What is the treatment for a dislocated thumb?

Treatment for Dislocated Thumb

The treatment for a dislocated thumb primarily involves closed reduction followed by appropriate immobilization, with surgical intervention reserved for cases where closed reduction fails or instability persists. 1, 2

Initial Assessment and Diagnosis

• Standard radiographs (3 views) of the hand are essential to assess:

  • Fracture pattern and displacement
  • Angulation and rotation
  • Articular involvement
  • Associated injuries 2

• If radiographs are equivocal, CT without IV contrast may be considered for better visualization 1, 2

• Ultrasound is useful for confirming diagnosis and identifying anatomical variations 2

Treatment Algorithm

1. Closed Reduction (First-Line Treatment)

• Performed under appropriate analgesia or anesthesia
• Technique:
  • Apply axial traction to the thumb
  • For metacarpophalangeal (MCP) joint: Apply forced flexion with continuous pressure over the dorsal aspect 3
  • For carpometacarpal (CMC) joint: Apply direct pressure over the dorsal aspect with full abduction of thumb 3
  • Verify reduction with post-reduction radiographs

2. Immobilization After Successful Reduction

• Thumb spica cast or custom-made orthosis for 3-4 weeks 2, 3
• Functional support is preferred over rigid immobilization for better outcomes 2
• Clinical and radiographic reassessment at 2-3 weeks to evaluate healing progression 2

3. Surgical Management (For Failed Closed Reduction)

• Indications for surgery:

  • Failed closed reduction
  • Unstable reduction
  • Significant displacement or angulation
  • Complex dislocations with soft tissue interposition 4, 5, 6

• Surgical options:

  • Open reduction with Kirschner wire fixation
  • Ligament repair or reconstruction (particularly for chronic cases)
  • Dorsal or volar surgical approaches depending on specific pathology 4, 5

Special Considerations

Timing of Treatment

• Early intervention yields better outcomes
• Delayed presentations (>1 week) often require open reduction due to soft tissue interposition 6
• The volar plate is commonly found interposed within the joint in cases requiring open reduction 6

Anatomical Variations

• Thumb dislocations can occur at the MCP or CMC joint, or rarely both ("floating first metacarpal") 3
• CMC joint dislocations are particularly prone to instability and may require more aggressive treatment 7, 4

Post-Reduction Care

• Directed home exercise program after immobilization period 2
• Progressive range of motion exercises beginning after 3-4 weeks 2
• Full recovery typically expected within 6-8 weeks 2

Common Pitfalls to Avoid

1. Missed diagnosis: Thumb dislocations, especially in children, can be mistaken for sprains 6
2. Inadequate immobilization: Insufficient immobilization may lead to recurrent instability
3. Delayed treatment: Increases likelihood of requiring open reduction 6
4. Failure to identify interposed structures: Volar plate, sesamoid bones, or tendons may block reduction 5
5. Overlooking associated injuries: Ligament tears or avulsion fractures may accompany dislocations

By following this structured approach to thumb dislocations, optimal functional outcomes can be achieved with minimal complications.