Guyon Canal Syndrome

Other Names

• Guyon's Canal Syndrome
• Ulnar Neuropathy
• Ulnar Tunnel Syndrome
• Cyclist's Palsy

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Background

• Rare periphal neuropathy of the Ulnar Nerve as it travels through Guyons Canal in the wrist

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Pathophysiology

• Zone 1
  • Proximal to the motor and sensory bifurcation
  • Area of the distal portion of the ulnar nerve before it splits into its superficial sensory and deep motor divisions
  • Symptoms: mixed motor, sensory symptoms
• Zone 2
  • Distal to motor/sensory bifurcation, radial to zone 3
  • Most commonly affected
  • Symptoms: Motor only
• Zone 3
  • Distal to motor/sensory bifurcation, ulnar to zone 2
  • Symptoms: sensory only

Pathoanatomy

• Anatomic borders of Guyons Canal
  • Volar: Volar Carpal Ligament
  • Dorsal: Transverse Carpal Ligament
  • Ulnar: Pisiform, Abductor Digiti Minimi, Pisohamate Ligament
  • Radial: Hook of Hamate

Etiology

• Ganglion Cyst of Wrist
• Acute Trauma
  • Hook of Hamate fracture
• Mass Effect (tumor, lipoma, etc)
• Repetitive trauma (cycling)
• Hypothenar Hammer Syndrome
• Injury to Ulnar Artery

Epidemiology

• Not well defined due to being a rare disease
• Most commonly due to ganglion cyst (need citation)

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Risk Factors

• Sports
  • Bicycling

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Differential Diagnosis

• Fractures
  • Distal Radius Fracture
    • Barton's Fracture
    • Chauffer's Fracture
    • Colles' Fracture
    • Die-Punch Fracture
    • Radial Styloid Fracture
    • Smith's Fracture
  • Distal Ulna Fracture
  • Carpal Fractures
    • Scaphoid Fracture
    • Lunate Fracture
    • Triquetrum Fracture
    • Pisiform Fracture
    • Trapezium Fracture
    • Trapezoid Fracture
    • Capitate Fracture
    • Hamate Fracture
  • Essex Lopresti Fracture
• Dislocations
  • Carpometacarpal Joint Dislocation
  • Distal Radioulnar Joint Dislocation
  • Lunate Dislocation
  • Perilunate Dislocation
• Instability & Degenerative
  • Scapholunate Instability
  • Lunotriquetral Instability
  • Scaphoid Nonunion Advanced Collapse
  • Distal Radial Ulnar Joint Instability
  • Kienbocks Disease
  • Dorsal Wrist Impingement
• Tendinopathies & Ligaments
  • De Quervain's Tenosynovitis
  • Intersection Syndrome
  • TFCC Injury
  • Wrist Tendinopathies
  • Extensor Carpi Ulnaris Instability
• Neuropathies
  • Carpal Tunnel Syndrome
  • Pronator Teres Syndrome
  • Anterior Interosseus Nerve Syndrome
  • Posterior Interosseus Nerve Syndrome
  • Guyon Canal Syndrome
• Pediatric Considerations
  • Distal Radial Epiphysitis (Gymnast's Wrist)
  • Torus Fracture
• Arthropathies
  • Wrist Osteoarthritis
  • Rheumatoid Arthritis
  • Gout
• Cartilage
  • Osteochondral Defect
• Vascular
  • Hypothenar Hammer Syndrome
• Other
  • Ganglion Cyst of Wrist
  • Ulnar Impingement Syndrome
  • Infectious Tenosynovitis

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Clinical Features

• General: Physical Exam Wrist
• History
  • Typically history of repetitive or direct trauma
  • Symptoms can be motor, sensory or mixed
• Physical Exam
  • Hypothenar atrophy is typically a late finding
• Special Tests
  • Tinels Test: Reproduce symptoms by tapping on canal
  • Froments Sign: Inability to grip thumb between thumb and index finger
  • Wartenbergs Sign: Exaggerated abduction of the fifth digit

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Evaluation

• Typically a clinical diagnosis

Radiographs

• Standard Radiographs Wrist
• 3 view standard to evaluate for etiology

MRI

• Can show anatomical variance within canal, mass effect

Ultrasound

• Evaluate vascular structures

EMG/NCS

• Helpful to assess distribution and localize affected nerves

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Classification

• Classified based on which part of ulnar nerve is affected
  • Zone 1: Proximal to the motor/sensory bifurcation
  • Zone 2: Distal to motor/sensory bifurcation, radial to zone 3
  • Zone 3: Distal to motor/sensory bifurcation, ulnar to zone 2

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Management

• Variable, depends on etiology

Nonoperative

• Indications
  • Etiologies: chronic repetitive trauma
  • Mild-moderate symptoms with acute, subacute duration
• Treatment
  • Medications:
  • Physical Therapy: Nerve glide exercises
  • Avoidance of provocative activities
  • Improve ergonomics
  • Splint: Neutral position
• Not beneficial (need reference)
  • NSAIDS, Corticosteroid Injection

Operative

• Indications
  • Mod-severe symptoms or duration > 3 months

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Return to Play

• Depends on etiology and management approach

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Complications

• Chronic pain
• Loss of function
• Inability to return to sport

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See Also

• Neuropathies (Main)
• Physical Examination Wrist
• Hand and Wrist Anatomy (Main)
• Hand Pain (Main)
• Wrist Pain (Main)
• Forearm Pain (Main)

External

• Sports Med Review Hand Pain: https://www.sportsmedreview.com/by-joint/hand/
• Sports Medicine Review Wrist Pain: https://www.sportsmedreview.com/by-joint/wrist/

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