The effects of ethylene oxide and gas-plasma sterilization on failure strength and failure mode of pre-tied monofilament ligature loops

OBJECTIVE: To evaluate the effects of ethylene oxide and gas-plasma sterilization on the failure strength and failure mode of pre-tied monofilament ligature loops. STUDY DESIGN: A randomized block design was used by blocking for suture (size 1 polyglyconate, size 2 polydioxanone) and sterilization technique (control, ethylene oxide, gas plasma). SAMPLE POPULATION: Twenty replicates of each suture-sterilization technique combination. METHODS: Ligature loops were pre-tied using a 4S-modified Roeder knot then exposed to 1 of 3 treatments (control, ethylene oxide, or gas-plasma sterilization). Ligature loops were mounted onto a mechanical testing machine to evaluate the effects of sterilization on failure strength and failure mode (disruption, untying). RESULTS: There were no differences between polydioxanone and polyglyconate suture materials in failure strength or mode within sterilization methods. Both sterilization methods significantly increased the likelihood that suture loops would untie compared with controls subjects. Ligature loops that disrupted had a greater breaking strength than those that untied, regardless of sterilization method or suture type. CONCLUSIONS/CLINICAL RELEVANCE: Sterilization with either ethylene oxide or gas plasma of pre-tied, polyglyconate, or polydioxanone ligature loops significantly increases the in vitro likelihood of a modified Roeder knot untying. Further studies need to be conducted to determine the in vivo requirements for ligature loops.