Arthritis of the knee comes in two major forms: osteoarthritis and rheumatoid arthritis. Osteoarthritis is the most common, and it is a degenerative disease that affects the cartilage. Rheumatoid arthritis, which also affects the cartilage, is characterized by swollen, inflammed joints. Below is a table outlining the differences between osteoarthritis and rheumatoid arthritis. It is important to note, however, that overlap between the two does exist.
- Pain and stiffness worsens with use (symptoms worse later in the day)
- Older age of onset
- Inflammation and swelling is minor
- Often non-symmetrical
- Pain and stiffness often better with use (symptoms worse beginning of the day)
- Younger age of onset
- Inflammation and swelling is apparent
- Often symmetrical
Below is an image (courtesy of Merck & Co., Inc.) illustrating the difference between an osteoarthritic knee (A) and a normal knee (B). Notice the joint space narrowing and sclerotic or white areas in (A).
To treat arthritis, lifestyle modifications such as losing weight, changing your sport from high-impact sports like running to cycling and swimming, excercise, braces and other supportive devices, anti-inflammatory medications, glucosamine and chondroitin sulfate (which help alleviate osteoarthritic pain), among other medications.
For severe arthritis that does not respond to the above therapies, surgery may be indicated. At this point, the knee cartilage is often very worn and damaged. Surgical treatments differ depending on each case. Options include:
- Arthroscopic surgery — repairs torn cartilage and cleans up the joint.
- Knee arthroplasty — after the joint is cleaned, metal and plastic parts are used to partially or completely rebuild the knee.
- Osteotomy — a bone or bones in the leg are trimmed to improve alignment of the knee.
- Cartilage graft — a relatively new procedure, it involves replacing the damaged cartilage with new cartilage.