All the major orthopedics makers sell these devices. Several companies said in statements that the implants did not pose a significant risk and that the incidence of metal debris problems was extremely low.

For example, Zimmer Holdings, one of this country’s biggest producers of artificial joints, said in a statement that published data “suggests that ion release levels from Zimmer’s metal-on-metal hip systems are commensurate with other metal-on-metal systems in the industry, and are not associated with significant risk to patients.”

But some surgeons are concerned that they may only now be seeing the leading edge of a mounting problem. The current generation of metal-on-metal devices is still relatively new, having been used increasingly over the last decade.

Studies show that the devices can shed atomic-size particles of metals like chromium and cobalt that can be readily absorbed by tissue or enter the bloodstream.

Surgeons at Rush University Medical Center have performed about two dozen replacement procedures because of metal debris over the last year, said Dr. Joshua J. Jacobs, the head the orthopedic surgery department there. A similar number of patients have had metal-on-metal hips removed at the Mayo Clinic, according to Dr. Daniel J. Berry, Mayo’s head of orthopedic surgery.

Dr. Berry added that surgeons at the Mayo Clinic had reduced by 80 percent their use of metal-on-metal implants over the last year in favor of those made from other materials, like combinations of metal and plastic. Other doctors said that to be cautious they were also scaling back their use of the all-metal implants until the scientific evidence became clearer.

It is not clear whether some makers’ devices are more prone to the debris problem than others. But some experts argue that some manufacturers, in a rush to meet the demand for metal-on-metal devices, marketed some poorly designed implants and that some doctors fail to properly implant even well-designed ones.