Nodo-Tie: an innovative, 3-D printed simulator for surgical knot-tying skills development.

Introduction: Clinical simulators are an important resource for medical students seeking to improve their fundamental surgical skills. Three-dimensional (3-D) printing offers an innovative method to create simulators due to its low production costs and reliable printing fidelity. We aimed to validate a 3-D printed knot-tying simulator named Nodo-Tie. Methods: We designed a 3-D printed knot-tying simulator integrated with a series of knot-tying challenges and a designated video curriculum made accessible via a quick-response (QR) code. The Nodo-Tie, which costs less than $1 to print and assemble, was distributed to second-year medical students starting their surgical clerkship. Participants were asked to complete a survey gauging the simulator's usability and educational utility. The time between simulator distribution and survey completion was eight weeks. Results: Students perceived the Nodo-Tie as easy-to-use (4.6 ± 0.8) and agreed it increased both their motor skills (4.5 ± 0.9) and confidence (4.5 ± 0.8) for tying surgical knots in the clinical setting. Many students agreed the Nodo-Tie provided a stable, durable surface for knot-tying practice (83.7%, Discussion: Medical students found this interactive, 3-D printed knot-tying simulator to be an effective tool to use for self-directed development of their knot-tying skills. Given the Nodo-Tie's low cost, students were able to keep the Nodo-Tie for use beyond the study period. This increases the opportunity for students to engage in the longitudinal practice necessary to master knot-tying as they progress through their medical education. Key messages: Clinical simulators provide proactive learners with reliable, stress-free environments to engage in self-directed surgical skills development. The Nodo-Tie, a 3-D printed simulator, serves as a cost-effective, interactive tool for medical students to develop their knot-tying abilities beyond the clinical setting.