Total knee replacement


Treatment and prevention

 A total knee replacement removes the entire knee joint and replaces it with an artificial one, often called a knee implant. The new joint will allow you to bend your knee and use it without pain or stiffness.

A total knee replacement treats severe knee damage. If other treatments haven’t worked for you, this procedure may be the next step.

Orthopedic surgeons at Dignity Health specialize in knee replacement to reduce discomfort and restore mobility and proper joint function. Find a Doctor to learn more about our orthopedic services.

Why it's necessary

A total knee replacement is typically only considered if your knee joint has been damaged beyond repair.

This typically is the case for those with rheumatoid arthritis, gout, or osteoarthritis in which the knee joint has worn down enough to need replacing. In rare cases, trauma such as a sudden, severe injury might also require a knee replacement.

Before recommending a total knee replacement, your surgeon will likely conduct several tests to make sure you are a good candidate. These tests may include:

  • A physical exam to evaluate your range of motion and check for signs of injury, such as bruising, swelling, or deformity.
  • Imaging scans such as x-rays, MRIs, and PET scans, depending on the suspected cause of your knee pain, to get a picture of injuries and the extent of damage.
  • Blood or joint fluid tests, to fully diagnose your condition prior to the procedure.

Your surgeon may also ask you about your condition, how long you have had pain in your knee, and the degree to which your activities have been affected.

Before recommending surgery, your doctor will carefully look at your hip and ankle joints to ensure that fixing your knee will have the desired results. If your ankle or hip is also affected, a total knee replacement may not yield the desired pain reduction or increased mobility. You may notice increased pain in your other joints once your knee is replaced. Your thigh (quadriceps) muscle must also be strong enough to support the new joint.

Your doctor may recommend additional diagnostic testing to make sure you are healthy enough for surgery. Total knee replacement requires general anesthesia, meaning you will be asleep (unconscious) for the duration of the operation. Since general anesthesia carries some risk, particularly for older adults, your doctor will ensure that you are healthy enough before recommending surgery.

Common conditions treated

The most common condition treated with total knee replacement is age-related osteoarthritis or joint degeneration. Other possible reasons to seek a knee replacement include:

  • Trauma, such as a fall or other injury
  • Cancer affecting the bones or joint tissues of the knee
  • Rheumatoid arthritis or other degenerative conditions affecting the joint
  • Other conditions affecting the bones and joints
  • Osteonecrosis, a rare condition in which bone tissue within the knee joint does not have good blood supply and dies
  • Infections of the knee joint

Types

The approach your surgeon chooses for your knee replacement will vary depending on your underlying health and the state of your knee. Knee replacement surgery can be broken into several categories, including:

  • Total knee replacement, in which the entire joint is replaced with a synthetic (metal or plastic) or animal knee joint
  • Partial knee replacement, in which only part of the knee is replaced
  • Kneecap replacement, in which only the kneecap is removed and replaced
  • A complex or revision kneecap replacement, which includes several types of procedures, including repairs or reinstallations of a previous knee replacement

Risks

Knee replacement surgery is usually only used to replace knees that have been irreparably damaged by conditions like osteoarthritis.

Depending on your age, health history, and overall health going into the surgery, you may be at risk for complications. While a knee replacement rarely leads to complications, any surgery comes with some risks, such as:

  • Infection
  • Bleeding
  • Blood clots
  • Pain or swelling around the incision site
  • Nerve damage
  • Allergic reaction to the replacement joint or anesthesia
  • Implant rejection or failure, in which your immune system attacks the replacement joint