The Extensile Lateral Approach to the Calcaneus and the Sural Nerve

Abstract

Category: Hindfoot Introduction/Purpose: Sural nerve related symptoms following the extensile lateral approach to the calcaneus (ELA) are a known postoperative complication despite awareness of the course the sural nerve. While the main trunk of the sural nerve and its location relative to the ELA have been previously described, the nerve gives rise to lateral calcaneal branches (LCBs) that may be at risk of injury. The relation of the LCBs to the ELA has not been previously reported in the literature. The purpose of this study was to describe the course of the sural nerve and its LCBs in relation to the ELA. Methods: 17 cadaveric foot specimens were dissected, exposing the sural nerve and the LCBs. A line representing the ELA incision was then created. It was noted if the line crossed any of the LCBs, how many branches were crossed, and at what distance they were crossed using the distal tip of the fibula as a reference. Results: The sural nerve was identified in all specimens, and the main trunk was noted to cross the path of the ELA in no specimens. At least one LCB of the sural nerve was identified in all specimens. The mean number of LCBs was 2 (range, 1 – 4). The ELA crossed the path of at least one LCB in 15 specimens (88%). The mean number of LCBs that were crossed by the path of the ELA was 1 (range, 0 – 3) The mean distance from the distal tip of the fibula at which an LCB was encountered along the ELA path was 2.4 cm (+/- 1.2) posterior and 2.6 cm (+/- 1.6) inferior. Conclusion: The ELA traverses the paths of the LCBs in the majority of specimens, potentially accounting for the presence of sural nerve postoperative symptoms despite careful dissection.