For about 50 years people who have arthritis, that cannot be managed without surgery, have benefited from the ability to replace those joints. In reality, the joints are not so much replaced as resurfaced. The knee for example can have a unicondylar resurfacing arthroplasty where one side of the knee is resurfaced or a bicondylar resurfacing arthroplasty where both sides of the knee is resurfaced. It is even possible to completely replace the knee with a hinged implant in the case of tumor or other disease process.
These procedures are becoming more and more commonplace and will continue to increase as the population ages. What are some of the factors that result in the need for such procedures? There are a lot of factors that, in combination, result in a joint wearing out prematurely. Some of the factors include: genetics, weight, lifestyle, diet, trauma, inflammatory conditions. Genetics cannot be altered, but is mostly relevant to hip arthritis where a significant number of people have issues with the way the hip was formed that predisposes it to wear. Hips resemble a ball and socket so the joint is protected from abnormal motion by design. Knees have a lot of potential motion by design that makes them more susceptible to wear. Cartilage lining joints need to be used to be healthy, but it does not like overuse. Normal walking puts about 4 times body weight on a knee. Every extra pound puts 4 times more force on the cartilage. Cartilage likes walking in people with ideal body weight. It does not like acute or chronic overload or sheer stress. Sheer stress means forces at angles to the joint like what happens when someone is pivoting on a basketball court. Chronic overload is what happens with normal walking while carrying extra pounds. Acute overload would be a sudden force like jumping to the ground from a height. The joints need to be used to be healthy, but used wisely. Numerous studies demonstrate the value of exercise. Things like swimming and biking and modern elliptical trainers are ways of using joints without exposing them to excess forces from gravity.
Diet and nutrition plays a role in a variety of ways. Good nutrition grows healthy bones that support the cartilage, healthy muscles and tendons that keep the joints protected and keeps excess weight off, among other factors. Food even plays a role in creating inflammation. Simple sugars and other diet issues appear to cause more inflammation leading to many health problems of which arthritis is but one.
Your weight bearing joints, like knees and hips, are kind of like the tires on your car. If you take care of them, you can go farther. Both are expensive to replace when worn out. One difference though is replacing joints can sometimes have problems like infection and operative complications that can be prevented by taking care of them and avoiding the need for surgery if possible. I can discuss how to avoid operative complications in a future article. Take care of your joints and they potentially can last you a lifetime.