Advancements in joint replacements permit active aging

6/28/2010

This is one of a series of columns about health issues written by staff members of ProMedica and Mercy Health Partners and the Toledo Clinic.

Joints such as knees, hips, and shoulders are formed when two or more bones meet and are connected with tissue called cartilage. As injury, disease, or normal wear and tear damage the cartilage, it becomes inflamed, making normal movement of that joint painful. The cartilage will begin to wear away, leaving bone rubbing against bone and much more pain.

So, what's the remedy? While there is no cure for diseases that cause joint pain,such as arthritis, joint replacements help alleviate the pain and immobility that disease and injuries inflict. Joint replacement is one of the most valuable developments in modern medicine, allowing patients to stay active longer throughout their lives.

Joint replacement is when a portion of the joint or the entire joint is replaced with an artificial part, called an implant, made of metal, plastic, or sometimes both. Damaged and worn surfaces of the joint are resurfaced and the diseased joint is replaced with the implant. Replacing the joint will help relieve pain, allowing the patient to move easier and feel better.

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), more than 773,000 people in the Unites States have a knee or hip replaced every year. But this number doesn't come close to the 70 million Americans living with arthritis. Why such a wide gap? In many cases, patients fear the discomfort and pain following surgery. Additionally, in the past, implants would require follow-up procedures in as little as five years, so patients would delay initial replacements for as long as possible.

But the good news is, that's all changing.

Implants used in joint replacement have been overhauled in recent years. Surgeons now use stronger materials, including plastics that wear much more slowly, more flexible bearings, and metals that reduce friction. There are even entirely new materials like oxidized zirconium, which is smooth like ceramic with the crucial characteristics of metal – strength and durability.

The change in materials has increased the longevity of replacements from the current 10 to 15 years to an estimated 20 to 25 years. Of course, the true test will come in 20 to 25 years when we measure how new materials are holding up in patients. And because these implants are lasting longer, they can be used earlier in life. Injured athletes can get back in the game with joint replacements, without the fear of multiple more surgeries in the near future. Of course, the younger the patient is, the more active they tend to be, so new implants may not last 25 years in younger, more active patients.

If you have chronic joint pain, see your physician. And don't be afraid to ask questions and explore your options. Newer implants are far from indestructible, but we're getting there.

Joe Assenmacher, M.D., is a board-certified orthopaedic surgeon and member of ProMedica Physician Group.