Knee replacement surgery can relieve pain and restore function to a knee joint that's severely damaged, usually by arthritis.
Knee replacement surgery replaces parts of injured or worn-out knee joints. The surgery can help ease pain and make the knee work better. During the surgery, damaged bone and cartilage are replaced with parts made of metal and plastic.
To decide whether a knee replacement is right for you, a surgeon checks your knee's range of motion, stability, and strength. X-rays help show the extent of damage.
The right artificial joints and surgical techniques for you depend on your age, weight, activity level, knee size and shape, and overall health.
One of the most common reasons for knee replacement surgery is severe pain from joint damage caused by wear-and-tear arthritis, also called osteoarthritis. An artificial knee joint has metal caps for the thighbone and shinbone, and high-density plastic to replace damaged cartilage. Each of these artificial parts is called a prosthesis.
The most common reason for knee replacement surgery is to ease pain caused by arthritis. People who need knee replacement surgery usually have problems walking, climbing stairs and getting up out of chairs.
If only one part of the knee is damaged, surgeons often can replace just that part. If the entire joint needs to be replaced, the ends of the thighbone and shinbone are reshaped and the entire joint resurfaced. These bones are hard tubes that contain a soft center. The ends of the artificial parts are inserted into the softer central part of the bones.
Ligaments are bands of tissue that help hold joints together. If the knee's ligaments aren't strong enough to hold the joint together by themselves, the surgeon may choose implants that can be connected so they can't come apart.
Knee replacement surgery, like any surgery, carries risks. They include:
The implants used for knee replacements are durable, but they may loosen or become worn over time. If this happens, another surgery may be needed to replace the loose or worn parts.
Your health care team might advise you to stop taking certain medications and dietary supplements before your surgery. You'll likely be instructed not to eat anything after midnight the day of your surgery.
For several weeks after the procedure, you might need to use crutches or a walker, so arrange for them before your surgery. Make sure you have a ride home from the hospital and help with everyday tasks, such as cooking, bathing and doing laundry.
To make your home safer and easier to navigate during recovery, consider doing the following:
When you check in for your surgery, you'll be asked to remove your clothes and put on a hospital gown. You'll be given either a spinal block, which numbs the lower half of your body, or a general anesthetic, which puts you into a sleep-like state.
Your surgeon might also inject a numbing medicine around nerves or in and around the joint to help block pain after your surgery.
Knee replacement surgery usually takes 1 to 2 hours. To perform the procedure, the surgeon:
After surgery, you'll rest in a recovery area for a short time. How long you stay in the hospital after surgery depends on your individual needs. Many people can go home the same day.
The risk of blood clots increases after knee replacement surgery. To prevent this complication, you may need to:
You'll also likely be asked to do frequent breathing exercises and gradually increase your activity level. A physical therapist can show you how to exercise your new knee. After you leave the hospital, you'll likely continue physical therapy at home or at a center.
Artificial knee joints used in knee replacement surgery are typically made of metal and plastic. Metal parts replace the damaged thighbone and shinbone. Plastic replaces cartilage on the shin and kneecap parts.
For most people, knee replacement provides pain relief, improved mobility and a better quality of life. Most knee replacements can be expected to last at least 15 to 20 years.
After recovery, you can engage in various low-impact activities, such as walking, swimming, golfing or biking. But you should avoid higher impact activities, such as jogging, and sports that involve contact or jumping. Talk to your health care team about ways to stay active after knee replacement.