Metal on Metal Hip Replacements - The Facts

Metal on Metal Hip Replacements – The Facts

Far from participating in a “large uncontrolled experiment” as described in the media the British Orthopaedic Association (BOA), the National Joint Registry and the MHRA have been working closely together in looking after our patients by identifying the problems relating to Metal on Metal Hip Replacements, highlighted by yesterday’s updated published advice to surgeons.

It is important to understand that the move from a traditional hip replacement with a metal head and plastic socket was intended to benefit young patients. This was because the traditional implant was more likely to fail over time and require a complex revision operation. All the initial evidence suggested that changing the bearing surface to Metal on Metal could help the artificial joint to last longer. No manufacturer deliberately sets out to design a bad implant for patients.

The information on failures of Metal on Metal implants accumulated slowly – as is always the case – but came to a point when, based on Joint Registry data in Australia and the UK, one implant in particular – De Puy’s ASR system – was identified as performing significantly less well than others used to replace painful arthritic hip joints. The BOA brought this to the attention of the MHRA, helped provide senior and expert clinical input into the Expert Advisory Group on Metal on Metal Implants, and addressed the question of how to monitor implants introduced by forming the Orthopaedic Devices Evaluation Panel.

The Expert Advisory Group triggered the first MHRA ASR alert in 2010 and has been continually reviewing Joint Registry data since then. From the further data accumulated on stemmed large head Metal on Metal articulation it was appropriate that our advice to hip surgeons was updated now in the form of a further MHRA alert.

As our members conduct over one million orthopaedic operations each year in England alone, the BOA takes its responsibilities to patients extremely seriously. We helped to develop the advice to clinicians and formulate the initial MHRA alert on the ASR, asking that patients are seen each year and investigated for the metal Cobalt and Chromium in their blood. We have also recommended using an MRI scan to look for changes in the tissues, including those muscles around the hip replacement that may indicate the body reacting to the presence of metal debris released by metal ball of the hip rubbing on the metal cup.

Earlier we wrote to the Chief Executive Officers of each Trust and all orthopaedic surgeons reminding them of their responsibility to follow up all patients with ASR Metal on Metal Implants.

Following the earlier ASR alert the BOA, with the MHRA, have worked in briefing all relevant parties on the problems with CE marking and suggested ways of improving post market surveillance, to use Patient Reported Outcomes Measures data and other ways of identifying failing implants earlier, and suggesting methods of safer introduction of implants. This culminated last November in an international conference (attended by the US FDA, Care Canada and others), jointly led by the BOA and MHRA, to develop an initiative called “Beyond Compliance” that is currently being considered by the Department of Health.

In all our work we are guided our motto of ‘Caring for Patients, Supporting Surgeons’. We take pride in the quality of the care that we deliver, we promote excellence in surgical practice through continuous improvement and critical review of our outcomes. Accordingly we are working hard with partners, including the National Institute for Health Research and Arthritis Research UK, to enhance considerably the amount of funding available for trauma and orthopaedic research – precisely to focus on even better on improving our treatments and delivering safer outcomes that transform our patients’ lives. 

Further information about Metal on Metal can be found here.

An explanatory video about Metal on Metal for consultants and patients can be found here.

Explanatory note: we are updating our information on Metal on metal, and link to the latest MHRA guidance which is here