When a knee implant fails from age or a product defect, doctors perform revision surgery to replace the old implant. This surgery is more complex than the original and has a higher risk of complications.
When a person has knee replacement surgery for the first time, this initial surgery is referred to as primary surgery. If complications arise from the primary surgery or the knee implant fails, doctors perform revision surgery to correct any problems. Joint replacement revision surgery is considered one of the most complex procedures in modern orthopaedics.
The number of people requiring this procedure continues to rise as more people receive knee implants each year. About 67,000 people required knee replacement revision surgeries in the Unites States in 2010, a 5 percent increase from 2009. More than 600,000 had primary knee replacement surgery in 2010. Projected hospital costs for total knee revision surgeries are expected to exceed $2 billion by 2030. Because primary knee replacement surgeries are expected to grow by 673 percent to 3.48 million procedures annually by 2030, revision surgery is also expected to grow by 601 percent.
- In 2010, there were 67,000 knee replacement revision surgeries.
- In 2030, 3.48 million knee replacements are projected to be completed.
- In 2006, the average cost of revision surgery was $74,000.
- Revision surgery has a higher rate of complications than primary surgery.
Knee implants last between 10 and 20 years in 90 percent of people. At the end of a device’s lifespan, it ceases to work properly. This is usually not a problem for older people, as the device typically lasts for the rest of their lives. However, younger patients require revision surgery at the end of the device’s lifespan. In addition, younger, more active people are more likely to wear out the components sooner, requiring an implant replacement sooner. Studies show that younger, male patients have a significantly higher rate of revision than other patients. Other factors that influence the lifespan of a prosthesis include a patient’s weight and bone condition. While most devices simply wear out over time, a growing number of devices fail in a year or less because of faulty design.
Complications from primary surgery — specifically due to a faulty implant — also may require revision surgery to replace the device. Revision surgeries arising from complications are usually more costly, complex and dangerous procedures, and fewer surgeons and centers perform revision surgeries. In addition to long recovery times and the possibility of painful complications, people are often left with large medical bills. In 2006, the average charge for a total knee revision surgery was almost $74,000. Most surgeons will only perform knee replacement revision surgery if more conservative methods for managing pain are exhausted. Unfortunately, many people who suffer because of serious complications or faulty implants often find themselves with revision surgery as the only option. Many of these patients have sued the manufacturers of defective knee devices to recoup some of their medical costs and to compensate them for pain and suffering.
Complications Leading to Revision Surgery
There are several complications that can lead to knee replacement revision surgery. One of these is device failure. The device may fail because of a manufacturer defect or because of a patient’s lifestyle. For example, people who are overweight may have to replace their implants sooner. Excessive weight-bearing or high-impact activities can also cause an implant to fail early.
|Complications arising from defective implants that may require revision surgery include:|
|Bone Fracture||Component breaking|
|Joint pain||Joint swelling|
|Loosening of implant||Misaligned component|
Activity Recommendations after Knee Replacement Surgery to Avoid Early Revision Surgery
While knee replacements allow a person to live a relatively normal life, doctors stress that caution should still be exercised when performing high-impact or weight-bearing activities to avoid the need for revision surgery.
|Expected Activities||Activities Exceeding Recommendations||Dangerous Activities|
|Recreational walking||Vigorous walking or hiking||Jogging or running|
|Driving||Repetitive lifting of more than 50 pounds||High-impact aerobics|
|Ballroom dancing||Repetitive aerobic stair climbing|
|Normal stair climbing|
Source: University of Connecticut Health Center, Total Joint Replacement Conditions and Treatments
Osteolysis is another complication that can occur over time and require revision surgery. In osteolysis, particles from the plastic parts of knee implants cause the body’s immune system to attack and digest the patient’s bone. The implant loosens from severe bone damage, and revision surgery is required to adjust the implant. This is more common in patients with polyethylene implants.
Revision surgery may also be required to resolve other complications experienced from the primary knee surgery. Some of these are more serious than others. In some cases, multiple revision surgeries are required.
|Serious complications that can arise after a primary knee replacement and require immediate revision surgery include:|
|Joint infection||Joint stiffness|
|Ligament instability||Patellar dislocation|
|Excessive scar tissue||Nerve or blood vessel damage|
Revision Surgery Procedure
After running a series of tests, including blood tests, imaging tests, joint fluid tests and a physical examination, an orthopaedic surgeon will determine if revision surgery is necessary. Then, the condition of the implant is carefully assessed to determine how extensive the procedure will be. A primary knee replacement typically takes 1 to 2 hours, but a knee replacement revision can take 3 hours. In most cases, the surgeon will follow the line of the incision made during the primary knee replacement, which is usually 8 to 12 inches long. However, the incision may be longer than the original to allow for removal of the old components. Next, the surgeon moves the patella and attached tendon to reveal the joint. The old device components are removed carefully to preserve as much bone as possible. If cement was used, this is also removed.
After removing old components, the surgeon prepares the bone surfaces for the revision implant. Revision implants are different from primary knee surgery implants and have longer, thicker stems that fit deeper inside the tibia and femur for extra support. Any damaged bone is removed. Usually, the damage to the bone is extensive, and a bone graft is required to fill in any spaces left by removing damaged bone. This new bone can come from another part of the patient’s body (autograft) or cadaver bone (allograft) obtained from the bone bank. Additional hardware such as screws, metal wedges or wires may be used to improve bone strength.
Finally, the revision components can be fixed to the bone, and the patella is moved back into place. Any tissues that were damaged around the joint are repaired. The motion of the knee is carefully tested before repairing the tendons, quadriceps muscles and closing the skin. Drains are placed in the knee to allow any fluid that may build up in the joint to exit.
Revision Surgery Recovery
Recovery time varies depending on the individual. For primary knee replacement surgery, short-term recovery can take as long as half a year, and a full recovery can take as long as a year. Because knee revision surgery is more complicated, it usually takes longer to recover. Rehabilitation after revision surgery is also more aggressive and usually begins within 24 hours of surgery and continues for about 3 months. Patients are restricted in movement for 6 to 12 weeks. A protective brace may also be used to protect the knee joint.
Complications after Revision Surgery
After revision surgery, there are several complications that can occur and many are similar to those for primary knee replacement surgery. The risk of complications, some fatal, is higher than during primary surgery. Studies show that the rate of hospital re-admissions within 30 days of revision surgery was 8.9 percent from 2007 to 2010 . The risk of heart-related complications, such as congestive heart failure and stroke, are more elevated after revision surgery, especially during the first 30 days. Patients also experience a greater risk for blood clots because revision surgery causes more trauma to the blood vessels than primary surgery. Because the patient is immobile for a longer period of time after surgery, there is an increased risk of developing life threatening blood clots.
One of the most serious complications of knee replacement revision surgery is infection. While the risk of infection is relatively low in primary knee replacement surgery (less than 1 percent), the risk can be as high as 10 percent after knee replacement revision surgery. In one study, doctors found that infection caused implant failure after revision surgery in 46 percent of patients; loosening was the cause in 19 percent of patients; and instability was to blame in 13 percent.
More painful and complicated surgical procedures are required to cure infections. In severe cases, if infection does not respond to antibiotics and surgery, the limb must be amputated or fused together with metal rods and nails in a procedure called arthrodesis. Arthrodesis is a viable alternative to amputation, but the patient loses the ability to bend the limb.
Recalled Implants and Lawsuits
Unfortunately, most manufacturers of knee implants release these components for public use without testing, and it is perfectly legal for them to do so. The Food and Drug Administration (FDA) does not require them to test new devices as long as there are similar products on the market. When the products prove to be defective, it leaves many people with severe knee pain, loss of joint mobility and the need for revision surgery.
Because of a growing number of serious problems resulting from defective implants, many manufacturers have issued recalls. One woman was implanted with Stryker’s Triathlon knee implant. Only two months after her surgery, she experienced severe pain and underwent the first of five revision surgeries to correct the pain. Stryker has recalled a number of its products, including the EIUS Unicompartmental Knee System and Triathlon TS Knee System. This injured woman filed suit against Stryker for ongoing pain, suffering and compensation for medical expenses.
If you have had revision surgery or your doctor has recommended revision surgery because of a problematic device, your knee implant may have been recalled. When companies issue recalls, they usually send out notifications to surgeons who may have implanted the devices. Many people who have had to have revision surgery because of an implant recall have filed lawsuits against the manufacturers. If you are concerned, you should contact a product liability attorney and try to identify your implant. Some manufacturers that have been named in lawsuits for defective and recalled knee implants include Zimmer Holdings, Stryker and Smith & Nephew.