Osteoarthritis of the knee and hip
What is osteoarthritis?
Osteoarthritis is the most common form of the more than 100 kinds of arthritis. Osteoarthritis, also called degenerative joint disease or "wear and tear" arthritis, affects more than 20 million Americans and is more common as we age. Osteoarthritis results when the protective cushion of cartilage covering the ends of the bones breaks down and wears away, causing irritation, stiffness and pain. Osteoarthritis can affect any joint, but is most common in the hands, spine and especially the large weight-bearing joints — the knees and hips.
What causes osteoarthritis?
In most cases, the exact cause of osteoarthritis is unknown, and is referred to as "primary osteoarthritis." Primary osteoarthritis is related to aging and wear and tear. With aging, the water content of the cartilage increases, while its protein structure deteriorates. The cartilage may then become flaky and covered with tiny cracks. In advanced cases, the entire cushion of cartilage is lost, resulting in painful bone-on-bone contact.
When the cause of osteoarthritis is known, it is called "secondary osteoarthritis." Conditions and diseases that can lead to secondary osteoarthritis include obesity, trauma, diabetes, gout and congenital joint defects.
With either primary or secondary osteoarthritis, the symptoms are the same. As the cartilage wears away, the nerves become irritated. Pain can range from mild to severe. Other symptoms include morning stiffness, a loss of easy movement, and heat and swelling of the affected joint.
How is osteoarthritis diagnosed?
There is no blood test for osteoarthritis. However, blood tests may be ordered to rule out some of the conditions that may cause secondary osteoarthritis or the other types of arthritis that mimic osteoarthritis symptoms. In some cases, an arthrocentesis is performed. With arthrocentesis, a sterile needle is used to remove some joint fluid, which is then analyzed to confirm or rule out joint infection, gout or other conditions.
Once other problems have been ruled out, a simple X-ray and an examination by an orthopedic specialist will confirm the diagnosis of osteoarthritis and, more importantly, its severity. When osteoarthritis is present in a weight-bearing joint (hip or knee), the X-rays will show a narrowing of the space between the joint, confirming the loss of protective cartilage.
How is osteoarthritis treated?
While there are no cures for arthritis, the past few years have seen dramatic new ways to manage the pain, lack of mobility and fatigue that are among its most disabling symptoms. Specific treatment for osteoarthritis will be determined by you and your physician based on the following:
- Your age, overall health and medical history
- Severity of the disease
- Your tolerance for specific medications, procedures and therapies
- Your opinion or preference
Whatever course you and your doctor decide, the goals of treatment are the same: to reduce joint pain and stiffness, and improve joint movement.
Treatment may include:
- Exercise — Frequent stretching and strengthening exercises may help reduce the symptoms and pain associated with osteoarthritis.
- Prolonged rest and days of inactivity will increase stiffness and make it harder to move around.
- Remember, motion is lotion for arthritis. At the same time, excessive or improper exercise can overwork your arthritic joint and cause further damage. A balanced routine of rest and exercise is very important. Check with your doctor on resources available to help design an exercise program just for you.
- Diet — While there is no evidence that any particular foods can relieve arthritis symptoms, every extra pound you carry puts added stress on your knees and hips. Keeping an optimum weight can prevent or reduce the symptoms of osteoarthritis.
- Heat therapy — Heat applied directly to the painful joint can sometimes reduce pain and stiffness.
- Medications — There are a large number of medications available to help reduce the pain and inflammation of osteoarthritis.
- Most commonly used are analgesics (pain relievers) such as acetaminophen, and nonsteroidal anti-inflammatory medications (NSAIDS) such as aspirin, ibuprofen and naproxen. It is important to talk to your doctor to discuss which medications may be best for you.
- Cortisone injections — Injections of cortisone mixed with an anesthetic directly into the joint can often reduce pain and restore function, sometimes for months at a time.
- Cortisone injections can be harmful to tissues and bones if done too frequently.
- When recommended, they are usually limited to no more than three or four times a year.
- Visco-supplementation — The injection of a gel-like medication (hyaluronates) into a joint to supplement the viscous properties of synovial fluid can sometimes be helpful.
- Currently, hyaluronate injections are approved for the treatment of osteoarthritis of the knee, though its use for other joints is being investigated. Insurance coverage for this treatment is variable.
- Surgery — For those whose symptoms no longer respond to conservative treatment, surgery may be considered. Knee and hip replacement may be a very positive solution to the pain and disability of advanced osteoarthritis. The rough, worn surfaces of the joint are relined with smooth-surfaced metal and plastic components.