Metal-on-metal implants have been marketed as a more durable option than traditional hip devices that incorporate ceramic components. However, the safety of metal-on-metal implants has been scrutinized since the recall of the DePuy ASR hip device. The most prevalent problem is that the metal components can rub against each other, releasing chromium and cobalt into tissues and the bloodstream. This condition is referred to as metallosis.
A study published in The Lancet reported failure rates of six percent in some metal-on-metal implants, versus only 1.7 to 2.3 percent in traditional implants. The researchers concluded that metal-on-metal have "poor implant survival compared with other options and should not be implanted."
The Stryker implants are not considered traditional metal-on-metal implants as they contain a ceramic cup. This means they do not place a metal ball against a metal socket. However, the devices place a metal femoral stem against a metal neck. Regular wear on the junction between these components can increase the risk of metallosis.