What is the treatment for ulnar subluxation of the first metacarpal joint in psoriatic arthritis?

Treatment of Ulnar Subluxation of First Metacarpal Joint in Psoriatic Arthritis

For ulnar subluxation of the first metacarpal joint in psoriatic arthritis, treatment should follow a stepwise approach starting with NSAIDs and intra-articular glucocorticoid injections, followed by DMARDs (particularly methotrexate), and progressing to biologic agents if needed, with surgical intervention reserved for cases with severe structural damage. 1, 2

Initial Management

First-line Treatments

• NSAIDs: Recommended as first-line therapy for mild peripheral joint involvement with Level A evidence 1, 2

  • Should provide relief within a few weeks
  • Not effective for skin manifestations
  • Should not be the only therapy beyond 3 months if active disease persists 1

• Intra-articular glucocorticoid injections 1, 2

  • Particularly useful for monoarticular/oligoarticular involvement
  • Should be administered judiciously
  • Caution: Avoid injection through psoriatic plaques
  • May be helpful for the first metacarpal joint specifically to stabilize the joint and reduce inflammation

Second-line Treatments

Disease-Modifying Antirheumatic Drugs (DMARDs)

• Methotrexate: Preferred option for patients with clinically relevant psoriasis and joint involvement 1, 2

  • Dosage: 15-25 mg/week
  • Consider route (subcutaneous or oral) and folate supplementation
  • Particularly beneficial when skin and joint manifestations coexist

• Alternative DMARDs if methotrexate is contraindicated or ineffective:

  • Leflunomide: Level A evidence 1, 2
  • Sulfasalazine: Level A evidence 1, 2
  • Cyclosporine: Level B evidence (limited by toxicity) 1, 2

• DMARD failure is defined as:

  • Treatment for >3 months with >2 months at standard target dose without adequate response 1
  • Or intolerance/toxicity leading to withdrawal 1

Third-line Treatments

Biologic Agents

• TNF inhibitors: Recommended when DMARDs fail to control disease 2

  • Particularly effective for both joint and skin manifestations
  • Higher efficacy than traditional DMARDs for structural damage prevention

• IL-17 inhibitors: Consider if significant skin involvement accompanies joint disease 2

Special Considerations for First Metacarpal Joint Subluxation

1. Joint Protection and Splinting:

   • Stabilization of the first metacarpal joint is crucial to prevent further subluxation and deformity
   • Custom splinting may help maintain proper joint alignment

2. Regular Monitoring:

   • Assess disease activity using validated measures (DAS28, ACR criteria) 1, 2
   • Monitor for progression of joint damage with radiographs

3. Surgical Intervention:

   • Consider if conservative treatments fail and there is progressive joint damage or severe functional limitation
   • Options include synovectomy, arthroplasty, or arthrodesis depending on the degree of damage

Treatment Algorithm

1. Mild Disease:

   • NSAIDs + intra-articular glucocorticoid injections
   • Joint protection education and splinting

2. Moderate Disease or Inadequate Response to First-line Treatment:

   • Add methotrexate (preferred) or alternative DMARD
   • Continue joint protection measures

3. Severe Disease or Inadequate Response to DMARDs:

   • Add or switch to biologic therapy (TNF inhibitors first-line)
   • Consider surgical consultation if structural damage is significant

Pitfalls and Caveats

• Systemic corticosteroids: Not typically recommended for chronic use in psoriatic arthritis due to potential for post-steroid psoriasis flare 1

• Gold salts, chloroquine, and hydroxychloroquine: Not recommended for use in psoriatic arthritis 1

• Combination therapy: Although evidence is limited, combination of two or more DMARDs could be considered in patients who fail to respond to a single agent 1

• Monitoring: Regular assessment is essential to evaluate treatment response and adjust therapy accordingly 1, 2

• Early intervention: Critical to prevent irreversible joint damage and preserve function, especially in a functionally important joint like the first metacarpal 2