The European Commission's Scientific Committee on Emerging Newly Identified Health Risks (SCENIHR) -a scientific committee which conducts risk assessments for EU officials-has announced the publication of its initial draft assessment of the safety of metal-on-metal hip implants.

Background

Metal-on-metal hip implants have been plagued with controversy around the globe. The devices, which claimed to be similar enough to predicate devices made with non-metal parts, have since been associated with high revision rates and the generation of metal (often chromium) shavings that have damaged the tissue of some patients. Most manufacturers have recalled the products from the market in the US, while influential researchers have called for the devices to be banned.

Globally, some regulators have advised patients against using the devices. In June 2012, a panel of experts convened by the US Food and Drug Administration indicated that they would recommend against their use, saying the devices' risks outweighed their benefits. The panel did not recommend removing the devices from the market, however. FDA later initiated a study regarding the causes of failure in hip implants, and also voted to institute new and more stringent regulatory requirements for the devices, which now require the submission of a premarket application (PMA).

New Assessment

In August 2012, SCENIHR launched a safety assessment of metal-on-metal joint replacements, and particularly hip implants (hip arthroplasties).

SCENIHR said it was particularly interested in assessing the range of materials used in the implants, the number and severity of adverse events associated with metal-on-metal implants versus those with non-metal-on-metal implants, postmarketing data and the effectiveness of surveillance systems.

Now SCENIHR has published its preliminary opinion based on that investigation, stating that while the products should not be banned, they should be "carefully" considered on a case-by-case basis based on the elevated risks to patients.

However, certain subgroups should entirely avoid using large-headed metal-on-metal implants, the committee wrote. Those groups include young and active men with a large bony femoral head larger than 50 mm, and all women with a femoral head smaller than 50 mm.

Only the most experienced surgeons should perform the procedures, the committee's assessment continued, and patients should be followed up with "rigorously" to determine if revisions are needed.

The opinion is open for comment until 25 April 2014.

 

SCENIHR Opinion