Knee Replacement FAQs

Before Surgery

How do I know it’s time to have a knee replacement?

Timing is up to you. If your knee pain is an occasional inconvenience, it may be best to wait. If it is bothering you and significantly impacting your life every day, or preventing you from sleeping, working, or doing the things you want to do, and non-operative treatments have failed, it may be time to consider a knee replacement.

Do I need a medical evaluation before surgery?

Yes. You should be evaluated by your primary care provider to ensure you are in optimal health to undergo the surgery. If you have a medical issue (heart, lung, kidney, etc.) that needs to be addressed, it should be taken care of prior to surgery. Chronic conditions, such as diabetes, should be controlled as well as possible to minimize surgical risks.

Do I need to have physical therapy before surgery?

No, you do not need physical therapy before surgery. However, it is important to remain generally active, strong, and flexible as this will make your recovery easier. Patients who are deconditioned prior to surgery may have more difficulty with their recovery.

Should I take all of my medications before surgery?

Your primary care provider and I will discuss this with you on an individual basis. In general, most medications can be taken as usual. Most blood thinners should be stopped prior to surgery.

Surgery

What type of anesthesia will I have?

Your knee replacement can be done under general anesthesia (fully asleep with a breathing tube) or spinal anesthesia (an injection into your lower back that numbs you from the waist down). This will be up to you and your anesthesiologist. I can perform your knee replacement with either.

How long does the surgery take?

One to two hours, depending on several factors.

What knee implants do you use?

I use a variety of implants based on your individual anatomy. I use both traditional “off-the-shelf” implants (which come in various shapes and sizes) and personalized ConforMIS implants, which are custom-made for each individual patient. ConforMIS implants require you to have a CT scan of your leg before surgery so custom implants can be manufactured with a 3D Printer for your surgery.

What will my wound be closed with?

Your wound will be closed with an absorbable suture beneath the skin and skin glue on the surface, so there is nothing that needs to be removed. In my experience, this is the most cosmetic closure method.

What complications could occur and how do you prevent them?

In general, knee replacement is a very safe procedure and major complication rates are very low (in the 1-2% range). Certain medical conditions can increase your risk of complications, which is why it is important to optimize your health prior to surgery.

Infection is a very rare but potentially serious complication. Certain types of infections can be treated with antibiotics alone, others require repeat surgery, and severe or chronic infections may require removal of all of your implants and a delay prior to reimplantation of another knee replacement. I am extremely meticulous about preventing infection. I will perform your procedure using the most sterile surgical techniques and you will receive intravenous antibiotics before, during, and after your operation.

Blood clots can form in your legs and can also travel to your lungs. Although rare, a blood clot in your lungs (pulmonary embolism) can be harmful and even fatal. You will have compression stockings, pneumatic boots, and a medication (usually aspirin) to prevent blood clots after your surgery.

Injury to nerves or blood vessels is rare but can occur. I use surgical retractors to safely protect nerves and blood vessels in the surrounding area to avoid injury.

Stiffness can occur after knee replacement and can lead to patient dissatisfaction. I test different sizes of implants during surgery to choose the ones that will give you the best knee motion and stability. Physical therapy after surgery is critically important to maximize your range of motion and this will begin immediately after your operation.

Bleeding occurs to a small degree during all knee replacements. If your blood count is low prior to surgery, you may require a blood transfusion after, although this is extremely rare after a knee replacement. I use a tourniquet and electrocautery to reduce bleeding, and also give an intravenous medication to reduce blood loss during and after the operation.

Medical complications including heart attack, stroke, and kidney failure are rare but can occur. This is another reason to optimize your health prior to surgery. We have a dedicated team of medical doctors to deal with any medical complications that arise. We will give you medications to prevent and treat minor issues such as nausea and constipation.

Loosening, breakage, or failure of the knee replacement can happen, but this is very uncommon and may happen years later. This may require more surgery to fix. I do not know exactly how long your knee replacement will last, but for the vast majority, it should last the rest of your life. A successful knee replacement should provide you with decades of pain-free activity.

After Surgery

What will I have for pain medication after surgery?

In addition to the anesthesia (spinal or general) you received during the surgery, I inject local analgesic medication in and around the knee joint to lessen the pain. After surgery, you will be given Tylenol and a strong intravenous anti-inflammatory medication around the clock while you are in the hospital. Additionally, you will be given a narcotic pain medication and you will be given a prescription for this medication to take home.

How long will I be in the hospital?

Usually two nights. A few patients will go home the next day and a few will stay longer than two days, but most will be discharged two days after surgery.

Will I go home or to a rehabilitation facility?

The majority of patients will go home. This will depend on your mobility after surgery and your living situation. Our dedicated team of physical therapists will assess you and help prepare you to take care of yourself after discharge.

How long is the recovery?

Everyone is different, but generally 6-8 weeks for strenuous activities. You will be able to do simple things right away, such as getting around your house, and will even go up and down stairs before you leave the hospital, but it may take several weeks before you feel comfortable walking long distances. You will use an assistive device (walker, cane, or crutches) at first but should only need it for a few weeks.

Do I need to have physical therapy?

Absolutely. Physical therapy is very important after knee replacement because the knee tends to get stiff after surgery. You should work on your knee motion every day under the guidance of a physical therapist. You should aim for 0° (full extension) to at least 120° of flexion. Whatever motion you achieve in the first few months after surgery will be a good indication of the knee motion you will have forever, so work hard to regain as much motion as possible. You will probably require an assistive device (walker, cane, or crutches) for a few weeks.

Can I put full weight on my leg immediately?

Yes. You can put as much weight on your leg as you are comfortable with. Your leg may feel weak and unsteady at first, so an assistive device will be helpful for walking.

Do I have any restrictions after surgery?

No. You should bend and straighten your knee as much as you can tolerate.

How do I take care of the wound and bandage?

You will have a bandage over the wound that can remain on for a week. After one week, you may take it off and leave the wound open to the air. You can place something soft over the wound if you want to avoid irritating it. Call our office if you have any drainage beyond one week.

When can I take a shower?

You can shower as soon as you leave the hospital. If your bandage is still on, you can let water run over it. If it is already removed, you can let water run over the incision. Gently pat it dry when done. Do not soak or submerge the wound in a tub or pool for one month.

When can I drive?

Everyone is different but, on average, you should be able to drive 2-4 weeks after a knee replacement based on driving simulator studies. DO NOT drive while on narcotic pain medication.

When can I go back to work?

It depends on what you do. If you sit at a desk, you can go back as soon as you feel comfortable, are off narcotic medications, and can travel to work, even within a week or two. If your job is more physically demanding, it may take several weeks or even months. I can discuss this with you on an individual basis.

After my initial recovery, can I do anything I want with my knee?

Yes. You can do anything you want with your knee including running, jumping, squatting, and weightlifting. There are no restrictions.

Do I need to take antibiotics before dental procedures?

Yes. There is not overwhelming evidence that this is necessary, but any time bacteria enter your blood stream (such as from dental work), your artificial knee can become infected because it does not have an immune system to protect itself. An infected knee replacement can be a serious problem, so I believe taking one dose of an antibiotic before dental work is worth it. I can provide you with the antibiotic and discuss it with your dentist as well.

Will my knee replacement ever wear out or need to be redone?

The technology of knee implants has improved in recent years, so I think it is very unlikely that your knee replacement will “wear out.” Other problems can occur including infection, loosening of the implant from the bone, or fracture of the bone around the implant, and any of these problems could require revision surgery. For the vast majority, however, this knee replacement will last the rest of your life.

  • Newton-Wellesley Hospital
  • Tufts University School of Medicine
  • Mid Coast Hospital
  • American Academy of Orthopaedic Surgeons
  • American Association of Hip and Knee Surgeons