What are some Differences between Osteoarthritis and rheumatoid arthritis(RA)?
OA is generally secondary to articular cartilage damage from repetitive microtrauma throughout life, whereas RA is an inflammatory arthritis in which inflamed synovium produces erosive changes of the adjacent bones and cartilage. Joint space narrowing in osteoarthritis is usually asymmetric, whereas joint space narrowing in RA is classically symmetric. For example, joint space narrowing tends to occur more superiorly in the hip joint in OA, whereas a more axial (i.e., concentric) distribution of joint space involvement is observed with RA. Subchondral sclerosis and osteophyte formation are reparative responses seen in OA due to chronic wear and tear. These are characteristically absent in RA.