What is Jaccoud's arthritis?

What is Jaccoud's Arthritis

Jaccoud's arthritis is a chronic, deforming but traditionally non-erosive arthropathy characterized by reversible joint deformities—particularly ulnar deviation, swan neck deformities, and Z-thumb—that can be passively corrected on physical examination. 1, 2

Historical Context and Current Associations

Originally described in patients with rheumatic fever over a century ago, Jaccoud's arthropathy is now predominantly associated with systemic lupus erythematosus (SLE), occurring in approximately 2-5% of SLE patients 3, 2, 4. It has also been reported rarely with cancer immunotherapy (anti-PD-1 agents) 5.

Clinical Features

Characteristic Deformities

The hallmark of Jaccoud's arthropathy includes specific joint deformities that distinguish it from other arthropathies:

• Ulnar deviation at the metacarpophalangeal (MCP) joints is one of the most common presentations 1, 2
• Swan neck deformities (hyperextension at proximal interphalangeal joints with flexion at distal interphalangeal joints) occur frequently 2, 6
• Z-thumb deformity (thumb subluxation) is characteristic 2, 6
• Boutonniere deformities and hallux valgus may also develop 4

Key Distinguishing Feature: Reducibility

The defining characteristic is that these deformities are passively correctable—they return to normal appearance with manual manipulation—differentiating Jaccoud's from rheumatoid arthritis. 1, 2 However, in severe cases, fixed deformities at MCP joints can develop, compromising this reducibility 6.

Imaging and Erosive Potential: A Critical Update

Traditional Teaching vs. Modern Evidence

Historically, Jaccoud's arthropathy was considered strictly non-erosive on plain radiographs 1, 4. However, this paradigm has shifted with modern imaging techniques revealing that bone erosions can occur in more than half of patients, particularly those who are anti-citrullinated protein antibody (ACPA) positive. 3

• Plain radiographs characteristically show no bone erosions 2, 4
• High-resolution ultrasound and MRI detect small bone erosions in 58.8% of patients with Jaccoud's arthropathy 3
• ACPA-positive patients show erosive damage more frequently (75% vs. 53.8% in ACPA-negative patients, p=0.002) 3
• MRI findings typically reveal mild to moderate synovitis and flexor tenosynovitis 6

Laboratory Associations

Serological Profile

• Anti-double stranded DNA (anti-dsDNA) antibodies are typically elevated in SLE-associated cases 1
• Antinuclear antibodies (ANA) are positive 1
• ACPA positivity occurs in approximately 23.5% of patients and correlates with erosive disease 3
• Rheumatoid factor may be present but is not diagnostic 3

Clinical Severity Spectrum

Severe Jaccoud's Arthropathy

A subset of patients develops severe forms with significant functional impairment:

• All three classic deformities present simultaneously (swan neck, ulnar deviation, Z-thumb) 6
• "Mutilans-type" presentations can occur 6
• Fixed deformities at MCP joints develop in advanced cases 6
• Severe forms compromise functional capacity and daily activities, significantly impacting quality of life 2, 6

Differential Diagnosis: Critical Distinction from Rheumatoid Arthritis

Timely identification of Jaccoud's arthropathy as a non-erosive but deforming arthritis is crucial in differentiating SLE from rheumatoid arthritis. 1 Key distinguishing features include:

• Passive reducibility of deformities (in early stages) 2, 4
• Absence of significant erosions on plain radiographs 2
• Association with SLE serologies rather than high-titer RF/ACPA 1
• Different pattern of synovitis on imaging 6

Management Approach

Current Treatment Limitations

There is no preventive measure against Jaccoud's arthropathy development, no specific clinical treatment, and no convincing surgical approach for correcting the deformities. 2

Conservative Management

Treatment focuses on the underlying SLE and symptomatic relief:

• Prednisone, hydroxychloroquine, and NSAIDs (such as diclofenac) form the mainstay of therapy 1, 4
• Low-dose corticosteroids for inflammation control 4
• Methotrexate may be considered 4
• Antimalarials (hydroxychloroquine) are standard 4

Surgical Considerations

Surgical options remain controversial and unproven:

• Soft tissue realignment around joints 4
• More aggressive procedures (arthrodesis, silastic implants, arthroplasty) lack evidence of efficacy 4

Pathogenesis

The etiopathogenic mechanisms remain unknown, though some authors suggest an association with hypermobility syndrome 4. The development of erosions in ACPA-positive patients suggests a potential autoimmune-mediated bone damage mechanism distinct from the traditional understanding 3.

Clinical Implications

With improved survival rates in SLE and lack of specific prophylactic measures, more cases of severe Jaccoud's arthropathy are expected to be identified, making recognition and appropriate management increasingly important. 6