Cervical Laminoplasty Training System Using Visual Force Feedback and Shadowing Methodology
Taiga TANAKA, Hideki YOSHINO, Hokuto MORII, Kengo OHNISHI, Susumu NAKAJIMA, Kouichi INOKUCHI, Tatsuhiko ARAFUNE
Vol. 15 (2026) p. 235-241
Early decompression for traumatic spinal cord injury (SCI) benefits neurological recovery, yet executing timely surgery demands precise, safe bone cutting adjacent to the cord. We developed and evaluated a skills training system for cervical laminoplasty that provides real-time visual feedback on drill pressing force and spinal cord contact, using an expert-derived “teacher” waveform (median rhythm ≈ 1.06 Hz) and shadowing to guide novice performance. Twenty students without surgical experience were randomized to a training group (n = 10) or control group (n = 10). Both groups performed pre- and post-training cutting trials on standardized 3D-printed cervical models. The system measured vertical pressing force (load cell, 40 Hz) and flagged spinal cord contact via an optical threshold. Over two weeks, the training group completed six shadowing sessions with metronome guidance and on-screen warnings when exceeding force/contact thresholds; the control group received only one expert video critique during the study period. Primary outcomes were cutting time, maximum pressing force, and number of spinal cord contacts. The results were analyzed using nonparametric tests. Cutting time decreased within both groups, but was not significant (control: median time 38.0 to 28.5 s, p = 0.160; training: 47.8 to 31.7 s, p = 0.064), and the between-group difference after training was also not significant (p = 0.353). Maximum pressing force showed no significant change within groups (control: 4.2 to 3.6 N, p = 0.241; training: 3.5 to 4.0 N, p = 0.554) and also no significant difference between groups after training (p = 0.519). In contrast, post-training spinal cord contacts were significantly fewer in the training group than in the control group (median 0 vs 1.5, p = 0.006), with no significant within-group changes. This laminoplasty-specific training system prioritizes the safety goal of “cutting without contacting the cord” while maintaining efficiency and output. Visual feedback based on expert force patterns reduces spinal cord contact events and provides a reproducible, quantitative framework to accelerate safe skill acquisition in decompressive cervical surgery.