What is the recommended treatment for osteoarthritic changes at the scaphotrapezial joint and first carpometacarpal joint?

Treatment for Osteoarthritis of the Scaphotrapezial and First Carpometacarpal Joints

Start with a custom-made rigid or neoprene thumb orthosis for the first CMC joint, combined with topical NSAIDs, joint protection education, and a structured exercise program—this combination forms the foundation of evidence-based management for these joints. 1, 2

Initial Non-Pharmacological Management

Orthoses and Splinting (First-Line)

• Hand orthoses are strongly recommended for first CMC joint OA and should be prescribed immediately upon diagnosis 1
• Custom-made orthoses are preferred over off-the-shelf options to ensure proper fit and improve compliance 2
• Long-term use for at least 3 months is essential—shorter periods fail to demonstrate significant benefit 2
• For the scaphotrapezial joint specifically, wrist-based splints that limit radial deviation and extension may provide additional support 3
• Custom-made splints have been shown to reduce pain within 30 days and improve grip strength, pinch strength, and hand function by 60-90 days 4

Exercise and Rehabilitation

• Range of motion and strengthening exercises should be initiated for all patients, specifically targeting joint mobility, muscle strength, and thumb base stability 2
• Exercise regimens for the first CMC joint differ from those for other hand joints and must be tailored accordingly 2
• Joint protection education is essential to minimize stress on affected joints during daily activities 1, 2

Thermal Modalities

• Local application of heat (paraffin wax or hot packs) before exercise provides symptomatic relief and has stronger evidence (77% recommendation strength) than other physical modalities 2
• Heat therapy should be applied for 10-20 minutes before exercise sessions 1, 2

Patient Education

• All patients should receive education on self-management principles, the nature and course of hand OA, and treatment options 2
• Evaluation of ability to perform activities of daily living with provision of assistive devices as needed 1, 2

Pharmacological Management

Topical Agents (Preferred First-Line)

• Topical NSAIDs are the first-line pharmacological treatment due to superior safety profile, particularly in older adults 2
• Topical treatments are preferred over systemic medications when only a few joints are affected and for mild to moderate pain 2
• Topical capsaicin may be used as an alternative topical agent 1, 2

Oral Medications (Second-Line)

• Acetaminophen up to 4g/day is the oral analgesic of first choice when topical agents are insufficient 2
• Oral NSAIDs should be used at the lowest effective dose for the shortest duration in patients who respond inadequately to acetaminophen 2
• In persons age ≥75 years, topical rather than oral NSAIDs must be used due to safety concerns 1, 2
• For patients with increased gastrointestinal risk, use non-selective NSAIDs plus gastroprotective agent or selective COX-2 inhibitor 2
• Tramadol may be considered for inadequate response to other analgesics 1

Intra-articular Injections (For Flares)

• Intra-articular corticosteroid injection is effective for painful flares, especially in the trapeziometacarpal joint 2
• This should be reserved for acute exacerbations rather than routine management 2

Treatment Algorithm

Step 1: Initial Management (All Patients)

• Custom-made first CMC joint orthosis (use for minimum 3 months) 1, 2
• Joint protection education and structured exercise program 1, 2
• Topical NSAIDs 2
• Heat therapy before exercises 2

Step 2: If Inadequate Response After 4-6 Weeks

• Add acetaminophen up to 4g/day 2
• Ensure orthosis compliance and proper fit 2
• Intensify exercise program with occupational therapy guidance 2

Step 3: If Still Inadequate Response

• Short-term oral NSAIDs at lowest effective dose (avoid in patients ≥75 years) 1, 2
• Consider intra-articular corticosteroid injection for painful flares 2
• Reassess diagnosis and consider imaging to evaluate disease progression 3

Step 4: Refractory Cases After 8-12 Weeks of Conservative Management

• Refer for surgical evaluation if marked pain and/or disability persist 2, 3
• Surgical options include STT arthrodesis, distal scaphoid excision, trapeziectomy with or without proximal trapezoid excision, or interposition arthroplasty 3, 5

Critical Pitfalls to Avoid

• Do not use splints for less than 3 months—shorter periods fail to show benefit and lead to premature abandonment of effective therapy 2
• Avoid intra-articular therapies and opioid analgesics in initial management—these are conditionally recommended against 1
• Do not use disease-modifying antirheumatic drugs (conventional or biological) for hand OA—they have no role 2
• Avoid prolonged oral NSAID use due to gastrointestinal, cardiovascular, and renal risks 2
• Never prescribe oral NSAIDs to patients ≥75 years without compelling reason—topical formulations are mandated in this age group 1, 2

Special Considerations for Combined STT and CMC Arthritis

When both scaphotrapezial and first CMC joints are involved (peritrapezial osteoarthritis), the treatment approach remains the same initially, but surgical planning becomes more complex if conservative management fails 3, 5:

• Trapeziectomy addresses both sites but carries risks of strength loss, prolonged recovery, and trapeziometacarpal impingement 5
• Maintaining scaphoid height is crucial—resection of more than 3-4mm of distal scaphoid can exacerbate carpal instability 5
• Oblique trapezoidal osteotomy prevents scaphoid-metacarpal impingement 5