Hip and knee replacement surgeries are among the most common procedures performed today, with over 1 million surgeries performed each year. With baby boomers aging, the demand for total hip replacement and total knee replacement surgeries will continue to rise as more Americans are diagnosed with osteoarthritis.
Metal Allergy? A Rare but Painful Occurrence
Most joint replacement procedures are successful, but about ten percent will fail every year. Metal hypersensitivity is one of the causes of failure in a knee or a hip replacement, especially in patients undergoing revision surgery.
According to research, between 10 and 15 percent of the general population are sensitive to metal. Nickel is the most common metal allergy, followed by cobalt and chromium.
Some patients can experience allergies to metal in the joint hardware or the bone cement used to attach the joint to the bone. The allergies can cause symptoms including:
- Loosening of the joint
Non-Allergenic Components Improve Joint Replacement Success
According to a recent study published in the Journal of Allergy and Clinical Immunology: In Practice, using non-allergenic components in artificial joints can reduce complications. Karin Pacheco, MD, professor of medicine at National Jewish Health, has been analyzing allergies as a potential reason artificial joints fail. She asserts that replacing the artificial joint with non-allergenic materials may bring relief to many patients.
Pacheco and a group of research associates examined 105 patients with a failed joint that neither infection nor mechanical issues caused. The study found 34 patients were allergic to the metal, 39 were allergic to the bone cement, and 11 were allergic to both.
The research team also found:
- Patients who had metal sensitivity felt a sensation of “internal itching.”
- Two-thirds of the allergic patients had never previously experienced skin rashes or itching from contact with metals in jewelry, jean snaps or watchbands.
After a 12-month follow-up, Dr. Pacheco said the patients who had the artificial joint replaced with non-allergenic materials reported they experienced significant improvement in swelling, pain and instability.
More research is necessary to determine firm conclusions about metal allergies and joint replacement. However, this study shows the importance of testing for metal allergies when there seems to be no other cause for joint failure.
“Allergies to the metals or bone cement used in artificial joints are an under-appreciated cause of artificial joint failure,” said Pacheco. “Testing for allergies and replacement of the joints with non-allergenic materials can provide significant improvement in pain and limitation” (Medical Xpress).
Patients should talk to their physicians about the type of joint they will receive and any potential risks.