COMMON PERONEAL NERVE

Common Peroneal Nerve Injury & Foot Drop Treatment

What Is the Common Peroneal Nerve?

The common peroneal nerve (also called the common fibular nerve) is a branch of the sciatic nerve that travels around the outside of the knee at the fibular neck. It controls muscles that lift the foot and toes (dorsiflexion) and provides sensation to the top of the foot and outer leg.

Because it sits close to the surface near the fibular head, it is particularly vulnerable to compression and injury.

What Causes Common Peroneal Nerve Injury?

Injuries to the common peroneal nerve are relatively common and can occur from:

• Compression at the knee (fibular head) – prolonged leg crossing, tight casts or braces

• Trauma – knee dislocations, fibular fractures, sports injuries

• Surgical complications – especially after knee or leg procedures

• Weight loss – loss of protective fat padding around the nerve

• Masses or cysts – such as ganglion cysts near the proximal tibiofibular joint

• Systemic conditions – including diabetes or neuropathy

Signs and Symptoms

Symptoms can range from mild numbness to significant functional impairment:

• Foot drop (difficulty lifting the foot)

• Frequent tripping or slapping gait

• Numbness or tingling on the top of the foot or outer leg

• Weakness in ankle dorsiflexion and toe extension

• Pain or burning along the outer knee or upper leg

How Is It Diagnosed?

Accurate diagnosis is essential to guide treatment. Evaluation may include:

• Physical examination focusing on strength, sensation, and gait

• Nerve conduction studies (EMG/NCV) to assess nerve function

• Ultrasound or MRI to identify compression, scarring, or masses

• X-rays if trauma or fracture is suspected

Surgical Treatment Options

If there is persistent weakness, severe compression, or no improvement with conservative care, surgery may be recommended:

• Common peroneal nerve decompression

  • Relieves pressure at the fibular neck

• Neurolysis

  • Removal of scar tissue around the nerve

• Nerve repair or grafting

  • For traumatic injuries with nerve damage

• Tendon transfer procedures

  • Restore function in cases of long-standing foot drop

Recovery and Prognosis

Recovery depends on the severity and duration of the injury:

• Mild compression injuries may recover within weeks to months

• More severe injuries may take several months to a year

• Early diagnosis and treatment significantly improve outcomes

When to Seek Specialist Care

You should seek evaluation if you experience:

• Sudden onset of foot drop

• Persistent numbness or weakness

• Symptoms following knee injury or surgery

• Progressive worsening of function