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.

Novel Branching Pattern of the Common Fibular Nerve: Emergence of the Superficial Fibular Nerve Within the Anterior Crural Compartment

Distal to its origination from the sciatic nerve, the common fibular (peroneal) nerve divides into the superficial and deep fibular (peroneal) nerves. Whereas the deep fibular nerve continues its course into the anterior compartment, the superficial fibular nerve (SFN) usually arises near the fibular neck and projects distally within the lateral crural compartment before entering the superficial fascia proximal to the ankle. In this report, we describe a unilateral case where the SFN arises within the anterior crural compartment and remains there for the remainder of its course deep to the deep fascia of the leg. Surgeons should be aware of anomalies such as this, for example, when performing fasciotomies to avoid inadvertently damaging an anomalously placed SFN.