Knee Replacement

In total knee replacement surgery, the damaged bone surfaces and cartilage are removed and replaced with artificial surfaces made of metal and a plastic material. These surfaces are called "implants" or "prostheses" and restore the alignment and function of your knee.

Typically, a total knee replacement takes about two hours. To learn more about the procedure, see the illustrations in Total Knee Replacement.

Preparing for Surgery

Before your surgery, you will undergo a physical exam and complete several tests to rule out any medical problems that could interfere with your surgery.

An appointment at the Prepare Clinic will be scheduled two to three weeks before your surgery. At the clinic, you'll meet with an anesthesiologist or nurse pratitioner to review your medical history, complete pre-surgery tests such as a chest X-ray and blood tests and to sign surgery and blood transfusion consent forms.

Read more about Preparing for Knee Replacement.

Day of Surgery

On the day of your surgery, please arrive two hours before the start of the procedure to allow time for the admissions process and to meet with your anesthesiologist.

After you're admitted, you'll move to the pre-operative area where you'll meet an anesthesiologist. The most common type of anesthesia is called general anesthesia, which is administered intravenously or directly into a vein. General anesthesia will keep you in a "sleep" or unconscious state during the entire operation.

Your anesthesiologist also may discuss the option of an epidural or spinal injection to block pain. Your anesthesiologist will discuss your options before your surgery.


Typically, patients remain in the hospital for three to four days after surgery, depending on the course of recovery.

The day after your surgery, a physical therapist will teach you exercises to regain full leg and knee movement. During your hospital stay, you’ll attend physical therapy one to two times a day.

Your doctor may recommend a continuous passive motion (CPM) machine that bends and straightens your knee. Special elastic stockings may be provided to help reduce swelling. An anticoagulant medication, such as lovenox, also may be administered to help circulation and prevent blood clots.

To learn more about the recovery process, read Recovering from Knee Surgery.

More Information

Computer Assisted Surgery

Our experts are trained in computer-assisted orthopedic surgery, which uses special cameras and intra-operative imaging tools that project images of the area being operated onto a television screen. On-screen prompts help guide surgeons to the ideal alignment of the implant and provide real-time vision of the surgical site.

High-precision alignment may extend the long-term survival of the implanted artificial hip or knee, reducing the need for future corrective surgeries. UCSF Medical Center surgeons are involved in studying these new technologies to determine their impact on total knee replacement.

Advances in Joint Replacement


Reviewed by health care specialists at UCSF Medical Center.

Related Information

UCSF Clinics & Centers

Arthritis & Joint Replacement Center
1500 Owens St., Suite 430
San Francisco, CA 94158
Phone: (415) 353–2808
Fax: (415) 885–3862

Cartilage Repair & Regeneration Center
1500 Owens St.
San Francisco, CA 94158
Phone: (415) 353–7566

Our Experts

Erik Hansen
Dr. Erik Hansen,
orthopedic surgeon
Hubert Kim
Dr. Hubert Kim,
orthopedic surgeon
C. Benjamin Ma
Dr. C. Benjamin Ma,
orthopedic surgeon
Thomas Vail
Dr. Thomas Vail,
orthopedic surgeon