Updated: 11/18/2019

Deep Peroneal Nerve Entrapment

Review Topic
  •  A compression neuropathy of DPN within fibro-osseous tunnel formed by inferior extensor retinaculum, most commonly at inferior edge
    • also known as anterior Anterior Tarsal Tunnel Syndrome
  • Epidemiology
    • incidence
      • rare
    • demographics
      • adults of all ages and genders
    • risk factors
      • high heel use
      • compressive shoe wear
      • previous fracture
  • Pathophysiology
    • site of compression
      • anterior leg/ankle/foot from 1 cm proximal to ankle joint proximally to talonavicular joint distally
    • position of compression
      • ankle inversion and plantar flexion (when traumatic)
    • pathoanatomy
      • intrinsic impingement
        • dorsal osteophytes over tibiotalar or talonavicular joints
        • other bony deformity (pes cavus, post-fracture)
        • ganglion cyst
        • tumor
        • tendinitis or hypertrophic muscle belly of EHL, EDL or TA
        • peripheral edema
      • extrinsic impingement
        • tight laces or ski boots
        • high heels (induces plantar flexion)
        • trauma (including recurrent ankle instability)
  • Associated conditions
    • pes cavus
    • fracture
      • navicular nonunion
    • talonavicular arthritis
    • systemic conditions causing peripheral edema
  • Prognosis
    • recalcitrant cases may require surgery, which may yield 80% good to excellent results
  • Anterior Tarsal Tunnel Anatomy  
    • borders
      • superficial
        • inferior extensor retinaculum
      • deep
        • capsule of talonavicular joint
      • lateral
        • lateral malleolus
      • medial
        • medial malleolus
    • contents of anterior tarsal tunnel    
      • EDL
      • EHL
      • Tibialis anterior
      • peroneus tertius
      • Deep peroneal nerve
        • within tunnel division of nerve between mixed (lateral) and sensory only (medial) occurs
      • dorsalis pedis artery and vein
  • Symptoms
    • dysesthesia and paresthesias on dorsal foot
      • lateral hallux, medial second toe and first web space are most common locations
    • vague pain on dorsum of foot
  • Physical exam
    • motor
      • weakness or atrophy of EDB
    • sensory
      • decreased two-point discrimination
    • provocative tests
      • Tinel sign over course of DPN with possible radiation to first web space
      • exacerbation with plantar flexion and inversion (puts nerve on stretch)
      • relief of symptoms with injection of lidocaine (DPN nerve block)
  • Radiographs
    • recommended views 
      • lateral view of foot and ankle
    • findings
      • dorsal osteophytes
      • sequelae of prior fracture
  • CT
    • to define bony anatomy of canal
  • MRI
    • best for evaluation of mass lesions
  • Nonoperative
    • shoe modifications
      • indications
        • first line of treatment
      • techniques
        • NSAIDs
        • PT (if ankle instability contributing)
        • injection
        • well padded tongue on shoe
        • alternative lacing configurations  
        • full length rocker-sole steel shank
        • night splint (to prevent natural tendency for ankle to assume plantar flexion)
        • diuretic if chronic peripheral edema is implicated
  • Operative
    • surgical release of DPN by releasing inferior extensor retinaculum and osteophyte / ganglion resection
      • indications
        • failure of nonoperative treatment
        • symptoms of RSD are a contraindication to release
      • outcomes
        • 80% satisfactory
  • Surgical release of DPN by releasing inferior extensor retinaculum and osteophyte / ganglion resection
    • approach
      • S-shaped incision over dorsum of foot from ankle joint proximally to base of first and second metatarsals distally
    • decompression
      • start distal, identify nerve, and release both branches proximally (nerve lies lateral to EHL)
      • resect osteophytes, debulk hypertrophic muscle bellies
    • postoperative
      • no compressive shoe wear
  • Persistent symptoms following decompression
    • warn patient that recovery is prolonged

Please rate topic.

Average 4.4 of 7 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Topic COMMENTS (8)
Private Note