THUMB CMC ARTHRITIS (TRAPEZIOMETACARPAL OSTEOARTHRITIS)
Saddle Joint Degeneration | Beak Ligament Failure | Grind Test | Eaton-Littler Staging
EATON-LITTLER CLASSIFICATION
Critical Must-Knows
- Saddle joint anatomy - unique biaxial motion allows opposition and circumduction
- Anterior oblique (beak) ligament is primary stabilizer - failure leads to subluxation
- Grind test is pathognomonic - axial compression with rotation reproduces pain
- Eaton-Littler staging guides treatment - Stage I-II conservative, III-IV surgical
- Trapeziectomy with LRTI is gold standard - 90%+ satisfaction, preserves motion
- CMC arthroplasty emerging option - preserves height but higher complication rate
Examiner's Pearls
- "CMC arthritis is the most common site of hand osteoarthritis
- "Anterior oblique ligament (beak ligament) is the key primary restraint
- "Grind test positive = pain with axial load and rotation of thumb metacarpal
- "Stage IV includes scaphotrapezial-trapezoid (STT) joint involvement
- "LRTI = Ligament Reconstruction and Tendon Interposition
- "FCR is most commonly used donor tendon for LRTI
Clinical Imaging
Imaging Gallery
Critical Thumb CMC Arthritis Exam Points
Saddle Joint Biomechanics
The CMC joint is a saddle joint (sellar joint) with reciprocally curved surfaces allowing biaxial motion. This unique anatomy permits opposition and circumduction but creates high contact stresses predisposing to arthritis.
Beak Ligament is Key
The anterior oblique ligament (AOL), also called the beak ligament, is the primary restraint to dorsoradial subluxation. Its attenuation or failure is the initial pathologic step leading to progressive arthritis.
Eaton-Littler Staging
Stage I-II can be treated conservatively. Stage III has isolated CMC arthritis requiring trapeziectomy plus or minus LRTI. Stage IV involves the STT joint and may require extended procedures like arthrodesis.
Surgical Gold Standard
Trapeziectomy with LRTI remains the gold standard with over 90% patient satisfaction. Simple trapeziectomy alone has higher subsidence rates. CMC arthroplasty is emerging but has higher revision rates.
Treatment Algorithm by Eaton-Littler Stage
| Stage | Radiographic Findings | First-Line Treatment | Surgical Options |
|---|---|---|---|
| I | Widening of joint space, no narrowing, synovitis | Splinting, NSAIDs, activity modification, steroid injection | Arthroscopic synovectomy (rarely indicated) |
| II | Joint space narrowing, osteophytes less than 2mm | Splinting, NSAIDs, steroid injection, trial of 3-6 months | Trapeziectomy with LRTI, ligament reconstruction alone |
| III | Severe narrowing, osteophytes greater than 2mm, sclerosis | Surgery if conservative fails | Trapeziectomy with LRTI (gold standard), CMC arthroplasty, arthrodesis |
| IV | Pantrapezial arthritis, STT joint involved | Surgery addressing all involved joints | Trapeziectomy with LRTI, STT fusion, complete arthrodesis |
SADDLE - Anatomy and Biomechanics
Memory Hook:SADDLE describes the joint anatomy - remember the beak ligament is anterior oblique
GRIND - Clinical Diagnosis
Memory Hook:GRIND is the pathognomonic test - axial compression and rotation of thumb metacarpal
LRTI - Surgical Technique
Memory Hook:LRTI stands for Ligament Reconstruction and Tendon Interposition - the gold standard
FCR SLIP - Donor Tendon
Memory Hook:FCR SLIP is the most common donor - half the tendon used, wrist flexion preserved
Overview and Epidemiology
Thumb carpometacarpal (CMC) arthritis, also known as trapeziometacarpal osteoarthritis or basilar joint arthritis, is the most common site of osteoarthritis in the hand. It affects the articulation between the first metacarpal and the trapezium.
Epidemiology:
- Prevalence increases with age - affects up to 33% of postmenopausal women
- Female to male ratio approximately 15:1
- Bilateral involvement in 40-70% of cases
- Most common symptomatic presentation is Stage II-III disease
Risk factors:
- Female sex (hormonal factors, ligamentous laxity)
- Age greater than 50 years
- Previous trauma or fracture
- Repetitive pinch activities (occupational)
- Joint laxity or hypermobility
- Genetic predisposition
Why So Common at CMC Joint?
The CMC joint is a saddle joint with unique biomechanics. High contact stresses during pinch (up to 120 kg/cm²) combined with the small articular surface area predispose to cartilage degeneration. The anterior oblique ligament (beak ligament) acts as the primary restraint, and its attenuation initiates the degenerative cascade.
Natural history:
- Initial ligamentous laxity leads to joint instability
- Abnormal kinematics increase contact stresses
- Progressive cartilage loss and osteophyte formation
- Dorsoradial subluxation of metacarpal base
- Adduction contracture (first web space narrowing)
- Secondary STT arthritis in advanced cases (Stage IV)
Anatomy and Pathophysiology
Osseous anatomy:
- Trapezium: distal carpal row bone with saddle-shaped articular surface
- First metacarpal base: reciprocally curved saddle surface
- Saddle joint (sellar joint): biaxial motion - flexion/extension and abduction/adduction
- Opposition is a combination of abduction, flexion, and pronation
Ligamentous anatomy (16 ligaments described):
The CMC joint has complex ligamentous support with 16 described ligaments. The key structures:
Key CMC Ligaments
| Ligament | Location | Function | Clinical Significance |
|---|---|---|---|
| Anterior Oblique (AOL) | Volar-ulnar, beak-shaped | Primary restraint to dorsoradial subluxation | Failure is initiating event in arthritis |
| Posterior Oblique | Dorsal-radial | Secondary restraint | Contributes to stability in extension |
| Intermetacarpal (IML) | Between MC1 and MC2 | Prevents dorsal subluxation | May be used for reconstruction |
| Dorsoradial ligament | Dorsal aspect | Restraint in flexion | Less critical than AOL |
Beak Ligament
The anterior oblique ligament (AOL) is also called the beak ligament due to its shape. It originates from the volar-ulnar tubercle of the trapezium and inserts on the volar-ulnar aspect of the metacarpal base. It is the primary restraint and its attenuation is the initial pathologic event. Think of it as the ACL of the thumb CMC joint.
Biomechanics:
- Saddle joint allows two degrees of freedom: flexion/extension and abduction/adduction
- Combination movements create opposition (pronation component from muscle action)
- Contact stresses during pinch are extremely high: 120 kg/cm² (12 MPa)
- Small articular surface area (1-2 cm²) concentrates forces
- Ligamentous restraints prevent subluxation under these high loads
Pathophysiology:
The degenerative cascade:
Anterior oblique ligament stretches or partially tears, often from repetitive microtrauma or hormonal-related laxity. Joint kinematics become abnormal with subluxation during pinch.
Dorsoradial subluxation of the metacarpal base occurs with pinch. Altered contact areas and increased peak stresses damage articular cartilage.
Progressive cartilage loss with fibrillation, fissuring, and full-thickness defects. Subchondral bone exposure and sclerosis. Osteophyte formation at joint margins.
Severe joint space loss, large osteophytes, cyst formation. Adduction contracture develops. In Stage IV, pantrapezial arthritis with STT joint involvement.
Secondary deformities:
- Adduction contracture: first web space narrowing
- Metacarpal base dorsoradial subluxation: prominent "shoulder" at base
- MCP hyperextension: compensatory for adduction (swan neck of thumb)
- Z-deformity: adduction at CMC, hyperextension at MCP, flexion at IP
Classification Systems
The Eaton-Littler classification (modified Eaton classification) is the standard staging system for thumb CMC arthritis. It is based on radiographic findings and guides treatment decisions.
Stage I: Pre-Arthritic
Radiographic findings:
- Normal joint space or slight widening
- No osteophytes
- Possible joint effusion (synovitis)
- Subluxation may be present on stress views
Clinical presentation:
- Pain with activities
- Tenderness over CMC joint
- Grind test positive
- Maintained pinch strength
Treatment:
- Conservative management primary
- Splinting (thumb spica)
- NSAIDs
- Activity modification
- Corticosteroid injection (diagnostic and therapeutic)
- Arthroscopic synovectomy (rarely indicated)
Stage I is relatively uncommon as patients often present later.
Stage IV Key Point
The defining feature of Stage IV is involvement of the STT joint (scaphotrapezial-trapezoid articulation). This is pantrapezial arthritis. Treatment requires addressing the STT joint, either with trapeziectomy (which removes the trapezium articulating with scaphoid) or with combined procedures like STT fusion.
Clinical Presentation and Examination
History:
- Chief complaint: pain at base of thumb, difficulty with pinch activities
- Pain characteristics: worse with pinch, opening jars, turning keys, writing
- Functional impact: reduced grip strength, difficulty with ADLs
- Duration: often gradual onset over months to years
- Previous treatments: splinting, NSAIDs, injections
- Hand dominance: affects functional expectations
- Occupation: heavy manual labor vs. sedentary
Physical examination:
Inspection:
- Squaring of thumb base: prominence from dorsoradial subluxation and osteophytes
- Thenar atrophy: in advanced cases
- Adduction contracture: reduced first web space
- MCP hyperextension: compensatory Z-deformity
- Skin changes: overlying the joint
Palpation:
- Tenderness: directly over CMC joint (volar and dorsal)
- Osteophyte palpation: bony prominences at base
- Crepitus: with joint motion
- Synovitis: soft tissue fullness
Range of motion:
- Opposition: thumb tip to small finger base (Kapandji score)
- Abduction: measure first web space
- Radial abduction and palmar abduction: often reduced
- Extension: may have compensatory MCP hyperextension
Special tests:
Special Tests for CMC Arthritis
| Test | Technique | Positive Finding | Sensitivity |
|---|---|---|---|
| Grind test (Compression-Rotation) | Axial compression of thumb metacarpal with rotation | Pain and/or crepitus reproduced | Very high (pathognomonic) |
| CMC shear test | Stabilize trapezium, translate metacarpal dorsally and volarly | Pain, crepitus, or excessive translation | High for instability |
| Radial stress test (STT) | Radial deviation of wrist with compression | Pain over STT joint (Stage IV) | Moderate for STT involvement |
| Pinch strength measurement | Key pinch (lateral) and tip pinch measured | Reduced compared to contralateral (greater than 30%) | Functional assessment |
Grind Test
The grind test is the most specific examination finding for CMC arthritis. Hold the thumb metacarpal, apply axial compression (pushing the base toward the trapezium), and rotate the metacarpal. Pain and crepitus are pathognomonic. The test reproduces the high contact stresses that occur during pinch.
Differential diagnosis:
- De Quervain tenosynovitis: pain at radial styloid, Finkelstein test positive
- Scaphoid fracture or nonunion: snuffbox tenderness, different pain location
- STT arthritis: isolated STT pain without CMC involvement
- Flexor carpi radialis tendinitis: pain over FCR at wrist
- First dorsal compartment arthritis: rare
- Carpal tunnel syndrome: may coexist, different symptom pattern
- Trigger thumb: locking and catching at IP or MCP joint
Investigations and Imaging
Radiographic assessment:
Standard radiographic series for CMC arthritis:
1. PA view of hand:
- Shows joint space narrowing
- Osteophytes
- Subluxation pattern
2. Lateral view of hand:
- Dorsal subluxation visible
- Osteophyte size assessment
3. Robert view (Bett view, stress AP):
- True AP of CMC joint
- Positioning: forearm pronated, thumb extended and opposed
- Best view for joint space narrowing and subluxation
- Most useful for staging
4. Eaton stress view:
- Resisted tip pinch during radiograph
- Demonstrates dynamic subluxation
- Useful in early disease (Stage I-II)
Radiographic findings by stage:
- Stage I: Normal joint space or widening, stress view shows subluxation
- Stage II: Narrowing, osteophytes less than 2mm
- Stage III: Severe narrowing, osteophytes greater than 2mm, sclerosis
- Stage IV: Above findings plus STT joint involvement
Robert View
The Robert view (also called Bett view) is the most important radiograph for CMC arthritis. It provides a true AP view of the CMC joint by pronating the forearm and placing the thumb flat on the cassette. This view best demonstrates joint space narrowing and subluxation for Eaton-Littler staging.
Advanced imaging:
MRI:
- Not routinely required for diagnosis
- May be useful to assess:
- Ligament integrity (AOL)
- Synovitis severity
- Articular cartilage status
- Occult fractures
- STT joint involvement when X-ray equivocal
CT scan:
- Rarely indicated
- May be useful for:
- Preoperative planning for arthrodesis
- Complex deformity assessment
- Failed prior surgery
Ultrasound:
- Can assess synovitis
- Guide injection procedures
- Limited role compared to radiographs
Injection testing:
- Diagnostic injection: local anesthetic into CMC joint
- Pain relief confirms CMC as source
- Distinguishes from de Quervain or STT arthritis
- Therapeutic injection: corticosteroid
- May provide temporary relief (weeks to months)
- Up to 3 injections can be attempted
- Helps select appropriate surgical candidates
Management Approach
Conservative Management (Stage I-II)
Non-operative treatment trial (3-6 months):
- Thumb spica splinting (removable, worn during activities and night)
- Activity modification (avoid repetitive pinch)
- NSAIDs (oral or topical)
- Hand therapy (strengthening, ROM, adaptive equipment)
- Corticosteroid injection (up to 3 attempts)
Success rate: 40-60% of patients achieve adequate symptom control. Better outcomes in Stage I-II disease.
Surgical Indications
Consider surgery when:
- Failure of conservative management for 3-6 months
- Persistent pain affecting function
- Significant functional limitation (ADLs, occupation)
- Pinch strength loss greater than 30-50%
- Patient motivation for surgical intervention
- Stage III-IV disease (earlier surgical consideration)
These indications apply to properly selected patients with realistic expectations.
Surgical Techniques
Trapeziectomy with Ligament Reconstruction and Tendon Interposition
Indications:
- Stage II-IV disease with failed conservative treatment
- Primary surgical option for most patients
- Standard procedure with best long-term evidence
Technique (Burton-Pellegrini or variations):
1. Incision and approach:
- Dorsal or volar approach (volar more common)
- Wagner incision: longitudinal over thenar eminence
- Identify and protect radial sensory nerve branches
- Protect palmar cutaneous branch of median nerve
2. Trapeziectomy:
- Identify CMC joint and trapezium
- Dissect circumferentially around trapezium
- Protect FCR tendon (volar approach) or ECRB (dorsal)
- Remove trapezium completely
- Ensure no fragments remain
- Inspect STT joint (Stage IV)
3. Tendon harvest:
- Harvest half-width of FCR (most common) or entire APL
- FCR: make distal window, retrieve with tendon stripper
- Leave proximal attachment intact
- Length: 10-12 cm typically adequate
4. Ligament reconstruction (suspensionplasty):
- Drill hole in metacarpal base (dorsal-radial to volar-ulnar)
- Second drill hole in index metacarpal base or through FCR tunnel
- Thread tendon through metacarpal hole
- Create sling or anchor to suspend first metacarpal
- Prevents proximal migration and subsidence
5. Tendon interposition:
- Remaining tendon rolled into ball or figure-of-eight
- Placed in trapezial space as spacer
- Suture to capsule to prevent migration
- Maintains space and prevents subsidence
6. Closure:
- Repair capsule
- Close skin
- Apply thumb spica splint with IP joint free
Technical pearls:
- Complete trapezium removal is essential (prevents pain)
- FCR harvest: take only half width to preserve wrist flexion
- Ensure adequate tension on suspension (not too tight)
- Interposition prevents bone-on-bone contact
Postoperative care:
- Thumb spica splint for 3-4 weeks
- Remove sutures at 2 weeks
- ROM exercises begin at 4 weeks
- Strengthening at 8-12 weeks
- Avoid heavy lifting for 3 months
This concludes the LRTI technique description.
Complications of Surgical Treatment
Early complications (less than 6 weeks):
Early Complications
| Complication | Incidence | Management | Prevention |
|---|---|---|---|
| Radial sensory nerve injury (neuroma or paresthesia) | 5-10% | Observation (most resolve), neuroma excision if persistent | Careful dissection, protect nerve branches |
| Wound infection | 1-2% | Antibiotics, wound care, possible debridement | Perioperative antibiotics, sterile technique |
| Hematoma | 2-3% | Compression, drainage if large | Hemostasis, drain consideration |
| Reflex sympathetic dystrophy (CRPS) | 1-5% | Early mobilization, therapy, medications | Early ROM, avoid prolonged immobilization |
Late complications (greater than 6 weeks):
Late Complications
| Complication | Incidence | Management | Prevention |
|---|---|---|---|
| Subsidence (proximal migration of metacarpal) | 20-30% simple, less than 10% LRTI | Usually asymptomatic, revision LRTI if symptomatic | LRTI technique, adequate suspensionplasty |
| Instability or weakness | 5-10% | Therapy, revision reconstruction if severe | Proper LRTI tension, adequate rehabilitation |
| Persistent pain | 5-10% | Investigate cause (incomplete trapeziectomy, STT, de Quervain), treat accordingly | Complete trapezium removal, assess STT joint |
| Tendon adhesions or rupture | 2-3% | Tenolysis if adhesions, reconstruction if rupture | Gentle technique, early ROM |
| Scar sensitivity | 5-10% | Desensitization therapy, scar massage | Meticulous skin closure, therapy |
Arthroplasty-specific complications:
- Implant loosening (10-15%)
- Dislocation (5-10%)
- Subsidence (5-10%)
- Periprosthetic fracture (2-5%)
- Metallosis (rare)
Arthrodesis-specific complications:
- Nonunion (5-10%)
- Malunion (improper positioning)
- Hardware failure or irritation
- Adjacent joint arthritis (MCP, STT)
Subsidence
Subsidence (proximal migration of the thumb metacarpal into the trapezial space) occurs in 20-30% of simple trapeziectomy cases but is less common with LRTI (less than 10%). Importantly, radiographic subsidence does not always correlate with poor clinical outcomes. Many patients with subsidence have excellent pain relief and function. Symptomatic subsidence requires revision LRTI.
Postoperative Care and Rehabilitation
Immobilization phase (0-4 weeks):
- Thumb spica splint or cast
- Includes wrist and thumb CMC/MCP joints
- IP joint free for motion
- Elevate hand to reduce swelling
- Suture removal at 2 weeks
- Continue splinting until week 4
Early mobilization phase (4-8 weeks):
- Remove splint at 4 weeks
- Begin gentle ROM exercises
- Thumb opposition
- Radial and palmar abduction
- CMC and MCP flexion/extension
- Progress to active ROM without resistance
- Custom splint for protection during activities
- Scar massage and desensitization
Strengthening phase (8-12 weeks):
- Begin progressive resistance exercises
- Pinch strengthening (putty, grippers)
- Grip strengthening
- Functional activities training
- Gradual return to work (light duty)
Return to full activity (12+ weeks):
- Full ROM usually achieved by 3 months
- Strengthening continues for 6 months
- Maximal improvement at 6-12 months
- Return to unrestricted activities at 3-6 months
- Heavy manual labor may require 6 months
Expected outcomes:
- Pain relief: 90-95% of patients
- Pinch strength: 80-90% of contralateral side
- ROM: Slightly reduced but functional
- Satisfaction: 85-95%
- Return to activities: 90%+
Early Motion is Critical
Starting ROM at 4 weeks is critical to prevent stiffness and adhesions. Prolonged immobilization beyond 4 weeks increases risk of CRPS and poor functional outcomes. Balance protection of reconstruction with need for early mobilization.
Outcomes and Prognosis
Trapeziectomy with LRTI: Gold Standard
- Pain relief achieved in over 90% of patients
- Satisfaction rates 85-95% at long-term follow-up
- Pinch strength recovers to 80-90% of contralateral side
- Low reoperation rate (less than 5%)
- Subsidence occurs but often asymptomatic
LRTI vs Simple Trapeziectomy
- No significant difference in pain relief (VAS scores equivalent)
- No significant difference in pinch strength at 1 year
- LRTI has less radiographic subsidence (statistically significant)
- Subsidence does not correlate with clinical outcomes
- Simple trapeziectomy may be adequate for many patients
- LRTI adds cost and complexity without proven benefit
CMC Arthroplasty vs LRTI
- Short-term pain relief similar to LRTI (1-2 years)
- Revision rate 10-15% vs. less than 5% for LRTI
- Dislocation risk 5-10% with total joint
- Hemiarthroplasty better than total joint
- Longer-term data needed (most studies less than 5 years)
- Not yet considered gold standard
Arthrodesis for CMC Arthritis
- Pinch strength 100%+ of preoperative (highest of all procedures)
- Pain relief in 90%+ of patients
- Nonunion rate 5-10%
- Loss of CMC motion (compensatory MCP motion)
- Risk of MCP hyperextension and arthritis long-term
- Best results in young male manual workers
Conservative Management Efficacy
- Success rate 40-60% for Stage I-II disease
- Thumb spica splinting reduces pain and improves function
- Corticosteroid injections provide temporary relief (3-6 months average)
- Up to 3 injections can be attempted before considering surgery
- Activity modification and hand therapy improve outcomes
- Progression to surgery more likely with Stage III-IV disease
References
-
Becker SJE, Makarawung DJS, Spit SA, et al. Disability in patients with trapeziometacarpal joint arthrosis: incidental versus presenting diagnosis. J Hand Surg Am. 2014;39(10):2009-2015. doi:10.1016/j.jhsa.2014.07.009
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Wajon A, Vinycomb T, Carr E, et al. Surgery for thumb (trapeziometacarpal joint) osteoarthritis. Cochrane Database Syst Rev. 2015;2015(2):CD004631. doi:10.1002/14651858.CD004631.pub4
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Eaton RG, Littler JW. Ligament reconstruction for the painful thumb carpometacarpal joint. J Bone Joint Surg Am. 1973;55(8):1655-1666.
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Bettinger PC, Linscheid RL, Berger RA, et al. An anatomic study of the stabilizing ligaments of the trapezium and trapeziometacarpal joint. J Hand Surg Am. 1999;24(4):786-798. doi:10.1053/jhsu.1999.0786
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Pellegrini VD Jr. Osteoarthritis of the trapeziometacarpal joint: the pathophysiology of articular cartilage degeneration. I. Anatomy and pathology of the aging joint. J Hand Surg Am. 1991;16(6):967-974.
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Vermeulen GM, Slijper H, Feitz R, et al. Surgical management of primary thumb carpometacarpal osteoarthritis: a systematic review. J Hand Surg Am. 2011;36(1):157-169. doi:10.1016/j.jhsa.2010.10.028
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Salem H, Davis TR. Six year outcome excision of the trapezium for trapeziometacarpal joint osteoarthritis: is it improved by ligament reconstruction and temporary Kirschner wire insertion? J Hand Surg Eur Vol. 2012;37(3):211-219. doi:10.1177/1753193411414518
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Huang K, Hollevoet N, Giddins G. Thumb carpometacarpal joint total arthroplasty: a systematic review. J Hand Surg Eur Vol. 2015;40(4):338-350. doi:10.1177/1753193414563243
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Vitale MA, Hettinger RM, O'Connor JP, et al. Trapeziometacarpal arthroplasty. J Am Acad Orthop Surg. 2016;24(8):555-562. doi:10.5435/JAAOS-D-15-00266
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Gottschalk MB, Carpenter E, Oakes D, et al. Thumb carpometacarpal arthrodesis for arthritis: patient-reported outcomes and satisfaction at greater than 5-year follow-up. J Hand Surg Am. 2018;43(9):815-821. doi:10.1016/j.jhsa.2018.05.012
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Burton RI, Pellegrini VD Jr. Surgical management of basal joint arthritis of the thumb. Part II. Ligament reconstruction with tendon interposition arthroplasty. J Hand Surg Am. 1986;11(3):324-332.
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Forestier E, Vidoni E, Corain M, et al. Radiographic progression in thumb base osteoarthritis: a follow-up study. Clin Exp Rheumatol. 2018;36(6):1059-1064.
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Marks M, Hensler S, Wehrli M, et al. Trapeziectomy with suspension-interposition arthroplasty for thumb carpometacarpal osteoarthritis: a randomized controlled trial comparing the use of allograft versus flexor carpi radialis tendon. J Hand Surg Am. 2017;42(12):978-986. doi:10.1016/j.jhsa.2017.07.004
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Spekreijse KR, Vermeulen GM, Kedilioglu MA, et al. The effect of a bone tunnel during ligament reconstruction for trapeziometacarpal osteoarthritis: a 5-year follow-up. J Hand Surg Am. 2013;38(4):690-696. doi:10.1016/j.jhsa.2013.01.023
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Marks M, Audigé L, Herren DB, et al. Trapeziometacarpal joint implant arthroplasty outcomes and approach-related complications: a systematic review. J Hand Surg Eur Vol. 2014;39(9):927-938. doi:10.1177/1753193413511936
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Gangopadhyay S, McKenna H, Burke FD, et al. Five- to 18-year follow-up for treatment of trapeziometacarpal osteoarthritis: a prospective comparison of excision, tendon interposition, and ligament reconstruction and tendon interposition. J Hand Surg Am. 2012;37(3):411-417. doi:10.1016/j.jhsa.2011.11.027
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Davis TR, Brady O, Dias JJ. Excision of the trapezium for osteoarthritis of the trapeziometacarpal joint: a study of the benefit of ligament reconstruction or tendon interposition. J Hand Surg Am. 2004;29(6):1069-1077. doi:10.1016/j.jhsa.2004.06.017
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Hartigan BJ, Stern PJ, Kiefhaber TR. Thumb carpometacarpal osteoarthritis: arthrodesis compared with ligament reconstruction and tendon interposition. J Bone Joint Surg Am. 2001;83(10):1470-1478.
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Spaans AJ, van Laarhoven CM, Schuurman AH, et al. Interobserver agreement of the Eaton-Littler classification system and treatment strategy of thumb carpometacarpal joint osteoarthritis. J Hand Surg Am. 2011;36(9):1467-1470. doi:10.1016/j.jhsa.2011.06.009
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Raven EE, Haverkamp D, Sierevelt IN, et al. Long-term results of surgical intervention for osteoarthritis of the trapeziometacarpal joint: comparison of resection arthroplasty, trapeziectomy with tendon interposition and trapezio-metacarpal arthrodesis. Int Orthop. 2007;31(4):547-554. doi:10.1007/s00264-006-0224-5
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
Scenario 1: Stage III CMC Arthritis
"A 62-year-old right-hand-dominant female presents with 2 years of progressive right thumb base pain. She reports difficulty opening jars, turning keys, and writing. Conservative treatment with splinting and NSAIDs for 6 months has failed. X-rays show Eaton-Littler Stage III changes. She asks about surgical options."
Scenario 2: Young Manual Laborer
"A 35-year-old male carpenter presents with left thumb base pain. He does heavy manual work requiring strong grip and pinch. Examination reveals positive grind test, reduced pinch strength 40% compared to right side. X-rays show Stage III CMC arthritis. He has tried conservative treatment for 4 months without benefit. He asks what operation will give him the strongest grip to return to his carpentry work."
Scenario 3: Persistent Pain After Trapeziectomy
"A 58-year-old female underwent trapeziectomy with LRTI 6 months ago for Stage III CMC arthritis. She initially improved but now has persistent radial-sided wrist pain, especially with gripping. Examination shows tenderness over the scaphoid and STT joint area. Post-operative X-rays show complete trapezium removal with some subsidence but good alignment. How would you manage this?"
Scenario 4: Stage II Decision-Making
"A 55-year-old female office worker has Stage II CMC arthritis. She has had splinting and two corticosteroid injections over 8 months with temporary relief but pain returns. She asks if she should have surgery now or continue with injections."
MCQ and Exam Practice Points
High-yield facts for MCQs:
-
Epidemiology:
- Most common site of osteoarthritis in the hand
- Female to male ratio 15:1
- Affects 33% of postmenopausal women
-
Anatomy:
- Saddle joint (sellar joint) with biaxial motion
- Anterior oblique ligament (beak ligament) is primary stabilizer
- 16 ligaments described around CMC joint
- Contact stress during pinch: 120 kg/cm²
-
Pathophysiology:
- Initial event is AOL attenuation or failure
- Leads to dorsoradial subluxation
- Abnormal kinematics cause cartilage degeneration
-
Clinical examination:
- Grind test is pathognomonic: axial compression with rotation
- Squaring of thumb base from subluxation and osteophytes
- Adduction contracture reduces first web space
-
Eaton-Littler classification:
- Stage I: widening, no narrowing
- Stage II: narrowing, osteophytes less than 2mm
- Stage III: severe narrowing, osteophytes greater than 2mm
- Stage IV: pantrapezial arthritis (STT joint involved)
-
Imaging:
- Robert view (Bett view) is best radiograph for staging
- True AP of CMC joint with forearm pronated
-
Treatment:
- Stage I-II: conservative first (splinting, NSAIDs, injection)
- Stage III-IV: surgery if conservative fails
- Trapeziectomy with LRTI is gold standard
- Success rate 90-95% for pain relief
-
Surgical techniques:
- LRTI: FCR most common donor tendon (half width harvested)
- Simple trapeziectomy has equivalent outcomes but higher subsidence
- Arthrodesis: best for young male manual laborers (maximal strength)
- CMC arthroplasty: higher revision rate (10-15%)
-
Complications:
- Radial sensory nerve injury: 5-10%
- Subsidence: 20-30% simple trapeziectomy, less than 10% LRTI
- Nonunion after arthrodesis: 5-10%
-
Outcomes:
- Pain relief in 90-95% with LRTI
- Pinch strength recovers to 80-90% of contralateral
- Maximal improvement at 6-12 months
Common exam scenarios:
- Stage III disease with failed conservative treatment → LRTI
- Young male laborer → arthrodesis
- Persistent post-operative pain → assess for STT arthritis (Stage IV)
- Stage II disease → conservative vs. surgical (shared decision)
Australian Context
Epidemiology: CMC arthritis prevalence in Australia is similar to international data, affecting approximately 30-35% of women over age 60. The increasing aging population has led to rising surgical rates for this condition across Australian hand surgery centers.
Management considerations: Trapeziectomy with or without LRTI is the standard of care in Australian hand surgery practice. The Australian Hand Surgery Society recommends careful patient selection for CMC arthroplasty given limited long-term data. Arthrodesis is reserved for high-demand patients such as manual laborers in trades who require maximal pinch strength for return to work.
Healthcare access: Public hospital waiting lists for elective hand surgery can range from 6-12 months, while private patients may have shorter wait times. Rehabilitation support is available through both public and private systems, though access varies between metropolitan and rural regions. NSAIDs and corticosteroid injections are readily available for conservative management.
THUMB CMC ARTHRITIS
High-Yield Exam Summary
Key Anatomy
- •Saddle joint (sellar) - biaxial motion: flexion/extension + abduction/adduction
- •Anterior oblique ligament (AOL/beak ligament) - PRIMARY stabilizer, prevents dorsoradial subluxation
- •16 ligaments total described, AOL most important
- •High contact stress: 120 kg/cm² during pinch
- •Small articular surface (1-2 cm²) predisposes to arthritis
Eaton-Littler Classification
- •Stage I: Normal/widened space, synovitis, stress view shows subluxation → Conservative
- •Stage II: Narrowing, osteophytes less than 2mm → Conservative trial, surgery if fails
- •Stage III: Severe narrowing, osteophytes greater than 2mm, CMC only → Surgery (LRTI gold standard)
- •Stage IV: Stage III + STT joint arthritis (pantrapezial) → Surgery addressing all joints
Clinical Examination
- •GRIND TEST: axial compression + rotation of MC = pain/crepitus (PATHOGNOMONIC)
- •Squaring of thumb base (subluxation + osteophytes)
- •Adduction contracture (reduced first web space)
- •Thenar atrophy in advanced cases
- •Pinch strength reduced (compare to contralateral)
Imaging
- •Robert view (Bett view): TRUE AP of CMC joint - BEST for staging
- •Eaton stress view: resisted pinch shows dynamic subluxation
- •PA and lateral hand views
- •Assess STT joint for Stage IV disease
Conservative Treatment
- •Thumb spica splinting (activities + night)
- •NSAIDs (oral or topical)
- •Activity modification
- •Corticosteroid injection (up to 3 attempts)
- •Hand therapy (strengthening, adaptive equipment)
- •Success in 40-60% of Stage I-II patients
Surgical Options
- •Trapeziectomy + LRTI: GOLD STANDARD, 90-95% success, FCR tendon most common donor
- •Simple trapeziectomy: equivalent outcomes, higher subsidence (20-30% vs less than 10%)
- •Arthrodesis: young male laborers, MAX strength (100%+), loses motion, nonunion 5-10%
- •CMC arthroplasty: emerging, higher revision (10-15%), not yet standard
- •Recovery: 4 weeks splint, ROM at 4 weeks, strengthen 8-12 weeks, full recovery 6-12 months
LRTI Technique
- •Complete trapeziectomy (no fragments)
- •Harvest HALF of FCR tendon (or entire APL)
- •Suspensionplasty: drill MC base, weave tendon, anchor to MC2 or through FCR tunnel
- •Interposition: remaining tendon rolled into space as spacer
- •Prevents subsidence and bone-on-bone contact
Complications
- •Radial sensory nerve injury: 5-10% (paresthesia, neuroma)
- •Subsidence: 20-30% simple, less than 10% LRTI (often asymptomatic)
- •CRPS: 1-5% (early ROM prevents)
- •Persistent pain: incomplete trapezium, STT arthritis, de Quervain
- •Arthrodesis: nonunion 5-10%, MCP hyperextension/arthritis long-term
Exam Viva Answers
- •Stage III failed conservative → Recommend LRTI, discuss simple trapeziectomy equivalent evidence
- •Young male laborer → Arthrodesis for MAX strength, accept loss of motion
- •Persistent pain post-op → DDx: STT arthritis (Stage IV), de Quervain, nerve, incomplete removal
- •Stage II → Shared decision: surgery justified if failed conservative, or continue if managing
- •Difference LRTI vs simple → Subsidence lower with LRTI but outcomes equivalent at 1 year
High-Yield Numbers
- •33% of postmenopausal women affected
- •15:1 female to male ratio
- •90-95% surgical success rate
- •80-90% pinch strength recovery
- •120 kg/cm² contact stress during pinch
- •4 weeks immobilization, 6-12 months full recovery