Before you undergo a total knee replacement (TKR), your surgeon will carry out a thorough preoperative evaluation, sometimes called a pre-op.

The doctor who is going to perform the procedure will need to spend time evaluating your health and checking that you’re a suitable candidate for surgery.

They will also need to conduct routine tests and possibly adjust your current medications to ensure the best result.

They will usually do this review several weeks before the scheduled surgery date.

The doctor will evaluate your health with you and make sure that surgery is the right choice for you.

Here are several things they may review and some of the tests they will order.

Physical examination

During a physical exam, the surgeon will check:

  • the condition of your soft tissues and ligaments
  • the health of your neurovascular system, which links the brain, the spinal cord, and the blood vessels
  • the range of motion of the knee joint
  • any deformity that has developed

All these factors may affect the surgeon’s strategy during and after the procedure.

Overall health review and checkup

A presurgery checkup will provide clues about the state of your overall health and whether you meet the criteria for a TKR.

It will also help the surgeon know how to best approach the procedure, especially if you have an underlying health condition, such as high blood pressure, blood clotting issues, diabetes, or irregular heart rhythms.

If you have diabetes and other conditions that affect your immune system, your healthcare providers may need to take extra precautions to prevent infections.

If you have a high risk or history of stroke or cardiovascular disease, they may also need to take precautions to ensure blood clots don’t develop.

People with additional health needs may also need to stay longer in the hospital.

Blood and urine tests

A surgeon will want to know that your key organs are healthy before operating.

A urine test can provide clues about your kidney and liver health. A blood test can show if you have anemia or another blood disorder that may affect surgery.

A blood test can also reveal your blood type. This is important to know in case you need a transfusion.

It isn’t unusual to lose some blood during surgery. A 2015 study found that on average people lose 789 milliliters of blood during knee replacement surgery, and 11 percent need a transfusion.

If you’re unable to bank your own blood, the hospital will need to know your blood type to make a proper match.

Chest X-ray and EKG

Your doctor may request a chest X-ray and electrocardiogram (EKG) to ensure that your heart and lungs are healthy enough for surgery.

Any disease that affects these organs may increase your risk of problems during the procedure.

In some cases, the doctor may advise against surgery for safety reasons.


The medical team will need to know about all your medications, including:

  • prescription drugs
  • over-the-counter (OTC) treatment
  • supplements

Your doctor may need to:

  • change your prescription
  • advise a change in your OTC drug use
  • ask you to stop taking some kinds of medication, such as blood thinners, a few days before surgery


You’ll need to give informed consent before any intervention.

The doctor will ask you to sign a form that describes the procedures and the devices that they will use.

In signing this document, you acknowledge that you understand the operation and recognize the risks. It’s essential that you ask about anything you don’t understand before signing the form.

Although it’s impossible to cover the full spectrum of risks involved, it’s important that you know about the procedure and the most frequent complications.

The consent process may include questions about your willingness to accept blood transfusions and, in a worst-case scenario, your desires involving life support.

Most states require this consent by law.

To ensure you have the best possible idea of what is going to happen before, during, and after surgery, it’s essential to ask a lot of questions.

Here are some of the questions you might ask:

Understanding the implant

  1. Why did you choose the prosthesis you’re planning to give me? How long have you been implanting this device in people with osteoarthritis (OA) of the knee?
  2. Who makes this device? Is this the brand of implant you typically use? Do you have a relationship with the maker of the prosthesis you’re implanting?
  3. What is the typical lifespan of the implant? Is there anything I should know about it? Has this device ever been recalled by the FDA?
  4. What are the advantages and disadvantages of this device, compared with others?
  5. What are your short-term and long-term complication rates for things such as breakage, clicking, the device not working right, and unidentified pain?

Surgical approach

  1. Where will the incision be, and what will its size be?
  2. What type of surgical approach will you take?
  3. What type of surgical planning will you do?
  4. Will you use a computer-assisted method?
  5. How long will the surgery take?

Risks and complications

  1. What is your infection rate? (For reference, 0.5 percent or less is considered good.)
  2. How will you know you’re operating on the correct knee?
  3. What risks do I face, and how likely am I to face complications?
  4. What type of anesthesia will you use? What are the risks of anesthesia?


  1. How long will I be in the hospital?
  2. How long will the recovery process last? What will it entail?
  3. How much pain will I have following surgery? What will the pain be like when I get home and start rehab?
  4. When will the pain go away? What can I do to manage the pain?
  5. What mobility or movement restrictions or limitations will I have, and how long will they last?
  6. When can I restart more strenuous activities I want to do, such as golf and walking? What activities should I avoid?
  7. How do you expect my new knee will function in 6 months? A year?
  8. Will there be follow-up appointments needed? When will the first follow-up appointment be? And how regularly after that?
  9. If I travel after the operation, will I need to do anything special for airport security?

During the pre-op, the surgeon will ask a lot of questions, and you will have the chance to tell them everything they need to know about your health.

What they learn from you during this interview will help them make the best decisions for you before, during, and after surgery.