Modern Study Review (AI-Generated)
High-Yield Summary
Rheumatoid arthritis (RA) frequently causes complex finger deformities due to chronic synovitis leading to tendon rupture, joint subluxation, and ligamentous laxity. Extensor tendon ruptures are common and often result from attrition against subluxed bony prominences, while flexor tendon ruptures are less frequent but more challenging to manage. Arthrodesis remains a cornerstone for stabilizing painful, deformed joints, especially when reconstructive options are limited. Understanding the Nalebuff classification for thumb deformities and modern surgical indications is essential for optimizing hand function and pain relief.
Key Diagnostic Findings
| Aspect | Details |
|---|---|
| Anatomy | Extensor tendons (middle, ring, little fingers), flexor tendons (FPL), MCP, PIP, DIP joints, CMC joint, ulnar collateral ligament of thumb |
| Clinical Presentation | Dorsal wrist swelling, finger extensor lag, flexion deformities, thumb deformities (boutonniere, swan neck), pain, loss of function |
| Imaging | X-rays for joint subluxation, erosions, and deformities; MRI/Ultrasound for tendon integrity and synovitis assessment |
| Classification Systems | Nalebuff classification for RA thumb deformities (Types I-IV) — guides surgical approach |
Current Gold Standard Treatment
| Treatment Type | Indications & Approach |
|---|---|
| Non-operative | Disease-modifying antirheumatic drugs (DMARDs), biologics, splinting, occupational therapy |
| Extensor Tendon Rupture | Acute: direct repair; Chronic: tendon grafts (extensor indicis proprius, EPB, sublimis) |
| Flexor Tendon Rupture | Rare; tendon grafts have poor outcomes; FPL rupture often treated with thumb IP fusion |
| Arthrodesis | Preferred for painful, unstable joints or severe deformity: – MCP: 20-30° flexion – PIP: 25-40° flexion – DIP: 15-20° flexion |
| Thumb Deformities | Nalebuff-guided surgery: – Type I: MCP synovectomy, extensor reconstruction, or MCP arthrodesis/arthroplasty – Type II: Add CMC arthroplasty – Type III: Trapeziometacarpal interposition arthroplasty ± MCP fusion – Type IV: Ligament reconstruction or MCP arthrodesis |
| Wrist Involvement | Synovectomy for persistent dorsal swelling; arthrodesis favored for severe deformity, carpal dislocation, or tendon rupture |
Modern Complications & Outcomes
- Complications: Tendon graft failure (especially flexor tendons), nonunion after arthrodesis, persistent pain, stiffness, and recurrence of deformity.
- Outcomes: Arthrodesis provides reliable pain relief and stability but sacrifices joint motion; tendon transfers and grafts restore function variably.
- Board Exam Pearls: Know Nalebuff thumb deformity types, tendon rupture mechanisms, and arthrodesis positioning angles. Recognize the importance of early synovectomy to prevent tendon rupture.
Classic Clinical Notes
Finger Deformities 3
TENDON RUPTURE
Extensor Tendon
- Basically caused by rheumatoid tenosynovitis
- The long extensors of the middle, ring, and little fingers rupture as a group – usually related to the dorsal subluxation of the distal ulna, forcing the tendons to rub up against the rough bone and the dorsal carpal ligament
- Acutely, direct repair may be done.
- Chronically, a segmental tendon graft will be required
- Potential graft sources are the extensor indicis, EPB (especially when the MCP is going to be fused anyways), or sublimis to the ring finger
Flexor Tendon
- Not as common to rupture as the extensor tendons, but harder to treat
- Tendon grafts almost always fail.
- FPL rupture may be treated with thumb IP fusion
ARTHRODESIS OF THE FINGER JOINTS
- Preferred position for arthrodesis:
- MCP – 20-30° flexion
- PIP – 25° flexion in the index to 40° in the small
- DIP – 15-20° flexion
DEFORMITIES OF THE THUMB
Nalebuff classification of thumb deformities in rheumatoid patients
| Type | Description | Treatment |
|---|---|---|
| I | Boutonniere deformity: synovitis at MCP stretches extensor hood; EPL migrates medially causing MCP flexion, IP extension, volar subluxation of proximal phalanx | Mild: MCP synovectomy and extensor reconstruction Severe: MCP arthrodesis (if IP and CMC intact) If IP and CMC involved, MCP arthroplasty may be better |
| II | MCP flexion, IP hyperextension, plus CMC subluxation | All of the above plus CMC arthroplasty |
| III | Swan neck deformity: synovitis at CMC joint subluxes trapeziometacarpal joint laterally; adduction contracture of metacarpal; MCP hyperextension due to volar plate laxity | Mild: trapeziometacarpal interposition arthroplasty Severe MCP deformity: add MCP fusion |
| IV | Ulnar collateral ligament laxity (Gamekeeper’s thumb) | Mild: synovectomy, ligament reconstruction, adductor release Severe: MCP arthrodesis |
RHEUMATOID DEFORMITIES OF THE WRIST
- The wrist may be the first location of painful swelling
- Persistent swelling at the dorsum of the wrist for 6 weeks failing medical treatment may be an indication for synovectomy, as prophylaxis against extensor tendon rupture
- On the volar surface, even a small bit of tenosynovitis can cause carpal tunnel syndrome
- The level of the deep transverse carpal ligament is a frequent site of rupture of flexor tendons
Arthrodesis
- Whether arthrodesis or arthroplasty is best in the wrist is controversial.
- Arthrodesis provides a painless, stable wrist with the chance to correct deformity
- Most consider it the procedure of choice for marked flexion deformity of the wrist and fingers, for carpal dislocation, or for a painful wrist with associated tendon ruptures
Last Updated on January 24, 2026 by orthonet
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