Several of Zimmer's NexGen knee implants were recalled for different problems. Some failed prematurely, causing painful complications.
Zimmer began as a small, Indiana-based manufacturer of aluminum splints in 1927. Today the company has a large product line that includes artificial joints, surgical products, and spinal and trauma devices. Zimmer is also the world’s largest producer of knee replacement implants and controls 26 percent of the knee replacement market. Its worldwide knee replacement market is estimated to be $7.2 billion.
Since Zimmer developed its first total knee replacement in 1968, it has unveiled several successful implant models. One of its most successful products is the NexGen Complete Knee Solution System, released in 1995. In 2001, Zimmer attempted to capitalize on the success of this product line by releasing a modified version of the original design, the NexGen Flex line of products. According to the company, the NexGen Flex is designed to achieve an industry-leading 155 degrees of flexion.
However, several reports of adverse events and complications related to the NexGen Flex Knee were reported to the U.S. Food and Drug Administration (FDA), and the FDA targeted Zimmer Holdings in four product recalls. Its NexGen Complete Knee Solution MIS Tibial Components, NexGen TM Tibial Trays and MIS Modular Tibial Plates and Keels were recalled in September 2010, and the NexGen LPS-Flex Gender Femoral Component was recalled in December 2010. Then, problems with another Zimmer knee device that is not a part of the NexGen Flex line, the Natural-Knee II Durasul All-Poly Patella, prompted the FDA to issue a Class II Recall on Jan. 25, 2012. In March, 2015, the FDA issued a recall for its Persona Trabecular Metal Tibial Plate.
More than 1,000 lawsuits were filed against Zimmer for a number of complications resulting from the faulty design of its NexGen Flex devices, including the recalled MIS Tibial Components, the NexGen LPS-Flex GSF Femoral Component and three other models. Lawsuits may soon follow for the Persona knee.
Issues with Persona Trabecular Metal Tibial Plate
Zimmer’s Persona Trabecular Metal Tibial Plate is a part of the Persona Knee system and is designed to be used without cement and provide proper fixation to the bone. It can also be used with a wide variety of components. Surgeons may also use the implant in a number of surgical styles. According to the manufacturer, its design is very much like a natural knee.
The company reported it received an increased number of complaints about component loosening and radiolucent lines. Radiolucent lines are gaps in between the component and the bone or between components. Typically, this happens when a knee implant part is not secured correctly. These gaps can fill with joint fluid, tissue or debris from implant wear, causing osteolysis bone damage and lead to loosening and implant failure.
These issues led to the voluntary recall in March 2015 of 11,658 units. Zimmer sent an Urgent Medical Device Recall notice to hospitals and healthcare providers on February 16, 2015 with the instructions that “all affected product are to be located and quarantined immediately.
Complications and Problems with MIS Tibial Components
Zimmer designed the NexGen MIS Tibial component for use with two other NexGen Flex Knee products, the LPS-Flex and CR-Flex. The MIS Tibial component is used in minimally invasive surgical procedures, in which surgeons operate through a 4- to 5-inch incision as opposed to an 8- to 12-inch incision for traditional surgery. This technique aims to reduce blood loss and recovery time after surgery, but it is also more challenging and leaves more room for error.
After reports of high failure rates with the MIS Tibial Component, Zimmer issued an “Urgent Field Safety Notice”/”Urgent Device Correction” letter in April 2010, leading to the FDA recall in September of the same year. Zimmer admitted that part of the problem with the MIS Tibial Component design is that “MIS procedures are inherently challenging and can involve reduced visibility, which may lead to difficulty with achieving proper implant alignment and cement fixation.” After the company marketed this defective product and surgical technique, a number of implants loosened, and patients who received the knee were forced to have revision surgery to correct the problem.
NexGen LPS-Flex GSF Femoral Component and Natural-Knee II Durasul All-Poly Patella Problems
The second Zimmer knee device to be recalled was the NexGen LPS-Flex GSF Femoral Component. This device is marketed for use in female patients, and Zimmer claims it provides a superior fit and increased stability. One of the biggest problems with this component is its tendency to loosen, and the FDA reports “collapse” of the component that requires revision surgery. The device was recalled by the FDA because several of the implants had “nonconforming geometry,” meaning the parts of the implant did not fit together properly once implanted.
One of the least publicized recalls was the January 2012 recall of the Natural-Knee II Durasul All-Poly Patella. This product was recalled because it was prone to fracture, causing device failure and patellar problems. At the time of the recall, more than 100,000 devices had already been implanted.