Knee Replacement

What is knee replacement surgery?

A knee replacement is surgery to replace all or some of your knee joint. It’s a type of procedure called an arthroplasty (joint replacement).

A surgeon will remove damaged parts of your natural knee joint and replace them with an artificial joint (a prosthesis) made of metal and plastic.

Types of knee replacement

Your surgeon will recommend either a total or partial knee replacement:

• Total knee replacement: Total knee replacement is the most common type of knee replacement. Your surgeon will replace all three areas of your knee joint — the inside (medial), outside (lateral) and under your kneecap (patellofemoral).
• Partial knee replacement: A partial knee replacement is just what it sounds like. Your surgeon will only replace some areas of your knee joint — usually if only one or two areas are damaged. Partial knee replacements are more common in younger adults who’ve experienced an injury or trauma.

What conditions are treated with a knee replacement?

A healthcare provider might recommend knee replacement if you have severe symptoms that don’t get better after trying nonsurgical treatments, including:

• Joint pain.
• Stiffness.
• Limited mobility (trouble moving your knee).
• Swelling.

Arthritis is the most common condition that causes people to need knee replacement surgery. Most people who choose to have a knee replacement have osteoarthritis, but some people with rheumatoid arthritis may need one, too.

It’s rare, but a healthcare provider might suggest knee replacement if you’ve experienced a bone fracture in your knee that causes post-traumatic arthritis after you’ve experienced a:

• Car accident.
• Fall.
• Sports injury.

How common is knee replacement surgery?

Knee replacements are one of the most common types of arthroplasties. Surgeons in the U.S. perform more than 850,000 knee replacements each year.

How should I prepare for a knee replacement?

Your healthcare provider and surgeon will tell you what you need to do to get ready for surgery. In general, you’ll need:

• A physical exam to make sure you’re healthy enough for surgery.
• Blood tests.
• An electrocardiogram to check your heart health.
• A dental exam to reduce your risk of developing an infection after surgery.
• Imaging tests, including a knee X-ray. You might also need magnetic resonance imaging (MRI) or a computed tomography (CT) scan.

Tell your provider and surgeon about any medications and over-the-counter supplements you take. You may have to stop taking some medications or supplements before your surgery.

Your surgeon will tell you when you should stop eating and drinking the day before your surgery. Most people need to avoid eating and drinking 12 hours before their surgery.

What happens during a knee replacement?

On the day of your surgery, you’ll receive anesthesia to numb your body and make sure you don’t feel any pain. An anesthesiologist will give you either general anesthesia to put you to sleep during your surgery or a regional anesthesia to numb you from the waist down.

During a knee replacement, your surgeon will:

• Remove damaged cartilage and bone.
• Insert the prosthetic knee joint.
• Insert a plastic spacer that recreates the smooth cushion of your cartilage that was damaged or removed.
• Reshape your patella (kneecap) to fit the new prosthetic knee joint (if needed).

How long does a knee replacement take?

Knee replacements usually take an hour or two.

What does a knee replacement look like?

The prosthetic parts your surgeon will use during a knee replacement will look very similar to your original knee. Instead of bone and cartilage, the prosthetic joint is made of metal and plastic. It’s made to replicate the shape, size and function of a natural knee joint.

What happens after a knee replacement?

After surgery, you’ll be moved to a recovery room. Your surgery team will keep an eye on you for a few hours to make sure you wake up from the anesthesia without complications. They’ll also monitor your vital signs and pain level.

Some people who have knee replacement surgery go home the same day. You might need to stay in the hospital overnight. Your surgeon will tell you when it’s safe for you to go home.

What are the benefits of knee replacement surgery?

Knee arthroplasty is a safe, effective procedure that helps people regain their mobility and relieves long-term pain. Most people who have a knee replacement have reduced pain, increased ability to move and use their knee, and improved quality of life.

How does a knee replacement last?

A knee replacement usually lasts a long time. In fact, more than 90% of people who have knee replacement surgery have improved function in their knee for 10 to 15 years.

What are potential complications of a knee replacement?

Some people who have knee replacement surgery still experience pain and other symptoms in their knee. Rare complications include:

• Blood clots.
• Infection inside of your knee or at your surgery site.
• Nerve issues.
• Blood vessel issues.
• Problems with the prosthetic implant, including the device wearing down too soon or loosening.
• Scar tissue inside of your knee.
• Reduced range of motion (how far you can move your knee) and stiffness.

Certain health conditions can make recovery from a knee replacement more difficult. Talk to your surgeon about your health history. Tell them if you have:

• Hemophilia.
• Diabetes.
• Other autoimmune disorders (like lupus).

Your surgeon will let you know what to expect after your surgery and how you can reduce your chances of experiencing complications.

How long does it take to recover from a knee replacement?

It usually takes around a year to recover fully after a knee replacement. But you should be able to resume most of your usual activities six weeks after surgery.

Your recovery time will depend on several factors, including your:

• Activity level before surgery.
• Age.
• Other health conditions.

Your surgeon will give you a customized recovery plan, but in general, you should:

• Ice your knee: Icing your knee a few times a day for 20 minutes at a time will help relieve pain and swelling.
• Elevate your knee: Keep your knee above the level of your heart as often as possible. You can prop it up on cushions or pillows while lying down or rest it on a footstool if you’re sitting in a chair.
• Keep your incision clean and covered: Follow your surgeon’s incision care instructions carefully. Ask your surgeon when you should change the dressing on your incision site and when it’s safe to take a shower or bathe.
• Home exercises: Your surgeon will give you exercises to do as soon as possible after your surgery. They’ll show you how to perform movements and exercises to strengthen the muscles around your knee and prevent stiffness. Do your exercises as often as your surgeon instructs. They’ll help your recovery and make sure your joint regains its function.
• Physical therapy: You’ll work with a physical therapist for up to a few months after your surgery. They’ll help you start moving safely, including bending your knee and walking.

Pain management after knee replacement

After surgery, you’ll feel pain, especially in the first few weeks of your recovery. You’ll feel pain from the surgery itself and pain as your body begins to heal.

Your surgeon will suggest a combination of prescription pain medication, over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) (if it’s safe for you to take them) and acetaminophen to relieve your pain. Your surgeon will tell you how much of each kind of medication you can take each day or in a certain amount of time.

Talk to your surgeon if you feel like you’re experiencing too much pain or if you’re worried about any complications from taking pain medication.

When can I go back to work or school after a knee replacement?

How long you’ll need to miss work or school depends on how much stress your job or other activities put on your knee. Most people need to rest at home for a few weeks after a knee replacement. Your surgeon will let you know when it’s safe to return to work or school.

What can I do to help my recovery after a knee replacement?

You’ll be able to walk with a cane or a walker a few days after your surgery. But you’ll probably need help with some everyday activities, including:

• Bathing.
• Cleaning.
• Doing laundry.
• Cooking.
• Shopping.

Plan ahead to have a loved one help you after surgery. Your surgeon or healthcare provider can suggest resources if you need help while you’re recovering.

Your recovery will be easier and safer if you prepare your home ahead of time, including:

• Get a bench or chair for your shower.
• Install grab bars or get a commode chair to help you get on and off the toilet.
• Remove all tripping hazards like power cords, rugs and loose carpets.
• Secure handrails along any stairs.

When should I call my healthcare provider?

Call your surgeon or healthcare provider right away if you experience any of the following symptoms:

• Chest pain.
• Shortness of breath (dyspnea).
• Fever higher than 101 degrees Fahrenheit (39 degrees Celsius).
• Bleeding.
• Signs of an infection at your surgery site, including leaking, swelling, discoloration, odor or a feeling of warmth.
• New or worsening pain in your calf, ankle or foot.
• Severe pain that doesn’t get better after you take pain medication.