Deep peroneal nerve

Deep peroneal nerve

The deep peroneal nerve (also known as the deep fibular nerve) is a nerve in the lower leg that provides innervation to certain muscles of the lower leg and foot, as well as sensory innervation to the skin between the first and second toes. It is a branch of the common peroneal nerve, which itself is a division of the sciatic nerve. The deep peroneal nerve plays a crucial role in the movement and sensation of the lower extremity, particularly in the actions of dorsiflexion and toe extension.

Anatomy

The deep peroneal nerve originates from the common peroneal nerve at the neck of the fibula. It travels downward along the anterior compartment of the leg, innervating the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and peroneus tertius muscles. These muscles are primarily responsible for dorsiflexion of the foot and extension of the toes. As it descends, the nerve lies adjacent to the anterior tibial artery.

Upon reaching the ankle, the deep peroneal nerve divides into a superficial branch, which continues to provide motor innervation, and a deep branch, which provides sensory innervation to the web space between the first and second toes. This sensory branch is significant for its role in the sensation of the dorsal aspect of the foot.

Clinical Significance

Injury to the deep peroneal nerve can result in a condition known as foot drop, where the individual is unable to dorsiflex the foot at the ankle joint. This can lead to a characteristic high-stepping gait or "steppage gait" as the person attempts to lift their foot higher off the ground to prevent the toes from dragging. Causes of deep peroneal nerve injury include trauma, compression, or surgery in the region of the knee or lower leg.

Additionally, the nerve can be affected in conditions such as diabetic neuropathy, where high blood sugar levels lead to nerve damage, or in compartment syndrome, where increased pressure within the compartments of the leg leads to decreased blood flow and nerve function.

Diagnosis and Treatment

Diagnosis of deep peroneal nerve dysfunction typically involves a combination of clinical examination, nerve conduction studies, and electromyography (EMG). Treatment depends on the underlying cause but may include physical therapy, orthotic devices to support the foot, or surgery to relieve nerve compression.

See Also

• Common peroneal nerve
• Sciatic nerve
• Foot drop
• Diabetic neuropathy
• Compartment syndrome