Osteoarthritis (OA) ranks among the most common joint disorders worldwide, affecting more than 500 million patients across the globe. In Western Europe, more than 57 million people suffer from OA. Long considered a “wear and tear” condition of the elderly, it is now known that OA is a highly complex disease of the entire joint affecting a large proportion of the population under the age of 65.
Typically developing over time as a chronic disease, OA involves all tissues of the joint, including the bone, ligaments, cartilage, fat, and the tissues lining the joint. While any joint of the body can be affected, it is most frequently caused in the knee, hand, and hip. Major symptoms include:
- chronic pain
- limited flexibility and mobility
Clinically, OA is characterised by loss of articular cartilage, remodelling of the bone, and associated inflammation besides affecting all other tissues constituting a joint. The radiological Kellgren-Lawrence Classification of Osteoarthritis is a common system for describing the stages of knee OA. It measures the progression of knee OA based on joint space narrowing and other parameters. The stages range from 0 (normal space between the joints) to stage 4 (no space between the joints causing bone-on-bone contact and the growth of osteophytes).