Osteoarthritis (OA) is a degenerative condition that directly affects the joints.
In a normal joint, a layer of cartilage covers the ends of the bones. In OA, the cartilage breaks down and becomes thin. This leaves the ends of the bones unprotected, and the joint loses its ability to move smoothly. This leads to the growth of bony spurs (called osteophytes) into the joint surface, inflammation of the tissue around a joint, deterioration of ligaments, and loss of joint range of motion.
The arthritic process at a joint has many possible causes, including: normal wear and tear, anatomical deformities, injury, surgery, and having a family history. People over 45 are most at risk.
The most common symptoms are pain and stiffness of the joints – usually at their worst after prolonged periods of immobility. Additional symptoms may include clicking, grating, and grinding sensations.