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Revision Knee Replacement

If your knee replacement fails, your doctor may recommend that you have a second surgery—revision total knee replacement. In this procedure, your doctor removes some or all of the parts of the original prosthesis and replaces them with new ones.
Although both procedures have the same goal—to relieve pain and improve function—revision surgery is different than primary total knee replacement. It is a longer, more complex procedure that requires extensive planning, and specialized implants and tools to achieve a good result.

During primary total knee replacement, the knee joint is replaced with an implant, or prosthesis, made of metal and plastic components. Although most total knee replacements are very successful, over time problems such as implant wear and loosening may require a revision procedure to replace the original components.

There are different types of revision surgery. In some cases, only one implant or component of the prosthesis has to be revised. Other times, all three components—femoral, tibial, and patellar—need to removed or replaced and the bone around the knee needs to be rebuilt with augments (metal pieces that substitute for missing bone) or bone graft.
Damage to the bone may make it difficult for the doctor to use standard total knee implants for revision knee replacement. In most cases, he or she will use specialized implants with longer, thicker stems that fit deeper inside the bone for extra support.

Procedure

Revision total knee replacement is more complex and takes longer to perform than primary total knee replacement. In most cases, the surgery takes from 2-3 hours.
To begin, your doctor will follow the line of the incision made during your primary total knee replacement. The incision may be longer than the original, however, to allow the old components to be removed. Once the incision is made, the doctor will move the kneecap and tendons to the side to reveal your knee joint.
Your doctor will examine the soft tissues in your knee to make sure that they are free from infection. He or she will assess all the metal and/or plastic parts of the prosthesis to determine which parts have become worn or loose or shifted out of position.
Your doctor will remove the original implant very carefully to preserve as much bone as possible. If cement was used in the primary total knee replacement, this is removed, as well. Removing this cement from the bone is a time-consuming process that adds to the complexity and length of the revision surgery.
After removing the original implant, the doctor will prepare the bone surfaces for the revision implant. In some cases, there may be significant bone loss around the knee. If this occurs, metal augments and platform blocks can be added to the main components to make up for the bony deficits.

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