Total knee replacement has become a very common procedure for the treatment of knee arthritis. This surgery is generally safe and when properly performed provides predictable and durable results. However, there are reports that patients may be allergic to the metal in the implant, but metal allergies are uncommon.
Make sure you let us know if you have a metal or nickel allergy
Current total knee parts contain both metal and plastic. Chromium, nickel, cobalt and molybdenum are among the most common metals found in implants. Often, a prosthetic joint will contain more than one of these metals. As many as 10% to 15% of the general population has a sensitivity to one of more of these metals, with the most common allergy being to nickel. Patients who are sensitive to nickel should inform their doctor, so that he can choose an implant without nickel, such as a titanium prosthesis.
Can you be tested for a metal allergy?
Because metal allergies are not very common, testing before total knee replacement is not recommended for everyone. If you have had a skin reaction to metal jewelry in the past, you should discuss this with your doctor and consider being tested.
The most common test for metal allergy is skin patch testing. Very small amount of various metals are placed on your skin and the covered with a patch. After a couple of days, the patches are removed and if the skin under the patch is irritated then you are most likely allergic to that metal. The skin patch test is not 100% accurate and it is possible to have a false positive or false negative results.
The lymphocyte transformation test is a blood test that more accurately diagnoses metal or nickel allergy before surgery. This test is only available at limited laboratories, therefore if blood is drawn it must be sent out for analysis.
My total knee replacement hurts so am I allergic?
Pain around the site of the total knee replacement has many causes, and before blame can be assigned to metal sensitivity or allergy, a thorough investigation must occur.