Osteoarthritis vs. Rheumatoid Arthritis

Osteoarthritis (OA):

• Degenerative disease that causes articular cartilage loss and joint space narrowing.

• Heberden's nodes are bony prominences located at the distal interphalangeal (DIP) joints. Bouchard's nodes are located at the proximal interphalangeal (PIP) joints.

• Typically affects joint asymmetrically.

• Usually negative/normal lab findings.

• Radiograph: subchondral sclerosis, osteophytes, cysts, joint space narrowing, subluxation.

Rheumatoid Arthritis (RA)

• Autoimmune disease that causes inflammatory synovitis.

• Heberden's nodes are absent. Bouchard's nodes are not common, but may be present.

• Typically affects joints symmetrically.

• Positive rheumatoid factor, anti-CCP antibody, and elevated ESR and CRP.

• Radiograph: periarticular osteopenia, bone erosions, joint space narrowing, subluxation.