The surgery itself lasts one to two hours

A total knee replacement operation typically takes between 60 and 120 minutes from the moment the surgeon makes the first incision to the moment they close the wound. Most surgeries fall in the 90-minute range. The exact time depends on your anatomy, the complexity of your case, whether you have scar tissue from a previous surgery, and how quickly your surgeon works.

The time on the operating table does not include the time you spend in the pre-operative area getting anesthesia or in the recovery room waking up. Those phases add another two to three hours to your total time at the surgical facility.

Key Takeaways

  • The actual surgical procedure takes between one and two hours, with most cases finishing in about 90 minutes.
  • You will spend additional time in pre-operative preparation and post-operative recovery, making your total facility time four to five hours.
  • Surgeons may take longer if you have arthritis in other joints, previous knee surgery, or bone that is harder to cut through.
  • Hospital discharge happens the same day or the next morning, but full recovery at home takes three to six months.

What happens during those 60 to 120 minutes

The surgeon begins by making an incision down the front of your knee, usually four to six inches long. They then remove the damaged cartilage and bone from the end of your femur (thighbone) and tibia (shinbone). This removal takes time because the surgeon must measure and cut at precise angles to may support the artificial joint sits correctly.

Once the bone is prepared, the surgeon cements the metal and plastic components of the artificial knee into place. Cementing takes several minutes because the cement must set properly. The surgeon then tests the knee's range of motion and alignment before closing the incision with sutures or staples.

Why some surgeries take longer than others

If you have severe arthritis in your hip or ankle, the surgeon may need to adjust how they position your knee during surgery, which adds time. Previous knee surgery or injury can mean scar tissue that must be carefully removed. Bone that is very dense or osteoporotic (weak and crumbly) takes longer to cut and shape.

Obesity and very muscular legs can make it harder for the surgeon to access the joint clearly, adding 15 to 30 minutes. Conversely, a straightforward case with healthy bone and no previous surgery may finish closer to 60 minutes.

The hours before and after the actual surgery

You will arrive at the surgical facility 60 to 90 minutes before your scheduled surgery time. During this period, nursing staff will check your vital signs, review your medical history, start an IV line, and give you pre-operative medications. An anesthesiologist will meet with you to discuss anesthesia options — usually general anesthesia or spinal anesthesia with sedation.

After surgery ends, you move to the recovery room (also called post-anesthesia care unit or PACU) where nurses monitor you as the anesthesia wears off. This phase typically lasts one to two hours. You will wake gradually, your pain will be managed with medication, and staff will check your surgical dressing and leg circulation. Once you are alert and your vital signs are stable, you move to a hospital room or are discharged home.

Same-day discharge versus overnight stay

Many total knee replacements are done as outpatient surgery, meaning you go home the same day. This is possible if you have someone to drive you home and stay with you for at least the first night, and if you have no serious complications during surgery or recovery. You will leave the facility four to five hours after arriving.

Some patients stay overnight in the hospital. This may happen if you live alone, have medical conditions that need monitoring, or if your surgeon prefers overnight observation. If you stay overnight, you will spend the evening and night in a hospital room where nursing staff can manage your pain and help you begin moving your leg.

Recovery timeline after you leave the surgical facility

The first two weeks at home focus on managing swelling and pain, keeping your leg elevated, and beginning gentle movement exercises. You will use crutches or a walker and ice your knee regularly. Physical therapy usually starts within a few days of surgery, either at home or at an outpatient clinic.

By six weeks, most people can walk without crutches and resume light activities. By three months, you can usually return to most daily tasks. Full recovery — meaning the knee feels natural and you have regained strength and flexibility — typically takes four to six months. Some people continue to see improvement for up to a year.

What to expect on surgery day itself

Plan to be at the surgical facility for four to five hours total. Wear loose, comfortable clothing that is straightforward to remove. Bring your insurance card and photo ID. You will not be able to eat or drink after midnight the night before surgery, as instructed by your surgeon's office.

Arrange for someone to pick you up and stay with you that first night — you cannot drive after anesthesia. If you are staying overnight, bring a change of clothes and toiletries. Ask your surgeon's office what medications you should or should not take the morning of surgery, as some blood thinners and diabetes medications need to be held.

Frequently Asked Questions

Can the surgery take longer than two hours?

Yes. Revision surgeries (replacing a previous artificial knee) often take two to three hours because the surgeon must remove the old components first. Complex cases with severe deformity or multiple previous surgeries can also exceed two hours. Your surgeon will give you a more specific estimate based on your X-rays and medical history.

Will I be awake during the surgery?

No. You will receive either general anesthesia (you are fully asleep) or spinal anesthesia with sedation (you are numb from the waist down and lightly sedated). Either way, you will not be aware of the surgery happening. Discuss your preference with the anesthesiologist before the procedure.

What if something goes wrong and the surgery takes much longer?

If complications arise — such as unexpected bone damage or difficulty with component placement — your surgeon may need additional time. The surgical team will manage this, and your family will be updated. Complications that extend surgery time are uncommon but possible, which is why your surgeon reviews your imaging carefully beforehand.

How soon after surgery can I go home?

If you are having outpatient surgery, you typically go home four to five hours after arriving at the facility, once you are alert and can move your leg. If you are staying overnight, you will be discharged the next morning after your surgeon rounds and confirms you are ready. Your discharge time depends on how well you are managing pain and how much you can move your knee.

Do I need to do anything to prepare to shorten surgery time?

No. Surgery time is determined by your anatomy and the complexity of your case, not by anything you do beforehand. Focus instead on following pre-operative instructions — stopping certain medications, fasting, and arranging transportation — so the surgery can proceed smoothly without delays.