What are the characteristic physical examination findings of deformities of the hands and feet in Rheumatoid Arthritis (RA)?

From the Guidelines

Physical examination of hand and foot deformities in rheumatoid arthritis should focus on identifying characteristic changes that result from synovial inflammation, joint destruction, and tendon involvement, with a particular emphasis on assessing for ulnar deviation, boutonnière deformities, swan-neck deformities, and Z-thumb or hitchhiker's thumb deformity in the hands, and hallux valgus, claw toe deformities, and subluxation of the metatarsophalangeal joints in the feet, as recommended by recent guidelines 1. When examining the hands, look for ulnar deviation of the fingers at the metacarpophalangeal joints, which creates a characteristic slanting appearance. Check for:

• Boutonnière deformities (flexion of the proximal interphalangeal joint with hyperextension of the distal interphalangeal joint)
• Swan-neck deformities (hyperextension of the proximal interphalangeal joint with flexion of the distal interphalangeal joint)
• Z-thumb or hitchhiker's thumb deformity, characterized by hyperextension of the interphalangeal joint and flexion with subluxation of the metacarpophalangeal joint Note any visible joint swelling, particularly the fusiform (spindle-shaped) swelling of proximal interphalangeal joints, and examine for reduced grip strength. In the feet, look for:
• Hallux valgus (lateral deviation of the great toe)
• Claw toe deformities
• Subluxation of the metatarsophalangeal joints which can create prominent metatarsal heads on the plantar surface, leading to painful callosities Palpate for synovial thickening, warmth, and tenderness around affected joints. Assess range of motion, noting any limitations or pain with movement. These deformities result from persistent inflammation causing ligament laxity, tendon rupture, and joint destruction, ultimately leading to joint instability and muscle imbalance, as highlighted in the 2016 update of the recommendations of an international task force 1. The importance of considering comorbidities and structural changes in the context of making clinical decisions is also emphasized in the 2014 update of the recommendations 1, and the use of composite activity measures is recommended to assess disease activity, as stated in the 2017 EULAR recommendations 1.

From the Research

Characteristic Physical Examination Findings

The characteristic physical examination findings of deformities of the hands and feet in Rheumatoid Arthritis (RA) are not explicitly described in the provided studies. However, the studies suggest that physical examination is an important part of the assessment and diagnosis of RA.

Diagnostic Tools

• Ultrasonography (US) has been shown to be a useful tool in the diagnosis and assessment of RA, particularly in the examination of joints in the hands and feet 2, 3, 4.
• US can detect joint effusion, synovial membrane hypertrophy, and synovial membrane hyperaemia, which are common features of RA 4.
• The use of US can help identify patients with early arthritis and predict the development of RA in patients with undifferentiated arthritis 4.

Treatment and Management

• The treatment and management of RA typically involve a combination of medication, exercise, and education 5, 6.
• Physical therapy can play an important role in the management of RA, with a focus on exercise and education to improve function and reduce disability 5.
• The use of biologic disease-modifying antirheumatic drugs (DMARDs) and targeted synthetic DMARDs has improved patient outcomes in RA, but these medications can increase the risk of infection 6.

Limitations

• The provided studies do not specifically describe the characteristic physical examination findings of deformities of the hands and feet in RA.
• Further research is needed to fully understand the role of physical examination in the diagnosis and management of RA.