Zimmer Knee Replacement
The complications experienced by a number of people who have received Zimmer knee replacement systems since 2003 have prompted some patients to file Zimmer NexGen knee replacement lawsuit claims. A small number of surgeons, dismayed at the joint manufacturer’s refusal to issue a Zimmer knee recall for the CR-Flex system, have looked at alternative knee implants. A few, like Dr. Richard Berger – once a high-profile consultant for the company – have publicly stated the prostheses are unsuitable for patients.
With these issues in mind, we’ll review the components involved, and the reasons patients and orthopedists have complained. Along the way, we’ll address the question of whether a Zimmer NexGen recall for the CR-Flex knee replacement system is a future possibility.
There are technically two pieces that comprise the tibial component: a metal plate and a layer of polyethylene. The metal plate is positioned on the top portion of the tibia, and is usually attached to a stem. The stem is inserted into the center of the tibia for added support for the prosthesis.
The layer of polyethylene (a durable plastic) sits atop the tibial plate. It is the knee bearing surface of the implant. The plastic material provides a cushion between the tibial and femoral components, serving a function similar to cartilage.
It’s worth noting that a limited Zimmer knee recall was issued by the Food and Drug Administration (FDA) in September 2010. At the time, the agency noted it had received 114 MDRs (Medical Device Reports) regarding premature loosening in the tibial component. This loosening had required the recipients to undergo painful and complex revision surgery to have the prosthesis removed and replaced. The current controversy surrounding the Zimmer knee replacement systems is focused mainly on the femoral component, not the tibial piece.
This piece of the knee prosthesis attaches to the bottom of the femur. It is curved in the front, and extends upward over a small portion of the bone’s surface. A groove on the front of the component allows the kneecap (i.e. patella) to move up and down against it when the recipient bends her knee.
The femoral component can be implanted with or without surgical cement depending on the prosthesis. The NexGen CR-Flex is designed in two versions in order to accommodate both approaches. When cement is used, the implant is stable on the day it is installed. When cement is not used, the bone surrounding the femoral piece provides stability. Over time, it grows into the component’s porous surface, holding it in place.
Some patients have experienced problems with this version of the implant. Orthopedists have complained that the cementless femoral component is prone to premature loosening. Thus far, a NexGen knee recall addressing this problem has not been issued.
This piece is placed on the back of the kneecap. It is constructed of the same polyethylene used for the layer of cushion that sits atop the tibial component. In cases where the kneecap has not suffered damage from arthritis or trauma, the orthopedist may decide to preserve the original surface. As mentioned earlier, the patellar component moves up and down in the groove etched into the front of the femoral component.
To date, the artificial kneecap seems to be relatively free of problems. Unlike the tibial and femoral components, there have been no reports filed with the FDA regarding premature loosening.
A recent study showed that among 108 recipients of the Zimmer NexGen CR-Flex knee implant, 9 percent needed revision surgery within two years. A much higher percentage experienced loosening in the joint. This failure rate is far above the industry standard, a circumstance some critics have suggested is due to a design flaw. If you have suffered from knee pain, loosening or dislocation of the joint, or other Zimmer NexGen knee failure side effects, you may be due compensation for your injuries. Contact a Zimmer NexGen knee replacement lawsuit attorney to discuss your options.