Joint Implants May Release Toxic Metal in Patient’s Bloodstream and Spinal Fluid: Study

Full extent of potential adverse health effects from metal entering the bloodstream still needs further examination, researchers say.

A new study indicates that joint replacement implants, including popular artificial components commonly used during hip replacements and knee replacements, may leach toxic heavy metals into the body, like chromium, cobalt and titanium, which may increase the risk of adverse events and complications years later.

According to findings published in JAMA Network Open on March 28, German researchers say they found concentrations of heavy metals in the blood and cerebrospinal fluid (CSF) of individuals who received arthroplasty, also known as joint replacement surgery.

For years, metal joint replacement implants, such as metal-on-metal hip implants, have been known to release chromium, cobalt and other heavy metals into the body. These devices can shed metal particles, leading to metal blood poisoning, also known as metallosis, which has been linked to adverse events such as tumors, tissue damage and an increased risk of cancer.

As early as May 2011, the FDA asked device managers to gather more information on metal implant shedding. In 2012, Britain’s health agency, the Medicines and Healthcare Products Regulatory Agency (MHRA) issued guidance calling for patients who received metal-on-metal hip implants to get annual blood tests to check for metallosis.

For this new study, a team of researchers led by Dr. Anastasia Rakow conducted a cross-sectional study involving 204 patients as part of the NeuroWear pilot study from April 2018 and November 2019. They compared levels of metals used in joint replacement implants found in the blood or cerebrospinal fluid.

According to the findings, metal joint implants were linked to higher levels of cobalt, chromium, titanium, niobium and zirconium in the blood. The researchers found that cobalt, in particular, was present in high levels of those with metal implants.

“Notably, in the CSF of patients with at least 1 implant component made of cobalt-chromium-molybdenum, cobalt and chromium were found to be significantly higher than in the matched control participants,” the researchers concluded. “This finding emphasizes that the use of the cobalt-chromium-molybdenum alloy in particular bears the risk of exposure to arthroprosthetic metals in the CNS (central nervous system).”

The researchers called for more studies to determine whether accumulation of metal in cerebrospinal fluid is linked to adverse neurotoxic effects.

Over the last two decades a number of hip replacement recalls and problems have been associated with metal-on-metal designs, leading to tens of thousands of hip replacement lawsuits filed against major medical device manufacturers. Most of the litigation has been settled, resulting in billions of dollars in settlement agreements.