MRI Can Detect Metal-on-Metal Zimmer Hip Complications

According to a new medical study, magnetic resonance imaging (MRI) can be used to identify and measure inflammation of the joint lining in patients with metal-on-metal hip implants. Measuring this type of inflammation, called synovitis, can help doctors to diagnose unexplained pain in hip implant recipients and may also be able to warn doctors about the onset of tissue damage and implant failure before patients begin to experience joint pain and other symptoms.

MRI can help diagnose Zimmer hip complications

The study, published in the Journal of Bone & Joint Surgery, involved measuring the volume of synovitis inflammation in different hip implant recipients. Patients were divided into three groups: one group who had no symptoms, one group with pain due to mechanical failure (such as implant loosening, joint dislocation, or bone fracture), and one group with unexplained joint pain. The research showed that 78% of the hips causing unexplained pain showed synovitis, with a significant amount of inflamed tissue. This inflammation suggests a diagnosis of “adverse local tissue reaction”, a condition caused by the shedding of metallic debris from certain types of metal hip implants.

According to the FDA, metal-on-metal hip implants, where two or more metal components rub against each other, “have unique risks in addition to the general risks of all hip implants.” In particular, these implants – such as the DePuy ASR XL or the Zimmer Durom Cup – have a tendency to release microscopic metallic particles from the intersection of the metal components. These metallic particles cause adverse local tissue reactions, which can include pain, inflammation, and tissue necrosis. Soft tissue damage can also lead to implant loosening, bone fracture, and device failure, all of which may require additional surgeries to correct. For this reason, an FDA recall has been issued for both the DePuy ASR XL and the Zimmer Durom Cup hip replacement.

Early detection of hip replacement problems

The study also found that 68% of hips without joint pain had measurable inflammation of the joint lining. The study’s authors suggest that this inflammation suggests that the devices are shedding metallic debris and therefore may be likely to fail. The study concludes that MRI scans can be used to track the progress of inflammation and help doctors determine when an implant will need to be replaced before extensive bone and soft tissue damage makes that surgery more difficult and complicated.

This diagnostic testing could help the thousands of people with metal-on-metal implants prevent the debilitating tissue damage characteristic of Zimmer hip complications. Over 12,000 patients have received Durom Cup implants and studies show that 24% of the implants fail within the first four years. Over 200 Zimmer hip lawsuits have been filed alleging injury and product defect as a result of these complications.

Manufacturer settling Zimmer hip lawsuits

Court records show that nearly 200 federal Zimmer hip lawsuits have been consolidated in U.S. District Court in New Jersey, and more than half have already been settled. By Zimmer’s estimates, the company may end up being liable for hundreds of millions of dollars in damages to patients who were injured by Zimmer’s Durom Cup. Meanwhile, DePuy Orthopedics is facing over 14,000 lawsuits in state and federal courts over its ASR XL and Pinnacle hip systems, which also feature metal-on-metal construction.