The Surgery Itself Takes 1 to 2 Hours

Total knee replacement surgery typically lasts between 60 and 120 minutes from the moment the surgeon makes the first incision to the moment they close the wound. Most procedures fall closer to 90 minutes. The exact time depends on the complexity of your knee, whether you have arthritis damage on multiple surfaces, scar tissue from previous surgery, and how straightforward your anatomy is for the surgeon to work with.

Your total time in the operating room will be longer than the surgery itself. You arrive 30 to 60 minutes early for final checks, positioning, and anesthesia. After the surgeon finishes, the surgical team spends another 20 to 30 minutes closing the incision in layers, explore the dressing, and moving you to recovery. Plan on being in the operating room for roughly 2.5 to 3.5 hours total.

Key Takeaways

  • The actual surgical work takes 60 to 120 minutes, with most procedures finishing around 90 minutes.
  • Your total time in the operating room, including setup and closing, runs 2.5 to 3.5 hours.
  • Recovery room time adds another 1 to 2 hours before you move to a hospital bed or go home.
  • Surgeon experience, your knee's condition, and whether complications arise during surgery all affect the final time.
  • You should plan for a full day at the surgical facility even though the procedure itself is relatively quick.

What Happens Before the Surgeon Starts

Before you enter the operating room, the surgical team prepares you for about 30 to 60 minutes. You change into a surgical gown, a nurse places an IV line, and the anesthesiologist reviews your medical history and any medications you take. They may ask you to empty your bladder and remove jewelry, dentures, or hearing aids.

Once you are in the operating room, the team positions your leg, cleans the surgical area with antiseptic solution, and drapes you with sterile sheets. The anesthesiologist administers anesthesia — usually general anesthesia, though some surgeons use regional anesthesia (numbing from the waist down) combined with sedation. This setup takes another 15 to 20 minutes before the surgeon makes the first incision.

What the Surgeon Does During the Procedure

The surgeon makes an incision down the front of your knee, usually 8 to 10 inches long. They move the kneecap to the side to access the joint. Using specialized instruments, they remove the damaged cartilage and bone from the end of your thighbone, shinbone, and kneecap. This removal and shaping takes the bulk of the surgical time.

Next, the surgeon positions the metal and plastic implant components to replace the damaged surfaces. They test the alignment and range of motion to may support the knee bends and straightens smoothly. If adjustments are needed, the surgeon makes them now. Once satisfied with the fit and function, they cement the components in place (in most cases) and close the incision with stitches or staples.

Recovery Room Time After Surgery

After the surgeon finishes, you move to the recovery room, where you wake from anesthesia under close monitoring. A nurse checks your blood pressure, heart rate, oxygen level, and pain. This phase typically lasts 1 to 2 hours. You may feel groggy, nauseous, or cold — all normal responses to anesthesia.

Once you are alert and your vital signs are stable, you move to a hospital room if you are staying overnight, or you are discharged home if your surgery was outpatient. Some facilities keep patients for observation; others send them home the same day. Your surgeon and anesthesiologist determine this based on your overall health and how well you are recovering.

Factors That Make Surgery Longer or Shorter

A straightforward knee replacement in a patient with no previous surgery or complications may finish in 60 to 75 minutes. A more complex case — one with severe arthritis, bone loss, previous knee surgery, or unusual anatomy — can stretch to 2 hours or beyond. Revision surgery (replacing a knee replacement that failed) almost always takes longer because the surgeon must remove the old implant first.

The surgeon's experience also matters. An experienced surgeon who performs many knee replacements may work more efficiently than one who does fewer procedures. However, speed is not the goal; accuracy and proper alignment are. A surgeon may take extra time to may support the implant is positioned correctly, which actually reduces your risk of problems later.

What to Expect on Your Surgery Day

Arrive at the surgical facility 1 to 2 hours before your scheduled surgery time. Bring your insurance card, photo ID, and a list of all medications and supplements you take. Wear loose, comfortable clothing that is straightforward to remove. Do not eat or drink after midnight the night before (your surgeon will give you exact instructions).

Plan for someone to drive you home or stay with you if you are discharged the same day. Even if you feel alert, anesthesia impairs your judgment and reaction time for several hours. If you are staying overnight, a family member or friend can visit during designated hours. Bring a change of clothes and toiletries, though the hospital provides basics.

How Long Until You Can Resume Normal Activities

The surgery itself is quick, but recovery is a longer process. Most people use crutches or a walker for 2 to 6 weeks after surgery. Physical therapy begins within days and continues for several weeks. You can usually return to light activities like walking and gentle stretching within 3 to 6 weeks, but high-impact activities like running or jumping may take 3 to 6 months or longer.

Pain and swelling gradually decrease over the first 6 weeks, then more slowly over several months. Some swelling and stiffness can persist for up to a year. Your surgeon will give you a timeline based on your progress and will clear you to return to specific activities as you heal.

Frequently Asked Questions

Can the surgery take longer than 2 hours?

Yes. If your knee has severe damage, previous surgery, bone loss, or unusual anatomy, the procedure can extend beyond 2 hours. Revision surgery (replacing a failed implant) typically takes longer. Your surgeon can estimate the likely duration based on your X-rays and medical history.

Will I be asleep the whole time?

Usually yes. Most total knee replacements use general anesthesia, which puts you completely asleep. Some surgeons offer regional anesthesia (numbing from the waist down) with sedation, so you are drowsy but not fully unconscious. Your anesthesiologist will discuss which option is best for you.

What if something goes wrong during surgery and it takes longer?

If the surgeon encounters unexpected bone loss, infection, or other complications, the procedure may take longer. The surgical team will manage the situation and inform your family of any changes. Complications during surgery are uncommon but your surgeon is trained to handle them.

How long will I be at the hospital or surgical center?

Plan for 4 to 6 hours total if you are having outpatient surgery. This includes pre-op preparation, the procedure, and recovery room time. If you are staying overnight, you will be admitted to a hospital room after recovery and typically discharged the next morning.

When can I drive after surgery?

Do not drive for at least 2 to 4 weeks after surgery, and only after your surgeon clears you. Anesthesia, pain medication, and reduced mobility all affect your ability to control a vehicle safely. Many people are not comfortable driving until 6 weeks or longer.