Pathology - Osteoarthritis

Pathology -  Osteoarthritis 
wear-and-tear arthritis, which is the degeneration of articular cartilage as a result of cumulative mechanical stress to the joints.
affects women more frequently than men; typically manifests after age 50 and is linked to obesity.

Pathology 
Joint: Osteophyte formation (growth of new bone at articular edges); joint mice (fractured osteophytes floating in synovial fluid); eburnation of bone (polishing of bone due to rubbing of bone with bone); joint cartilage flakes off and is eroded, exposing underlying bone.

Clinical Signs and Symptoms 
Heberden nodes and Bouchard nodes, which are osteophytes at the DIP and PIP joints, respectively, may be seen. Joint pain and stiffness that gets worse with use most frequently occurs in the hip, knee, lumbosacral spine, MTP joint of the toe, and DIP and PIP joints of the fingers.
Visualization: joint space narrowing accompanied by subchondral sclerosis and osteophytes.

Treatment options include NSAIDs, weight loss if obese, injections of corticosteroids into the afflicted joint, and joint replacement surgery.

The location of joint involvement, laboratory tests (which are normal in osteoarthritis), and description of joint pain (the impact of mobility on pain) can be used to differentiate osteoarthritis from rheumatoid arthritis.