Search  Search
Font Size:     Small text Medium text Large text   email pageemail pageprint pageprint page

Metal-on-metal hip implants

NJR Statement regarding metal-on metal implants
The majority of patients with metal-on-metal hip replacements do very well but because of the negative side-effects that have been experienced by a small number of patients, careful follow-up for all has been important. In accordance with the patient-safety driven mission of the National Joint Registry (NJR), patients with any metal-on-metal implant who have consented to their data being registered, have been identified and recalled for monitoring. Without such a comprehensive registry, working in the interests of patients, hospitals would be unable to identify which patients had specific implants.
The NJR enables the mandatory collection of data on hip, knee, ankle, elbow and shoulder joint replacements and its organisational structure encompasses various specialist groups, such as the implant scrutiny committee, and surgeon performance committee, which closely monitor  the performance of implants, hospitals and surgeons. Where there are performance issues, these can be quickly processed and addressed in line with NJR procedures and in the case of implants, referred for consideration by the Regulator [MHRA] and expert representatives, such as those on the Orthopaedic Expert Advisory Group, who proposed the alert and recommendations made regarding metal-on-metal hip implants by the MHRA in 2010. 
NJR therefore advises any patients who have had metal-on-metal implants that should they be concerned about symptoms that they consider may be related to their implants, they should consult their Surgeon or GP, who can discuss these with them.                                                                                                                    


2017 MHRA Medical Device Alerts

The Medicines and Healthcare Products Regulatory Agency’s (MHRA) recently revised guidance on metal on metal (MoM) hip replacements (Ref: MDA/2017/018). To support hospitals in identifying patients, the National Joint Registry will supply NHS Trusts and Local Health Boards with records of patients registered with MoM hip replacements. Please download the following confidential information request form to enable you to access these data:

2015 MHRA Medical Device Alerts

2012/13 MHRA Medical Device Alerts

Frequently asked questions

Q: What are metal-on-metal implants? 
In metal-on-metal devices, both the ball and socket components are made of metal (metal bearing surfaces). These metal implants have been used in total hip replacement surgeries and hip resurfacing procedures. Metal bearings can allow for the use or larger femoral head sizes which more closely resemble the natural hip ball and socket (these are often called large head metal-on-metal).

Q: Why are there concerns about metal-on-metal hip implants? 
In 2010 the National Joint Registry (NJR) data identified higher than expected revision rates for the metal-on-metal implants. (A revision is an operation to remove or replace one of more components of a joint prosthesis and all types of devices have incidences of revision). Studies have shown concerns for patient outcomes, relating to pain and function, and the possibility of metal debris damage to surrounding soft tissues. Attention has focused on whether these problems could be associated with the use of larger femoral head sizes and particular designs. For example, the ASR implants which were withdrawn by the manufacturer (DePuy) in 2010 following the publication of NJR statistics (see timeline).

Q: What is the NJR's role in identifying failing devices?
It is a key aim of the NJR to identify any brand of prosthesis showing high failure rates and allow prompt removal from the market. To do this, the NJR seeks patient consent to monitor any replacement hip, knee, ankle, elbow or shoulder joint procedure. Data including the procedure type and the brand of prostheses is recorded for initial implant procedures and for any revisions of the device.

Fundamental to identifying failing devices is the close monitoring of patient time incidence rates (an incident is defined as a revision procedure where an implant has had to be replaced and patient time is defined as the number of years an implant has been in a patient). The NJR monitors the number of revisions per 100 patient years.

Information about implant performance is reported every six months to the NJR's Implant Performance Group. If the results of the monitoring show that an individual implant's performance lies outside of what would normally be expected, the Implant Scrutiny Group notify the Medicines and Healthcare Products Regulatory Agency (MHRA) that it may be an outlier.

The MHRA then undertakes an investigation in conjunction with the device manufacturer. The NJR will provide any additional data necessary to support that investigation.

Q: I'm a patient, can I find out more about my implant from the NJR including what size it is?
Yes, if you gave consent to the NJR to hold your personal information alongside your operation information, you can request a copy by contacting us.  This can be done by downloading a Patient Operation Request form (▼) and submitting it by email or by post to the NJR Centre (information on the form).

These requests may take between 2-4 weeks to process, as appropriate checks need to be carried out before disclosing patient personal information. Additionally or alternatively, patients may it find it a greater convenience to phone their hospital or surgeon directly where they can also seek out medical advice as appropriate.


Q: I'm a patient with a metal-on-metal implant and I am concerned, where should I go for help?
If you have a concern about your implant for whatever reason, please contact your GP, surgeon or the hospital where your operation took place. They will be able to advise on appropriate follow-up procedures.

Q: How is the NJR supporting hospitals to identify patients registered with MoM hip replacements?
To support hospitals in identifying patients, the National Joint Registry will supply NHS Trusts and Local Health Boards with records of patients registered with MoM hip replacements. Please download an NJR MoM data request template (▼) to enable you to access these data.

You can contact the NJR Service Centre using the following methods:

Telephone on 0845 345 9991 or email:



Copyright © 2020 National Joint Registry Terms and conditions Privacy policy Login