Innervation of the sinus tarsi and implications for treating anterolateralankle pain

Anterolateral ankle pain can persist despite the best care of sprains or fr actures. It is possible that this pain is related to stretch or traction in juries to the nerves that innervate the subtalar joint. If this were true, identification of these nerve branches by local anesthetic block would prov ide an indication that surgical interruption of the function of these nerve s may provide pain relief. In 28 feet of 14 cadavers (7 male/7 female), inv estigation of the deep peroneal nerve demonstrated a consistent pattern whe reby a series of 2 to 4 (mean, 2.9 +/- 0.6) branches innervated the anterol ateral part of the subtalar joint. All these nerve branches originated from the lateral terminal branch of the deep peroneal nerve on the dorsum of th e foot. The mean distance between the exit of the first articular branch an d the exit of the terminal motor branch both originating from the lateral t erminal branch was 3.8 +/- 1.1 cm. The motor branch passed under the extens or digitorum brevis muscle at a mean distance of 5.3 +/- 0.6 cm from the ti p of the lateral malleolus. The presented anatomy provides a basis for the diagnosis and treatment of persistent anterolateral ankle pain of neural or igin.