Knee Replacement Surgery

One of the most important orthopaedic surgical advances of this century, knee replacement was first performed in 1968. Improvements in surgical materials and techniques since then have greatly increased its effectiveness. According to the American Academy of Orthopaedic Surgeons about 267,000 total knee replacements are performed each year in the United States.

Most Common Causes

  • Arthritis: Arthritis is a wearing away of the surfaces (articular cartilage) of the joint, caused either by aging or disease. As the cartilage wears away, the raw bones rub together whenever the joint moves. This rubbing causes pain and a roughening of the surfaces of the bone.
  • Osteonecrosis: If the blood supply to the thighbone is decreased, part of the bone will die and break from weight-bearing activity. The result is a very painful joint.
  • Injuries: Injures include trauma and accidents, or continue abuse from sports injuries.

If medications, changing activity level, and using walking supports are no longer helpful, you may want to consider total knee replacement surgery. By replacing the knee's damaged and worn surfaces, total knee replacement surgery relieves pain, corrects leg deformity, and helps patients to resume your normal activities.

The physicians at the Cedars-Sinai Orthopedic Center are consistently developing new technologies, instrumentation and more minimally invasive techniques for knee replacement surgery. This leads the way to more accurate outcomes, shorter hospital stays, faster recovery and less pain. Knee replacement surgery procedures include:

Total Knee Replacement: Traditional Procedure

Total knee replacement surgery is very effective, relieving nearly all pain in most cases. Approximately 90 percent of replacement joints last 10 years, while 80 percent are good for 20 years, depending on patient activity levels. Outcomes vary from patient to patient.

It is important to realize that a knee "replacement" is actually just a "resurfacing" of the knee joint. The femur or thighbone is covered with a metal covering and plastic is placed on the tibia so that instead of irregular arthritic surfaces, one has metal and plastic articulating which produces a smooth non-patent surface. In most cases the undersurface of the kneecap is also replaced with a plastic surface so that this articulates with the femoral surface.

The actual procedure involving knee replacement involves a three to six day hospitalization. Weight bearing begins immediately the first postoperative day. Post-operative care after hospital discharge usually consists of a combination of home health care, physical and occupational therapy and other forms of rehabilitation. Patients usually use a walker for a period of one to two weeks, going to crutches and then a cane. People are off all walking aids anywhere from three weeks to two months.

Activities after knee replacement that should produce no difficulty are simple walking, bicycling, golfing, and swimming. The prosthesis is not designed form impact loading sports such as skiing, basketball, and racquetball. People have been known to play doubles tennis with bilateral knee replacements. To prepare you for surgery, the Cedars-Sinai Orthopaedic Center has developed an extensive surgery education class and daily recovery guide for your hospital stay so you understand all aspects and anticipations prior to surgery. This leads to a faster recovery and an easier transition.

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Partial Knee Replacement

A parital knee replacement or uni-compartmental knee replacement involves replacing only the part of the knee that is arthritic. Traditionally, this procedurle was reserved for older and more sedentary patients. Now, a partial knee replacement is recommended more often for younger individuals. Benefits include:

  • A smaller, more minimally-invasive incision
  • The removal of less bone leads to preservation or normal, healthy bone
  • Less pain
  • Less blood loss
  • A faster recovery and return to work within a couple of weeks versus up to a month or more.
  • Much easier transition to a total joint replacement (fi it is needed later)
  • 91 percent of partial knee replacements last longer than 10 years.
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Mini-Incision Knee Replacement

In traditional knee replacement surgery, the surgeon makes a long incision over the middle of the knee and cuts muscles, tendons and ligaments to get to the knee joint. When more tissues, muscles and tendons are cut during surgery, the recovery is more painful and the healing process takes longer. Cedars-Sinai offers a minimally invasive knee replacement surgery technique that significantly reduces overall surgery trauma and recovery time. The procedure is called the mini-incision total knee replacement and involves a smaller incision that the traditional total knee replacement. By doing a smaller incision using special instrument to approach the knee from the side, there is minimal trauma to the soft tissue, muscles and tendons. Even the kneecap does not have to be moved as far to get to the knee joint. The same types of joint prosthetics are used as the total knee replacement; however, it is more precisely and carefully placed through the muscle and tendons.

This careful placement of the knee replacement leads to the following benefits:

  • Less pain after surgery due to less manipulation and more precise placement.
  • Eliminates the amount of cutting done to replace the knee joint, for an overall faster recovery.
  • Reduces hospital stay is 1 to 2 days versus 4 to 6 days.
  • Less time is need for rehabilitation therapy
  • Return to work and normal activities within a couple of weeks versus up to a month or more.
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