Validation of the VIEW score: a novel intraoperative grading scale for visualization in endoscopic spine surgery

Clear intraoperative visualization is essential for safe and effective endoscopic spine surgery, yet existing assessments remain subjective and lack standardization. The Visualization in Endoscopic Workspace (VIEW) Score was developed to provide an objective, reproducible grading system for evaluating intraoperative visualization quality. This study aimed to validate the VIEW Score as a standardized and reliable tool for assessing visualization during endoscopic spine surgery.

The VIEW Score is a 4-point ordinal scale (0 = Excellent, defined as no bleeding observed, to 3 = Poor) developed through expert consensus to evaluate bleeding, clarity of anatomical structures, and impact on surgical progress. Five experienced endoscopic spine surgeons independently rated 40 de-identified, 5-second video clips of interlaminar endoscopic lumbar spine surgery. After a 4-week washout period, the raters re-evaluated the same clips in a randomized order. Inter- and intra-rater reliability were analyzed using the Intraclass Correlation Coefficient (ICC) with a two-way random effects model for absolute agreement.

The VIEW Score demonstrated excellent inter-rater reliability for mean ratings (ICC(2,5) = 0.963; 95% CI 0.940-0.979) and good single-rater reliability (ICC(2,1) = 0.839; 95% CI 0.758-0.902). Intra-rater reliability was also high (mean ICC 0.889 ± 0.04; range 0.840-0.943). Reliability remained consistently strong across approach (ICC(2,5) = 0.965) and decompression phases (ICC(2,5) = 0.945).

The VIEW Score is a reliable and objective grading system for assessing intraoperative visualization during endoscopic lumbar decompression. Its strong reproducibility supports its use for standardized communication, surgical training evaluation, quality assessment, and future research examining visualization, hemostasis, and surgical workflow.