The Food and Drug Administration (FDA) – the United States agency responsible for the regulation of medical products – has issued an update to its warning for patients implanted with metal on metal hip devices.
Although primarily focusing on issues known to exist with the recalled DePuy hip replacement systems, the FDA has identified all metal on metal hip devices as having similar risks due to microscopic metallic particles released into the blood stream when friction occurs between the metal ball and cup of the implant.
In addition to the friction wearing down the metal on metal hip devices – necessitating the requirement for revision surgery when the hip replacement system becomes loose or starts to cause pain – the FDA has advised on “adverse reactions to metal debris” which manifest when particles of chromium and cobalt cause symptoms or illnesses in other parts of the body.
These symptoms and illnesses can relate to the heart, nervous system, thyroid gland or the bone and/or tissue surrounding the metal on metal hip device. It has already been established that tissue necrosis can lead to more complicated revision surgery with an extended rehabilitation period when further hip replacement surgery is required, and due to this possibility, the FDA have recommended that recipients of metal on metal hip devices pay close attention to their general health, with particular focus on any changes in the following areas:-
- The heart (chest pains or shortage of breath)
- The nerves (numbness, weakness and changes in vision or hearing)
- The thyroid (fatigue, feeling cold and weight gain)
- The kidneys (a change in urination habits)
The FDA has advised that people will react to the presence of metal particles in the blood in different ways and has recommended that if recipients of metal on metal hip devices experience any changes in their health which are not directly related to their replacement hip system they should consult a doctor at the first possible opportunity.
Although it will be necessary for an orthopaedic surgeon to confirm that irregularities in the blood are directly attributable to metal particles released from metal on metal hip devices, the FDA has recommended several tests to evaluate the symptoms including:-
- Special imaging tests (MRIs, Cat Scans and X-rays)
- Blood tests (to determine the volume of metal ions in the blood)
- Joint aspiration (where a needle removes fluid from around the hip replacement system for analysis)
In the UK, similar recommendations have been in place for almost a year. In April 2010 – four months prior to the worldwide DePuy hip replacement recall – the Medicines and Healthcare products Regulatory Agency (MHRA) issued a medical device alert which highlighted concerns with metal on metal hip devices and recommended that recipients of all such hip replacement systems should have annual check-ups for a period of five years to determine whether metallic ions had entered the blood stream.
For those who have suffered an adverse reaction or injury due to a faulty metal on metal hip device, the possibility exists to make a personal injury compensation claim on the grounds of product liability. However, in much the same way as the FDA acknowledges that people will suffer different reactions to the presence of metal particles in the blood; people in dissimilar situations will be entitled to varying amounts of failed metal on metal hip device compensation depending on their personal circumstances.