In the past decade, a specific type of implant, called metal-on-metal implants, have been implanted with increasing frequency. Metal-on-metal implants do not have a plastic spacer between the ball and socket, like standard hip replacements, and are thought to possibly last longer. Metal-on-metal hip replacements have been used in about 1/3 of hip replacements, and metal-on-metal is always used in hip resurfacing surgery.
New studies have shown that a small number of patients are having a reaction to the microscopic metallic debris that is created by the motion of these metal-on-metal implants. About 1-3% of patients may experience this complication where the metallic debris causes destruction of surrounding soft-tissue and bone. This is not an allergic reaction, but rather a response to the debris that causes damage to the surrounding tissues.
If you have a metal-on-metal hip replacement or hip resurfacing implant, be sure to check in regularly with your surgeon. Symptoms of this complication may include increasing pain, and your doctor should be able to see the bone destruction on an x-ray. The is no recommendation to remove the implants unless this complication should occur. Metal-on-metal implants are likely to continue to have a significant role in the future of hip replacement and hip resurfacing, and to date, there is no recommendation that these implants should not be used. Rather, caution and judgment must be weight to determine the best implant for each individual patient.
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