Arthritis is a degenerative joint disease which causes inflammation and damage to the surface of the joint.
The wearing down of the articular cartilage is a natural symptom of aging. Like other types of tissue in the human body (such as the skin), articular cartilage is able to heal and repair itself. However, articular cartilage heals only slowly. If the rate of wear exceeds the rate of repair, progressive loss of articular cartilage occurs and this leads to painful functional impairment.
As a consequence, the cartilage gets thinner and increasingly uneven and the fluid that lubricates the joint increases in quantity causing the knee joint to swell.
Mobility worsens steadily and the person concerned suffers from more severe pain.
In addition the joint can form osteophytes otherwise called ‘bony spurs’. This is the body’s attempt to heal, a process that is, however, not entirely effective.
Pain is the main symptom of arthritis. The pain frequently causes the sufferer to rest the joint. This in turn causes the condition of the cartilage, which needs movement for its nutrition to deteriorate.
The most frequent form of knee arthritis is osteoarthritis. This is currently considered a typical symptom of old age, but can also arise as a consequence of injury. The disease develops slowly over the course of years. In many cases the cartilage is already irremediably damaged by the time pain and restricted movements occur.