Introduction: Development of technical skills for a cervical laminectomy are traditionally acquired through intraoperative learning and cadaveric courses. These methods provide little objective assessment, involve financial and biohazard considerations, and may not incorporate desired pathology. We aim to develop and assess face, content, and construct validity of a high-fidelity, inexpensive cervical laminectomy simulator.
Methods: A spondylotic cervical spine model was generated and 3D printed into negative molds, which were filled with multilayer polyvinyl alcohol hydrogels, plaster, and fiber glass to replicate neck tissues. A pressurized balloon placed in the spinal canal and connected to a pressure transducer to measure potential cord manipulation. Twelve surgeons (novice designated by prior laminectomy case load <100) performed a "skin-to-skin" C4-C6 posterior laminectomy simulation. Surveys assessed face and content validity using a 5 point-Likert scale. Construct validity was assessed by comparing procedural metrics (thecal-sac pressure wave count, amplitude, slope, time of elevated pressure, operative time, blood loss, incision length, complications) between groups.
Results: The simulator received an average face and content validity rating of 4/5. Significant differences between experts and novices were found in total intra-thecal pressure wave count (84 vs 153, p = 0.023), amplitude (4% vs 12% >2SD above expert mean, p < 0.001), area under curve (4% vs 11% >2SD above expert mean, p < 0.001), and procedure time (35 vs 69 min p = 0.003). Insignificant differences were found in mean pressure wave slope or blood loss. There was a significant difference in complication rate between novices (3 incorrect levels decompressed, 1 dural tear) and experts (p = 0.03).
Conclusions: This full procedural cervical laminectomy simulator received excellent validity ratings and was successfully able to measure operator performance. Further studies are needed to determine the role of physical simulators in the training and maintenance of surgical skills.
Patient Care: We designed a training simulator that may eventually supplement traditional residency curricula by providing objective assessment of trainee operative skill.
Learning Objectives: 1. Understand how 3D printing can be used to create high fidelity low cost surgical simulators.
2. Discuss various forms of validation for simulation and describe how to conduct a simulation study.
3. Recognize how the incorporation of sensors into simulation permits the evaluation of technical performance.