What is the diagnosis and treatment for a patient with wrist pain, no fracture, and radiographic findings of moderate first carpometacarpal and mild to moderate STT joint osteoarthrosis?

Diagnosis and Treatment of First Carpometacarpal and STT Joint Osteoarthritis

The radiographic findings indicate moderate first carpometacarpal (CMC) and mild to moderate scaphotrapeziotrapezoid (STT) joint osteoarthritis, which is the cause of the patient's wrist pain and should be treated initially with conservative measures including activity modification, splinting, and anti-inflammatory medications. 1

Diagnosis

The radiographic findings clearly show:

• No fracture with anatomic alignment of bones
• Moderate first carpometacarpal joint osteoarthritis with joint space narrowing
• Mild to moderate STT joint osteoarthritis with:
  • Small marginal osteophyte formation
  • Subchondral/subcortical cysts
  • Subcortical cyst of the capitate
• No frank osseous erosions
• No apparent soft tissue abnormality

These findings are consistent with degenerative osteoarthritis affecting two common sites in the wrist:

1. First carpometacarpal joint (thumb base)
2. Scaphotrapeziotrapezoid joint

Clinical Correlation

The radiographic findings should be correlated with clinical symptoms:

• Pain at the base of the thumb on the volar aspect is characteristic of symptomatic STT osteoarthritis 2
• Pain during resisted extension of the thumb may indicate STT involvement
• First CMC joint involvement typically presents with pain during pinch and grip activities

Treatment Algorithm

Step 1: Conservative Management (First-Line)

• Activity modification to reduce stress on the affected joints
• Splinting/bracing to immobilize and support the thumb and wrist
• Anti-inflammatory medications (NSAIDs) to reduce pain and inflammation
• Occupational therapy to improve function and teach joint protection techniques 3

Step 2: Intermediate Interventions

• Corticosteroid injections into the affected joints
  • Can provide significant relief in many cases
  • May be guided by ultrasound for accuracy
  • American College of Radiology guidelines note that corticosteroid injections can resolve symptoms in approximately 61% of cases after a single injection 4

Step 3: Surgical Options (if conservative treatment fails)

For persistent symptoms despite conservative management, surgical options include:

1. For isolated STT osteoarthritis:

   • Distal scaphoid excision (removing 3-4mm maximum to prevent carpal instability)
   • STT arthrodesis (fusion)
   • Interposition arthroplasty 3, 2

2. For combined first CMC and STT osteoarthritis:

   • Trapeziectomy with or without ligament reconstruction
   • Pyrocarbon implant arthroplasty
   • Combined procedures addressing both joints 2

Important Considerations and Pitfalls

1. Carpal Instability Risk:

   • STT osteoarthritis may be associated with dorsal intercalated segment instability (DISI) 5
   • Removing more than 3-4mm of the distal scaphoid can exacerbate carpal instability 2
   • Careful radiographic assessment for any signs of instability is essential before surgical intervention

2. Concomitant Conditions:

   • First CMC and STT osteoarthritis frequently occur together (as in this case)
   • Treatment should address both conditions when present 2

3. Imaging Limitations:

   • Plain radiographs are the gold standard for initial assessment of hand osteoarthritis 1
   • However, early manifestations may require CT or MRI for complete evaluation 6
   • If symptoms persist despite normal radiographs, advanced imaging may be warranted 1

4. Differential Diagnosis:

   • The differential diagnosis for hand osteoarthritis is wide, including psoriatic arthritis, rheumatoid arthritis, gout, and hemochromatosis 1
   • The absence of erosions in this case makes inflammatory arthritis less likely

Follow-up Recommendations

• Re-evaluate after 4-6 weeks of conservative treatment
• If symptoms persist, consider corticosteroid injection
• If conservative measures fail after 3-6 months, consider surgical consultation
• Repeat radiographs within one year if symptoms persist to monitor disease progression 1

This approach prioritizes conservative management while recognizing that surgical intervention may be necessary for patients with persistent symptoms and functional limitations that affect quality of life.