Anatomic Study of Exposed Posterior Malleolus Using the Posterolateral Ankle Approach

We compared the effect of the posterolateral ankle approach on the exposed posterior malleolus and vascular nerves in order to reduce the probability of vascular nerve injury during surgical exposure. Five corpses were randomly allocated to incision A and B groups. The tip of the lateral malleolus was used as a starting point, while the lateral line of the Achilles tendon was used as the endpoint to its trisection. Using the two points near the side of the Achilles tendon, we drew two vertical horizontal lines to represent incisions A and B, then measured the horizontal distances between the tip of the lateral malleolus and incision A (a), the tip of the lateral malleolus and incision B (b), and the tip of the lateral malleolus and the midpoint of the sural nerve and small saphenous vein (c). We then exposed the fibula from the posterior portion of the peroneus brevis muscles, dissected the flexor pollicis longus from the posterior edge of the fibula, and used Vernier calipers to measure the maximum length and width of the exposed bone block. There was no statistically significant difference between distances (a) and (c), but there was a significant difference between distances (b) and (c). The length of the exposed posterior malleolus did not differ significantly between incisions A and B, but the width differed significantly. Exposing the posterior malleolus using an approach closer to the lateral Achilles tendon is less likely to injure the sural nerve and small saphenous vein and results in a larger exposed area and easier manipulation. Thus, this could be a better surgical treatment for ankle fractures.