Basal Joint Arthritisof the Thumb

(Trapeziometacarpal Arthritis)(Carpometacarpal Arthritis)

Ligamentous Anatomy

16 total ligaments Imaeda, et al, J Hand Surg, 1993

Five main stabilizing ligamentous structures Palmar Beak Ligament (Anterior Oblique Ligament) Dorsoradial Ligament Ulnar Collateral Ligament First Intermetacarpal Ligament Posterior Oblique Ligament

Ligamentous Anatomy

Palmar Beak Ligament Dorsoradial Ligament

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Epidemiology and Etiology

Epidemiology

Most common site of osteoarthritis in the hand

Most common site requiring surgery

Most common in post-menopausal females 1:4 women will show radiographic degeneration

Only ~ 20-30% symptomatic 8% with ST arthritis Only 1:12 men affected

Epidemiology

Armstrong, et al, J Hand Surg (Br), 1994 evaluated 143 post-menopausal women 25% had isolated basal thumb osteoarthritis of those with isolated CMC osteoarthritis, 28% complained of thumb pain

Etiology

No clear association with employment Repetitive motion suggests higher incidence

Carpentry, manual labor Cow Milking (Seoane, 1997)

Males with increased grip strength - increased radiographic changes (Chaisson, 2001)

Etiology

1) Trauma - dislocation, fracture

2) Inflammatory diseases - RA, gout

3) Idiopathic Osteoarthritis

4) Hypermobile States Moulton (2001) showed increased joint forces in TM joints with hyperextension laxity at the MCP joint

Etiology

5) TM Instability Acute: severe trauma (complete dislocation) Chronic: can be caused by recurrent stress or overuse

more common often seen in young to middle-aged women

Etiology

Pellegrini, Orth Clin N Amer, 1992 The palmar beak ligament was essential for translational stability of the MC on the trapezium There was a direct correlation between the status of the articular surfaces and the integrity of the beak ligament

EtiologyPelligrini’s Theory: 1) Attritional changes in palmar beak ligament 2) Detachment of the palmar beak ligament 3) Instability of TM joint 4) Increased dorsopalmar translation 5) Increased shear forces in the palmar contact areas 6) Hyaline cartilage wear and OA

Clinical Evaluation

Clinical Presentation

Pain Aggravated by power pinch, grip movements, axial load or flexion/adduction maneuvers

Turning jar lids, doorknobs, opening car doors

Weakness with pinch Typically secondary to pain

Dorsoradial subluxation of the metacarpal base in later stages

Physical Exam

Well localized CMC joint tenderness Localized to radial margin of metacarpal base one finger-breadth distal to scaphoid tubercle

Physical Exam

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Grind Test Pain with axial compression with rotation

Physical Exam

Laxity Test Dorsal-to-volar translation of the metacarpal base will reveal any dorsal subluxation

Torque Test Pain with axial rotation and distraction of the thumb metacarpal

Coexisting Conditions

DeQuervain’s tenosynovitis CMC arthritis may cause DeQuervain’s Good PE, x-rays, injections help differentiate

Carpal Tunnel Syndrome Up to 43% coexists (Florak,1992) Dimensions of carpal tunnel affected by CMC arthritis

ST arthritis FCR tendonitis MCP joint instability

Requires intervention if severe enough

Radiographic Evaluation

PA, lat and oblique views

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30° oblique stress views Technique

Thumbs w/ nail plates parallel to x-ray film Push thumb tips against each other

Advantages Good visualization of pan-trapezial joints Helps assess TM joint laxity

Classification

Eaton Stage I

Radiographs Pre-arthritic joint Normal articular contours Slight widening of joint space

2° effusion or ligament laxity

Clinically Intermittent mild pain with heavy use Mild loss of strength + Grind test

Eaton Stage II

Radiographs TM joint slightly narrowed Minimal sclerosis ± osteophytes (<2mm & ulnar) < 1/3 metacarpal base subluxation

Clinically Frequent pain with normal activity + Grind test Metacarpal base subluxed radial and dorsal

Eaton Stage III

Radiographs Marked narrowing TM joint Osteophytes > 2mm Increased sclerosis, cystic changes subluxation > 1/3 of metacarpal base

Clinically Passive reduction of metacarpal base may be impossible Adduction of metacarpal and MCP joint hyperextension

Eaton Stage IV

Radiographs Advanced degenerative changes & subluxation ST joint involvement

Clinically Decreased mobility of TM joint Patients with relatively less pain

Treatment

Treatment Options

Depends on stage of disease as well as degree of the patient’s discomfort

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Conservative: Rest, NSAID’s, steroid injections, splinting with thumb in abduction (Stage I)

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Surgical: Multiple surgical treatment methods (more advanced stages)

Conservative Treatment

Swigart, et al, J of Hand Surg, 1999 Evaluated 130 thumbs treated with 6 weeks of splinting

Stage I/II: 76% improvement Stage III/IV: 54% improvement

Overall… splinting is well-tolerated effective protocol to diminish, but not eliminate the symptoms of basal joint OA

Operative Treatments

Metacarpal Osteotomy Ligament reconstruction Arthroplasty

Resection arthroplasty - trapeziectomy Prosthetic arthroplasty Ligament reconstruction with tendon interposition

Arthrodesis

Prosthetic Arthroplasty

Multiple Types: Silicone Metallic Ceramic Zirconia

WMT.com

Silicone implant

Swanson Implant

Orthosphere

Prosthetic Arthroplasty

Advantages (theoretical) Immediate stability and no need for long term immobilization

Disadvantages Wear, loosening, osteolysis, infection, synovitis (silicone), periprosthetic fracture !

No report exists with results superior to biologic arthroplasty

Ligament Reconstruction and Tendon Interposition

1) Palmar beak ligament reconstruction 2) Tendon interposition arthroplasty using

radial ½ of FCR tendon !

Often used for Stage II or Stage III disease

LRTI - Approach & Bone Resection

Straight incision is made over dorsoradial aspect of TM joint

avoid sensory branch of radial nerve and radial artery

Partial or complete trapeziectomy Decision based on status of scaphotrapezial joint

Base of metacarpal resected

LRTI -Tendon Harvest

FCR tendon graft of 10 -12 cm in length Leading end passed into and through the base of the thumb MC Remaining tendon is folded to act as a spacer

LRTI

MCP Joint Hyperextension Must be addressed if > than 30 degrees

Volar capsulodesis EPB transfer from the base of the proximal phalanx to the metacarpal shaft

Eliminates the EPB hyperextension force at the MCP joint

Postoperative Care

Short-arm, thumb spica casting for 4 weeks

Active ROM exercises

Need for hand therapy depends on individual patient

LRTI

Burton and Pellegrini, J Hand Surg, 1986 25 LRTI, average 2 yr f/u More consistent improvement in grip, pinch, thumb web space than silicone arthroplasty Excellent results in 23 of 25

Arthrodesis

Often used in young laborers

Post-traumatic

Orient by “fist position”

Surgical Complications

Approach related Injury to radial artery or dorsal sensory branch of the radial nerve

Implant related Silicone synovitis, implant subluxation, carpal erosion

Failure of ligament reconstruction Loss of pinch strength Proximal migration of the metacarpal

Cost Analysis

Conservative Management Costs NSAID - Celebrex 200mg #60 = $250 Celestone Injection = $175 Custom OT splint = $200

Cost Analysis

Surgical Costs Metacarpal Osteotomy = $2150 LRTI = $5665 Arthroplasty = $7260