Revision surgery is often required when a knee replacement no longer functions correctly, During this procedure, a surgeon replaces the old device with a new one.
Revision surgery is more complicated than a primary (or initial) total knee replacement (TKR) and involves many of the same risks.
In our country, many patients undergo knee replacement surgery each year. More than half of these procedures take place within two years of the initial knee replacement.
Why revision surgery is more complicated than the initial surgery?
Revision knee replacement is not as lasting as an initial replacement which usually lasts for 10 to 20 years. The revisions are also more susceptible to complications as the piled-up trauma scared tissue, and mechanical breakdown of components leads to reduced performance.
A revision procedure is typically more complex and painful than the original knee replacement surgery as the original implant needs to be taken out which would have grown into the existing bone.
Also once the surgeon removes the prosthesis, there is less bone remaining. In some cases, a bone graft — transplanting a piece of bone from another part of the body or from a donor —is required to support the new prosthesis. A bone graft adds support and encourages new bone growth.
The procedure requires additional preoperative planning, specialized tools, and greater surgical skill. The surgery takes more time to get over than a primary initial knee replacement.
Revision surgery is necessary if you experience specific symptoms. Indications of excessive wear or failure include:
- Reduced function and stability in the knee.
- A lot of pain or infection (which usually occurs soon after the initial procedure)
- A bone fracture or outright device failure
In some other cases, bits and pieces of the prosthetic device break off and cause tiny particles to accumulate around the joint.
Reasons for a revision
Short term reasons:
- implant loosening from the failed procedure,
- or a mechanical failure
An infection will usually manifest itself within days or weeks of surgery. However, an infection can also occur many years after surgery.
The infection causes severe complications. The cause of infection is bacteria that settle around the wound or within the device. Infection can also be spread by contaminated instruments or by people or other items within the operating room.
Infection rarely occurs as an extreme precaution is taken in the operating room. However, if an infection takes place, it can lead to a buildup of fluids and potentially a revision surgery.
If any unusual swelling, tenderness, or fluid leakage is felt then, contact the surgeon immediately. If the surgeon suspects a problem with your existing artificial knee, you’ll be asked to undergo an examination and assessment. After that, it will be determined if you need revision or not.
People experiencing fluid buildup around their artificial knee usually undergo an aspiration procedure to remove the fluid. The fluid is sent to a lab to determine the type of infection and whether a revision surgery or other treatment steps are in order.
- loosening due to wear of mechanical components,
Long-term wear and loosening of the implant can occur over years.
The data on long-term revision rates varies and depends on numerous factors, including age. For younger people, the chances of revision are lower. Weight is another factor. You can reduce future problems by maintaining your weight. Avoiding activities that place undue stress on the joint, such as running, jumping, court sports, and high-impact aerobics also lowers the risk of a revision.
In the process called aseptic loosening, the bond between the bone and the implant breaks down as the body attempts to digest the particles. If this happens, the body begins to digest bone, which is known as osteolysis. This can lead to a weakened bone, fracture, or problems with the original implant. Aseptic loosening doesn’t involve an infection.
Revision surgery for an infection
Typically, a revision required because of infection involves two separate operations: Initially, the old prosthesis is removed, and a polyethylene and cement block known as a spacer that has been treated with antibiotics is inserted.
During the second procedure, the spacer or molds are removed and reshaped and the resurfaced knee is implanted. Both the procedures usually take place at a gap of about six weeks. Inserting the new device typically requires 2 to 3 hours in surgery, compared to 1 1/2 hours for a primary knee replacement.
If a bone graft is required then, the surgeon will either take bone from another part of your own body or use bone from a donor. Metal pieces might also be installed such as wedges, wires, or screws to brace the bone for the implant or fasten the implant to the bone. A specialized prosthetic device is needed by the surgeon for a revision.
Complications following knee revision surgery are similar to those for knee replacement. They include:
- Deep vein thrombosis
- The new implant getting infected.
- Implant loosening, in case you’re overweight
- Dislocation of the new implant, the risk of which is twice as high for revision surgery.
- Additional or more rapid loss of bone tissue
- Bone fractures may occur if the surgeon must use force or pressure to remove the old implant during the surgery.
- The difference in leg length as a result of the shortening of the leg with the new prosthesis.
- Development of bone at the lower end of the femur following surgery known as a heterotopic bone. (Joint infections after surgery increase the risk for this.)
Recovery and rehabilitation are almost the same as someone who receives a primary knee replacement including medication, physical therapy, and the administration of blood thinners to prevent clots. An assistive walking device such as a cane, crutches, or walker is needed in the beginning. Physical therapy may continue for three months or longer.
It’s important to stand and walk as quickly as possible as with the original knee replacement. For the bone to grow and to properly bond with the implant, pressure, compression, or resistance is needed as well.
The period of recovery after revision knee surgery differs in comparison to a first knee replacement. Some individuals take longer to recover from revision surgery, while others recover more rapidly and experience less discomfort.
If you think you require a revision knee surgery then, speak to your doctor and look over your condition to make sure whether you’re a good candidate for the surgery or not.