clamps, particularly on the medial tibial cortex (MTC), is critical for achieving optimal syndesmotic alignment. The trans-syndesmotic axis (TSA) has been proposed as a reliable reference for clamp tine positioning. This study aims to identify a consistent anatomical landmark on the medial side of the tibia for optimal clamp placement during syndesmotic reduction. We hypothesize that the medial malleolar tip serves as the most reliable landmark for identifying the TSA-MTC intersection, providing a reproducible reference point for clamp placement. By confirming this anatomical correlation, surgeons can improve reduction accuracy, minimize operative time, and reduce radiation exposure, ultimately enhancing clinical outcomes. Methods: Eighteen fresh-frozen cadaveric specimens with intact syndesmosis and ankle ligaments were analyzed using weight-bearing CT (WBCT) imaging. The TSA was identified on axial images 1 cm above the tibial plafond, corresponding to the optimal syndesmotic screw placement. The TSA-MTC intersection was first located at this level and then tracked distally to its most inferior projected point on the medial malleolus. The distance from the TSA-MTC intersection distal projection to the most distal point of the medial malleolar tip (designated as the zero point) was measured and categorized into three distinct 5 mm zones (Figure 1). Descriptive statistics were used for the analysis and values were presented in Mean ± Standard Deviation. Results: The mean distance from the true TSA-MTC intersection to the tibial plafond was 11 ± 2.5 mm. The TSA-MTC distally projected point was consistently located 2.1 ± 1.6 mm from the medial malleolar tip (range: 0.12–5.1 mm). In 94.4% (17/18) of cases, the intersection point fell within Zone 1, with one case in Zone 2 and none in Zone 3 (Figure 1). Conclusion: This study establishes Zone 1, within a 5 mm distance from the medial malleolar tip, as a consistent and reliable anatomical landmark for medial clamp placement in syndesmotic reduction. The findings support our hypothesis that the medial malleolar tip is an optimal reference point for locating the TSA-MTC intersection. Standardizing this approach may improve the accuracy of syndesmotic fixation, reducing malreduction rates and improving surgical efficiency. Further clinical validation is warranted to assess the impact on patient outcomes.