MONDAY, Nov. 28 (HealthDay News) -- Patients who receive artificial joints made with titanium may develop painful inflammation that could destroy bone and loosen the new joint, according to a new study of mice published by the Journal of Immunology.

Contrary to previous studies that blamed bacteria for the inflammation, researchers at the University of Medicine and Dentistry of New Jersey reported that tiny titanium particles that flake off the artificial joints through normal wear and tear may be the cause of the inflammation.

The type of inflammatory response triggered, known as a Th2 response, is more commonly associated with allergic responses and parasitic worm infections, the researchers said in a university news release. The titanium particles, which were seen an invading parasites or allergens, resulted in the generation of immune cells called "alternatively activated macrophages" in the mice.

The release noted although the potential effects of inflammation in the joint are not entirely clear, there is increasing evidence that alternatively activated macrophages contribute to bone destruction in patients who receive prostheses and in those with certain forms of arthritis.

More information

The American Society of Orthopaedic Surgeons provides more information on joint replacement.