MATTHIEU GATINEAU, DMV 1 , LOUIS HUNEAULT, DMV, MSc, Diplomate ACVS 1 , BERTRAND LUSSIER, DMV, MSc, Diplomate ACVS 1 , and JOSIANE LEFEVRE-LAVOIE, MSc 1 1 Companion Animal Research Group, Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada Corresponding author: Louis Huneault, Hôpital Vétérinaire Rive-Sud, 7415 Blvd Taschereau, Vet Surg January 2010 39 1 48-53 ABSTRACT Objective—To compare the effects of hydrogen peroxide gas plasma (HPGP) and ethylene oxide (EO) sterilizations on the mechanical properties of nylon lines used for stabilization of the canine stifle. Secondarily, to compare the performance of crimped and knotted lines. Study Design—In vitro mechanical evaluation. Sample Population—Nonsterilized, EO- and HPGP-sterilized specimens of 36.3 kg test nylon leader line (NLL) and 57.8 kg test nylon fishing line (NFL). Methods—Single strands and looped specimens of NLL or NFL were positioned on a material testing machine. To create looped specimens, NLL were crimped using the Securos system, and NFL were knotted, as used clinically. Elongation (%) and ultimate load (N) variables were studied. Results—Elongation and ultimate load of NLL groups were not significantly different between EO and HPGP. For NFL, HPGP sterilization led to slightly greater elongation than EO in loops only. Ultimate load of NFL single strands was not significantly different between EO and HPGP, but was higher after HPGP compared with EO in NFL loops. All NLL groups had less elongation and ultimate load than NFL. Conclusion—The effects of HPGP on NLL compared positively to EO, making HPGP an attractive alternative. As HPGP led to a slightly greater elongation of NFL than EO, the latter could be favored to sterilize NFL. Crimped NLL minimized elongation better than knotted NFL. Clinical Relevance—Sterilization with HPGP seems a good alternative to EO for NLL. EO may be a better choice for NFL; however, it is difficult to judge the clinical relevance of this result. Crimped NLL minimizes elongation and may help reducing the recurrence of stifle instability postoperatively.