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Negative study on metal prostheses for hip joints

Negative study on metal prostheses for hip joints

British doctors are calling for a ban on metal prostheses for hip joints

According to a recent study, artificial hip joints made of metal fail earlier than previously thought. British researchers are therefore calling for a ban on metal implants. In Germany, the Federal Institute for Drugs and Medical Devices (BfArM) is currently carrying out a risk assessment of the so-called "metal-on-metal hip prostheses".

German risk assessment for hip implants not yet completed
In the renowned journal "The Lancet", the British scientists wrote that data analyzes had clearly proven that implants in which metal slides on metal would result in further hip operations more quickly than other products on the market. As a result, the researchers are therefore calling for a ban on metal-on-metal hip implants. It is also better to test medical products longer and more thoroughly before they are approved.

In Germany, the Federal Institute for Drugs and Medical Devices (BfArM) is currently carrying out a risk assessment. According to the BfArM, the authority is in contact with the English health authority MHRA and medical associations and manufacturers. "The aim is to be able to reliably limit possible health risks for patients." The medical associations DGOOC and DGU have already been informed by the BfArM about extended follow-up recommendations that were published by the MHRA in February as recommendations of an expert group For example, the recommended follow-up period for certain types of prosthesis has been extended from five years to the time of wearing the prosthesis.

So-called metal-on-metal joint implants have long had a reputation for being particularly stable and durable. They were mainly used in very active patients. But for some time now, the implants have been suspected of not being able to deliver what they promise. Therefore, British researchers led by Alison Smith from the University of Bristol evaluated the data from around 402,000 hip surgeries from 2003 to 2011 in England and Wales. They found that the metal-on-metal hip implants were used in around 31,200 cases. Alternative models made of ceramic or polyethylene were used in the remaining operations. About six percent of the metal-on-metal hip prostheses had to be replaced after five years because those affected complained of health problems. In the case of the alternative models, only about two percent had to be replaced.

Inflammation can result from metal abrasion
The British scientists also found that the size of the articular surfaces of the metal-on-metal prostheses was decisive. The larger the area, the higher the risk that the prosthesis must be replaced. The researchers were able to find the opposite in the alternative models made of ceramic. The larger the articular surfaces, the longer the durability.

In the case of discredited prostheses, a metal joint head sits in a metal socket. Rubbing the metal parts together can cause toxic abrasion, which can cause inflammation. "All patients who have such implants should be carefully monitored," write the scientists in "The Lancet". Doctors should monitor affected patients with blood tests carried out annually. It can be determined in the blood whether metal compounds have got into the body of the person concerned.

The BfArM reported that the medical associations, which include the German Society for Orthopedics and Orthopedic Surgery (DGOOC) and the German Society for Trauma Surgery (DGU), were informed that extended follow-up recommendations were made for those affected. "For example, the recommended follow-up period for certain types of prosthesis has been extended from five years to the time of wearing the prosthesis."

Today almost every older person receives a knee or hip prosthesis
The number of hip and knee prostheses has been increasing significantly in Germany for some time. Experts are already saying that almost every older person in Germany will soon need a knee or hip prosthesis. With roughly an estimated 30 million retirees, these are worrying numbers. Experts in the field of naturopathy ask why health insurance companies continue to refuse to pay costs for alternative methods such as osteopathy. In many cases, these much gentler treatment methods could save a lot of money. In addition, the side effects of the treatments are much less for the patient. Surgery is always a risk, especially for older people. Certainly, alternative procedures cannot always provide relief, but they could contribute to healing as a supplement to conventional medicine. (ag)

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