Knee Replacement Surgery: Who Needs It, What Happens, and Recovery

What it is

Knee replacement replaces parts of the knee joint with artificial parts. It may be needed when knee damage causes severe pain and makes daily tasks like walking and climbing stairs hard — usually after other treatments haven't helped enough. The aim is less pain and better movement. People of any age can have it, but it's more common in older people; the decision depends on your overall health and how much your knee bothers you.

What it treats

Conditions that wear away the knee's cartilage:

• knee osteoarthritis — the most common reason, usually developing over time after an injury or with age;
• damage from other types of arthritis;
• problems from knee joints that didn't form correctly.

The surgery

Cartilage covers the ends of bones where they meet; healthy cartilage is smooth and lets bones glide. When it roughens and wears away, bone rubs on bone, causing pain. The surgeon removes damaged cartilage and some bone and attaches metal and plastic parts that give the knee new, smooth surfaces.

• A total knee replacement replaces three surfaces: the end of the shinbone, the end of the thighbone, and the back of the kneecap.
• A partial knee replacement replaces only part of the knee.

Recovery

• Some people go home the same day; others stay a few days.
• To prevent blood clots, you'll likely take blood thinners and wear special socks or leg coverings for a while.
• Success depends a lot on what you do at home: a physical therapist will teach exercises to strengthen the knee and help it bend — do them regularly.
• You may need a cane or walker for several weeks, and it will probably be several weeks before you can drive (your doctor will say when).
• Most people who follow their instructions are back to nearly all normal activities within 3 to 6 weeks.

Life with a new knee

Most people move better with less pain than before — but an artificial knee isn't a healthy natural one. Protect it by:

• staying at a healthy weight;
• getting regular physical activity;
• avoiding high-impact activities such as jogging, running and jumping, and choosing low-impact ones like walking, biking and swimming.

Risks

Problems are uncommon, but any surgery carries risk. Possible complications include infection, blood clots, heart attack, stroke, nerve damage, and scarring that limits how far the knee bends. Your age, health and activity level affect your risk.

How long it lasts

A knee replacement doesn't last forever: after 15 to 20 years, the parts may loosen or wear, and you may need another surgery on the same knee. If you're considering it, talk with your doctor about the risks and benefits and decide together.

Sources

Based on "Knee Replacement," MedlinePlus, National Library of Medicine; a work of the United States government in the public domain.