The operation itself takes one to three hours, depending on your anatomy and the surgeon's approach

A total knee replacement surgery typically lasts between 60 and 180 minutes from the moment the surgeon makes the first incision to the moment they close the wound. Most procedures fall in the 90-minute range. The time varies based on whether you have arthritis damage on one side of the knee or both, whether you have had previous knee surgery, the size and shape of your bones, and how quickly your tissues respond to the surgical instruments.

The actual operating time is only part of what you will spend in the surgical suite. You will arrive 60 to 90 minutes before surgery for anesthesia preparation, positioning, and sterilization of the surgical field. After the surgeon finishes, you will spend another 30 to 60 minutes in the recovery room while anesthesia wears off and nurses monitor your vital signs. Total time from when you enter the surgical area to when you leave it is usually four to five hours.

Key Takeaways

  • The surgery itself lasts 60 to 180 minutes, with most procedures taking around 90 minutes.
  • Time in the surgical suite from arrival to discharge is typically four to five hours because of anesthesia prep and recovery monitoring.
  • Your personal anatomy, previous knee injuries, and surgeon experience affect how long the operation takes.
  • Longer surgery time does not necessarily mean a worse outcome, and rushing the procedure does not improve results.
  • You will be asleep under general or regional anesthesia for the entire operation and will not feel pain or remember the procedure.

What happens during the operation timeline

Once you are under anesthesia, the surgeon makes an incision down the front of your knee, usually 8 to 10 inches long. They then remove the damaged cartilage and bone from the ends of your thighbone and shinbone. This removal phase takes 20 to 30 minutes and requires precision to may support the replacement parts sit at the correct angle.

Next, the surgeon cements or presses the metal and plastic components into place. This step takes another 20 to 40 minutes depending on whether cement is used and how well the implant fits your bone. The surgeon then tests the knee's range of motion, checks that the implant is stable, and makes any final adjustments. Closing the incision with stitches or staples takes 10 to 15 minutes.

Why some surgeries take longer than others

A surgeon who has performed thousands of knee replacements may finish in 60 to 75 minutes. A surgeon with less experience or one working on a complex case may need 120 to 150 minutes. Neither timeline predicts a better outcome — studies show that operating time alone does not determine how well your knee functions after surgery.

Certain patient factors add time. If you have severe arthritis that has deformed your knee bone, the surgeon must remove more bone and may need to use special cutting guides or custom implants. If you have had previous knee surgery, scar tissue must be removed first. If you are very overweight, the surgeon may need more time to position your leg and access the joint safely. If you have bone loss from osteoporosis, the surgeon may need to use bone cement or special implant designs that take longer to position correctly.

Anesthesia and what you experience

You will receive either general anesthesia (you are completely asleep) or regional anesthesia (your lower body is numb but you remain conscious, though sedated). Most knee replacements use regional anesthesia with a nerve block, which numbs your leg from the hip down. You will not feel pain, pressure, or movement during the operation.

The anesthesiologist monitors your heart rate, blood pressure, oxygen level, and breathing throughout the procedure. If you are under general anesthesia, a breathing tube is placed in your windpipe to help you breathe. You will have no memory of the surgery itself. Most people wake up in the recovery room with no sense of time having passed.

Recovery room time and what happens next

After surgery, you move to a recovery room where nurses check your vital signs every 15 minutes for the first hour, then less frequently. They monitor for bleeding, infection signs, and blood clots. A physical therapist may visit to help you move your knee gently or stand with information, depending on your surgeon's protocol.

You will stay in the recovery room for 30 to 60 minutes. Once you are alert, your pain is controlled, and your vital signs are stable, you move to a hospital room or are discharged home if you had outpatient surgery. Some surgeons perform knee replacements as same-day procedures; others keep patients overnight for observation and pain management.

Hospital stay length after surgery

If your surgery is performed at a hospital, you may go home the same day or stay overnight. Many surgeons now perform outpatient knee replacements, meaning you leave within a few hours of waking up. If you stay overnight, you will typically be discharged the next morning after physical therapy and pain assessment.

Staying longer than one night is uncommon unless you have complications such as excessive bleeding, infection signs, or difficulty managing pain. Some patients with multiple health conditions or limited home support may stay two nights. The length of your hospital stay does not affect how well your knee heals — what matters is following your surgeon's instructions at home and attending physical therapy.

Preparing for the time commitment

Plan to have someone drive you home and stay with you for at least the first 24 hours. You will not be able to drive for at least one week after surgery, and most surgeons recommend waiting two to four weeks. Arrange time off work — most people need four to six weeks before returning to desk work and eight to twelve weeks before returning to physical jobs.

Physical therapy begins within days of surgery and continues for eight to twelve weeks. Sessions typically last 45 to 60 minutes and occur two to three times per week. The time you invest in therapy directly affects how much strength and motion you regain in your knee.

Frequently Asked Questions

Can the surgeon finish faster if I ask them to hurry?

No. Rushing a knee replacement increases the risk of misalignment, implant loosening, and poor long-term function. The surgery takes as long as it takes to position your implant correctly. A surgeon who works at a steady, careful pace produces better results than one who prioritizes speed.

What if my surgery takes longer than three hours?

Surgeries that exceed three hours are uncommon but can happen with severe arthritis, previous surgery, or bone loss. Longer operating time increases the risk of blood clots and infection slightly, but your surgical team will take steps to reduce these risks, such as using compression devices on your legs and administering preventive antibiotics.

Will I be awake during any part of the surgery?

If you receive regional anesthesia with sedation, you may drift in and out of consciousness but will not feel pain or remember the procedure. You can request general anesthesia if you prefer to be completely asleep. Discuss your preference with your anesthesiologist before surgery.

How long until I can walk normally after surgery?

Most people walk with crutches or a walker for two to four weeks after surgery. Walking without information typically takes four to six weeks. Full recovery, including return to exercise and sports, takes three to six months. Physical therapy progress varies based on your age, overall health, and effort.

Is same-day discharge safe after knee replacement?

Yes, for most patients. Same-day discharge is safe if you have reliable transportation, someone to care for you at home, and access to follow-up care. Your surgeon will determine whether you are a candidate based on your health, the complexity of your surgery, and your home situation. If you have complications or live alone without support, staying overnight is the safer choice.