Peroneal nerve

Peroneal Nerve

The peroneal nerve, also known as the fibular nerve, is a major nerve in the lower extremity. It is a branch of the sciatic nerve and plays a crucial role in the innervation of the muscles and skin of the lower leg and foot. In this article, we will explore the anatomy, function, and clinical significance of the peroneal nerve.

Anatomy

The peroneal nerve originates from the sciatic nerve, which is formed by the fusion of the ventral rami of the fourth and fifth lumbar nerves and the first, second, and third sacral nerves. The sciatic nerve descends through the posterior thigh and divides into its two major branches, the tibial nerve and the peroneal nerve, at the level of the popliteal fossa.

The peroneal nerve courses laterally around the neck of the fibula, giving off several branches along its course. These branches include the articular branches, which innervate the knee joint, and the muscular branches, which supply the muscles of the anterior and lateral compartments of the leg. The peroneal nerve then continues its course, wrapping around the fibular head and dividing into the superficial peroneal nerve and the deep peroneal nerve.

The superficial peroneal nerve provides sensory innervation to the skin on the anterior and lateral aspects of the leg, as well as the dorsum of the foot. The deep peroneal nerve, on the other hand, innervates the muscles in the anterior compartment of the leg and provides sensory innervation to the web space between the first and second toes.

Function

The peroneal nerve plays a crucial role in the movement and sensation of the lower leg and foot. The muscles innervated by the peroneal nerve are responsible for dorsiflexion of the foot, which allows for lifting the foot and toes off the ground. These muscles also aid in eversion of the foot, which is the movement of the sole of the foot away from the midline.

In addition to motor function, the peroneal nerve provides sensory innervation to specific areas of the leg and foot. The superficial peroneal nerve is responsible for providing sensation to the skin on the anterior and lateral aspects of the leg, as well as the dorsum of the foot. The deep peroneal nerve provides sensory innervation to the web space between the first and second toes.

Clinical Significance

Injuries or compression of the peroneal nerve can lead to various clinical manifestations. Common causes of peroneal nerve injury include trauma, such as fractures or dislocations of the fibula, as well as compression due to prolonged immobilization or pressure on the nerve.

One of the most common clinical presentations of peroneal nerve injury is foot drop, which is characterized by the inability to dorsiflex the foot. This can result in a high-stepping gait pattern and difficulty in walking on uneven surfaces. Sensory deficits may also be present, depending on the location and severity of the nerve injury.

Treatment of peroneal nerve injuries depends on the underlying cause and severity of the injury. Conservative management, such as physical therapy and bracing, may be sufficient for mild cases. However, more severe cases may require surgical intervention to decompress or repair the nerve.