ORIGINAL REPORTS Optimizing Assessment of Surgical Knot Tying Skill Elizabeth Huffman, MD,* Nicholas Anton, MS,* John Martin, MD,* Lava Timsina, PhD,* Walter Dearing, BSE, † Benjamin Breece, BSE, † Ian Mann, BSE, † and Dimitrios Stefanidis, MD, PhD* , * Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana; and † Rose-Hulman Institute of Technology, Terre Haute, Indiana OBJECTIVES: Knot tying is a fundamental surgical skill. Existing knot tying models assess tying efficiency and errors but do not address respect for tissue. Develop- ment of a model that assesses tissue displacement during knot tying may provide a good surrogate for respect for tissue, allow detection of expertise, and offer an improved training platform for skill acquisition. This study aimed to develop a novel, low-cost, knot tying board (KTB) that collects objective, automated metrics of knot displacement, and assesses knot displacement by level of surgical expertise. DESIGN: The novel KTB was developed in collaboration between engineering students and surgical educators. Joystick potentiometers were incorporated on 2 parallel rubber tubes to measure vertical and horizontal displace- ment while tying. Participants used a standardized tech- nique to tie 1- and 2-handed knots. Differences in time and tubing displacement were compared among junior residents (postgraduate year 1-2), senior residents (post- graduate year 3-5), and attending surgeons; p < 0.05 was considered statistically significant. SETTING: This study was conducted at the Indiana Uni- versity Surgical Skills Center in Indianapolis, IN. PARTICIPANTS: Forty-seven residents and faculty partic- ipated in the study (26 juniors, 14 seniors, 7 attendings). RESULTS: KTB development required 100 hours and $70.00. The attending surgeons tied 2-handed knots faster and with significantly more vertical tubing dis- placement than residents. Senior residents tied knots sig- nificantly faster but with similar tubing displacement as juniors. Similar trends were found for 1-handed knots. CONCLUSIONS: A novel, low-cost KTB was devel- oped to measure knot displacement as a surrogate for tissue handling. The new performance metric of verti- cal knot displacement proved more sensitive in detecting performance differences among groups compared with horizontal knot displacement. This board and its novel metrics may promote the develop- ment of robust knot tying skill by residents. ( J Surg Ed 000:16. Ó 2020 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.) ABBREVIATIONS: PGY, Post Graduate Year; GEE, Gen- eralized Estimating Equations; SEM, Standard Error around the Mean KEY WORDS: simulation, surgical education, open knot- tying, technical skills training, proficiency-based train- ing, assessment COMPETENCIES: Patient Care INTRODUCTION Knot tying is a fundamental skill for all surgeons and one of the very first skills every surgical trainee acquires. It is a core component of every basic surgical skills curricu- lum for surgical residents 1 and is practiced deliberately in the initial years of training. Mastery of this essential skill prior to use in the operating room enables trainees to devote their attention to the acquisition of other important surgical skills in the operating room, and has the potential to decrease operative time and improve Funding: This project was supported by Indiana University Health and the Indi- ana Clinical and Translational Sciences Institute (Indianapolis, IN) and funded in part by the National Institutes of Health, National Center for Advancing Transla- tional Sciences, Clinical and Translational Science Award and The Advances in Medicine (AIM) grant from Cook Medical (grant #ULI TR002529). Disclosure Statement: This project was made possible by Indiana University Health and the Indiana Clinical and Translational Sciences Institute, funded in part by grant #ULI TR002529 from the National Institutes of Health, National Center for Advancing Translational Sciences, Clinical and Translational Science Award and The Advances in Medicine (AIM) grant from Cook Medical. The con- tent is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or Cook Medical. Correspondence: Inquiries to Dimitrios Stefanidis, MD, PhD, FACS, FASMBS, Vice Chair of Education, Department of Surgery, Indiana University School of Medi- cine, 545 Barnhill Drive, Emerson Hall 130, Indianapolis 46202, IN; fax: (317) 274-8769.; e-mail: dimstefa@iu.edu 1 Journal of Surgical Education  1931-7204/$30.00 © 2020 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jsurg.2020.05.004 ARTICLE IN PRESS