What is osteoarthritis?

Osteoarthritis is defined as a degenerative joint disease. It primarily involves the breakdown of cartilage in the joints, leading to pain, stiffness, and reduced mobility over time. This condition is characterized by wear and tear on the joints, often associated with aging and repetitive stress on the joints, rather than inflammation, which distinguishes it from other forms of arthritis.

The term "degenerative" reflects the nature of the disease as it progressively worsens, with the cartilage deteriorating and sometimes leading to bone changes. While there may be inflammatory components involved, particularly in later stages of the disease, the fundamental pathology of osteoarthritis revolves around the degeneration of joint structures.

In contrast to the other options, osteoarthritis is not primarily inflammatory (which would be more characteristic of rheumatoid arthritis), nor is it an autoimmune disorder where the body's immune system attacks its own tissues. It also does not involve joint infections, which are distinct conditions that can cause inflammation but have different underlying causes and treatments. Thus, identifying osteoarthritis as a degenerative joint disease encapsulates its key characteristics accurately.