Insights From ISASS Webinar Series on Current and Emerging Techniques in Endoscopic Spine Surgery | Part 3: A Polytomous Rasch Analysis on Surgeons' Endorsement of Multiportal Access, Treatment of Lumbar Facet Cyst, Grade I Spondylolisthesis, and Interbody Fusion.

Abstract

Background: The International Society for the Advancement of Spine Surgery hosted the third in a series of webinars focused on innovative endoscopic spine surgery techniques. This session aimed to discuss and evaluate advanced treatments for lumbar spinal stenosis and related conditions utilizing multiportal endoscopic approaches; articulating instruments; unilateral biportal endoscopy; transforaminal techniques for facet cysts, herniated disc, and spinal stenosis; as well as percutaneous endoscopic lumbar interbody fusion (PELIF).

Objective: To analyze the level of surgeon endorsement for the presented endoscopic spine surgery techniques before and after the webinar, utilizing polytomous Rasch analysis, and to evaluate the potential for these insights to inform clinical guideline recommendations.

Methods: An online survey was administered to 868 surgeons during a sponsored webinar hosted by the International Society for the Advancement of Spine Surgery. The survey used Likert-scale ratings to evaluate 5 main topics and additional surgical experiences and was distributed before and after the webinar. Survey responses were analyzed using descriptive statistics and Polytomous Rasch analysis to evaluate shifts in acceptance and perception.

Results: Of the 793 surgeons who attended the webinar, 229 accessed the prewebinar survey, 154 began it, and 119 completed it, yielding a completion rate of 77.3%. The respondents included 52.9% orthopedic surgeons, 37.0% neurosurgeons, 1.7% fellows, 0.8% residents, and 0.8% medical students. In the postwebinar phase, engagement remained high, with 298 accessing the survey, 169 starting it, and 128 completing it, resulting in a 75.7% completion rate. The postwebinar participant demographics closely resembled the initial distribution, consisting of 53.1% orthopedic surgeons, 35.9% neurosurgeons, 6.2% residents, 3.1% fellows, and 1.6% medical students. The confidence in various endoscopic techniques saw notable changes, particularly for procedures involving transforaminal lateral canal decompression for stenosis, herniated disc, and low-grade spondylolisthesis. Unilateral biportal endoscopy facet joint decompression and PELIF saw an increase in high-level endorsements after the webinar. Polytomous Rasch analysis provided insights into procedural techniques. The study showed consensus on the effectiveness of percutaneous endoscopic decompression of low-grade spondylolisthesis, reflecting evolving surgeon preferences and consensus on best practices. Infit and outfit statistics from the Rasch analysis suggested a good fit between the survey responses and the Rasch model both before and after the webinar, indicating minimal data distortion due to bias except for transforaminal decompression for posterolateral and central herniated nucleus pulposus. Differential item functioning analysis showed no significant bias in item responses between orthopedic surgeons and neurosurgeons in the prewebinar survey but identified potential bias for 1 item postwebinar in PELIF and articulating instruments.

Conclusion: The webinar influenced surgeon perceptions and endorsements of advanced endoscopic techniques, substantially impacting professional practice. Continued use of Rasch analysis in evaluating educational interventions offered a nuanced understanding of changes in surgical practice toward more complex and controversial issues such as central and migrated herniated nucleus pulposus, facet cyst, low-grade spondylolisthesis, and fusion while potentially guiding future clinical guidelines and training programs to align with evolving endoscopic techniques.

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.