Treatment of Triscaphe (STT) Osteoarthritis
Begin with conservative management including splinting, activity modification, NSAIDs, and corticosteroid injections, reserving surgery only for patients who fail these measures after an adequate trial of 3-6 months. 1, 2
Initial Conservative Management (First-Line Treatment)
Core Non-Pharmacological Interventions
- Patient education about joint protection techniques to avoid adverse mechanical factors that stress the STT joint, combined with a structured exercise program involving range of motion and strengthening exercises 3
- Thumb spica splinting or custom orthoses to immobilize the affected joint and reduce pain during activities 3, 1
- Activity modification to avoid repetitive gripping, pinching, or wrist extension that exacerbates symptoms 1, 2
- Local heat application (paraffin wax or hot packs) before exercise sessions for temporary pain relief 3
Pharmacological Treatment Algorithm
Step 1: First-Line Analgesics
- Paracetamol (acetaminophen) up to 4 g/day is the preferred initial oral analgesic due to its safety profile and should be used regularly, not just as needed 3
- Topical NSAIDs should be considered before oral NSAIDs, especially for localized pain affecting only the STT joint 3
Step 2: Oral NSAIDs (if topical agents fail)
- Oral NSAIDs at the lowest effective dose for the shortest duration when paracetamol and topical NSAIDs provide insufficient relief 3
- Always prescribe with a proton pump inhibitor for gastroprotection, particularly in patients with GI risk factors 3
- Assess cardiovascular and renal risk factors before initiating oral NSAIDs, using caution in elderly patients and those with comorbidities 3
Step 3: Intra-articular Corticosteroid Injection
- Long-acting corticosteroid injection into the STT joint is effective for painful flares and can provide significant temporary relief 3, 1
- This is particularly useful as a diagnostic and therapeutic tool to confirm STT joint as the pain source 1, 2
Important Caveats
- Do not recommend glucosamine or chondroitin as evidence for benefit is insufficient and effect sizes are small 3
- Occupational therapy referral may be beneficial for joint protection education and custom splint fabrication 2
Surgical Management (When Conservative Treatment Fails)
Surgery should only be considered after 3-6 months of failed conservative treatment when pain and functional limitations substantially affect quality of life 1, 2
Surgical Options Based on Disease Pattern
For Isolated STT Osteoarthritis:
- STT arthrodesis provides excellent pain relief (100% in available studies) but reduces wrist range of motion (average flexion-extension arc 101°) 4, 2
- Distal scaphoid excision (3-4 mm maximum) with or without interposition arthroplasty, though this carries risk of exacerbating DISI deformity if more than 3-4 mm is resected 5, 2, 6
- Pyrocarbon implant arthroplasty may be preferred in younger, active patients as it preserves motion, though it has a 3% dislocation rate requiring revision 6
For STT OA with Concomitant Thumb CMC Arthritis (Peritrapezial OA):
- Trapeziectomy with or without ligament reconstruction/tendon interposition (LRTI) addresses both sites but has longer recovery and risk of strength loss 5, 2, 6
- Oblique trapezoidal osteotomy must be performed to prevent scaphoid-metacarpal impingement 5
For STT OA with SLAC Pattern:
- Four-corner fusion with scaphoid excision or proximal row carpectomy depending on capitate cartilage status 2
Critical Surgical Principles
- Maintain scaphoid height through either arthrodesis, limited resection (<3-4 mm), or interposition to prevent DISI progression 5, 6
- Asymptomatic DISI occurs in 7.5% of cases after distal scaphoid resection but rarely requires intervention 6
- Overall complication rate is 15% across all surgical techniques 6