| Osteoarthritis (OA) | Rheumatoid Arthritis (RA) |
|---|---|
| Degenerative disease that causes articular cartilage loss and joint space narrowing. | Autoimmune disease that causes inflammatory synovitis. |
| Heberden's nodes are bony prominences located at the distal interphalangeal (DIP) joints. Bouchard's nodes are located at the proximal interphalangeal (PIP) joints. | Heberden's nodes are absent. Bouchard's nodes are not common, but may be present. |
| Typically affects joint asymmetrically. | Typically affects joints symmetrically. |
| Usually negative/normal lab findings. | Positive rheumatoid factor, anti-CCP antibody, and elevated ESR and CRP. |
| Radiograph: subchondral sclerosis, osteophytes, cysts, joint space narrowing, subluxation. | Radiograph: periarticular osteopenia, bone erosions, joint space narrowing, subluxation. |