Thursday, June 30, 2011

Systemic effects of metal debris (7k of 7); excerpts from the Committee on Mutagenicity

Excerpts and commentary based on the 6/4 post-Metal on Metal Bearings, The Evidence So Far http://www.mydepuyhiprecall.com/2011/06/metal-on-metal-bearings-evidence-so-far.html

Genotoxic issues surrounding systemic effects of metal debris (continued from prior posts)

The committee on mutagenicity has reported that internal exposure to orthopedic metals is associated with increased genotoxicity.

This is a series of commentary from the committee on mutangenicity evidence based on the the key journal articles examined by that committee. I think you will find the results really interesting if you are concerned about the systemic effects of the metal.

I said this would be the last in this series however, there seem to be 6 items provided in confidence and I am going to try to locate the source data (more time so I myself would like to take time to review each one daily.

6th and final group of comments from the committee (In confidence data sumbitted by the BIRC)...[6 individual comments provided.. 6-11] 

2 of 6

The following report was preliminary when it was provided to the committee in abstract form only.  This report published a higher incidence of periperal blood lymphocytes in patients undergoing  hip revisions. [the interesting point with the last two posts is that it suggests that there appears that systemic issues arise upon revision. I posted this observation in back in May.  this point is pretty interesting because not one of my consults shared this information with me and I find  this to be really  important.]

Looks like this abstract is NOT available publicly via PUB MED so I will have to find it another way..Put on my To do list.

Lets move to 3 of 6

Members of the committee commented that the available information suggested that metal-on metal replacements results in elevated blood levels which, 7 years later, we all know is the case but I can print their resource anyway.

J Orthop Res. 2005 May;23(3):526-35. Epub 2005 Apr 7.

Serum levels of cobalt and chromium in patients with Sikomet metal-metal total hip replacements.

Source

Jozef Stefan Institute, Department of Physical and Organic Chemistry, Ljubljana, Slovenia.

Abstract

Metal/metal total hip replacements (M/M THRs) made of CoCr-based alloys were reintroduced in hip arthroplasty in order to avoid the problem of polyethylene wear and consequently to diminish the wear debris-related osteolysis. Emerging concerns accompanying the reintroduction of M/M THRs are related to the possibility increase of Co and Cr serum levels and, therefore, a careful surveillance of M/M patients is recommended. In the present work three groups of patients with Sikomet SM21 low-carbon alloy were investigated: retrospective group, prospective group and revision group. The investigation of these different groups of patients provided data concerning the metal concentration as a function of time in situ, as well as time ex situ, i.e., following the removal of M/M bearing. A retrospective group of 25 patients sampled at average 60 +/- 20 months postoperatively showed a 3-fold increase in cobalt and a 4.4-fold increase in chromium compared with the control group. In the prospective group of seven patients both cobalt and chromium increase with time and at average 140 +/- 80 days achieved a significant increase compared with preoperative values. An important contribution of this study to the current knowledge on M/M bearings is achieved by the measurements in the revision group of 10 patients, where we observed a decline of serum Co and Cr levels following the removal of M/M articulation. While the link between the increase in metal serum levels and the presence of M/M THR is proved, the biological impact of these results remains to be elucidated.

[ Kind of interesting that in 2005, there was active investigation into high levels of Chromium and Cobalt in the blood with metal-on metal implants isn't it?  Kind of hard for Depuy to claim that they didn't know about the levels when the medical community began publishing these observations years ago. Kind of interesting that no one funded research to actively investigate the implications of these levels isn't it?  Apparently, at that point-as is still the case- no one really has a good handle on what the implication of these levels are.

I think any Depuy settlement by the litigation group (MDL) MUST include providing a significant research fund to finally explore the systemic issues in depth, especially in light of this committee's findings.  All of this litigation is for naught if the if the litigation doesn't result in funded work to understand the systemic effects of these hips.]

connie

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