Durom Special
Today this information is old and only kept as
reference.
This page is dedicated to the Durom
range of prostheses from the company Zimmer and the current discussions due to
apparent acetabular cup problems. This cup is used in both the Durom Hip Resurfacing and Durom
Total Arthroplasty systems.
Internet links are given for sites with information.
( Dutch or Swedish translations will not be made due
to the shear amount of information and complexity of the subject. )
Zimmer maintains that the problems with the Durom cup are contained within the USA only.
Question:
Why would the problem be only limited to the USA?
Information from a law firm in the USA indicates that
the acetabular cups in the USA differ from those in the rest of the world, with
a thicker coating on the rear of the cups and a different structure.
A thicker coating of this bone ingrowth promoting
material does however not seem a reason why the ingrowth would not take place
in the patients having one of these cups, unless the coating was first polluted
with a substance that is not compatible with bone.
I may be a layman, but keep question marks until a
good reason is offered by Zimmer for the absence of bone ingrowth.
Latest news:-----------------------
In April 2010 I found out that Zimmer actually has had
knowledge that their Durom acetabular cups used
outside of the USA also had problems. While they publically still claim that
the cup loosening only occurred under some series manufactured for the American
market and that only the Durom cups for shafted
prostheses are involved, the following document from Zimmer itself proofs the
exact opposite for each point. The document an “Urgent Field
Safety Notice” from the 13th of October 2009 clearly
shows data on series of Durom prostheses with
acetabular cup loosening problems and occurring outside the USA, Europe more
explicitly. The document further indicates that the loosening is not limited to
acetabular cups of shafted prostheses with Durom
joint technology but even applies to acetabular cups of the Durom
hip resurfacings.
Zimmer still tries to minimize the problem by more or
less blaming the “Durom surgeons” not having used the
prescribed surgical technique to fit the cups. But if that were true, how then
in the whole world can this incorrect use of the surgical technique by surgeons
ever apply only to certain series of the cups? What is Zimmer trying to hide
this time? See: http://www.mhra.gov.uk/home/idcplg?IdcService=GET_FILE&dDocName=CON059966&RevisionSelectionMethod=LatestReleased or: http://resurfacingscan.be/Durom-Zimmers
Own Admittance.pdf
------------------------------------
About 1200 patients in the USA have received a Durom acetabular cup together with the Durom
cap (for resurfaced patients) or the Durom stemmed
head (for patients receiving Total Hip Arthroplasty).
Question:
Is the cup failure limited to just one of these two
groups or to both of them?
One problem that Dr. Larry Dorr of the “Dorr Institute for
Arthritis Research and Education” found out is that the cup’s loosening does
not have to show up on x-ray images, this becomes clearer only under time
(perhaps some years even). Only prying or pushing on the cup’s rim while opened
up in an operation will make the cup move and show that the cup lacked proper
bone ingrowth. A cup may also migrate in the patient under other circumstances,
perhaps at times when the lubrication from the synovial fluid lacks and high
friction exists.
Normally the bone ingrowth into the porous coating of acetabular cups
will improve under time but the Durom cups under
investigation seem to do just the opposite.
This website talks about Dr.Dorr’s
findings and the sluggish response from Zimmer:
http://www.defective-implant.com/implant/durom.php
For those of you that have a Durom
Hip Resurfacing, here is a brochure on it in PDF format:
http://www.jointline.co.uk/downloads/Durom_Hip_Resurfacing_ST.pdf
Zimmer does admit that some very experienced surgeons
reported difficulties to implant the Durom cup.
http://www.youhaverights.com/legal_updates/read/zimmer-suspends-sales-of-durom-cup-hip-device
An American law firm writes about orthopaedic
surgeons insisting that the acetabular cup itself is the cause for the
loosening in patients. Zimmer however keeps denying and this could have great
consequences if more cups loosen even when the surgeons have followed the
adapted instructions from Zimmer to the letter.
http://www.duromrecall.com
This is a site from Zimmer that gives some
specifications for the Durom components:
http://www.zimmer.co.za/z/ctl/op/global/action/1/id/9226/template/MP/prcat/M2/prod/y
Reading between the lines, the following website
suggests that the present Durom acetabular cup in
fact originated from the company Centerpulse that has
in the past had problems with their own Sulzer
acetabular cup. Is there something to learn from this?
https://www.espicom.com/prodcat.nsf/Product_ID_Lookup/00002243?OpenDocument
Also, have a look at the address of the Zimmer
company:
Sulzer Allee 8
P.O. Box CH-8404
Winterthur - Switzerland
Doesn’t this indicate a connection with the Sulzer company who had an acetabular cup problem in the
past? Is it largely the same cup that is used now in the Durom
system?
Many patients have been injured due to Durom cups failure:
http://www.productdefectnewsandadviceblog.com/2008/07/defective_durom_cups_have_inju.html
Zimmer prefers a settlement with patients, logic,
since the settled amount would be much less than what Zimmer otherwise would
have to pay patients in independent cases.
http://www.mmdnewswire.com/zimmer-hip-settlements-offered-to-hip-revision-patients-wary-patients-seek-legal-advice-3774.html
This site shows a letter that mentions the finding of
titanium in the blood of a patient, coming from the acetabular cup of an
implanted Durom Hip Resurfacing
http://www.jbjs.org.uk/cgi/eletters/89-B/4/441
The USA lacks a proper system to track problems with
prostheses:
http://www.injuryboard.com/national-news/us-lacks-warning-system-on-artificial-joints.aspx?googleid=244746