Distal interphalangeal joint involvement in rheumatoid arthritis

Area of Science:

• Rheumatology
• Orthopedics
• Radiology

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease primarily affecting joints.
• Distal interphalangeal (DIP) joint involvement in RA is less understood compared to other joints.
• Distinguishing RA-related changes from osteoarthritis (OA) in DIP joints can be challenging.

Purpose of the Study:

• To evaluate the frequency and characteristics of distal interphalangeal (DIP) joint erosions in seropositive rheumatoid arthritis (RA) patients.
• To compare DIP joint involvement in RA patients with age- and sex-matched controls.
• To investigate the relationship between DIP erosions, disease duration, and overall hand/wrist involvement in RA.

Main Methods:

• Radiographic evaluation of DIP joints in 62 seropositive RA patients.
• Comparison with 50 age- and sex-matched control subjects.
• Assessment for erosions, osteophytes, and joint space narrowing in hand and wrist joints.

Main Results:

• DIP joint erosions were observed in 37% of RA patients versus 14% of controls, typically mild and unrelated to disease duration.
• Erosions elsewhere in the hand/wrist were of varying severity and correlated with disease duration.
• Joint space narrowing was significantly more frequent in RA patients (77%) than controls (46%).
• Osteophytes were common in both RA (71%) and control (60%) groups.

Conclusions:

• Distal interphalangeal (DIP) joint erosions are frequent in rheumatoid arthritis (RA) and do not solely indicate severe global disease.
• DIP erosions in RA do not occur in isolation.
• The high prevalence of osteophytosis and joint space narrowing suggests significant overlap between osteoarthritis and RA in affected patients.