Arthritis: Knee Replacement Surgery

Who Needs Knee Replacement Surgery?

A person may want to consider knee replacement surgery if they have a stiff, painful knee that prevents them from performing even the simplest of activities and other treatments are no longer working.

What Happens During Knee Joint Replacement Surgery?

Once you are under general anesthesia (meaning you are temporarily put to sleep), spinal, or epidural (numb below the waist) anesthesia, an eight- to twelve-inch cut is made in the front of the knee. The damaged part of the joint is removed from the surface of the bones, and the surfaces are then shaped to hold a metal or plastic artificial joint. The artificial joint is attached to the thigh bone, shin and knee cap either with cement or a special material. When fit together, the attached artificial parts form the joint, relying on the surrounding muscles and ligaments for support and function.

What Are Recent Advances in Knee Joint Replacement Surgery?

Minimally invasive surgery (MIS) has revolutionized knee replacement surgery as well as many fields of medicine. Its key characteristic is that it uses specialized techniques and instrumentation to enable the surgeon to perform major surgery without a large incision.

MIS knee joint replacement requires a much smaller incision, three to five inches, versus the standard approach and incision, which is typically eight to twelve inches. The smaller, less invasive approaches result in less tissue trauma by allowing the surgeon to work between the fibers of the quadriceps muscles instead of requiring an incision through the tendon. It may lead to less pain, decreased recovery time and better motion due to less scar tissue formation.

Currently this less invasive procedure is performed by only a small percentage of orthopaedic surgeons in North America. Because this type of surgery is still relatively new, research has been initiated to determine how the immediate and long-term results will compare to traditional surgery.

What Happens After the Surgery?

The average hospital stay after knee joint replacement is usually three to five days. The vast majority of people who undergo knee joint replacement surgery have dramatic improvement. This improvement is most notable one month or more after surgery. The pain caused by the damaged joint is relieved when the new gliding surface is constructed during surgery.

After knee joint replacement, people are standing and moving the joint the day after surgery. At first, you may walk with the help of parallel bars, and then a walking device -- such as crutches, walker, or cane -- will be used until your knee is able to support your full body weight. After about 6 weeks, most people are walking comfortably with minimal assistance. Once muscle strength is restored with physical therapy, people who have had knee joint replacement surgery can enjoy most activities (except running and jumping).