In three babies born to mothers with metal-on-metal hip implants, doctors have found high chromium and cobalt in the infant’s umbilical cord blood. The metals had been produced by hip implant parts rubbing together during normal movement.
The doctors saw an association between levels of cobalt and chromium — components of metal implants — in mothers and their babies at the time of delivery, the Spoked Blog reports. The finding was only for women with metal-on-metal (MoM) hip implants, in which both the ball of the joint and the cup of the socket are made of metal. The researchers stress that they are not sure if these metals have detrimental effects for either the mother or her baby.
Metal-on-metal hip implants have been linked to an increasing array of injuries and side effects, including pain at the implant site that can spread to the groin and back, tissue death, bone loss, loosening of the joint, swelling, inflammation, metallosis (metal poisoning), fluid collection around the hip joint, and high failure rates for the devices. Some patients have required painful revision surgeries just two or three years after original hip replacement.
MoM hips from a number of manufacturers—including DePuy Orthopaedics, Biomet, Smith & Nephew, and Stryker—have been recalled worldwide over these problems and thousands of patients have brought lawsuits against the manufacturers. Metal hip implants were originally marketed as being more durable and better suited for younger, active patients, but instead the devices have been associated with painful complications and a high rate of revision.
Normal rubbing together of the metal and the rubbing together may release metal into patients’ bodies and these tiny metal particles may lead to a variety of medical issues. The released metal damages bone and soft tissue in the area of the implant, a so-called adverse local tissue reaction (ALTR), according to the U.S. Food and Drug Administration (FDA).
Metallosis may cause pain, loosening of the device or device failure, and the patient may need revision surgery to remove the device and replace the device with a different hip implant, a longer and more complex surgery. Patients may also suffer from other adverse reactions when metal ions enter the bloodstream and reach other organs, including systemic reactions such as skin rash, cardiomyopathy, and renal function impairment, to name just a few.
The researchers do not know whether the metal in their bloodstreams will have an adverse impact on the newborns.