Total knee replacement; Knee arthroplasty; Knee replacement - total; Tricompartmental knee replacement; Subvastus knee replacement; Knee replacement - minimally invasive; Knee arthroplasty - minimally invasive; TKA - knee replacement; Osteoarthritis - replacement; OA - knee replacement
Knee joint replacement is a surgery to replace a knee joint with a man-made joint. The artificial joint is called a
Your knee has been hurting for a while, and it hurts bad. You've had trouble sleeping. It may be hard to bathe, to do normal chores like wash the car, or even be comfortable on the job. You may have severe arthritis in your knee, and if so there's a good chance you need a knee replacement. So, what is a knee replacement? Knee replacements are usually done in people age 60 and older. If you need one, you probably have severe arthritis that limits your daily life. During knee joint replacement, your surgeon will remove damaged cartilage and bone from the knee joint. The surgeon then puts man-made pieces, called prostheses, in their place. The lower end of the thigh bone, also called the femur, is usually replaced with a metal part. The part that replaces the upper end of the shin bone, the tibia, is usually made from metal and a strong plastic. The piece that replaces the back side of your kneecap, or patella, is usually made from a strong plastic. You shouldn't feel any pain during surgery because you will have medicine to make you fall asleep. The surgeon will make a cut over your knee to open it up. The cut is usually eight to ten inches long. Your surgeon will move your kneecap out of the way, then cut the ends of your thigh bone and shin bone to fit the replacement part. The surgeon will then cut the underside of your kneecap and prepare it for the new pieces that will attach there. The surgeon then fastens the two parts of the prosthesis to your bones (the upper end of the shin bone and the lower end of the thigh bone). Then the parts are attached to the underside of your kneecap using a special cement. The surgery usually takes a couple hours. After surgery, you will probably stay in the hospital for three to five days. As soon as the first day after surgery, you will be asked to start moving and walking around with a walker, crutches, or a cane. You will likely need physical therapy to strengthen your new joint after your operation. Some people need a short stay in a rehabilitation center after they leave the hospital. At the rehab center, you will learn how to safely do your daily activities on your own. Full recovery can take three months to a year. Your new knee should last for 15 years or maybe even 20. And in the mean time, your new knee should allow you to resume your daily activities once you have learned to move around. Most or all of your pain and stiffness should go away.
Damaged cartilage and bone are removed from the knee joint. Man-made pieces are then placed in the knee.
These pieces may be placed in the following places in the knee joint:
You will not feel any pain during the surgery. You will have 1 of these 2 types of anesthesia:
After you receive anesthesia, your surgeon will make a cut over your knee to open it up. This cut is often 8 to 10 inches (20 to 25 centimeters) long. Then your surgeon will:
The surgery takes about 2 hours.
Most artificial knees have both metal and plastic parts. Some surgeons now use different materials, including metal on metal, ceramic on ceramic, or ceramic on plastic.
The most common reason to have a knee joint replaced is to relieve severe arthritis pain. Your doctor may recommend knee joint replacement if:
Most of the time, knee joint replacement is done in people ages 60 and older. Younger people who have a knee joint replaced may put extra stress on the artificial knee and cause it to wear out early.
Always tell your health care provider what drugs you are taking, even drugs, supplements, or herbs you bought without a prescription.
During the 2 weeks before your surgery:
On the day of your surgery:
You will stay in the hospital for 3 to 4 days. During that time, you will recover from your anesthesia and from the surgery itself. You will be asked to start moving and walking as soon as the first day after surgery.
Full recovery will take 4 months to a year.
Some people need a short stay in a rehabilitation center after they leave the hospital and before they go home. At a rehabilitation center, you will learn how to safely do your daily activities on your own.
The results of a total knee replacement are often excellent. The operation relieves pain for most people. Most people DO NOT need help walking after they fully recover.
Most artificial knee joints last 10 to 15 years. Some last as long as 20 years before they loosen and need to be replaced again. Total knee replacements can be replaced again if they get loose or wear out. However, in most cases the results are not as good as the first time. It is important not to have the surgery too early so you will need another surgery at a young age or have it too late when you will not benefit the most.
American Academy of Orthopedic Surgeons (AAOS). Treatment of osteoarthritis of the knee: Evidence-based guideline 2nd edition (summary). Rosemont, IL. Updated May 18, 2013.
Jones CA, Beaupre LA, Johnston DW, Suarez-Almazor ME. Total joint arthroplasties: current concepts of patient outcomes after surgery. Rheum Dis Clin North Am. 2007;33(1):71-86. PMID: 17367693
Leopold SS. Minimally invasive total knee arthroplasty for osteoarthritis. N Engl J Med. 2009;360(17):1749-1758. PMID: 19387017
Mihalko WM. Arthroplasty of the knee. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics. 12th ed. Philadelphia, PA: Elsevier Mosby; 2013:chap 7.
Last reviewed on: 7/13/2015
Reviewed by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Internal review and update on 09/01/2016 by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.