Arthritis

Arthritis is the name for a group of conditions that generally affect the joints. Three important types are osteoarthritis, rheumatoid arthritis and traumatic arthritis.

Osteoarthritis is the most common form of arthritis. The American College of Rheumatology estimates 21 million Americans have the condition. It's caused by a degeneration or breakdown of the protective cartilage over the ends of the bones in the affected joints. As the cartilage wears away, the bones rub together during motion, leading to pain and stiffness, and eventually, loss of joint mobility. Osteoarthritis most commonly affects the hips, knees and spine.

Rheumatoid arthritis is a chronic inflammatory condition in which the body inappropriately attacks the tissues in the joint. It causes pain, stiffness, swelling and limited movement in the joints. The Arthritis Foundation estimates 2.1 million Americans have rheumatoid arthritis. The condition is about 2.5 times more common in women than in men. It can occur at any age, but most commonly begins in middle age.

Traumatic arthritis occurs sometime after an injury. Bone is living tissue and requires a supply of blood to stay healthy. Injury can lead to a decrease or interruption of blood supply to the bone, causing a part of the bone to die (called, osteonecrosis, or avascular necrosis). Eventually, the nearby joint degenerates. The American College of Rheumatology estimates 10,000 to 20,000 Americans develop osteonecrosis each year. The condition usually affects the hips and knees, but can occur in other joints as well.

Hip Replacement for Women

When pain or disability from arthritis becomes severe and doesn't respond to treatment, doctors may recommend a hip replacement. According to the American College of Rheumatology, more than 220,000 hip replacements were performed in 2003. With the growing number of older Americans, researchers estimate the demand for hip replacement will increase by 174 percent by 2030.

In hip replacement surgery, doctors remove all or part of the diseased hip joint and replace it with an artificial joint, or prosthesis. Richard Berger, M.D., a Joint Replacement Surgeon with Rush University Medical Center in Chicago, says the traditional artificial hip is based on a man's anatomy. However, women are built differently than men. Women tend to be more petite and have smaller bones and shorter hips. Thus, doctors often need to make adjustments during surgery. The results aren't always perfect. In some cases, the stem of the implant (the part that fits inside the upper thigh bone) may be too long, causing the hip to push out and the leg to be slightly longer than normal. The stress from the mismatch can cause the new hip to fail or lead to significant pain and disability, requiring another replacement.

Now Zimmer, Inc. offers a replacement hip that's specifically designed for women. It's called the Zimmer® M/L Taper Hip Prosthesis with Kinectiv™ Technology. The female artificial hip is the second in a line of products, called the Zimmer Gender Solutions (gender-specific knees made their debut in 2006).

Berger helped design the new hip. The gender-specific hip comes in three sections: a stem, the head and the neck (which connects the stem and head). During surgery, each component is hand selected to customize the final implant and provide a better fit. Once all three sections are connected, they lock in place and can't come apart.

Another advantage of the gender-specific hip is that only small incisions are needed to place each of the separate components. There is no need to cut through muscle and recovery time is minimal. Berger says patients are often in the hospital for only five to six hours and can walk out on their own or use just a cane for support. Most patients require little rehabilitation and are back to work within a week.

For information about the gender-specific hips: http://www.zimmer.com

For general information on hip replacement: American Academy of Orthopaedic Surgeons

For information on arthritis: American College of RheumatologyArthritis FoundationNational Institute of Arthritis and Musculoskeletal and Skin Diseases