4.06 Osteoarthritis vs Rheumatoid Arthritis

Rheumatology review for the USMLE Step 1 exam

• Rheumatoid arthritis and osteoarthritis both cause joint inflammation, joint pain, and can limit joint range of motion
• Osteoarthritis is a degenerative joint disease that occurs when the articular cartilage that covers the ends of bones begins to degrade and erode
• The most common joints affected by osteoarthritis are the hips and knees, and the distal interphalangeals of the hands are also commonly affected
• Osteoarthritis tends to be more asymmetric and localized, presenting as a single degenerated joint
• Rheumatoid arthritis is an inflammatory autoimmune disease that affects the joints and other parts of the body
• RA typically develops in patients who are genetically predisposed and triggered by environmental factors, such as smoking
• The two autoantibodies present in RA are rheumatoid factors and anti-cyclic citrullinated peptide (anti-CCP) antibodies
• Rheumatoid factors activate the complement system and stimulate the inflammatory response in the body.
• Anti-CCP antibodies bind citrullinated peptides and stimulate inflammation in the synovium of joints
• Rhematoid arthritis has extra-articular manifestations, the most common of which are rheumatoid nodules