Description

Arthritis is inflammation of a joint. The knee can be divided into three compartments: medial (inside), lateral (outside) and patellofemoral (front). Arthritis can be present in one, two or three compartments. Over time, the loss of the smooth covering on the ends of bones (aka - articular cartilage) causes pain and stiffness. This can lead to pain with motion or at rest, swelling, clicking or grinding and a loss of strength. When the cartilage is damaged or decreased, the bones rub together during joint motion, resulting in “bone-on-bone” arthritis. When arthritis becomes severe, inflammation occurs around the joint and extra bone is formed in an attempt to protect the joint, resulting in limited motion and strength.

What are the causes?

The primary cause of arthritis is osteoarthritis (aka – “wear and tear” arthritis). Trauma and other illnesses like rheumatoid arthritis, systemic lupus, septic arthritis and psoriasis can result in degeneration of a joint, leading to symptoms of pain and lack of motion.

What are the symptoms?

Arthritis of the knee causes pain, swelling, stiffness and loss of strength. Pain can be isolated to the medial, lateral or patellofemoral aspects of the joint or be generalized discomfort around the knee. Pain and swelling in the back of the knee may be from a Baker’s Cyst, an area of fluid collection that is caused by arthritis. A 'grinding', 'clicking' or 'locking' sensation may be felt. Loss of motion can become severe, and the patient may have trouble performing tasks, such as walking long distances. Patients suffering from arthritis of the patellofemoral joint will often complain of 'giving way' or buckling of the knee. Patients with patellofemoral arthritis have trouble using stairs, squatting, or standing after prolonged sitting.

How is it diagnosed?

Your surgeon will perform a thorough history and physical exam, which typically includes X-rays. Your surgeon will evaluate the range of motion, stability of the ligament and strength of the muscles surrounding the knee. X-rays may demonstrate decreasing space between the bones (joint space narrowing) and bone spurs (osteophytes) in areas of arthritis. MRI may be helpful to determine if other areas of joint cartilage or the meniscus has damage.

How is it treated?

Non-operative

Knee arthritis can be treated with physical therapy, to strengthen the muscles that support the joint. The stronger the supporting muscles, the less the body will need to rely on bony architecture to stabilize the joint. This will lead to less stress across the arthritic area. Your surgeon may prescribe anti-inflammatory medication or offer an injection to reduce the inflammation. Certain nutritional supplements may be beneficial to decrease pain and inflammation.

Operative

When non-operative treatment does not relieve symptoms, your surgeon may suggest surgery. Three surgical options are available for knee arthritis.

Minimally-invasive arthroscopy of the knee, or a 'knee scope', may be beneficial to “clean-out” the knee. Although not a cure, this procedure may provide relief in patients suffering mechanical symptoms, such as catching and locking. The entire knee joint, including joint cartilage, meniscus and ligaments can be evaluated during arthroscopy.

The definitive treatment for knee arthritis is joint replacement surgery. Your surgeon will resurface the ends of the bone where the cartilage has worn away, with metal and plastic implants. If the arthritis is localized to a single or two compartments (medial, lateral or patellofemoral), your surgeon will replace only the areas that are affected (unicompartmental or patellofemoral replacement). If the arthritis is present in all three compartments, a total knee replacement is required to alleviate symptoms. Reference “A Patient’s Guide to Partial Knee Resurfacing” or “A Patient's Guide to Total Knee Arthroplasty” for in-depth details about these surgeries.