Key Takeaways From ISASS Webinar Series on Endoscopic Spine Surgery Techniques | Part 4: Advancing the Curve on Surgeons' Experience With Complex Lumbar Revision Scenarios, Grades 1 to 3 Spondylolytic Spondylolisthesis, Cervical Foraminotomy, and Cervical Spondylotic Myelopathy.

Background: The fourth webinar in a 4-part series hosted by the International Society for the Advancement of Spine Surgery explored contemporary endoscopic spine surgery techniques. This session covered complex revision strategies, endoscopic management of grades 1-3 spondylolytic spondylolisthesis, cervical foraminotomy, and decompression techniques for cervical spondylotic myelopathy (CSM).

Objective: The aim was to assess surgeon endorsement of the discussed endoscopic spine surgery techniques both before and after the webinar using polytomous Rasch analysis. Additionally, the analysis sought to determine how these insights might shape clinical guideline recommendations.

Methods: Before the webinar, which was attended by 868 potential participants, a survey was distributed to collect data on the level of support for various techniques using a Likert scale. The polytomous Rasch model analyzed these responses by evaluating decision complexity relative to surgeon expertise. This approach helped develop a logarithmic scale to objectively analyze categorical responses, distinguish between congruent and incongruent items, and contribute to the enhancement of clinical guidelines.

Results: Of the 868 surgeons, 263 accessed, 150 started, and 118 completed the prewebinar survey, with a completion rate of 78.7%. The participants were mainly orthopedic surgeons (59.3%) and neurosurgeons (34.7%) but also included residents (2.5%), fellows (1.7%), and interventional radiologists (1.7%). In the postwebinar phase, 298 participants accessed the survey, 169 started it, and 128 completed it, achieving a 75.7% completion rate. The demographics of postwebinar participants closely mirrored the initial group: 66.4% orthopedic surgeons, 23.4% neurosurgeons, 3.6% residents, 2.9% fellows, 0.7% medical students, and 2.9% interventional radiologists. The Rasch analysis confirmed high surgeon confidence for the posterior cervical foraminotomy and endoscopic treatment of spondylolytic spondylolisthesis grades 1 to 3 and posterior endoscopic decompression for CSM. Both pre- and postwebinar responses showed a good fit to the Rasch model for these endoscopic techniques, indicating minimal bias, supported by differential item functioning analysis. The application of the endoscopic surgery platform for procedures such as lumbar revision surgery for adjacent segment disease or failed interbody fusion cages and posterior decompression of CSM saw little shift in endorsement, as evidenced both in descriptive and the logarithmically transformed Rasch statistics.

Conclusion: This webinar highlighted the evolving consensus on best practices in endoscopic spine surgery, displaying wide acceptance of endoscopic debridement of spondylolytic spondylolisthesis, cervical foraminotomy for herniated disc and bony stenosis, and posterior endoscopic decompression for CSM.

Clinical relevance: Assessing surgeon confidence and acceptance of endoscopic spinal surgeries using polytomous Rasch analysis.

Level of evidence: Level 2 (inferential) and 3 (observational) evidence because Rasch analysis provides statistical validation of instruments rather than direct clinical outcomes.