Knot Security in Gynecologic Surgery: Why Technique Matters as Much as Material

INTRODUCTION: Suture failure contributes significantly to surgical morbidity, with vaginal cuff dehiscence occurring in 0.14–4.1% of hysterectomies and 67% of cases resulting in bowel evisceration requiring emergency intervention. Despite the fundamental importance of knot security to surgical outcomes, there remains a paucity of data on the optimal pairing of suture material with tying technique. While previous studies have compared knot configuration or instrumentation exposure, no investigation has systematically examined how the three primary open surgical tying techniques (one-handed, two-handed, and instrument tying) affect tensile strength and failure mechanisms across the spectrum of suture materials commonly used in gynecologic surgery. Understanding these material–technique interactions is critical for surgical education and evidence-based practice. OBJECTIVE: To evaluate how different open surgical knot-tying methods (one-handed, two-handed, and instrument tying) affect the tensile strength at failure and mode of failure across seven suture materials commonly used in gynecologic surgery. METHODS: Seven 0-gauge suture materials were tested: polydioxanone, polyglactin 910, silk, chromic gut, poliglecaprone 25, polypropylene, and polyester. A single investigator tied each material 20 times using one-handed, two-handed, and instrument tie techniques in 2=1=1=1 configuration (420 total knots). The order of ties was randomized within each technique to mitigate performer bias. Knots were secured on a standardized jig (50-mm separation) and tested on a Mark-10 tensiometer at a rate of 3 mm/minute until failure. Failure was defined as suture breakage or knot slippage >3 mm. Peak tensile force (Newtons) was recorded. One-way ANOVA compared techniques within each suture type, while a two-way 7×3 ANOVA evaluated joint effects. Chi-square tests assessed the associations between technique and failure mode. Bonferroni correction controlled family-wise error. RESULTS: Two-way ANOVA revealed significant effects for both suture material (F=7.07, p