The surgery itself takes 1 to 2 hours, but the full process from arrival to discharge spans 4 to 6 hours

Knee replacement surgery — removing the damaged joint and installing an artificial one — typically runs 60 to 120 minutes once you are in the operating room. The surgeon removes bone and cartilage, positions the prosthetic components, and closes the incision. But you will spend far longer at the hospital or surgical center that day. You arrive 1 to 2 hours early for paperwork and anesthesia prep, and you stay in recovery for 2 to 3 hours after surgery ends while the anesthesia wears off and nurses monitor your vital signs and pain level.

The total time on-site — from check-in to discharge — is usually 4 to 6 hours for an outpatient procedure, or longer if you stay overnight. Most people go home the same day, though some hospitals keep patients for one night if they live far away or have other health conditions that need monitoring.

Key Takeaways

  • The actual surgery lasts 1 to 2 hours, but plan for 4 to 6 hours total at the facility including prep and recovery.
  • You will be under general or regional anesthesia and cannot drive or make decisions for 24 hours after surgery, so arrange a ride home in advance.
  • Recovery at home takes 6 to 12 weeks before you can walk without a walker and return to light activity, though full healing continues for up to a year.
  • Physical therapy begins within days of surgery and continues for several weeks; skipping sessions slows your progress significantly.
  • Most people can resume normal daily tasks like cooking and light housework within 4 to 6 weeks, but high-impact activities like running take 3 to 6 months or longer.

What happens during the surgery timeline

When you arrive at the surgical center or hospital, staff will check your vital signs, review your medical history, and have you change into a surgical gown. An anesthesiologist will discuss which type of anesthesia you will receive — usually general anesthesia (you are asleep) or a regional block (your leg is numb but you may be sedated). This prep phase takes 45 minutes to 2 hours depending on how busy the facility is and whether any last-minute tests are needed.

Once you are in the operating room, the surgical team positions you on the table, cleans the surgical site, and drapes it. The surgeon makes an incision over the knee, usually 8 to 10 inches long, and removes the damaged bone and cartilage. The prosthetic components — typically made of metal, plastic, or ceramic — are then fitted and cemented or press-fit into place. The surgeon checks the alignment and range of motion, then closes the incision with stitches or staples. This entire process takes 60 to 120 minutes.

After surgery, you move to a recovery room where nurses monitor your heart rate, blood pressure, oxygen level, and pain. You will receive pain medication and fluids through an IV. As the anesthesia wears off, you may feel groggy, nauseous, or confused — this is normal and temporary. Most people are alert enough to go home or to a hospital room within 2 to 3 hours, though some take longer depending on how they respond to anesthesia.

Recovery at home: the first 6 weeks

The first two weeks after surgery are the most demanding. Your knee will be swollen, bruised, and painful. You will wear a compression bandage and may use ice, elevation, and prescribed pain medication to manage discomfort. Most people use crutches or a walker and cannot put full weight on the leg. Nurses or a physical therapist will visit your home or you will attend outpatient sessions to teach you exercises and monitor your healing.

By week 3 or 4, swelling decreases and you can usually walk with a cane or without information, though your gait may be stiff. You can resume light activities like sitting at a desk, cooking with help, or short walks around the house. Driving is not safe until you can bend your knee enough to operate the pedals and have stopped taking strong pain medication — usually 4 to 6 weeks after surgery, though this varies by person and surgeon guidance.

By week 6, most people can walk on level ground without a cane, climb stairs with a rail, and manage basic self-care. You can return to work if your job does not require standing for long periods or heavy lifting. Physical therapy continues during this time, typically 2 to 3 sessions per week, and the exercises become more challenging as your strength and range of motion improve.

Months 2 through 3: building strength and range of motion

Between weeks 6 and 12, your focus shifts from pain management to regaining function. Swelling continues to decrease, and you can bend your knee more fully — ideally to 110 to 120 degrees by the end of week 12, though some people take longer. You can walk longer distances, climb stairs without a rail, and return to most daily activities. Many people stop using pain medication during this phase, though some continue for a few more weeks.

Physical therapy remains important. Your therapist will add exercises to strengthen the muscles around the knee, improve balance, and restore normal walking patterns. You may begin low-impact activities like swimming, stationary cycling, or walking on a treadmill. High-impact activities like running, jumping, or contact sports are still off-limits and will remain so for several more months.

Months 3 through 12: long-term healing and return to activity

Full recovery from knee replacement takes up to a year. By month 3, most people have returned to work and normal daily life. Swelling is minimal, pain is gone or very mild, and you can walk, climb stairs, and sit comfortably for extended periods. Many people stop formal physical therapy around this point, though home exercises remain beneficial.

Between months 3 and 6, you can gradually return to higher-impact activities if your surgeon approves. This might include light jogging, recreational sports, or hiking on flat terrain. The artificial knee is durable — most last 15 to 20 years — but it has limits. Your surgeon will advise you on which activities are safe long-term and which to avoid to protect the prosthetic.

By month 12, most people report that their knee feels normal during everyday life. Some residual swelling or stiffness may persist, especially after prolonged activity or in cold weather, but this typically does not interfere with function. Full healing of the soft tissues around the knee continues beyond a year, and some people notice continued improvement in strength and flexibility for up to 18 months.

Factors that affect your recovery timeline

Your age, overall health, and fitness level before surgery influence how quickly you heal. Younger, healthier people often recover faster than older adults or those with diabetes, heart disease, or obesity. Your commitment to physical therapy also matters significantly — people who attend sessions consistently and do home exercises between appointments regain function weeks faster than those who skip therapy.

The type of anesthesia, whether you have complications like infection or blood clots, and your pain tolerance also play a role. Some people experience stiffness that requires more aggressive physical therapy or even a second procedure to break up scar tissue. Others heal smoothly with minimal setbacks. Your surgeon can give you a more specific timeline based on your individual situation.

What to arrange before surgery

Plan for someone to drive you home and stay with you for at least the first 24 hours. You cannot drive or operate machinery while anesthesia is in your system, and you should not be alone in case you fall or have a medical problem. Arrange for help with cooking, cleaning, and laundry for at least the first 2 weeks, and ideally the first 4 to 6 weeks. If you live alone or have no family nearby, ask your surgeon about home health services — many insurance plans cover a nurse or aide to visit several times per week.

Prepare your home before surgery. Stock the freezer with straightforward meals, move frequently used items to waist height so you do not have to bend or reach, and clear pathways of clutter so you can move safely with crutches or a walker. Rent or borrow a walker and crutches in advance. Set up a comfortable recovery space on the main floor of your home with a bed or recliner, a small table for medications and water, and a phone within reach.

Frequently Asked Questions

Can I have both knees replaced at the same time?

Some surgeons will replace both knees in one surgery if you are young and healthy, which means one recovery period instead of two. However, this is more physically demanding and carries higher risks of blood clots and infection. Most surgeons prefer to do one knee at a time, spacing them 3 to 6 months apart so you can recover and regain strength between procedures.

When can I return to work?

If your job involves sitting at a desk with minimal walking, you may return after 4 to 6 weeks. If it requires standing, walking, or heavy lifting, plan on 8 to 12 weeks or longer. Your surgeon will clear you based on your progress in physical therapy and your specific job demands. Many employers allow a gradual return — part-time or modified duties for the first few weeks.

Will I need physical therapy after I leave the hospital?

Yes. Physical therapy is essential to regaining strength, range of motion, and normal walking patterns. Most people attend 2 to 3 sessions per week for 6 to 12 weeks, either at an outpatient clinic or at home. Skipping therapy or not doing home exercises between sessions significantly slows your progress and can leave you with permanent stiffness or weakness.

How long does the incision take to heal?

The skin incision closes within 2 to 3 weeks, and stitches or staples are usually removed around day 10 to 14. However, the deeper tissues and muscles take much longer — 6 to 12 weeks to heal fully. You should avoid soaking the incision in water until it is completely closed, and avoid heavy lifting or strenuous activity that stresses the surgical site during the first 6 weeks.

What if I am not improving as fast as expected?

Some people recover slower than average due to age, health conditions, or complications like infection or stiffness. If you are not meeting expected milestones — such as bending your knee to 90 degrees by week 6 — tell your surgeon. They may adjust your physical therapy, prescribe additional treatment, or investigate whether a complication is slowing your progress. Catching delays early usually leads to better outcomes.