What is the initial management for suspected ulnar abutment syndrome?

Management of Ulnar Abutment Syndrome

For suspected ulnar abutment syndrome, the initial management should include conservative treatment with activity modification, wrist splinting, and anti-inflammatory medications for 2-3 months before considering surgical intervention.

Diagnosis Confirmation

• MRI is the reference standard for confirming ulnar abutment syndrome, showing:

  • T2-weighted signal changes in the lunate and triquetrum
  • Triangular fibrocartilage complex (TFCC) tears or degeneration
  • Positive ulnar variance with impaction on the ulnar carpus 1

• Ultrasound can be used as an alternative or complementary imaging modality to assess:

  • Cross-sectional area of the ulnar nerve
  • Dynamic evaluation of potential nerve dislocation 1

Conservative Management (First-Line Approach)

Conservative treatment should be attempted for 2-3 months before considering surgical options:

1. Activity Modification:

   • Avoid activities that exacerbate ulnar-sided wrist pain
   • Modify wrist positioning during daily activities
   • Avoid prolonged wrist extension and ulnar deviation 1

2. Immobilization:

   • Wrist splinting in neutral position
   • Use of an ulnar-sided wrist support

3. Pain Management:

   • NSAIDs for pain and inflammation
   • For neuropathic pain components:
     • Calcium channel α2-δ ligands (gabapentin 900-3600 mg/day)
     • Tricyclic antidepressants (starting at 10 mg/day, up to 75 mg/day)
     • SNRIs (duloxetine 60-120 mg/day) 1

4. Physical Therapy:

   • Wrist strengthening exercises
   • Ergonomic training
   • Postural alignment optimization

Surgical Management

If conservative treatment fails after 2-3 months or in cases with severe symptoms, surgical intervention should be considered:

Surgical Options Based on Ulnar Variance:

1. For positive ulnar variance <3mm with central TFCC tears:

   • Arthroscopic wafer procedure is preferred
     • Involves debridement of the central TFCC tear and distal pole of the ulna
     • Reduces ulnar variance to neutral or slightly negative
     • Advantages: minimally invasive, avoids complications of open procedures (nonunion, hardware issues) 2

2. For positive ulnar variance >3mm:

   • Ulnar shortening osteotomy options:
     • Diaphyseal ulnar shortening osteotomy (traditional)
     • Distal ulnar metaphyseal wedge osteotomy
       • Provides faster bone union (average 2.6 months)
       • Improved grip strength and range of motion 3
     • Arthroscopic distal metaphyseal ulnar shortening osteotomy
       • Minimizes injury to dorsal capsule of distal radioulnar joint
       • Better protects joint stability 4

Special Considerations

• Smokers: Arthroscopic wafer procedure is preferable due to lower risk of nonunion 5

• Wrists with divergent orientation of sigmoid notch and ulnar articular surfaces: Arthroscopic wafer procedure is preferred to avoid arthritic complications 5

• Severe cases with significant functional limitation or progressive symptoms: Consider earlier surgical referral rather than prolonged conservative management 1

Follow-up and Monitoring

• Regular reassessment of pain and function
• For patients on medication: Monitor for side effects, especially with tricyclic antidepressants
• Post-surgical rehabilitation should focus on gradual return to activities and wrist strengthening

Common Pitfalls to Avoid

1. Failing to distinguish ulnar abutment syndrome from other causes of ulnar-sided wrist pain (TFCC tears, lunotriquetral ligament injuries, distal radioulnar joint instability)

2. Delaying surgical intervention in cases with clear radiographic evidence of impaction and significant functional limitation

3. Choosing inappropriate surgical technique based on ulnar variance measurement

4. Inadequate post-surgical rehabilitation leading to stiffness or persistent weakness