Knee Replacement Surgery: What to Expect on the Day of Surgery

Knee replacement surgery (knee arthroplasty) takes approximately one to two hours and is performed by an orthopedic surgeon in a hospital or surgical center. Damaged parts of the knee joint are surgically removed and replaced with an implant, resulting in greater joint stability and ease of movement. Most patients spend around one to three days in the hospital after this elective procedure. In select cases, the surgery may require no hospital stay.

Surgeon holding a scalpel
Caiaimage/Sam Edwards / Getty Images

Before the Surgery

You will first go to a surgical pre-operative room. After changing into a gown and relaxing on the hospital bed, a nurse will check your vital signs and place a peripheral IV in your arm. This IV is used to give you fluids and medications during the surgery. You will also receive an antibiotic through the IV prior to the procedure.

Next, your surgical team and anesthesiologist will come to greet you. They may briefly review the surgery with you and ask you to sign additional consent forms.

Finally, you will be wheeled into the operating room on your hospital bed. You will transfer to an operating table and be given anesthesia. A breathing tube connected to a ventilator will be placed by the anesthesiologist if you are getting general anesthesia.

The type of anesthesia you and your healthcare provider chose during your pre-operative consultation—general anesthesia, epidural or spinal anesthesia, or regional nerve block—will have no effect on your surgeon's ability to perform the knee replacement.

During the Surgery

Knee replacement surgery generally proceeds with the following steps:

  • Incision: In the operating room, your surgeon will make a six- to eight-inch cut over the knee.
  • Removal: They will then remove the damaged bone and cartilage on the end of the thigh bone (femur) and top of the shin bone (tibia) using precise instruments, leaving behind surfaces tailored to accommodate the prosthesis. the surgeon also removes damaged cartilage and bone along the patella (or knee cap).
  • Implant placement: After removing the damaged parts of the knee, the surgeon will attach an implant (prosthesis) to the bone. Usually, cement fixation is performed. This means that the implant is fit tightly into position and immediately and solidly fixed into the bone with cement. Sometimes, especially in younger patients, a cement-less fixation is used. This means that the implant is "press-fit" onto the bone. It is firmly held in position as surrounding bone grows into the implant over time.
  • Closing: Once the prosthesis is placed, the surgeon will close the incision site with staples or stitches. A drain may be placed at the wound site to remove excess fluid. A bandage will then be placed over the knee.

Once the surgery is done, the anesthesia medication will be stopped and your breathing tube will be removed.

After the Surgery

After your knee replacement surgery, you will be taken to a recovery room where a nurse will monitor your vital signs and manage your pain.

Once your vitals are stable and your pain is under control (usually within a few hours), you will be taken to a hospital room to recover more. Of note, in select circumstances, a patient may go home the same day as their procedure (this is not typical, but becoming more popular).

When recovering in the hospital, your surgical team will give you a blood thinner (anticoagulant) and compression boots to help prevent blood clots in your legs.For postoperative pain control, your surgeon will likely inject a combination of local anesthetic agents directly into the knee and surrounding skin while closing your incision while you are still intubated in the operating room. This can alleviate pain for several hours after surgery.

In other cases, if you received a regional nerve block, your anesthesiologist will often leave in a small catheter, or tube, that slowly releases numbing medication around the nerves surrounding the knee to provide comfort for days after your surgery. Additional injections through the catheter may be given if more pain control is needed.

A physical therapist will also come to visit you in your hospital room to teach you various exercises.

Upon being discharged from the hospital, you will be given various post-operative instructions to follow at home.

These instructions may include:

  • Applying ice and elevating your knee to reduce swelling
  • Taking any pain medication as directed: This may include an NSAID, an opioid, Tylenol (acetaminophen), a local anesthetic, or some combination
  • Taking an anticoagulant as advised (usually for 10 to 14 days, but can be up to 35 days)
  • Resuming your normal diet: Your surgeon may recommend iron supplements to optimize healing and muscle strength. Iron supplements are commonly prescribed in order to increase the body's production of red blood cells as it is common to experience mild to moderate anemia (or acute blood loss) after a total knee replacement.
  • Keeping your wound clean and dry until the stitches or surgical staples are removed (several weeks after surgery)
  • Waiting three to six weeks to resume normal activities
  • Performing home exercises and attending physical therapy appointments, which will begin immediately after surgery
  • Using a cane or walker, as well as other fall prevention measures, until your knee is adequately strong

A Word From Verywell

While much happens during knee replacement surgery, one can argue that the real work comes after the procedure is done. Success is due, in large part, to the rehabilitation that follows. If you expect a good result from knee replacement surgery, you must be an active rehab participant.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Jonathan Cluett, MD
Jonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men's and women's national soccer teams.