Using Millimeter Measurements and Force Gauges to Test the Security of Knots Tied by Residents Before and After Watching Online Didactic Videos.

IntroductionInsecure surgical knots can be responsible for a wide range of complications, ranging from fascial dehiscence to fatal exsanguination. Most surgeons are unfamiliar with the principles underlying the security of the commonly tied half-hitch knot. We aimed to identify whether the security of half-hitch knots tied by surgical residents could be improved by watching online educational videos.MethodsTen categorical general surgery residents tied 20 knots before and 20 knots after viewing 2 online educational videos on half-hitch knots. All knots were tied in a simulated cavity. The time of tying, knot apposition, and knot security were compared before and after viewing the videos.ResultsAll residents tied single-post half-hitch knots before viewing the videos and alternating-post half-hitch knots after viewing the videos. The mean securities of the silk (8.9 vs 40.4 N, < 0.0001) and nylon (8.3 vs 12.1 N, < 0.0001) knots to 3 mm increased significantly after viewing the didactic videos. The mean tying time for silk knots before viewing the videos was 24.3 seconds, and the mean tying time after viewing the videos was 28.0 seconds ( = 0.001). Before viewing the video, 180/200 (90%) knots were apposing and after 171/199 (85.9%) were apposing ( = 0.18).ConclusionsViewing of publicly available online educational knot-tying videos by surgical residents was associated with a clinically relevant and statistically significant increase in knot security. Knots tied after viewing the videos took significantly longer to tie.