Patients suffering from a defective Zimmer NexGen have started filing individual lawsuits and there is no national Zimmer class action lawsuit covering all cases. Orthopedic surgeons warn patients receiving knee implants that their prostheses can be expected to loosen after fifteen years. This problem can occur for a number of reasons, including infection, bone deterioration and resorption, and most commonly, mechanical failures. The CR-Flex knee implant manufactured by Zimmer Orthopaedics has been known to loosen much earlier – often, within two years of implantation. This is one of the reasons prominent orthopedists have urged the joint manufacturer to announce a wide-scale Zimmer knee recall.
Premature loosening is a serious complication with total knee arthroplasty. Not only does it cause immediate pain in the compromised joint, but it also accelerates the breakdown of the patient’s bone stock. Below, we’ll describe the symptoms of knee implant loosening, and highlight the factors that play a role.
Signs Of Premature Loosening Of The Prosthesis
If the tibial or femoral component of your NexGen CR-Flex implant becomes loose, you will experience one or more side effects. The severity of the symptoms is determined by the amount of loosening in the joint. Patients in whom the prosthesis has just begun to shift may feel minor stiffness in the knee. This stiffness will usually persist throughout the day.
Recipients with knee implants that have sustained extensive loosening will encounter more intense pain. This pain will begin in the site of implantation, but spread into the surrounding area as loosening becomes progressively worse. Some patients may have difficulty moving and placing their entire weight on the failing prostheses. Many develop a pronounced limp due to the discomfort that accompanies walking.
If you suspect that your Zimmer knee implant has become loose, ask your doctor to take x-rays of the joint. The images will reveal spaces between the bone and the tibial or femoral components. These spaces will often fill with connective tissue.
What Causes Loosening In The Zimmer Knee Implant?
There are many possible reasons your NexGen knee replacement can loosen prematurely. Earlier, we mentioned the bone of the joint may deteriorate or experience resorption. In the former case, a loose tibial or femoral piece can damage the surface of the tibia or femur (respectively). Sometimes, tiny fractures will form, causing the joint to becomes less stable.
With resorption, the bone to which the prosthesis is attached breaks down due to exposure to foreign particles. These particles flake off from the tibial and femoral components as well as the polyethylene spacer. The body attempts to “clean” the area of this foreign debris by initiating an autoimmune response. This response causes resorption.
It is also noteworthy that the Food and Drug Administration (FDA) issued a Class 2 Zimmer knee recall in September 2010. The recall was announced due to complaints of premature loosening in the NexGen tibial plate. This component was originally designed to be implanted with or without surgical cement. However, five months prior to the FDA’s Zimmer NexGen recall, the joint manufacturer sent a letter to orthopedists, warning that they should only implant the tibial plate with cement. This warning suggests the component may have been defective.
When Does Revision Knee Surgery Become Necessary?
A knee replacement that loosens will eventually need to be replaced. The problem will continue to worsen, causing increasing pain and reduced mobility. Unfortunately, revision surgery is often problematic due to the deterioration in the patient’s bone stock. The compromised tibia or femur (or both) is less capable of holding the replacement prosthesis in place.
For this reason, orthopedic surgeons usually urge their patients to wait until the pain becomes unbearable before undergoing revision surgery. The longevity of the replacement knee implant is rarely as good as the original.
The failure rate of the Zimmer NexGen CR-Flex is estimated at 9 percent, far higher than comparable knee replacements. Loosening, pain, and dislocation are the most serious complications stemming from a defective implant. If you are currently suffering from knee pain, swelling, looseness of the joint, or other serious Zimmer knee side effects, you may be due compensation for your injuries. Contact a Zimmer knee replacement recall lawyer to discuss your legal options.
