The peroneal nerve is a branch of the sciatic nerve in the posterior thigh that runs around the outside of the knee over the head of the fibula bone. The nerve has deep and superficial branches. These branches supply movement and sensation to the lower leg, foot and toes.
Patients with damage or injury to the peroneal nerve commonly experience the inability to raise their foot and have difficulties walking. They may experience the sensation that their toes are dragging on the floor.
Symptoms of peroneal nerve entrapment can include:
- Decreased sensationor tingling in the top of the foot or the outer part of the upper or lower calf
- Weakness of the foot or ankle
- Foot drop (unable to hold the foot up)
- Walking problems – toes dragging or foot slapping (high stepping gait)
- Muscle wasting in the leg
Common causes of damage to the peroneal nerve include:
- Trauma or injury to the knee
- Fractured fibula (lower leg bone)
- Use of a tight plaster cast or other constrictive devices
- Crossing the legs regularly
- Pressure to the knee from sleeping positions
- Autoimmune neuropathies
A physical assessment and imaging tests such as an MRI or ultrasound are used to diagnose peroneal nerve entrapment. Most patients will also require a nerve conduction study and EMG to confirm the diagnosis. MRI of the spine is often necessary to rule out a spinal cause of the symptoms.
Treatment comprises of conservative and surgical treatment options.
Conservative treatment options aim to reduce pain and associated symptoms. If conservative treatment is unsuccessful then surgery may be required. Treatment options include:
- Pain medication
- Surgery to release the compressed nerve