What is the treatment for a sesamoid fracture of the thumb?

Treatment of Sesamoid Fracture of the Thumb

Conservative management with thumb spica splint immobilization for 3-5 weeks is the recommended first-line treatment for sesamoid fractures of the thumb, followed by gradual mobilization and physical therapy to restore function.

Diagnosis and Imaging

• Initial evaluation should include standard radiographs of the thumb
  • Standard views may miss the fracture; oblique views are often necessary to visualize sesamoid fractures 1
• If radiographs are equivocal but clinical suspicion remains high:
  • CT without contrast is recommended to confirm the fracture and distinguish between a fracture and bipartite sesamoid 2
  • MRI without contrast can be useful to evaluate associated soft tissue injuries, particularly volar plate tears 2

Treatment Algorithm

Conservative Management (First-Line)

1. Immobilization:

   • Thumb spica splint for 3-5 weeks 3, 4
   • Position the thumb in slight flexion to counteract volar displacement of the fragment 3

2. Pain Management:

   • NSAIDs for pain and inflammation control 3
   • Cold therapy to reduce pain and edema (never apply directly to skin) 3

3. Rehabilitation (after immobilization period):

   • Directed home exercise program including active thumb motion exercises 3
   • Gradual return to activities as pain allows

Surgical Management (Reserved for Specific Cases)

Surgical intervention should be limited to:

• Painful nonunion after conservative treatment 4
• Associated significant volar plate injury with joint instability 5

Surgical options include:

• Temporary surgical immobilization of the joint with crossed K-wires or small plates for 8 weeks 6
• Sesamoidectomy (as a last resort due to potential biomechanical alterations)

Expected Outcomes and Recovery Timeline

• Most patients achieve pain-free normal function within 6-8 weeks 1
• Return to work: approximately 61 days (range 15-90 days) 6
• Return to sports: approximately 80 days (range 64-112 days) 6

Important Considerations and Pitfalls

1. Don't miss associated injuries: Sesamoid fractures may indicate significant hyperextension injury and can be associated with volar plate tears 7, 5

   • Failure to recognize associated ligament injuries may lead to long-term hyperextension instability on pinching 7

2. Avoid prolonged immobilization: Extended rigid immobilization can lead to joint stiffness, which is the most common complication 3

3. Diagnostic challenges: Standard AP and lateral radiographs may miss the fracture; oblique views are essential for proper diagnosis 1

4. Conservative treatment success rate: 64-90% of sesamoid fractures heal with non-operative management 6, making it the preferred initial approach

5. Monitor for complications: Watch for joint stiffness, chronic pain, and post-traumatic arthritis 3