Encyclopedia.com states that 267,000 total knee replacement surgeries are done each year in the U.S. Most of these surgeries are completely successful and add immensely to the quality of life for the patients. There are a number of side effects, however, that can afflict those who undergo knee replacement surgery. One of the most troubling and mysterious is an allergic reaction to the materials in the replacement knee.


The most common metal allergy is the sensitivity to nickel. According to a 2004 article in the "Journal of Investigative Dermatology," 30 percent of the population is allergic to nickel to some degree, and some are severely allergic. This can cause serious reactions in patients who undergo total knee replacement surgery because some knee replacements are made of cobalt chrome that contains around 1 percent of nickel. Even this small amount of nickel can cause a reaction at the site of the replacement or can cause more generalized reactions when microscopic bits of nickel are carried through the bloodstream to the kidneys and liver. There have also been cases of allergic reaction to the bone cement used to affix the implant during surgery.


Symptoms of allergic reaction to total knee implant materials can be vague and troubling, including swelling and redness at the site or other areas, fever, eczema, urticaria, or skin rashes of unexplained origin.


Allergic reactions to total knee replacement materials can be severe and long-lasting, causing chronic pain, inflammation of the tissues around the knee replacement, and loss of mobility. This may require constant antibiotic or steroid medication and continuous use of pain medication. The inflammation at the site can also cause loosening of the implant, requiring further surgery.

What to Do If You Have Metal Allergies

If you have a known allergy to the nickel in jewelry, it is important that you tell your doctor if you are considering total knee replacement surgery. You may need to have allergy tests done to confirm the allergy. Based on these results, your surgeon will consider what type of knee replacement material is best for your particular situation. If you suspect an allergic reaction to total knee replacements that you already have, consult with your doctor about options for treatment.

New Materials for Total Knee Replacements

Cobalt chrome has been a known offender for allergic reactions because of its nickel content. More recently, titanium has been used for total knee replacements. It is known to cause much fewer allergic reactions among patients. A new material called Oxinium has been developed, made from zirconium that is oxygenated to create a kind of ceramic surface that is much less apt to cause allergic reactions in patients. It is used for younger patients because it causes much less wear on the plastic parts of knee replacements and lasts longer for more active patients as well as for those patients who have allergies to nickel.