What are the causes and treatment options for peroneal nerve compression or injury?

Causes and Treatment of Peroneal Nerve Compression or Injury

The most common cause of peroneal nerve compression is external pressure at the fibular head, and treatment should focus on specific padding to prevent pressure on the peroneal nerve, avoidance of direct compression, and in refractory cases, surgical decompression may be necessary. 1

Common Causes of Peroneal Nerve Compression/Injury

• External compression (most common cause):

  • Pressure at the fibular head against hard surfaces 2, 1
  • Improper positioning during surgery or prolonged immobilization 2
  • Tight casts, braces, or bandages 1

• Traumatic causes:

  • Knee dislocations or fractures around the knee/fibular head 3
  • Direct trauma to the lateral knee area
  • Lacerations to the lateral leg 3

• Stretch injuries:

  • Excessive hip and knee positioning during surgery 2
  • Positions that stretch the hamstring muscle group 1

• Other causes:

  • Compression by anatomical structures (e.g., lateral gastrocnemius muscle) 4
  • Space-occupying lesions (tumors, cysts, ganglia) 3
  • Entrapment at the peroneal tunnel 5
  • Lumbar disk herniation with sciatic nerve involvement 6

Clinical Presentation

• Foot drop (inability to dorsiflex the foot) - most common presentation 3
• Weakness in ankle eversion
• Sensory loss over the dorsum of the foot and lateral lower leg
• Pain in the lateral knee or popliteal fossa
• Steppage gait (high-stepping to clear the foot from the ground) 6

Diagnostic Approach

• Physical examination:

  • Test ankle dorsiflexion and eversion strength
  • Assess sensation over dorsum of foot and lateral leg
  • Positive Tinel's sign at fibular head 5
  • Perform provocation tests for nerve entrapment 5

• Diagnostic studies:

  • Electromyography (EMG) and nerve conduction studies 6
  • Magnetic resonance imaging (MRI) to evaluate for structural causes 6

Treatment Options

Conservative Management (First-Line)

1. Protective padding and positioning:

   • Apply specific padding to prevent pressure on the peroneal nerve at the fibular head 2, 1
   • Avoid tight or restrictive padding which may worsen symptoms 2
   • Limit arm abduction to 90° in supine position for prevention of brachial plexus injuries 2

2. Bracing and support:

   • Ankle-foot orthosis (AFO) for foot drop 3
   • Gradual phasing out of braces as recovery occurs 2

3. Physical therapy:

   • Neural mobilization techniques 6, 5
   • Soft tissue mobilization of surrounding muscles (hamstrings, psoas) 6
   • Strengthening exercises for peroneal muscles and ankle dorsiflexors 2
   • Proprioception, coordination, and functional training 2

4. Pain management:

   • Gabapentin or pregabalin for neuropathic pain 1
   • Capsaicin cream for topical pain relief 1
   • Percutaneous electrical nerve stimulation 1

Surgical Management (For Refractory Cases)

1. Indications for surgery:

   • Failed conservative management after 3-6 months
   • Progressive neurological deficit
   • Space-occupying lesions
   • Severe conduction changes on EMG 3

2. Surgical techniques:

   • Nerve decompression at the fibular head 7
   • Circumferential nerve dissection 7
   • Fascial release 7
   • Removal of compressive structures 4
   • Neurolysis for neuroma formation 4

3. Advanced procedures for chronic cases:

   • Tendon transfers for persistent foot drop 3
   • Nerve transfers for severe cases with poor prognosis for recovery 3

Prognosis and Follow-up

• Early intervention (within 2 weeks) is associated with better outcomes 1
• Regular postoperative assessment of extremity nerve function is necessary 2, 1
• Monitor for improvement in motor function, particularly ankle dorsiflexion 1
• Supervised rehabilitation leads to faster recovery than unsupervised programs 2

Prevention Strategies

• Proper positioning during surgery or prolonged immobilization 2
• Avoid excessive pressure on the lateral knee/fibular head area
• Appropriate padding during surgical procedures 2
• Early mobilization after injury or surgery 2
• Avoid improper use of equipment that may compress the nerve 2

Special Considerations for Return to Work/Sports

• Supervised exercises focusing on proprioception, strength, coordination, and function lead to faster return to sports 2
• Phased rehabilitation focusing on work/sport-specific tasks 2
• For work resumption after lateral ankle injuries, a brace and immediate functional treatment are advised 2
• Return to physically demanding jobs may take 6-12 weeks depending on severity 2