All-Metal Hip Replacements: No Advantage Over Older Implants

We recently reported on a study that revealed that the metal-on-metal hip replacements failed three times more often than other artificial hips. In fact, the U.S. Food and Drug Administration (FDA) ordered twenty-one (21) artificial hip manufacturers to conduct studies of the Metal-on-metal (MoM) hip replacement devices, and how they can adversely affect patients, after having received close to 11,000 reports of defective hip failures from January through September of 2011.

All of this concern may be for nothing, as findings of a new study reveal that the all metal artificial hip replacements provide no advantage when compared to older types of hip implants – they just appear to carry a greater risk of problems.

FDA researchers just published a report in the British Medical Journal in which the effectiveness of a number of types of hip implants were examined. Metal-on-metal hip implants were examined, as were ceramic-on-ceramic implants, and they were compared to older metal on polyethylene implants and ceramic on polyethylene implants. The comparative study looked at 3,139 patients in 18 comparative studies. Data from 83,000 operations worldwide was reviewed.

What was discovered was that there is no advantage to metal-on-metal hip implants over the older designs that use other materials. As previously reported, there have been a number of problems identified in recent years with the metal-on-metal hip replacements.

Now, the FDA researchers are saying that, “Evidence on implant revision did not favor metal on metal implants.” The study further reveals that there is limited evidence regarding comparative effectiveness of various hip implant bearings, and the results do not indicate any advantage for metal on metal or ceramic on ceramic implants compared with traditional bearings.

In May 2011, the FDA asked device manufactures to obtain more information about the level at which the metal particles shed becomes dangerous, how much metal they actually shed, and what the potential side effects of metallosis are. As designed, the metal ball and the metal cup in a metal-on-metal implant slide against each other during walking or running, which can cause tiny metal particles to wear off of the device, and enter into the space around the implant. These metal ions can be detected in blood and urine samples, and the levels tend to increase as time passes. The metal particles, cobalt and chromium, enter the blood stream and can be distributed to other areas of the body, and have effects on the heart, nervous system, and thyroid gland. The discovery that these metal ions can slowly accumulate in the body have people concerned about higher rates of cancer and allergy-like reactions to the metal.

Where does that leave all of the people who have had metal-on-metal implants, and are now facing problems with them? People who were originally told that these implants wear much less than metal and plastic implants, but are now being told that there is no advantage over older implants. With lawsuits, where else. Patients have brought suits against hip makers in massive numbers. More than 90,000 of the recalled implants were sold worldwide before the problems were acknowledged by the manufacturer, and hundreds of individuals in the United States have filed lawsuits after experiencing complications with the implant.

I’m sure with the most recent findings that there is no real advantage over the older implants, the suits filed will continue to increase by the thousands.

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