Today's News

Friday, February 23, 1996

Gamma sterilization increases oxidation, says study

Increasing the success rate of surgical repair using polyethylene tibial components may hinge on uncovering the mechanisms behind delamination and damage. One of the scientific posters reports on a study by Dartmouth's Biomedical Engineering Center that addressed some of the questions surrounding the high failure rate of polyethylene tibial components.

Primary author Daniel K. Sperling, BS, said the study looked at the correlation between high oxidation levels and clinical damage. "Studies have shown that gamma sterilization in air may lead to high oxidation, so we investigated this theory and the rate of breakdown of gamma sterilized components on the shelf."

The study determined that gamma sterilization did in fact generate free radicals that could combine with available oxygen and lead to oxidation. Therefore, components gamma sterilized in air and then stored for long periods before use may be weaker than more recently sterilized components, and possibly have a higher failure rate.

"The next question to explore is, if not gamma sterilization, then what? We need to determine the differences in failure rates over time. Right now, no one has the clinical data to say that one process is superior to another."

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Last modified 27/September/1996