Is it possible to be allergic to a metal implant? I had a titanium plate put in my lumbar spine as part of a spinal fusion. It had to be removed six months later because it came loose. The pathology report said it was scratched and corroded.

Infection is the most common cause of implant loosening. But osteolysis (bone loss) caused by the implant can also result in a failed fusion.

Corrosion of the metal seems to be a possible cause of periprosthetic osteolysis. Periprosthetic means the bone loss occurs around the implant or prosthesis.

A recent study of failed and removed implants has shed some light on what may be causing the corrosion. It seems that when two pieces of metal are close to each other (such as plates and screws used in spinal fusion), an electric current can develop.

The loss of electrons due to the corrosion process starts this process. It seems to generate an increased effect over time. The longer the electromagnetic force (EMF) is present, the greater the bone loss.

Whether or not there is an actual allergic response has not been determined. It seems that the environment within the human body is not suitable for metal devices. The immune system tries to get rid of it. At the same time, the corrosion prevents bone from building up around the implant.

More studies are needed to understand the nature of the EMF. Exactly how is it generated? Can it be stopped? Are some people more susceptible to this problem than others? An allergic response may be one possible explanation. There may be multiple factors that when combined together cause corrosion and implant failure.