Metal Hypersensitivity and Allergies

More and more, it seems like we are faced with allergies of all types. Many people, even children, find that they have become (or maybe always were) allergic to many different things. In orthopedics, with metal implants, we certainly worry about metal hypersensitivity and allergies. Nickel is perhaps the most common allergy when it comes to metals.¹ In my practice, I rarely see anybody who has metal allergies in which nickel isn’t the most reactive metal allergen.

Most of the time, the people who experience skin break outs with cheap jewelry, watches, or bracelets are allergic to nickel.  

So, if you’re faced with the possibility of receiving a metal implant, what should you do if you’re sensitive to metals?

Orthopedic implants are made from several different materials, and many device manufacturers make metal allergy-sensitive alternatives. However, if you’re one of those very sensitive, highly-allergic people, it may be worth doing an allergy profile for orthopedic implants. Your doctor can help you do metal sensitivity testing to get an idea of what, if any, metals you’re allergic to. There’s also the option to do orthopedic implant specific testing which includes testing for the metals most commonly found in orthopedic implants as well as bone cement, ceramics, and polyethylene (medical-grade plastic).

Unfortunately, be aware that, many times, these types of tests aren’t covered by insurance. Out-of-pocket costs can be quite expensive. 

Almost every orthopedic manufacturer addresses metal allergies with different implant options. The metal most often used in orthopedic implants tends to be cobalt chrome alloy. Cobalt chrome alloy is the best wearing metal because it’s very strong and can last a long time; however, it does contain a small amount of nickel. Some people are also allergic to cobalt and/or chromium.

Another metal commonly used is titanium. In general, most people don’t react to titanium. Titanium is light and very strong, but not as strong as cobalt chrome alloy so it might not last quite as long in terms of implant wear.

Ceramic is another hypoallergenic, metal-sensitive material that is sometimes used. There are metals that are ceramicized and coated with a ceramic metal coating. These tend to have good wear characteristics; however, they can become scratched.

There are also nitrited metals that have multiple layers of protection which are also hypoallergenic. These tend to be very expensive to manufacture but are becoming more and more common as we see an increase in metal allergies.

Ceramicized metals and nitrited metals are both, in general, more costly options but good for highly metal allergic patients.

First, discuss your concerns with your surgeon. Ask what kind of an implant they plan to use. Discuss whether you should have further testing for metal or material sensitivities. You and your surgeon can come up with a suitable plan depending on the degree of allergic reaction you have and your surgeons experience with a particular implant. For example, if the implants used are cementless (don’t require bone cement), your tissues will have more exposure to the metal. If they are used with cement, you lessen your exposure to metal. So, there are choices that you and your doctor can make, depending on your level of sensitivity.

If you’re concerned about having metal allergies, consider testing for metal sensitivities so that you have more peace of mind when preparing for something like joint replacement surgery. Just remember that this may be an out-of-pocket expense.

With your surgeon, discuss your concerns and together decide what your best option is going to be. I’ve seen patients that are highly allergic and decide not to have implant surgery and instead, resort to non-operative treatment options. Most of the time, we are able to come up with a solution that works for you as an individual patient.