Frequently Asked Questions About Knee Replacements

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Frequently Asked Questions About Knee Replacements


  1. Who gets knee replacements?
  2. Are knee replacements successful?
  3. Are they safe?
  4. How do I know if a knee replacement is right for me?
  5. What types of knee replacements are available?
  6. What happens during surgery?
  7. How long does recovery take?
  8. What activities can I do afterward?
  9. How long do artificial knees last?

Deciding to get knee replacement surgery is a complex decision—and it's one that's all yours. Your doctor can discuss your treatment options with you, but ultimately, your health is in your hands.
Make sure you understand the benefits and risks of knee replacement surgery before you go under the knife. Here are answers to some of the most common questions. If you have more, ask your doctor or another member of your health care team.

1. Who gets knee replacements?

More than 600,000 Americans each year go into the operating room and come out with a whole new joint. Most of them are between ages 50 and 80 and have severe knee pain from osteoarthritis. But knee replacement surgeries have been effective in older and younger patients, too, along with those whose knees ache from other causes, such as previous injuries.

2. Are knee replacements successful?

Knee replacement surgeries have been performed since the late 1960s and are one of medicine's biggest success stories. As many as nine in 10 people who undergo the procedure will have significantly less pain afterward. Most people also do not need help walking after they complete recovery.

3. Are they safe?

Any surgery has risks. Those that accompany total knee replacement include:

  • Breathing, infection, and healing problems that can occur after any surgery

  • Falling in the hospital

  • Bleeding or blood clots

  • An allergic reaction to medications

Talk with your doctor about your risk for these or other problems before your procedure. Serious complications occur in less than 2% of patients who undergo knee replacement.
4. How do I know if a knee replacement is right for me?

Your doctor will help you decide. You may first want to consider other options for pain relief, including medications, physical therapy, cortisone injections, and other types of surgery. Many people choose knee replacement surgery if these treatments don't work, if they experience knee pain even when resting, if pain limits their activity, or if their knee is misshapen or constantly swollen.

5. What types of knee replacements are available?

Man-made, or prosthetic, parts can replace several damaged parts of your knee, including the lower end of your thighbone, the upper end of your shinbone, and the back side of your kneecap. Often, the new joints are called implants. Most implants are made of a combination of plastic and metal, although some include ceramic parts.

6. What happens during surgery?

Your doctor can talk you through the specifics of your procedure. Generally, you'll go to the hospital and get either general anesthesia, which puts you to sleep, or regional (spinal, epidural, or nerve block) anesthesia, which numbs you below the waist.

Once you're numb or asleep, your surgeon will make an 8- to 10-inch incision, through which he or she will remove the damaged parts of your knee. Your implant is then attached to your bones with cement. The surrounding muscles and other tissues are reattached, and then the incision is closed. The whole procedure typically takes one to two hours.

7. How long does recovery take?

Most patients stay at the hospital for three to five days. But total recovery can take anywhere from three months to a year. During this time, you may:

  • Take medications to relieve pain

  • Undergo physical therapy or other types of rehabilitation

  • Use special support hose and blood thinners to prevent blood clots and decrease swelling

  • Need extra help taking care of yourself or doing your daily activities

8. What activities can I do afterward? 

Knee replacement surgery can relieve pain and help you get back to the activities you enjoy. However, you won't be able to do more than you could before you developed knee pain. After surgery, you can return to low-impact movement, such as golf, swimming, cycling, ballroom dancing, and hiking. But most surgeons advise against high-impact sports like running, basketball, and jumping, which may cause your new joint to loosen and become painful.

9. How long do artificial knees last?

More than 90% of modern knee replacements are still working well 15 years after surgery. Some can go strong for 20 years. But eventually, the pieces may loosen and you'll need another operation.

To extend the life of your knee, do light exercise regularly, take steps to avoid falls and injuries, and see your orthopedic surgeon regularly. He or she may want to follow up with you once a year.

Key Takeaways

  • Knee replacement surgery is an effective and generally safe treatment option for people who suffer from severe knee pain.

  • Talk with your doctor about whether knee replacement surgery is right for you. Your doctor may recommend medications, physical therapy, or cortisone injections first.

  • Knee replacement surgery usually takes about one to two hours. But recovery can take anywhere from three months to a year. 

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2019 Aug 25
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.

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