The Changi TMH (total metal hip) does not exist. It is a large diameter metal-on-metal hip prosthesis invented by the BMJ and the Daily Telegraph to test Europe’s systems for regulating high risk medical devices. It was modelled on an implant that has been described as one of the biggest disasters in orthopaedic history.

In our submission to gain market entry, our fictitious company, Changi, explicitly stated that the device was similar to three controversial implants. Two of these have been recalled by their manufacturers and two are subject to legal action in the United States. And even though the dossier we created said that tests had shown that our hip prosthesis produced potentially toxic levels of metal ions in the body, the implant was passed as having an acceptable design for use in patients across Europe.

The European system of regulating medical implants has been heavily criticised after a series of high profile device failures and recalls, exposing large numbers of patients to additional investigations and revision surgery. Both the UK government and the European parliament are currently looking into whether the system is fit for purpose.1 2 Last year a BMJ investigation found that the UK Medicines and Healthcare Products Regulatory Agency (MHRA) was unable to provide even the most basic data on how many high risk devices—those implanted inside the body—were currently in use, and refused to say what data had been submitted by manufacturers because this was deemed commercially confidential.3

Under growing scrutiny, what has become clear is that the weakest link in this flawed and opaque system is the almost complete delegation of responsibility from the regulator to an ad hoc …