McMinn Responds to current MOM THR negative articles 2/29/2012

[Pat Walter]

Response to new MHRA Guidelines on MoM Total Hip Replacements
Wednesday 29th February 2012

There have been several press reports regarding the new MHRA (Medicines and Healthcare products Regulatory Agency) guidelines on metal-on-metal (MoM) hip replacements. We have had a number of enquiries from concerned patients. We have also been receiving calls and emails from patients who have enjoyed excellent quality of life following their BHRs - in some cases, performed over 10 years ago. These patients are understandably very angry that BBC Newsnight, amongst others, has produced such a biased, one-sided story leaving hundreds of people unnecessarily "terrified of poisoning, cancer, yearly blood tests and possible surgery to remove the metal hip," as one of our patients puts it.

The Newsnight report from 28.02.12 and the updated MHRA Alert relate specifically to large diameter MoM total hip replacements (THRs). These types of THRs sometimes suffer failure at the “taper junction” - between the femoral head (ball) and the stem of the implant. As a result of taper failure, metal ions are released causing adverse reactions in certain patients. Most modern THRs including those manufactured from metal, ceramic and polyethylene, have taper junctions. Metal release is not specific to MoM THRs, however and has been reported from taper junctions in all types of THRs including ceramic and polyethylene types also.

Birmingham Hip Resurfacing (BHR) Patients

The BHR does NOT have any taper junction and is therefore completely free of metal release from taper problems. If you have had a BHR, you are at no risk of taper wear and metal release from taper junctions. The BHR is a MoM joint, but the metal release from well-implanted BHRs is very low. The McMinn Centre continues to follow-up cohorts of patients in several ongoing longitudinal metal ion studies and we find no cause for concern either locally, in the region of the joint, or systemically. The MHRA does not recommend routine metal ion testing or imaging for asymptomatic patients with BHRs.

MoM Modular Total Hip Patients

Mr McMinn does not use MoM THRs unless absolutely necessary. Some patients are however, most suitable for a metal-on-metal THR due to their specific clinical circumstances. In such patients, Mr McMinn sometimes finds it necessary to use a BHR-type cup and modular head on a Smith and Nephew titanium total hip stem. He has not seen any taper junction problems in his series of MoM hip replacements. Analysis of the NJR’s (National Joint Register of England and Wales) data shows that the BHR type modular THRs performed with Smith and Nephew titanium stems have good results. In Mr McMinn's own series of MoM THRs, the success rate is 99% at 5 years and 98% at 10 years.

For further reassurance, please find below some related links you may be interested to read.

• The McMinn Research Team’s detailed response to list of questions on metal-on-metal implants & metal ions provided by hip resurfacing users here
http://www.mcminncentre.co.uk/metal-ions-questions-answers.html
• A debate in which Mr McMinn compares the BHR to the now recalled ASR resurfacing device here http://www.mcminncentre.co.uk/research-lectures-debate.html
• A three-part video interview in which Mr McMinn addresses the negative comments about MoM hips here
http://www.mcminncentre.co.uk/negative-comments-on-metal-on-metal-hips-mcminn.html
• The McMinn Centre’s response to a Channel 4 documentary on metal-on-metal hip replacements here
http://www.mcminncentre.co.uk/response-dispatches-program.html
• An interview with a patient who's had his well-functioning metal-on-metal hip resurfacing for 20 years herehttp://www.mcminncentre.co.uk/mitchell-hill-metal-on-metal-hip-resurfacing.html
 
Please also see the new MHRA guidelines here
http://www.mhra.gov.uk/NewsCentre/Pressreleases/CON143784

If patients have any further concerns and would like to speak to a member of our team about this matter, please call us on 0121 455 0411.

[hernanu]

Good response. Nice to have him there.

[Jeremy76761]

Even the MOM THR stats aren't too bad, 98% at 10 years. I wonder why he doesn't use something more bone-conserving though, where BHR is not possible?

[cwg]

Interesting