Leg
Title: Common Peroneal Nerve Release at the Fibular Head
Published: 8/18/2011, Updated: 8/18/2011.
Author(s): Andrew Yee BS, Susan E. Mackinnon MD.
Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, St. Louis, MO.
Figure 1 – Orientation, positioning, and incision for common peroneal nerve release. (A) Left leg is prepped. (B) The leg is positioned with the knee in 145° flexion during this procedure. In this position, the common peroneal nerve is not under tension. (C) The fibular head is marked and an incision is just below the fibular head. The common peroneal has a course just below the fibular head. The most important step in this release is marking the incision correctly just below or distal to the fibular head. The tendency is to make the incision too proximally. A sand bag placed diagonally at the lateral edge of the foot helps secure the leg with the knee slightly flexed.
Figure 2 – Anatomical structures for release of common peroneal nerve. (A) Proximal cross section of the leg depicts the position of the common peroneal nerve and the surrounding intermuscular septums. The posterior and anterior crural intermuscular septums, the intermuscular septum between the tibialis anterior and the extensor digitorum longus, and the deep tendinous fascia superficial to the soleus are released. (B) Longitudinal illustration of the common peroneal nerve and the surrounding muscles and intermuscular septums. In this illustration, the leg is flexed as depicted by the common peroneal nerve having a course around the head of the fibula.
Figure 3 – Exposure and division of fascial layers superficial to the common peroneal nerve. Upon exposure, the division between the peroneus longus and the proximal/lateral connective tissue discerns the common peroneal nerve deep. The peroneal nerve can be palpated just below the fibular head. Two fascial layers are identified superficial to the nerve and require division to expose the common peroneal nerve
Figure 4 – Exposure and identification of the common peroneal nerve. Following the division of the superficial fascial layers, the common peroneal nerve is identified along its course around the fibular head and continues distal and deep to the peroneus longus.
Figure 5 – Incision markings of the connective fascia superficial to the peroneus longus. The incision is marked on superficial connective fascia in the direction of the nerve to expose the peroneus longus and its compressive intermuscular septums.
Figure 6 – Incision of the connective fascia superficial to the peroneus longus and identification of the intermuscular septums. Three intermuscular septums (arrow) of the peroneus longus are identified for release to decompress the peroneal nerve following the division of the superficial fascia. The proximal septum (posterior crural intermuscular septum) is the primary entrapment point with the tendinous leading edge of the peroneus longus. Distally, are the anterior crural intermuscular septum and the less emphasized intermuscular septum between the extensor digitorum longus and tibialis anterior.
Figure 7 – Exposing the posterior crural intermuscular septum as the primary entrapment point. By retracting the peroneus longus muscle distally and off of the posterior crural intermuscular septum, a dense and tight tendinous septum is revealed superficial to the common peroneal nerve. This septum is the primary entrancement point. Note that the retraction of the muscle allows for the identification of the septum and facilitating its release.
Figure 8 – Release of the posterior crural intermuscular septum and identification of the deep tendinous fascia. The posterior crural intermuscular septum is released distally along the common peroneal nerve. The length of this septum can vary from patient to patient. Be sure to identify and release its most distal tendinous component. Afterwards, the tendinous fascia superficial to the soleus muscle is identified deep to the common peroneal nerve and it is designated for division to create a soft canal for the nerve. A nerve branch from the peroneal nerve is an articular joint branch.
Figure 9 – Division of the deep tendinous fascia and the soleus muscle. By dividing the deep tendinous fascia to the common peroneal nerve and a portion of the soleus muscle along the course of the peroneal nerve, this creates a canal for the nerve to rest in. Specifically, this allows the nerve to lie flat with a smooth path around the lateral knee.
Figure 10 – Identification of the anterior crural intermuscular septum between the peroneus longus and extensor digitorum longus. The anterior crural intermuscular septum between the peroneus longus and extensor digitorum longus is the second tendinous septum that is released. Its tendinous and sharp properties are demonstrated with the forceps. This septum is released during this procedure.
Figure 11 – Release of the anterior crural intermuscular septum between the peroneus longus and extensor digitorum longus. The tendinous anterior crural intermuscular septum is released and the vessels and small nerve branches can be identified within this plane. This septum is carefully released to avoid cautery of the vessels and possible injury of the surrounding small nerve branches.
Figure 12 – Identification of the distal intermuscular septum found between the extensor digitorum longus and tibialis anterior. The distal intermuscular septum between the extensor digitorum longus and tibialis anterior is the third tendinous septum that is released. Its tendinous and potentially compressive properties are demonstrated with the forceps just like the previously released middle septum. This is the third septum that is released during this procedure. This septum is carefully released to avoid cautery of the vessels and possible injury of the surrounding small nerve branches.
Title: Superficial Peroneal Nerve Release in the Lower Leg
Published: 10/13/2011, Updated: 10/13/2011.
Author(s): Andrew Yee BS, Susan E. Mackinnon MD.
Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, St. Louis, MO.
Figure 1 – Orientation, positioning, and incision for superficial peroneal nerve release. (A) Left leg is prepped. (B) The leg is positioned with the knee extended during this procedure to allow exposure of the lateral compartment. (C) An incision is marked on the lateral/anterior aspect of the distal leg along the course of the superficial peroneal nerve.
Figure 2 – Exposure and fascial landmarks to identifying the superficial peroneal nerve. Upon exposure, the superficial fascia is identified deep to the fat. Two yellow longitudinal landmarks are visible through the superficial fascia. The anterior landmark is a layer of fat that divides the tibialis anterior and extensor digitorum longus. The superficial fascia is incised to reveal this fat landmark. Avoid time looking for the nerve within the fat and move laterally. Posterior to this landmark, is the second yellow longitudinal landmark which is the superficial peroneal nerve as it courses through the superficial fascia.
Figure 3 – Exposing the superficial peroneal nerve. The superficial peroneal nerve is identified a couple of cm posterior to the fat landmark through the superficial fascia. Release of the superficial fascia over the nerve will expose it and its course. At this point the nerve is often within a fibrous tunnel.
Figure 4 – Identifying the compression point by the transverse crural ligament. As the peroneal nerve courses distal and superficial, the nerve will exit the superficial fascia and the transverse crural ligament. This ligament is the main contributor to the compression of the superficial peroneal nerve as seen in this image by its distal tendinous sharp edge (arrow). A Tinel’s sign can often be found at this location.
Figure 5 – Release of the transverse crural ligament and phenotypic characteristic of nerve compression. The superficial peroneal nerve is released distal through the superficial fascia and the transverse crural ligament until it exits. In this image, a subtle color change from dark yellow to white is observed as the nerve exits superficial (arrow). This observation is a characteristic of nerve compression.
Figure 6 – Identifying the proximal superficial fascia to release. The superficial fascia is identified proximally and released to the point where the superficial peroneal nerve exits from deep between the fibularis longus and extensor digitorum longus. This compressive fascia is seen in this image and is partially released thus far.
Figure 7 – Release of the proximal superficial fascia as the peroneal nerve exits from deep. The superficial fascia is released to the point where the superficial peroneal nerve exists from deep between the fibularis longus and extensor digitorum longus. This exit point is seen in this image (arrow). Also the superficial fascia is further incised over the fat landmark to relieve longitudinal tensile force.
Figure 8 – Markings for the horizontal release of the superficial fascia. The superficial fascia that was released along the fat landmark and the superficial peroneal nerve is horizontal marked in purple for release to relieve possible tensile force.
Figure 9 – Horizontal release of the superficial fascia. The superficial fascia is released horizontally to relieve possible tensile force.
Figure 10 – Superficial peroneal nerve release. The superficial fascia posterior to the superficial peroneal nerve is also released to relieve possible tensile force to complete the decompression of the superficial peroneal nerve. The nerve distal has a course over the extensor digitorum longus.
