Rheumatoid arthritis and osteoarthritis: Pathology review

Rheumatoid arthritis (RA) and osteoarthritis (OA) are both types of arthritis, but they have different causes and characteristics.

Rheumatoid arthritis is an autoimmune inflammatory disease that causes progressive and symmetric destruction of at least three joints, especially the proximal interphalangeal joints, which leads to morning stiffness that lasts for more than an hour and improves with use. It can also present with extra-articular symptoms like uveitis, pulmonary fibrosis, and rheumatoid nodules. The treatment of rheumatoid arthritis involves non-biological and biological DMARDs, nonsteroidal anti-inflammatory drugs (NSAIDs), and glucocorticoids.

Osteoarthritis, on the other hand, is a chronic condition characterized by the breakdown of joint cartilage and underlying bone followed by inadequate repair. Now, unlike rheumatoid arthritis, which is an autoimmune disorder, osteoarthritis is considered a mechanical degenerative joint disorder. This is because the main culprit seems to be the daily stress applied to joints in our lifetime, especially to weight-bearing joints like those of the ankle, knee, and hip. Symptoms of OA include joint pain, stiffness, and decreased range of motion. Treatment of OA involves losing weight, physical therapy, and pain management with drugs like acetaminophen and NSAIDs.