Rheumatoid arthritis of the hand

1. High-Yield Summary

• Systemic Autoimmune Synovitis: Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease characterized by symmetric, destructive synovial proliferation (pannus) targeting synovial joints, tendon sheaths, and bursa of the hand in over 85% of affected patients.
• Pathognomonic Deformity Patterns: Progressive soft-tissue attenuation, capsuloligamentous laxity, and articular erosions yield characteristic hand deformities: metacarpophalangeal (MCP) ulnar drift with volar subluxation, swan neck and boutonnière digital deformities, and Nalebuff types I through VI thumb deformities.
• Catastrophic Tendon Attrition Ruptures: Inherent bony erosion creates sharp spurs that cause painless, mechanical attrition ruptures: the Mannerfelt lesion (scaphoid spur rupturing the flexor pollicis longus [FPL]), Vaughan-Jackson syndrome (dorsal subluxation of the distal ulna rupturing extensor digitorum communis [EDC] tendons sequentially from ulnar to radial), and extensor pollicis longus (EPL) rupture at Lister’s tubercle.
• Proximal-to-Distal Surgical Hierarchy: Surgical planning mandates stabilizing the proximal foundation prior to distal digital reconstruction. A structurally painful, unstable, or supinated wrist must be reconstructed or fused before addressing MCP arthroplasty or interphalangeal finger balance.
• Modern Multidisciplinary Paradigm: Early escalation with conventional synthetic, biologic, and targeted synthetic disease-modifying antirheumatic drugs (DMARDs) has shifted surgery from late salvage arthrodesis toward early prophylactic tenosynovectomy, dynamic soft-tissue balancing, and durable silicone MCP resection arthroplasty.

2. Anatomy

The functional anatomy of the rheumatoid hand represents a complex balance of osseous articulations, intrinsic musculature, and extrinsic tendon excursion. Destruction of static ligamentous restraints unleashes dynamic deforming forces across the digit.

Metacarpophalangeal (MCP) Joint Restraints

The MCP joints are condyloid articulations providing flexion-extension and abduction-adduction. Static stability is mediated by the collateral ligaments (originating from the dorsal-lateral metacarpal condyle and inserting onto the volar-lateral proximal phalanx) and the dense fibrocartilaginous volar plate. The radial collateral ligament is physiologically longer and more obliquely oriented than the ulnar collateral ligament, rendering it inherently more vulnerable to attenuation under repetitive pinch vectors. Dynamic stability is conferred by the extensor hood, comprised of transverse sagittal bands that centralize the extensor digitorum communis (EDC) tendon over the metacarpal head, and the intrinsic tendons (dorsal and volar interossei, lumbricals) inserting into the lateral bands.

Interphalangeal Complex & Retinacular Apparatus

At the proximal interphalangeal (PIP) joint, the extensor mechanism divides into a central slip inserting onto the base of the middle phalanx and two lateral bands that receive contributions from the intrinsic lateral slips. Distal to the PIP joint, the lateral bands conjoin to form the terminal extensor tendon inserting at the base of the distal phalanx. Lateral band position is precisely regulated by the transverse retinacular ligament (TRL), which prevents dorsal migration of the lateral bands during extension, and the oblique retinacular ligament (ORL of Landsmeer), which passes volar to the PIP joint flexion axis and dorsal to the distal interphalangeal (DIP) joint axis, coordinating coupled interphalangeal motion.

Neurovascular Danger Zones & Surgical Internervous Intervals

Surgical exposure in the rheumatoid hand requires meticulous preservation of vulnerable neurovascular and cutaneous structures:

• Proper Digital Neurovascular Bundles: Lie immediately anterolateral to the flexor tendon sheath in the digit. In the presence of severe MCP joint volar subluxation and ulnar drift, the digital neurovascular bundles are displaced into the interdigital valleys and tensioned volarly; blind transverse dissection during volar plate release or intrinsic release risks catastrophic digital ischemia.
• Dorsal Cutaneous Branch of the Ulnar Nerve (DCBUN): Arises 5 to 7 cm proximal to the ulnar styloid, arborizing across the dorsoulnar wrist and distal radioulnar joint (DRUJ). Vulnerable during Darrach, Sauvé-Kapandji, or distal ulnar hemiresection procedures; injury triggers recalcitrant, disabling neuromas.
• Superficial Branch of the Radial Nerve (SBRN): Courses subcutaneously across the first dorsal extensor compartment and anatomical snuffbox. Extreme vulnerability during first compartment tenosynovectomy or radial styloidectomy requires blunt subcutaneous dissection.
• Recurrent Motor Branch of the Median Nerve: Arises within the carpal tunnel and branches extraligamentously, subligamentously, or transligamentously to innervate the thenar musculature. Proliferative flexor tenosynovitis obliterates fascial tissue planes, requiring direct visualization before division of the transverse carpal ligament.

3. Pathogenesis

The hallmark of rheumatoid pathology is invasive, hyperplastic synovial tissue (pannus) driven by T-cell activation, macrophage recruitment, and proinflammatory cytokines (TNF-alpha, IL-1, IL-6). Pannus secretes matrix metalloproteinases (MMPs, collagenases, stromelysin) and stimulates osteoclastic resorption, targeting the cartilage-bone junction at the bare areas devoid of protective hyaline coverage.

Metacarpophalangeal Ulnar Drift & Volar Subluxation Cascade

The progression of MCP joint destruction involves a multi-step biomechanical failure cascade:

• Initial Capsular Distension: Proliferative synovitis distends the MCP joint capsule, stretching the collateral ligaments and thinning the radial sagittal band.
• Extensor Tendon Subluxation: Normal physiologic forces during power grip exert an ulnar and volar vector. With attenuation of the radial sagittal band, the EDC tendon slips into the ulnar intermetacarpal groove, transforming from an extensor into a dynamic ulnar abductor and flexor.
• Intrinsic Muscle Contracture: The ulnar interosseous and hypothenar muscles experience unchecked shortening, pulling the base of the proximal phalanx into pronounced ulnar deviation and volar translation.
• Articular Destruction: Cartilage erosion and dorsal metacarpal head sloping culminate in fixed, non-reducible volar dislocation.

Pathomechanics of Digital Deformities: Swan Neck vs. Boutonnière

Interphalangeal joint deformities reflect opposing mechanical failures of the extensor hood and retinacular ligaments:

• Swan Neck Deformity (PIP Hyperextension + DIP Flexion): Initiated either by primary PIP volar plate attenuation (allowing dorsal migration of the lateral bands above the PIP flexion-extension axis), terminal extensor tendon rupture (mallet finger leading to compensatory PIP hyperextension), or intrinsic tightness pulling through the central slip. As lateral bands lock dorsally, extension force concentrates on the PIP joint, causing secondary DIP flexion due to reciprocal extensor tethering.
• Boutonnière Deformity (PIP Flexion + DIP Hyperextension): Initiated by chronic synovitis distending and attenuating the central slip insertion at the middle phalanx dorsal tubercle. The central slip ruptures or elongates, allowing the lateral bands to subluxate volarly below the PIP center of rotation. Once displaced volarly, the lateral bands become powerful PIP flexors while exerting increased tension on the terminal tendon, driving rigid DIP hyperextension.

Tendon Attrition Rupture Mechanisms

Tendon rupture in rheumatoid disease occurs via two distinct mechanisms: direct enzymatic/ischemic infiltration by invasive tenosynovium, and mechanical friction over sharp, eroded bony spicules:

• Vaughan-Jackson Syndrome: DRUJ disruption causes dorsal subluxation of the distal ulna (“caput ulnae”). The scalloped, sharp dorsal edge of the ulnar head erodes through the dorsal carpal capsule, sequentially wearing through the extensor digiti minimi (EDM) and extensor digitorum communis (EDC) to the small, ring, and middle fingers.
• Mannerfelt Lesion: Volar carpal synovitis erodes the floor of the carpal tunnel, exposing a sharp bony osteophyte on the volar-distal pole of the scaphoid tubercle. Repetitive excursion wears through the flexor pollicis longus (FPL) tendon, followed occasionally by the flexor digitorum profundus (FDP) to the index finger.
• Extensor Pollicis Longus (EPL) Rupture: Occurs within the rigid osteofibrous third dorsal compartment. High compartmental pressure and synovial proliferation produce localized ischemia at Lister’s tubercle, precipitating acute rupture without significant preceding pain.

4. Natural History

Rheumatoid arthritis affects approximately 0.5% to 1.0% of the adult population worldwide, with a recognized female predilection of approximately 3:1. The peak age of disease onset ranges between 35 and 55 years, although the condition can manifest at any age.

Untreated or refractory synovitis follows an aggressive, relentless trajectory. Over 75% of patients demonstrate objective radiographic evidence of hand or wrist involvement within the first two years of symptom onset. Without effective disease-modifying pharmacotherapy, persistent inflammatory synovitis inexorably progresses from soft-tissue swelling to irreversible osteocartilaginous destruction, joint subluxation, and severe disability.

The advent of biologic DMARDs (targeting TNF, IL-6, and B cells) and targeted synthetic Janus kinase (JAK) inhibitors has fundamentally transformed the natural history of rheumatoid hand disease. The incidence of end-stage mutilans destruction and spontaneous tendon rupture has decreased substantially over the past two decades. However, a significant cohort of patients continues to experience localized synovial flares, structural joint destruction, and disabling functional impairment requiring timely surgical intervention.

5. Clinical Presentation

History & Symptom Complex

Patients typically present with symmetric joint pain, prolonged morning stiffness exceeding 60 minutes, and diminished grip strength. The clinical history must systematically investigate:

• Functional Impairment: Specific deficits in fine motor activities (fastening buttons, managing keys, handwriting) versus power grip tasks (opening jars, lifting pans).
• Mechanical Catching vs. Tendon Rupture: Distinguishing flexor tenosynovitis (“rheumatoid trigger finger” with painful clicking) from painless, sudden loss of active digital extension signaling acute extensor tendon rupture.
• Neurologic Symptoms: Paresthesias in the median nerve distribution indicative of acute or chronic carpal tunnel syndrome secondary to volar tenosynovitis.
• Systemic Medication Regimen: Precise documentation of immunosuppressive therapy, particularly biologic timing and corticosteroid exposure, which directly impacts wound healing and perioperative infection risk.

Physical Examination & Provocative Maneuvers

Comprehensive evaluation requires systematic inspection, palpation of synovial bogginess, active and passive range of motion assessment, and targeted provocative testing:

• Synovial Assessment: Palpation of “doughy” fullness across the dorsal wrist compartments, MCP joints, and flexor tendon sheaths. Palpation of rheumatoid nodules along extensor surfaces and pressure points.
• Bunnell-Littler Intrinsic Tightness Test: Differentiates intrinsic muscle tightness from extrinsic extensor tightness or capsular contracture. The examiner passively flexes the PIP joint with the MCP held in extension, and repeats with the MCP held in flexion. If the PIP joint flexes more easily with the MCP flexed than extended, intrinsic muscle tightness is confirmed.
• Elson Test: Evaluates central slip integrity over the PIP joint. The patient flexes the PIP joint 90 degrees over the edge of a table and attempts to extend the middle phalanx against resistance. With an intact central slip, extension force is strong and the DIP remains completely floppy. With central slip disruption, PIP extension is weak and the DIP becomes rigidly extended due to lateral band recruitment.
• Wrist Tenodesis Test: Passive wrist flexion normally induces passive extension of the digits via extrinsic extensor tenodesis. Inability of a digit to extend passively during wrist flexion confirms structural extensor tendon rupture, ruling out posterior interosseous nerve (PIN) palsy.

6. Imaging and Diagnostic Studies

Accurate assessment requires a multimodality diagnostic approach combining standard radiographs, high-resolution cross-sectional imaging, and serologic profiling.

Plain Radiography

Standard radiographic evaluation includes bilateral posteroanterior (PA), lateral, and semi-pronated oblique views of both hands and wrists. Key radiographic hallmarks include:

• Periarticular Demineralization: Symmetrical osteopenia localized to the metaphyses and epiphyseal margins of the carpus, MCP, and PIP joints.
• Marginal Erosions: Cortical breaks occurring at the capsular and synovial reflection “bare areas” devoid of cartilage cover (frequently evident earliest at the radial aspect of the second and third metacarpal heads and the ulnar styloid).
• Symmetric Joint Space Narrowing: Diffuse chondral loss involving the radiocarpal, intercarpal, and MCP joints.
• Carpal Architecture & Subluxation: Scapholunate dissociation, ulnar carpal translocation, carpal height collapse (measured via Youm’s carpal height ratio < 0.54), and DRUJ diastasis.

Advanced Imaging: Ultrasound & MRI

High-frequency musculoskeletal ultrasound (12-18 MHz) with power Doppler is a sensitive, point-of-care modality capable of detecting subclinical synovial hypervascularity and occult tenosynovitis prior to radiographic erosion. Magnetic resonance imaging (MRI) of the wrist and hand with intravenous gadolinium demonstrates early synovial pannus enhancement and subchondral bone marrow edema (BME), an established independent prognostic marker for rapid structural progression.

Serology & 2010 ACR/EULAR Diagnostic Criteria

Serologic evaluation establishes systemic disease phenotype and immunological aggressiveness. Rheumatoid Factor (RF) exhibits a sensitivity of 60% to 80% and specificity of 70% to 85%. Anti-cyclic citrullinated peptide (anti-CCP) antibodies demonstrate equivalent sensitivity (70% to 80%) but superior specificity (95% to 98%), serving as a strong predictor of erosive joint destruction. Acute-phase reactants (erythrocyte sedimentation rate [ESR] and C-reactive protein [CRP]) track inflammatory burden.

Under the 2010 ACR/EULAR Classification Criteria, a cumulative score of >= 6 out of 10 points classifies definite rheumatoid arthritis based on: joint involvement (up to 5 points for >10 joints including small joints), serology (up to 3 points for high-titer RF or anti-CCP), acute-phase reactants (1 point for abnormal CRP or ESR), and duration of symptoms >= 6 weeks (1 point).

7. Classification

Structured classification systems guide surgical reconstruction by categorizing deformity morphology, joint reductibility, and structural integrity.

Nalebuff Classification of Rheumatoid Thumb Deformities

The thumb accounts for over 40% of total hand function. Nalebuff defined six distinct deformity patterns based on primary joint pathology and compensatory distal adaptation:

Swanson / Flatt Metacarpophalangeal Joint Deformity Staging

8. Treatment

Medical Therapy & Pharmacologic Optimization

Modern medical therapy operates under a strict “treat-to-target” protocol managed by rheumatology, aiming for clinical remission or low disease activity. Pharmacologic tiers include:

• Conventional Synthetic DMARDs (csDMARDs): Methotrexate is first-line anchor therapy (15-25 mg weekly), supplemented by leflunomide, sulfasalazine, or hydroxychloroquine. Contemporary surgical consensus supports continuing methotrexate throughout the perioperative period, as continuation does not increase postoperative wound infection rates while preventing debilitating rebound flares.
• Biologic DMARDs (bDMARDs): Anti-TNF agents (adalimumab, etanercept, infliximab), IL-6 receptor antagonists (tocilizumab), and T-cell co-stimulation inhibitors (abatacept). Due to impaired host defense and delayed wound healing, biologics are routinely held prior to elective surgery for a duration corresponding to one dosing interval plus one week, and resumed 10 to 14 days postoperatively following verified primary wound healing.
• Targeted Synthetic DMARDs (tsDMARDs): Oral JAK inhibitors (tofacitinib, baricitinib, upadacitinib). Held 3 to 7 days preoperatively based on half-life, with resumption upon epithelial closure.

Nonoperative Management & Hand Therapy

Hand therapy plays an essential role in preserving joint mobility, mitigating contractures, and optimizing remaining functional capacity. Key interventions include:

• Orthotic Splinting: Resting volar wrist-hand orthoses maintain neutral alignment during acute inflammatory flares. Silver ring splints or thermoplastic figure-of-eight splints successfully block PIP hyperextension in flexible swan neck deformities or support PIP extension in early boutonnière deformities.
• Structured Exercise Programs: Targeted strengthening, joint protection education, and active-assisted range of motion regimens (such as the evidence-based SARAH protocol) improve grip strength and functional dexterity without triggering systemic disease reactivation.

Operative Indications & Surgical Objectives

Surgical intervention is indicated for: unremitting pain refractory to medical optimization, progressive joint deformity causing functional decline, imminent or acute tendon attrition rupture, and compressive median or ulnar neuropathy. The overarching surgical objectives prioritize pain relief, structural stability, active functional arc, and hand balance over cosmetic correction.

Surgical Procedures by Anatomic Zone

• Wrist Foundation Reconstruction: In accordance with the “proximal-to-distal” hierarchy, the wrist must be addressed prior to digital reconstruction. Marked radiocarpal subluxation or supination drives recurrent ulnar drift at the fingers. Procedures include: dorsal wrist tenosynovectomy with retinacular transposition, distal ulna resection (Darrach procedure) or Sauvé-Kapandji arthrodesis for DRUJ destruction, radiolunate/radiocarpal arthrodesis for focal instability, or total wrist arthrodesis for end-stage multi-compartment destruction.
• Metacarpophalangeal Joint Arthroplasty: Flexible silicone implant resection arthroplasty (Swanson design) remains the gold standard for stage III and IV disease. Exposure via a transverse or longitudinal dorsal skin incision and longitudinal extensor split. Steps include: metacarpal head resection, intramedullary broaching, ulnar intrinsic (abductor digiti minimi / flexor brevis) release, radial collateral ligament reefing or reconstruction using a distally based slip of the EDC, and centralizing the EDC tendon over the implant. The silicone implant acts as a dynamic internal spacer while surrounding fibrous capsular envelope matures.
• Proximal Interphalangeal Joint Procedures:
  • Swan Neck Correction: For flexible deformities, spiral oblique retinacular ligament (SORL) reconstruction using a lateral band or free tendon graft, or flexor digitorum superficialis (FDS) tenodesis (Zancolli procedure) creates a check-rein against PIP hyperextension. For fixed, destroyed joints, PIP joint arthrodesis in 35° (index) to 45° (small finger) flexion provides stable, pain-free pinch.
  • Boutonnière Correction: Flexible deformities with preserved cartilage respond to extensor tenolysis, central slip shortening, and dorsal transposition of lateral bands. For fixed, destroyed joints, PIP arthrodesis is the definitive treatment of choice.
• Tendon Rupture Reconstruction:
  • EPL Rupture: Treated via extensor indicis proprius (EIP) to EPL tendon transfer, routing the transfer superficial to the extensor retinaculum to optimize excursion.
  • Extensor Digitorum Communis Rupture (Vaughan-Jackson): Immediate Darrach distal ulna resection to eliminate the offending spur. Single tendon rupture (small finger) is reconstructed via end-to-side tenodesis to the adjacent intact ring EDC. Rupture of two tendons is addressed by transferring EIP or adjacent side-to-side suture. Rupture of three or four tendons requires tendon transfer (flexor carpi radialis [FCR] or flexor carpi ulnaris [FCU] transfer to EDC) or interposition intercalary tendon grafts.
  • Mannerfelt FPL Rupture: Formal carpal tunnel release, extensive volar synovectomy, and radical excision of the offending scaphoid tubercle spur. Tendon continuity is restored via interposition palmaris longus graft, FDS IV transfer, or IP joint arthrodesis.

9. Outcome

Modern surgical reconstruction of the rheumatoid hand yields reliable, reproducible outcomes when executed within an integrated reconstructive framework. Patient-reported outcome measures (PROMs), including the Michigan Hand Outcomes Questionnaire (MHQ) and the Disabilities of the Arm, Shoulder and Hand (DASH) score, demonstrate substantial, durable improvements in pain relief, aesthetic self-image, and satisfaction with activities of daily living.

In silicone metacarpophalangeal joint arthroplasty, prospective multicenter investigations confirm dramatic initial correction of ulnar drift (mean correction > 20 degrees) and extensor lag. While functional range of motion typically settles into a functional arc of 30 to 40 degrees of active flexion-extension, patient satisfaction exceeds 85% to 90% at long-term follow-up.

Implant survivorship studies indicate that radiographic fracture of silicone implants occurs in approximately 15% to 30% of implants at 5 to 7 years. Crucially, longitudinal cohort studies demonstrate that radiographic implant fracture does not correlate with clinical deterioration or recurrent pain. The surrounding dense fibrous encapsulation formed around the flexible silicone spacer maintains joint alignment and stability, ensuring that routine revision for asymptomatic implant fracture is unnecessary.

10. Complications

Complications following rheumatoid hand surgery span immediate intraoperative pitfalls, early wound healing disturbances, and late mechanical or biological failure modes.

11. Pearls and Pitfalls

• The Wrist Anchor Principle: Never perform distal MCP arthroplasty in the setting of an uncorrected, painful, or supinated rheumatoid wrist. Radial deviation of the carpus creates an irresistible zigzag biomechanical collapse that guarantees recurrent ulnar drift at the MCP joints. Stabilize the wrist first.
• Gentle Flap Handling: Rheumatoid skin and subcutaneous tissue are exceptionally thin, ischemic, and easily bruised due to corticosteroid dependency. Elevate full-thickness skin flaps down to the extensor retinaculum and tendon sheath without undermining superficial fat.
• Volar Plate Release in MCP Subluxation: When mobilizing chronically dislocated MCP joints, perform a complete transverse volar capsulotomy from proximal to distal. Do not apply forceful hyperextension until the volar plate has been mobilized off the metacarpal neck to avoid avulsion of the osteopenic phalanx.
• Prophylactic Distal Ulna Resection: When exploring dorsal wrist extensor tenosynovitis with evidence of a prominent, scalloped distal ulna, perform a concurrent Darrach or Sauvé-Kapandji procedure. Leaving a sharp dorsal ulna beneath repaired extensor tendons leads to rapid secondary rupture.
• Pitfall – Over-Reaming the Medullary Canal: Metacarpal and phalangeal cortices are often paper-thin. Avoid power reaming or oversized broaches that can violate the diaphysis or blow out the lateral cortex, causing loss of implant stability.
• Pitfall – Misinterpreting Tendon Rupture as PIN Palsy: Always perform the passive wrist tenodesis test. Dropped fingers from extensor tendon rupture will not extend when the wrist is passively flexed, whereas digits with an intact motor tendon but a neuropathic PIN palsy retain passive tenodesis extension.

12. Controversy

Several clinical and surgical controversies remain active areas of investigation in rheumatoid hand reconstruction:

Silicone Spacers vs. Surface-Replacing Pyrocarbon / Modular Implants

Silicone one-piece flexible implants have served as the standard of care for over five decades. However, concerns over long-term implant fracture, limited active flexion arcs, and particle-induced reactive synovitis led to the development of anatomical two-component surface-replacing prostheses (pyrocarbon, metal-on-polyethylene). While surface-replacing designs offer superior theoretical joint kinematics, high rates of dislocation, soft-tissue imbalance, coronal tilting, and peri-implant osteolysis have limited their widespread adoption in inflammatory arthritis. In patients with severe osteopenia and soft-tissue deficiency, silicone arthroplasty remains the benchmark due to its forgiving tolerance of capsuloligamentous laxity.

Prophylactic Early Tenosynovectomy in the Biologic Era

Historically, aggressive surgical synovectomy was routinely advocated after 6 months of persistent synovitis to prevent irreversible articular erosion and tendon rupture. In the contemporary era of targeted biologic and JAK-inhibitor therapy, rapid pharmacological suppression of synovial proliferation has reduced the demand for early synovectomy. Controversy persists regarding the threshold for surgical intervention in patients with persistent, localized subclinical tenosynovitis on ultrasound or MRI despite clinical systemic remission.

Single-Stage vs. Staged Proximal and Distal Reconstruction

While the dictum of “proximal-to-distal” reconstruction is universally accepted, whether wrist stabilization and MCP arthroplasty can safely be performed under a single operative anesthesia remains debated. Single-stage reconstruction minimizes operative sessions and cumulative anesthesia exposure for medically fragile patients, but prolonged operative tourniquet times and conflicting postoperative rehabilitation protocols (wrist immobilization versus early protected MCP motion) lead many surgeons to advocate a staged approach separated by 6 to 12 weeks.

13. Evidence-Based Synthesis

Modern clinical decision-making is grounded in high-quality randomized controlled trials and prospective registry analyses, corroborated by seminal biomechanical and anatomical descriptions.

14. References

• Williams MA, Srikesavan C, Heine PJ et al. Exercise for rheumatoid arthritis of the hand. Cochrane Database Syst Rev. 2018. doi:10.1002/14651858.CD003832.pub3 [Level I: Systematic Review / Meta-Analysis]
• Williams MA, Williamson EM, Heine PJ et al. Strengthening And stretching for Rheumatoid Arthritis of the Hand (SARAH). A randomised controlled trial and economic evaluation. Health Technol Assess. 2015. doi:10.3310/hta19190 [Level I: Multicenter Randomized Controlled Trial]
• Chung KC, Burns PB, Wilgis EF et al. A multicenter clinical trial in rheumatoid arthritis comparing silicone metacarpophalangeal joint arthroplasty with medical treatment. J Hand Surg Am. 2009. doi:10.1016/j.jhsa.2009.01.018 [Level II: Prospective Controlled Comparative Cohort]
• Chung KC, Kotsis SV, Burns PB et al. Seven-Year Outcomes of the Silicone Arthroplasty in Rheumatoid Arthritis Prospective Cohort Study. Arthritis Care Res (Hoboken). 2017. doi:10.1002/acr.23105 [Level II: Prospective Multicenter Longitudinal Cohort]
• Aletaha D, Neogi T, Silman AJ et al. 2010 Rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2010. doi:10.1002/art.27584 [Level V: International Consensus & Diagnostic Validation Study]

15. Master Class Pro-Tip

When performing silicone metacarpophalangeal arthroplasty for severe fixed ulnar drift, the secret to long-term alignment retention does not lie within the implant itself, but within the reconstruction of the radial collateral ligament complex. Always harvest a distally based slip of the extensor digitorum communis tendon (approximately 3 to 4 cm in length and 2 mm in width) prior to joint resection. After seating the silicone spacer and thoroughly releasing the ulnar intrinsic contracture, route this extensor slip through a transosseous drill hole at the radial base of the proximal phalanx or weave it directly into the remnant of the radial collateral ligament. Tension this neo-ligament with the finger held in 10 degrees of radial deviation. This creates a non-attenuating static check-rein against recurrent ulnar drift, preserving functional digital balance long after the initial surgical encapsulation has matured.

Master Class Surgical Pearl: Metacarpophalangeal Soft-Tissue Rebalancing