The surgery itself takes 1 to 2 hours, but your total time at the hospital or surgical center will be 4 to 6 hours

The actual procedure—removing the damaged knee joint and installing the artificial components—usually runs between 60 and 120 minutes. But that is only the middle part of your day. You will arrive 1 to 2 hours early for pre-op checks, bloodwork, and anesthesia preparation. After surgery, you spend 1 to 2 hours in recovery while the anesthesia wears off and nurses monitor your vital signs. Add travel time, and you are looking at a full morning or afternoon commitment.

The length of surgery depends on a few real factors: whether this is your first knee replacement or a revision (fixing a previous one), how complex your knee damage is, and how quickly your surgeon works. A straightforward first replacement on a patient with no complications tends toward the shorter end. A revision or a knee with severe arthritis or previous injury can push toward two hours or beyond.

Key Takeaways

  • Plan to spend 4 to 6 hours at the surgical facility on the day of your procedure, though the surgery itself lasts 1 to 2 hours.
  • You will need someone to drive you home because anesthesia impairs judgment and reflexes for the rest of the day.
  • Recovery at home takes weeks: you can usually walk with a walker or crutches within days, but full healing takes 3 to 6 months.
  • Physical therapy begins within days of surgery and continues for weeks or months to restore strength and range of motion.
  • Most people return to light activities within 6 weeks and normal activities within 3 to 6 months, though timelines vary widely.

What happens before you go into the operating room

Arrive 60 to 90 minutes before your scheduled surgery time. You will check in, change into a hospital gown, and move to a pre-op area where nurses will take your blood pressure, temperature, and heart rate. An anesthesiologist will review your medical history and explain how they will put you to sleep—usually with intravenous medication, sometimes with a nerve block that numbs the leg.

If you have not done so already, you will sign consent forms and answer questions about medications, allergies, and previous surgeries. The surgical team will mark the correct knee with a pen to prevent mistakes. This whole phase typically takes 60 to 90 minutes, though it can stretch longer if there are questions about your health or if the operating room is running behind.

Recovery in the hospital or surgical center

After surgery ends, you move to a recovery room (sometimes called the post-anesthesia care unit, or PACU) where nurses watch you closely as the anesthesia wears off. This phase lasts 1 to 2 hours. You will feel groggy, your leg will be numb or tingly, and you may feel cold or nauseated—all normal. Nurses will check your pain level, give you medication if needed, and make sure your blood pressure and oxygen levels are stable.

Before you leave, a physical therapist or nurse will help you sit up, dangle your legs, and possibly stand or take a few steps with support. This is not about walking normally—it is about making sure you can move enough to go home safely. You will receive written instructions about wound care, medications, activity limits, and when to call your surgeon.

The first week at home

Your knee will be swollen, painful, and stiff. You will wear a compression bandage or sleeve and use ice and elevation to manage swelling. Most people use crutches or a walker for the first few days to a week. Pain medication helps, though many people find they need less as days pass.

Physical therapy usually starts within 3 to 5 days—either at a clinic or with a therapist who comes to your home. These sessions focus on gentle movement, swelling control, and preventing blood clots. You will do straightforward exercises like ankle pumps, quad sets (tightening the thigh muscle), and short walks. Sessions last 30 to 60 minutes and happen 2 to 3 times per week.

Weeks 2 through 6: regaining movement and strength

By week 2, most people can walk short distances without crutches, though many still use them for safety. Your range of motion improves steadily—bending the knee becomes less painful, and straightening it becomes easier. Swelling usually peaks around day 3 to 5, then gradually decreases over weeks.

Physical therapy continues 2 to 3 times per week. Exercises progress from passive (therapist moves your leg) to active (you move it yourself) to resistance-based (adding light weights or bands). You will work on walking, stairs, and basic strength. By week 6, many people can walk without aids, climb stairs with a rail, and return to light activities like desk work or short car rides.

Months 2 through 6: building strength and returning to activity

Full healing takes 3 to 6 months. By month 2, most people have stopped taking pain medication regularly and can walk 20 to 30 minutes without problems. Swelling is much less noticeable. Physical therapy may shift to a gym or home program focused on strength, balance, and endurance.

By month 3, many people return to activities like swimming, stationary cycling, or golf. By month 6, most can do normal daily activities—grocery shopping, light yard work, social outings—without thinking about the knee. Some people feel fully recovered by 3 months; others need the full 6 months. This variation is normal and depends on your age, fitness before surgery, and how hard you work at therapy.

Factors that can make recovery longer

Age, overall health, and fitness level all matter. Older patients or those with other health conditions may recover more slowly. Complications like infection, blood clots, or stiffness can extend recovery by weeks or months. If you develop a blood clot (deep vein thrombosis), you may need medication and delayed physical therapy. Stiffness—when the knee does not bend or straighten as much as expected—sometimes requires manipulation under anesthesia, a procedure done 6 to 12 weeks after surgery if therapy alone does not help.

How seriously you follow physical therapy also matters. People who do their exercises at home between therapy sessions and stay consistent tend to recover faster and with better results than those who skip sessions or avoid movement.

When to call your surgeon

Contact your surgeon when ready if you develop fever above 101°F, increasing redness or warmth around the incision, drainage from the wound, severe pain not controlled by medication, sudden swelling in the calf, chest pain, or shortness of breath. These can signal infection, blood clots, or other complications that need prompt treatment.

Mild swelling, bruising, and stiffness are expected. Discomfort during physical therapy is normal. But if something feels wrong—especially sudden changes—do not wait for your next appointment.

Frequently Asked Questions

Can I go home the same day as surgery?

Yes, most knee replacements are done as outpatient surgery, meaning you go home the same day. You must have someone drive you and stay with you for at least the first night because anesthesia affects judgment and coordination. Some patients with complications or health concerns stay overnight, but same-day discharge is standard.

How long before I can drive?

Most surgeons recommend waiting 4 to 6 weeks before driving, and only after you have stopped taking prescription pain medication and can bend and straighten your knee enough to operate pedals safely. Check your surgeon's specific guidance and your insurance policy, as some require written clearance before you drive.

When can I return to work?

If your job is desk work with no standing or walking, many people return within 2 to 4 weeks. Jobs requiring standing, walking, or physical labor may take 6 to 12 weeks or longer. Your surgeon can provide a work restriction letter if your employer needs one.

Will my knee ever feel completely normal?

Most people report their knee feels nearly normal within 3 to 6 months, though some notice minor stiffness or occasional swelling with activity for longer. A small percentage experience persistent stiffness or discomfort. The artificial joint itself does not wear out quickly—modern replacements last 15 to 20 years or more with normal use.

What if I need the other knee replaced too?

If both knees need replacement, surgeons typically space them 3 to 6 months apart so you can recover from the first and regain strength before the second. Doing both at once is rare and usually only for patients in excellent health with strong support at home.