Osteoarthritis of the knee is osteoarthritis of the knee joint. The knee is a joint, a relatively large weight-bearing joint of the body with a very large range of motion and a lot of synovial membranes inside. The knee joint can become arthritic for many reasons, the most common being osteoarthritis of the knee. This osteoarthritis is actually a degenerative change in the body, and as the body slowly ages, there will be wear and tear and strain on the joints and cartilage surfaces, including the meniscus, along with osteophytes. If improper exertion or excessive use of the knee joint results in osteoarthritis occurring earlier or with heavier symptoms than the average person. There are also common knee arthritis caused by rheumatism and rheumatoid arthritis, gout, ankylosing spondylitis, and trauma, all of which can cause knee arthritis.