Tissue Damage from Metal-on-Metal Hip Implants Can be Detected Before Symptoms Occur, New Study ReportsMay 21, 2013
A new study by researchers at New York’s Hospital for Special Surgery shows that metal-on-metal hip implants can cause inflammation of the joint lining long before symptoms appear.
The study findings demonstrate that MRI scans can identify implants that are going to fail before people become symptomatic, according to HealthCanal.com. The study will appear in the Journal of Bone & Joint Surgery.
Synovitis (inflammation of the joint lining) is fairly prevalent in asymptomatic implant recipients, said Dr. Hollis Potter, chief of the Division of Magnetic Resonance Imaging at the Hospital for Special Surgery. “If that is the case, symptoms alone are insufficient to determine the health of an implant,” Potter said. MRIs can help identify patients who need corrective surgery before further tissue damage makes revision surgery more difficult.
The researchers examined 69 subjects (74 hips) referred to the Hospital for Special Surgery for an MRI after a metal-on-metal hip resurfacing procedure. Some of the subjects were asymptomatic, others had unexplained pain, and some had pain from a mechanical cause (loosening or dislocation of the implant, for example), HealthCanal.com explains.
Analysis of the MRIs identified synovitis in 68 percent of asymptomatic hips, 75 percent of symptomatic hips with a mechanical cause, and 78 percent of hips with unexplained pain, HealthCanal.com reports.
“The data show that there is a high prevalence of abnormal synovial response in both symptomatic and highly functioning, asymptomatic patients,” Dr. Potter said. “What was really interesting about this study was that we found that synovitis was detected in the same amount in symptomatic and asymptomatic patients.”
Metal-on-metal hip devices have been the focus of investigations, manufacturer recalls, and extensive litigation because of high failure rates, injuries, and complications. Many patients have had to undergo additional surgeries to correct problems, with no guarantee of a full recovery. In thousands of pending lawsuits against hip implant manufacturers, patients allege that faulty device design and inadequate testing led to serious, sometimes permanent, injuries.