Talar neck fractures: anatomic landmarks of suitable position for posterolateral screw insertion

Objective: The posterolateral window is a suitable position for screw insertion. The aim of this study was to define this position for posterolateral screw insertion. Methods: Fifteen adult cadaver ankles were used in this study. When the ankle was positioned in a neutral position, the posterolateral window was exposed. Height and width of the window were mea- sured. Vertical distance from the center of the window to the lateral malleolus tip (LMT), horizontal distance from the center of the window to the lateral of the Achilles tendon (LAT), and horizontal distance from the lateral of the Achilles tendon to the sural nerve (SN) were measured. Additionally, the anatomical relationships between the center of the window (the screw insertion point) and sur- rounding tissues were noted. Results: The results indicated that the posterolateral window was bounded medially by the lateral tu- bercle of the posterior process of the talus (LTPT), laterally by the posterior border of lateral malleolar (PBLM), superiorly by the trochlear articular surface (TAS), and inferiorly by the posterior calcaneal facet (PCF). The height and width of the posterolateral window were 1.89±0.04 cm and 0.91±0.01 cm, respectively. LMT was 0.40±0.01 cm, LAT was 0.19±0.02 cm, and SN was 0.62±0.04 cm. The present data showed that posterior screw insertion may be a safer screw insertion technique for talar neck fractures. Performing the operation through the posterolateral window had no negative effect on surrounding tissues such as the flexor hallucis longus and posterior talofibular ligament tissues when the ankle joint was positioned in a neutral position. Additionally, the screw head should be counter- sunk to reduce intraoperative risk. Conclusion: The posterolateral window is a safer point for posterolateral screw insertion for talar neck fractures.