Circumflex Accessory Branch of the Superficial Fibular Nerve: An Unusual Cause of Nerve Entrapment.

The superficial fibular (peroneal) nerve traditionally courses through the anterolateral deep leg and pierces the deep crural fascia at the lower leg to divide into its terminal branches. Entrapment of the superficial fibular nerve is most commonly documented to occur at where it pierces the deep fascia, and numerous etiologies causing entrapment are described. In this case report, we describe an unusual cause of entrapment from a tertiary branch of the superficial fibular nerve taking a circumflex course and wrapping around the secondary branch of the main nerve. This was successfully treated by surgical excision. To the best of our knowledge, this cause of entrapment has not been described in the literature at the time of this publication.