Complications – Revision Arthroplasty
Complications can happen in all major surgical procedures. Some of the most common complications which can occur following revision knee arthroplasty are:
- Anesthesia complications
- Aenous thromboembolism
- Myositis ossificans
- Implant loosening
- Wound complications
Surgical procedures are performed either under general or regional anesthesia and most of them have no complications. However, a very small number of patients do develop problems with anesthesia. These problems can be reactions to the drugs, complications of general anesthesia and hypotension from regional anesthesia. Patients are advised to discuss their concerns with the anesthetist.
Deep Venous Thrombosis (DVT), can occur after any operation, but it is more likely to occur following surgery on the hip, pelvis, or knee. DVT occurs when the blood in the large veins of the leg forms blood clots. This may cause the leg to swell and become warm to the touch and painful. If the blood clots in the veins break apart, they can travel to the lung, where they lodge in the capillaries and cut off the blood supply to a portion of the lung. This is called a pulmonary embolism. (Pulmonary means lung, and embolism refers to a fragment of something traveling through the vascular system.) Most surgeons take DVT prevention very seriously. Two commonly used preventive measures include
- Mechanical prophylaxis: graduated pressure stockings to keep the blood in the legs moving, foot pumps
- Chemical prophylaxis : medications that thin the blood and prevent blood clots from forming
Infection can be a very serious complication following an artificial joint replacement revision. Some infections may show up very early, even before you leave the hospital. Others may not become apparent for months, or even years, after the operation. Infection can spread into the artificial joint from other infected areas. Your surgeon may want to make sure that you take antibiotics when you have dental procedure or surgical procedures on your bladder and colon to reduce the risk of spreading germs to the joint. The risk of infection is higher in revision arthroplasty than in primary joint arthroplasty. In a primary knee replacement, the risk of infection is less than one percent. It goes up to two percent or more in revision cases. These figures are only an estimate and vary between different scientific studies.
Myositis ossificans is a peculiar problem that can affect the knee after both primary knee replacement and revision knee replacement. The condition occurs when the soft tissue around the knee joint begins to develop calcium deposits. Myositis means inflammation of muscle, and ossificans refers to the formation of bone. This can lead to a situation where new bone actually forms along the sides and top of the knee. This leads to stiffness and loss of motion in the knee joint. Myositis ossificans is more common in people who have a long history of osteoarthritis with multiple bones spurs. Something about the genetic makeup in these people makes them more likely to produce bone tissue. Major reconstruction operations such as a knee revision seem to do more damage to the surrounding tissues than primary knee replacements. The operation is longer and more difficult to perform. Calcium deposits are also more likely to form.
The treatment of myositis ossificans may actually begin before you get it. In cases where you are at high risk for developing this condition, your surgeon may recommend that you take medications such as indomethacin after surgery. This medication reduces the tendency for bone to form and may protect you from developing myositis ossificans.
A much more effective method that has been used a great deal to prevent the development of myositis ossificans involves radiation treatments immediately after surgery. These are the same type of radiation treatments used to treat cancer. Several short radiation treatments begun the day after surgery and continued for three to five days seem to drastically reduce the risk of developing myositis ossificans.
If myositis ossificans forms despite these precautions, treatment will depend on how much it affects your knee. Your surgeon will note how much pain it causes and how much it restricts motion. In some severe cases, you may choose to have a second operation to remove the calcified tissue that has formed. This is usually followed by radiation treatments to prevent the calcium deposits from returning.
The major reason for failure of joint arthroplasty is mainly because of loosening where the metal or cement meets the bone. A loose prosthesis is a problem because it causes pain. Once the pain becomes unbearable, another revision surgery may be needed. The rate of loosening is higher after revision surgery than in primary arthroplasty.
Poor healing of the wound is a fairly common complication of knee revision arthroplasty. This is because the tissue is often scarred and thinner than when the original knee replacement was done. The blood supply to the skin may not be normal due to damage to the blood vessels from one or more previous knee surgeries. As mentioned earlier, previous skin incisions can make it hard for the incision to close after knee revision surgery, leading to complications. When the wound doesn’t heal properly, the chances of infection increases. The wound may continue to ooze, creating optimal conditions for bacterial growth.
Poor incision healing is more likely to occur in patients with one or more of the following factors:
- Previous wound healing problems
- Weak immune system
- Poor circulation
- Diabetes mellitus
Your surgeon’s goal is to prevent problems with the wound. If problems do happen, however one or more additional surgeries will likely be needed.
A revision joint replacement of the knee is more complex and unpredictable than a primary joint replacement. Since many factors can influence its lifespan, your surgeon will not be able to say exactly how long your revision will last. Also, keep in mind that because revision surgery is more complicated than primary joint replacement, it may take up to a year to be able to perform your routine daily activities. Often people continue to need a walking aid because knee pain increases when they are on their feet for prolonged periods. There is also a greater chance that the knee will be tight and unable to bend all the way after knee revision surgery.
Sometimes a choice other than knee revision is best because a big operation might result in a failure, or even death. Removing the prosthesis and not replacing it doesn’t mean the patient can’t walk any more. The surgeon may sometimes suggest fusing the knee joint, placing a spacer in the joint, or in some cases amputating the leg.