What Did They Implant Inside You? Accolade and Stryker Rejuvenate
Cal WarrinerAugust 06, 2012 12:07 PM
(866) 735-1102 Ext 701
Stryker has recalled its entire Rejuvenate Modular and ABG modular neck hip implant systems. This was on the heels of a Canadian recall and Urgent Safety Alert issued to physicians in the United States during April of 2012. Our firm has been investigating the problems with these products for some time.
I tried to do some research yesterday on TMZF, the Titanium alloy used in many Stryker hip implants. I was surprised to learn of the lack of information on this titanium alloy, considering its widespread use in Stryker products. For example, both the Accolade (TMZF) and the Rejuvenate employ this alloy in the femoral component of the implant.
So, what is it? TMZF is a combination of titanium, molybdenum, zirconium, and iron (Ti-12Mo-6Zr-2Fe) and was first created in 1986 by Howmedica Osteonics. Howmedica Osteonics later became Stryker Orthopaedics after Stryker bought the company from Pfizer. Stryker claims that the alloy has better “wear resistance” than other titanium alloys, and has less of a potential to generate “particulate wear debris.” Stryker also states that TMZF is more flexible and more closely resembles bone compared to other titanium alloys.
If this TMZF alloy is so great and revolutionary, we should find scholarly literature written about it, right? Well, there are a few articles here and there, and Stryker’s own website includes some citations. However, when I began to read abstracts, the tiny conflicts of interest section always stands proud beneath the authors –
A.A. Edidin: Principle Research Scientist for Stryker Orthopaedics
Kathy K. Wang, Larry J. Gustavson, and John H. Dumbleton, respectively: Assistant Director, Director, and Sr. Vice President for Howmedica Inc.
Murray, NGD: Research Engineer, Stryker Orthopaedics
After searching for hours, I still haven’t discovered any scientific articles written about TMZF by a non-Stryker/Pfizer/Howmedica employee. Perhaps they are out there, but it is clear that corporate science dominates the study of this particular alloy. I have no bias against corporate science, but it’s always important to be aware of where research is coming from, especially when science and money have become so intermingled in the 21st century.
So to summarize, what exactly do we know about the type of titanium alloy that may have been implanted into you?
Well, we know that it was developed by Howmedica, which later became Stryker Orthopaedics.
We know it was developed in the 1980s. And we know that not many implants employ this type of alloy (it is proprietary, after all – only Stryker can use it). And what do we not know?
We don’t know if this kind of alloy is better than other alloys and we don’t know if this kind of alloy does hold up better when paired with cobalt.
Stryker stresses that it does alleviate the long standing and known problem in implantable device research that when titanium and cobalt are paired together, corrosion can easily become a problem when the two materials rub against each other. And if what is happening inside Stryker Rejuvenate, Accolade and ABG II patients is not corrosion, then why are their hips turning black?
Perhaps if this substance was studied more thoroughly and if modular implants utilizing the substance were not failing in such high numbers, we’d be able to take Stryker and its scientists at their word.