Metacarpophalangeal ulnar ligament rupture

Background

• Also known as "Gamekeeper's thumb" or "Skier's thumb"
• Ulnar collateral ligament ruptures at insertion into proximal phalanx (due to radial deviation of MCP)
• If left untreated, it will causes decreased thumb adduction and inability to perform opposition.
• The mechanism of injury is usually a rapid deceleration while holding onto an objection (such as a ski pole)

Clinical Features

• Swelling and localized tenderness over ulnar border of joint
• Weakness of pinch

Differential Diagnosis

Hand and finger injuries

• Distal finger
  • Finger amputation
  • Fingertip laceration
  • Nail avulsion
  • Nailbed laceration
  • Subungual hematoma
• Other finger/thumb
  • Boutonniere deformity
  • Mallet finger
    • Swan neck deformity
  • Jammed finger
  • Jersey finger
  • Trigger finger
  • Ring avulsion injury
  • De Quervain tenosynovitis
  • Infiltrative tenosynovitis
  • Metacarpophalangeal ulnar ligament rupture (Gamekeeper's thumb)
• Hand
  • Dupuytren contracture
• Wrist
  • Drummer's wrist
  • Ganglion cyst
  • Lunotriquetral ligament instability
  • Scaphoid fracture
  • Extensor digitorum tenosynovitis
  • Compressive neuropathy ("bracelet syndrome")
  • Intersection syndrome
  • Snapping Extensor Carpi Ulnaris
  • Vaughn Jackson syndrome
• General
  • Hand and finger dislocations
  • Hand and finger fractures
  • Hand and finger infections
  • Gout and pseudogout
  • Hand and finger tendon injuries
  • High-pressure injection injury
  • Osteoarthritis
  • Rheumatoid arthritis
  • Ring removal

Evaluation

• X-ray (perform before joint stressing)
  • There is a high association with avulsion fractures from insertion of UCL into proximal phalanx
  • Proximal phalanx volar subluxation and radial deviation suggests complete UCL rupture
• Apply radial stress to the thumb with MCP in partial flexion
• Compare relative laxity to other thumb.
• >35 degrees of joint laxity or 15 degrees of releative laxity compared to other thumb is diagnostic of a complete UCL rupture

Stener Lesion

This phenomenon occurs when there is a UCL tear that results in entrapment of the adductor pollicis aponeurosis within the UCL. Patients will require surgical repair

Management

All patients with suspected UCL injury should be referred for a hand surgeon within 1 week. Reevaluation will dictate operative managment

• Partial rupture
  • Immobilization in thumb spica for 4 weeks
• Full rupture
  • Operative repair

Disposition

• Outpatient treatment

See Also

• Hand and finger injuries

Video

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