The surgery itself usually lasts one to three hours

Total knee replacement surgery typically takes between 60 and 120 minutes once you are in the operating room. The exact time depends on the surgeon's experience, the complexity of your knee damage, and whether your anatomy presents any surprises once the surgeon opens the joint. A straightforward replacement on a patient with no prior knee surgery often runs closer to 60 minutes. A revision surgery — replacing a knee that was already replaced — or a knee with severe bone loss or arthritis can stretch toward two hours or beyond.

The surgeon removes the damaged cartilage and bone from the end of your thighbone and the top of your shinbone, then cements metal and plastic components into place. The actual implantation is the fastest part. Most of the time goes to preparing the bone surfaces and ensuring the new joint sits in the correct alignment.

Key Takeaways

  • Surgery in the operating room takes one to three hours, with most procedures finishing in about 90 minutes.
  • You will spend two to four hours in the recovery room after surgery, where staff monitor your vital signs and manage pain.
  • From the moment you arrive at the hospital to the moment you leave, plan for a full day — typically six to eight hours total.
  • Hospital stay length varies: same-day discharge is possible for some patients, while others stay overnight or for two to three days depending on age, overall health, and home support.
  • The first few weeks after surgery involve physical therapy and gradual movement, not when ready full recovery.

What happens before you enter the operating room

You will arrive at the hospital one to two hours before your scheduled surgery time. During this window, staff check your vital signs, review your medical history, start an IV line, and have you change into a surgical gown. An anesthesiologist will meet with you to discuss pain management and confirm you have not eaten or drunk anything since midnight the night before.

Once you are ready, a nurse will walk you to the operating room. You may receive a sedative before the anesthesiologist puts you under general anesthesia or a regional block (numbing from the waist down). This pre-surgery period usually takes 30 to 45 minutes from arrival to the moment the surgeon makes the first incision.

Recovery room time after the procedure ends

After the surgeon closes the incision and applies a dressing, you move to the recovery room (also called the post-anesthesia care unit, or PACU). You will spend two to four hours here while anesthesia wears off and nurses monitor your heart rate, blood pressure, oxygen level, and pain. A nurse will help you wake up gradually and manage any nausea or discomfort.

During this time, a physical therapist may visit to show you how to move your new knee and use crutches or a walker. You will likely receive pain medication through your IV. Most people are alert enough to recognize family members by the end of this period, though grogginess is normal.

Total time from arrival to discharge on surgery day

Plan to be at the hospital for six to eight hours on the day of surgery. This includes pre-surgery preparation (one to two hours), the operation itself (one to three hours), and recovery room time (two to four hours). If you are discharged the same day, you will need someone to drive you home — you cannot drive after anesthesia, and you will still be drowsy and in pain.

Some surgeons and hospitals prefer to keep patients overnight for monitoring and pain management. If that is the case, you will move from the recovery room to a hospital bed, where you will stay until the following morning. Your surgeon will let you know before surgery whether same-day discharge or an overnight stay is the plan for your situation.

Hospital stay length varies by your health and home setup

Same-day discharge is increasingly common for total knee replacement, especially if you are younger, have no major health conditions, and have someone at home to help you for the first few days. In this case, you leave the hospital four to eight hours after surgery ends.

An overnight stay (one night in the hospital) is typical for many patients, particularly those over 65 or with conditions like heart disease or diabetes. A two- to three-day stay may be recommended if you live alone, have limited mobility at home, or had complications during surgery. Some hospitals offer a short-stay program where you go home after one night but receive a nurse visit at home the next day.

What to expect in the first weeks after going home

The first two weeks at home involve managing pain, keeping the incision clean and dry, and beginning gentle movement exercises. You will have physical therapy sessions two to three times per week, either at a clinic or at home. Most people can put weight on the leg within days, though walking will be slow and you will use crutches or a walker.

Swelling and stiffness peak around day three to day five after surgery, then gradually improve. By six weeks, many people can walk without information and resume light activities. Full recovery — including return to normal walking, stairs without rails, and low-impact exercise — typically takes three to six months. Some people continue to see improvement in strength and range of motion for up to a year.

Factors that can make surgery take longer

Revision surgery (replacing a knee that was already replaced) adds 30 to 60 minutes because the surgeon must remove the old implant and prepare the bone again. Severe bone loss, arthritis affecting multiple parts of the knee, or obesity can also extend operating time. A history of prior knee surgery, even if not a full replacement, may complicate the procedure.

Unexpected findings during surgery — such as bone that is softer or more damaged than imaging showed, or scar tissue that takes longer to remove — can push the operation past the original estimate. Your surgeon will update your family if the procedure is taking longer than planned.

Frequently Asked Questions

Can I go home the same day as surgery?

Yes, many patients are discharged the same day, typically four to eight hours after surgery ends. Your surgeon will determine whether same-day discharge is safe based on your age, health conditions, and home support. You must have someone drive you home and stay with you for at least the first night.

What if I need a second surgery on the other knee?

Most surgeons wait at least two to three weeks between surgeries on each knee, giving you time to regain some strength and mobility. Some patients choose to have both knees done within a few weeks of each other; others space them months apart. Discuss the timing with your surgeon based on your recovery progress and personal preference.

How much pain will I be in after I wake up?

Pain is common but managed with medication. Most people describe it as a dull ache or soreness rather than sharp pain. You will receive pain medication through your IV in the recovery room and oral pain relievers once you can swallow. Pain typically peaks in the first three to five days, then gradually decreases.

Will I need to stay in a rehabilitation facility after leaving the hospital?

Many patients go directly home with outpatient physical therapy. Others, particularly those living alone or with limited home support, may spend a few days in a rehabilitation facility for intensive therapy and monitoring. Your surgeon and hospital social worker will discuss this option before surgery if it seems necessary for your situation.

When can I start driving again?

Most surgeons recommend waiting four to six weeks before driving, depending on which knee was operated on and when you can safely stop pain medication. If your right knee was replaced, you may need to wait longer because you use that leg for the brake pedal. Check your surgeon's specific guidance and your insurance policy, as some insurers have their own restrictions.