Part 3


In paragraph 435 of the verdict, Mrs Justice Andrews wrote ...

"I am satisfied that there was a significant increase in the revision rates in and after April 2010, and that the increase was directly attributable to the impact of the issue of the MHRA guidance on surgeons and patients alike. That impact included the panic about MoM hips that was engendered in consequence of the increasingly hysterical media reporting (I was referred to and read a substantial number of the reports, which I am satisfied were a fair representative sample). Since some patients would have presented with symptoms leading to revision during this period in any event, it is impossible to evaluate how much of an impact these factors had on the revision rates, but it was obviously significant"

I've changed some of this text to bold, to identify key words.
Part 2 of this series made it clear that the UK National Joint Register is a valid source of data for this subject.

Here's an example page from the 2015 Annual National Joint Registry report.

It's based on surgical data for the period 1 April 2013 and 31 December 2014.

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Now, the first thing that you'll see if you look down the '7 years' column (i.e. 7 years since the hip was replaced) is that the Revision Probability for Pinnacle MOM hips is significantly larger than the probability for other hip types.
By taking NJR reports for consecutive years, and plotting the 1, 3, 5 and 7 year revision probabilities, it's possible to see how much panic there was in 2012 when the NHS wrote to all patients with MOM hips to arrange blood tests. See below ...

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As you can see, any changes in Revision Probability mount to less than 1%.
Just for comparison, here's a similar set of graphs for a Ceramic-on-Ceramic Furlong HAC CSF prosthesis.

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The outcome of all of this is that it seems certain that there was no
huge panic by surgeons and patients following the identification of the MoM problem.

It's certainly true that MOM patients blood ion levels were monitored far more than any other hip type, and some increase in revision rate was bound to follow. But DePuy's defective Pinnacle Ultamet hip is to blame for that.

It's incredibly unreasonable to blame press publicity for an increased revision rate. Should the NHS have not warned patients?

This means that the poor performance of Ultamet, reflected in NJR data, is purely due to its defective design.

Just how bad this performance was will be the subject of the 4th part of this series.

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