What is Peroneal Nerve Entrapment at the Fibular Head?
Peroneal nerve entrapment at the fibular head is a condition where the common peroneal nerve is compressed or irritated as it passes around the fibular head (the bony prominence on the outer side of the knee). This nerve is responsible for controlling the muscles involved in lifting the foot (dorsiflexion) and sensation on the outer lower leg and top of the foot.
Causes of Peroneal Nerve Entrapment at the Fibular Head
Causes of peroneal nerve entrapment at the fibular head include:
- Prolonged Pressure: From crossing legs, wearing tight boots, or prolonged bed rest
- Trauma: A blow to the outer knee or fibular head, fractures, or ligament injuries
- Repetitive Motion: Athletes (like runners or cyclists) may develop entrapment due to overuse.
- Mass Effect: Tumors, cysts, or ganglions near the nerve
- Surgical Complication: Post-surgical nerve injury (e.g., after knee surgery)
- Medical Conditions: Diabetes, peripheral neuropathy, or nerve inflammation
Symptoms of Peroneal Nerve Entrapment at the Fibular Head
Symptoms of peroneal nerve entrapment at the fibular head include:
- Foot drop: Inability to lift the front part of the foot, causing toes to drag while walking.
- Numbness or tingling: Over the outer lower leg and top of the foot.
- Weakness: Difficulty in dorsiflexion (lifting the foot) or eversion (turning the foot outward).
- Pain: Aching or sharp pain around the fibular head or along the nerve pathway.
Diagnosis of Peroneal Nerve Entrapment at the Fibular Head
In general, peroneal nerve entrapment at the fibular head may be diagnosed in the following methods:
- Physical examination to assess weakness, sensory loss, and gait abnormalities
- Nerve conduction studies (NCS) and electromyography (EMG) to assess nerve function and identify compression severity
- Imaging studies such as MRI or ultrasound to detect masses, structural issues, or nerve damage
Treatment for Peroneal Nerve Entrapment at the Fibular Head
Treatment options for peroneal nerve entrapment at the fibular head depend on the severity of symptoms and the underlying cause. Initial treatment is typically conservative, but surgical intervention may be necessary if symptoms persist or worsen.
Conservative Treatment:
- Rest & Activity Modification – Avoid prolonged leg crossing, tight footwear, or repetitive knee movements.
- Physical Therapy – Strengthening and stretching exercises to improve nerve function, mobility, and prevent muscle atrophy.
- Bracing (Ankle-Foot Orthosis - AFO) – Helps manage foot drop and improve walking.
- Medications – Such as NSAIDs help manage pain and inflammation, while neuropathic pain medications like gabapentin may be used for nerve-related discomfort.
- Nerve Blocks – Local anesthetic injections to relieve pain and reduce nerve irritation.
- Corticosteroid Injections – Used in cases with significant inflammation around the nerve.
Surgical Treatment:
- Decompression Surgery – This involves releasing any tight fascial bands around the nerve or removing structures compressing the nerve, such as a ganglion cyst, tumor, or bone spur to relieve pressure on the nerve.
- Nerve Repair or Grafting – This is employed for severe cases with nerve damage or laceration.
Early diagnosis and treatment usually result in a favorable outcome. Persistent compression can lead to permanent nerve damage and loss of function if left untreated.
