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arXiv · 2609.19772

Video Based Assessment of Surgical Skills Using Frozen Pretrained Video Foundation Models

Abstract

Automated video-based surgical skill assessment has advanced rapidly, yet rigorous evaluation of continuous standardized score prediction under participant-level generalization to unseen trainees remains limited. We introduce VBA-Net+, a video-only framework for Fundamentals of Laparoscopic Surgery (FLS) score regression and pass-fail classification using pretrained video foundation models as frozen feature extractors. We evaluate two FLS datasets, suturing and pattern cutting, using VideoPrism, V-JEPA2, and VideoMAE v2, with a frame-level SimCLR baseline. A lightweight fully convolutional head is trained on embeddings offline and evaluated using participant-level leave-one-user-out (LOUO) cross-validation within the standardized assessment protocol. For continuous score prediction, the best representation achieves $R^2$=0.6367 for suturing and 0.9261 for pattern cutting. For pass-fail classification at official FLS thresholds, area under the receiver operating characteristic curve (AUC) reaches 0.9073 and 0.9906, respectively. Frozen video-encoder pipelines generally outperformed the frame-level SimCLR pipeline, particularly for suturing, providing a benchmark for video-only FLS assessment.

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Sangrock Lee, FNU Rahul, Suvranu De. 2026-09-17. Video Based Assessment of Surgical Skills Using Frozen Pretrained Video Foundation Models. https://doi.org/10.1038/s41746-026-03249-2

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