One bizarre cause of joint replacement failure…
next Metal allergies may affect joint replacement
success Kathryn Doyle writing for Reuters reported
metal sensitivities can lead to failure of replacement joints, and patients should be
carefully evaluated for a possible reaction after the surgery, according to a new review
of past research. “We think patients and doctors should be
aware of hypersensitivity or allergy reactions to implanted joints and to monitor for signs
and symptoms,” said Dr. Michelle L. Pinson, one of the authors of the new paper. “However, a hypersensitivity reaction to
a hip or knee replacement is not that common, when you look at all the patients who have
had successful and stable joint replacements,” added Pinson, of Wilford Hall Ambulatory Surgical
Center in San Antonio, Texas. The number of total joint replacements in
the U.S. is on the rise, and so is the number of revisions, according to the authors.
Earlier replacement joints were all-metal and prone to shedding as the parts rubbed
against each other and surrounding tissue. Cobalt, chromium, molybdenum, tungsten, manganese,
titanium, aluminum, vanadium and nickel are all common metals used in joint replacements.
According to an unrelated 2010 study in Chemical Research in Toxicology, up to 17% of women
and 3% of men are allergic to nickel. “For some patients, an allergic reaction
to metal in a joint can be very serious, however many reactions are mild and not too serious,”
Pinson said. There is no consensus on how to treat that
kind of joint failure, they note, but for minor cases pain may be managed with medications,
physical therapy or steroid injections. If the joint swells or loosens, it may need
to be replaced with different components, for example non-nickel components if that’s
what causing the trouble. Pinson and her colleagues included randomized
controlled trials, case studies, observational studies and previous reviews in their analysis,
which was published in the Annals of Allergy, Asthma & Immunology.
Among their conclusions is that it’s still not clear whether metal joints increase sensitivity
to metal, or if existing metal sensitivity leads to more joint failure after implantation. Comment: A potentially serious complication
related to joint replacement.