Scientific Observations Point to Zimmer Knee Problems
The first major public event to draw public attention to Zimmer knee problems was instigated by Dr. Richard Berger when he presented his personal observations of 108 patients who had received a Zimmer NexGen CR-Flex device. But a lesser known study from Korea in 2008 also produced findings that a Zimmer knee lawyer might use in a Zimmer knee lawsuit in an attempt to show that the artificial knee maker might have known that its NexGen CR Flex devices were prone to premature knee failure, sometimes requiring knee revision surgery.
Dr. Richard Berger and the Zimmer NexGen CR Flex
Dr. Richard A. Berger was a consultant for Zimmer who specialized in training other doctors on the proper surgical technique for implanting the NexGen CR Flex implant. With a mechanical engineering degree from MIT, Dr. Berger was considered something of a revolutionary in hip and knee replacement surgery by developing new device implantation strategies.
Doctors’ observations suggest Zimmer knee problems
In 2005, Dr. Berger performed 125 replacement surgeries on patients using the Zimmer NexGen CR Flex model knee. Soon after, in 2006, Dr. Berger examined x-rays of these patients which revealed some Zimmer knee problems. Lines on some x-rays where the implant met the thigh bone indicated that the NexGen CR Flex was loose and had not fused completely with the patient’s bone. Meanwhile, a number of patients, some of whom went on to hire a Zimmer knee lawyer and file a Zimmer knee lawsuit, reported pain to Dr. Berger, with a percentage of those having to undergo knee revision surgery.
Based on this 2005 experience, Dr. Berger teamed up with fellow orthopedic surgeon Dr. Craig Della Valle to observe and review such Zimmer knee problems. They reported their findings at an American Academy of Orthopaedic Surgeons conference in March of 2010. Berger stated that out of a pool of 108 NexGen CR Flex recipients, 8.3% experienced failure in the device that required revision surgery. The actual failure rate was expected to be even higher, however, as 36% of patients experienced radiographic loosening in the device.
Dr. Berger concluded that the CR Flex knee “… should not be used for any patient.”
Previous Dr. H.S. Han Study also indicated Zimmer knee problems
Dr. Berger has received a great deal of publicity, but his conclusions about Zimmer knee problems built upon those of an earlier report from Korea. In 2008, Dr. H.S. Han studied Zimmer knee problems in the NexGen Legacy Flex model, which has the same design as the NexGen CR Flex model, except that the patient’s posterior cruciate ligament is not preserved, but replaced. The Han study found that while the Legacy device did provide increased flexibility compared to other artificial knee systems, the femoral components experienced a substantial loosening rate of 38%. Meanwhile, 21% of patients required revision surgery within only two years of initial implantation.
A Zimmer lawyer representing an injured patient in a Zimmer knee lawsuit could conceivably argue that the Han study’s concluding comments could have sent a reasonable warning to the artificial joint maker about Zimmer knee problems: “We have not previously experienced such a high rate of early loosening for any design of total knee replacement.”