Sunday, February 20, 2011

What seems to be the bottom line in the 14 or 15 Ion Toxicity research abstracts printed over the last 7 days?

These abstracts of the clinical work are cited most often when this subject is discussed.  Note that the date range of these journal articles is from 1995-2002. Bottom line comments from all of the studies I published covered only up to  2002:
·         “Our results do not support previous suggestions of an increased incidence of leukemia and lymphoma after total hip replacement.”
·         “The overall relative risk of cancer was increased by only 3%....but not statistically significant”
·         “The small but statistically significant increases in kidney and prostate cancers and the decrease in gastric cancer deserve further study.”
·         “The observed variation in the incidence of different cancers among patients who had total hip arthroplasty compared with the general population suggests that factors other than total hip arthroplasty play a major role in the origin of cancer”
·         “Although the toxicologic importance of these trace metal elevations has not been established, serum and urine metal concentrations may be useful markers for the tribologic performance of metal on metal bearings.”
·         “The serum and urine cobalt concentrations were below the detection limit in all patients.”
·         “The values seen in this study with the current generation of surface arthroplasties are: (a) lower than those seen in an earlier generation of surface arthroplasties; (b) in the same range as those observed in association with metal-on-metal conventional total hip replacements, which typically have smaller head sizes; (c) higher than values observed in patients with conventional metal-on-polyethylene articulating couples.”
·         “The association of metal release from orthopaedic implants with any metabolic, bacteriologic, immunologic, or carcinogenic toxicity currently remains conjectural because cause and effect have not been established in human subjects. However, continued surveillance of patient populations with metal implants, particularly those with metal-metal bearings, is warranted.”
·         “As compared with metal on polyethylene cases, the extent of the granulomatous inflammatory reaction and the presence of foreign body type giant cells was much less intense in metal on metal cases, likely because of the lower numbers and overall smaller size of metal wear debris particles.”
·         “….. protein binding is initiated in the periprosthetic space where metal concentrations are typically 2-3 orders of magnitude higher than that observed systemically in the serum. In vitro, high molecular weight proteins including immunoglobulins demonstrated the highest affinity to Cr. Determination of specific protein carriers of metal degradation products is an essential component in the assessment of the long-term biological effects of total joint replacement devices
·         “A multi-assay approach for measuring the prevalence of delayed-type hypersensitivity in orthopedic patients shows the propensity to yield a more comprehensive and, therefore, more conclusive determination than currently employed patch testing or single assay techniques.”
·         “A multi-assay approach for measuring the prevalence of delayed-type hypersensitivity in orthopedic patients shows the propensity to yield a more comprehensive and, therefore, more conclusive determination than currently employed patch testing or single assay techniques.”
·         “Until the roles of delayed hypersensitivity and humoral immune responses to metallic orthopaedic implants are more clearly defined, the risk to patients may be considered minimal. It is currently unclear whether metal sensitivity is a contributing factor to implant failure.”
·         “This in vitro study demonstrated a lymphocyte proliferative response to both Co-Cr-Mo and Ti alloy metalloprotein degradation products. This response was greatest when the metals were complexed with high molecular weight proteins, and with metal-protein complexes formed from Co-Cr-Mo alloy degradation.”
·         “Currently available methods lack the sensitivity and specificity necessary to detect very low concentrations of submicrometer polyethylene particles and probably underestimated the prevalence of polyethylene wear debris in the liver and spleen.

If I understood these articles,  I don’t hear any definitive conclusions about the cause and effect these hip implants seem to have systemically on the organs.  I think there is enough suspicion however to defiantly warrant additional study. I also wonder why the organs of implant patients are not sampled for metal levels in autopsies.  Some have been conducted but not enough.  The studies I found most interesting in raising questions were the 2000 Article By Josh Jacobs MD et al re the wear particles in the spleen, liver and lymph nodes were higher with a failed hip.  The study done in Sweden on the statistically significant increase in Kidney and prostate cancers.
 I will look at the recent Josh Jacobs papers to see if anything has happened since 2002 worth mentioning.  

Connie 

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