Endoscopy Simulation, Lumbar Vertebrae, Randomized Controlled Trial, Simulation Training, Spinal Diseases, Three-Dimensional
Conditions
Brief summary
This study aims to compare three-dimensional (3D) and two-dimensional (2D) visualization in biportal endoscopic spine surgery using a simulated environment. Surgeons will perform standardized tasks on a spine model while using either 3D or 2D endoscopic systems. The goal is to determine whether 3D technology can improve precision, efficiency, and movement control during surgery. The study uses a randomized, blinded, crossover design to ensure objective results and may help guide future training and technology use in spinal endoscopy.
Detailed description
Spinal endoscopy, particularly the unilateral biportal endoscopic (UBE) technique, is an increasingly adopted minimally invasive approach for treating lumbar spine pathologies. While it offers clinical advantages over traditional open surgery-including less tissue disruption, reduced blood loss, and faster recovery-its uptake has been limited, in part due to the technical challenges associated with two-dimensional (2D) endoscopic visualization. The lack of depth perception inherent to 2D imaging can impair spatial orientation, hand-eye coordination, and surgical precision, especially in anatomically complex regions such as the lumbar spine. Three-dimensional (3D) endoscopic systems are designed to address this limitation by restoring binocular depth cues and providing stereoscopic visualization. Preliminary evidence from other surgical fields-such as laparoscopy and cranial neurosurgery-suggests that 3D visualization improves operative performance, task efficiency, and user confidence. However, the benefits of 3D visualization in spinal endoscopy remain poorly understood, with no rigorous controlled studies to date assessing its impact on performance metrics under standardized conditions. This randomized, blinded, crossover pilot study is designed to objectively evaluate the effect of 3D versus 2D endoscopic visualization on technical performance during simulated UBE procedures. Participants-including surgeons at various experience levels-will complete standardized surgical tasks on high-fidelity lumbar spine models using both 2D and 3D endoscopic systems. Motion tracking technology will be employed to quantitatively analyze instrument movement, capturing key metrics such as path length, velocity, motion economy, and high-velocity excursions. The crossover design ensures that each participant serves as their own control, and blinding minimizes observational bias during performance assessment. The simulation setting allows for reproducible conditions free from patient-related variability, ensuring that observed differences can be attributed to visualization modality rather than anatomical or clinical complexity. Findings from this study will provide foundational data on the potential utility of 3D visualization in spinal endoscopy, with implications for surgical training, operative safety, and the future integration of stereoscopic technologies in spine surgery.
Interventions
DEVICEThree-Dimensional Endoscopic Visualization
Use of a stereoscopic 3D high-definition endoscopic system with dual optical channels, projecting to a stereoscopic monitor viewed with polarized glasses, to perform standardized spinal simulation tasks.
DEVICETwo-Dimensional Endoscopic Visualization
Use of the same high-definition endoscopic system with stereoscopic function deactivated, providing conventional monoscopic two-dimensional visualization, to perform standardized spinal simulation tasks.
Sponsors
Felix Corr
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DEVICE_FEASIBILITY
Masking
SINGLE (Outcomes Assessor)
Masking description
In this single-center crossover simulation study, outcomes assessors responsible for performance evaluation and motion data analysis are blinded to the visualization modality used during each session (3D or 2D). Participants are not blinded due to the inherent perceptual differences between the two visualization systems. Investigators supervising the simulation are aware of the intervention assignments for operational purposes but are not involved in outcome assessment. All video and motion tracking data are anonymized and coded prior to analysis to maintain assessor blinding.
Intervention model description
This study employs a randomized, single-center, blinded, crossover design in a high-fidelity simulated surgical environment. Each participant performs standardized unilateral biportal endoscopic spine surgery tasks using both 2D and 3D visualization systems in a randomized sequence. A washout period is incorporated between conditions to minimize carryover effects. This within-subjects crossover model allows each participant to serve as their own control, increasing statistical power and reducing inter-individual variability. Blinding is maintained for performance assessors, and objective motion tracking metrics are used to evaluate technical performance under each visualization condition.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Enrolled in the neurosurgical residency or fellowship program at the Department of Neurosurgery, Cantonal Hospital of St. Gallen, Switzerland * Completion of basic neurosurgical training modules, including introductory endoscopic handling * Age ≥ 18 years * Willingness and ability to provide informed consent
Exclusion criteria
* Prior substantial experience with three-dimensional (3D) endoscopy (defined as \> 5 independent procedures performed with 3D visualization systems) * Ocular or neurological conditions impairing stereopsis, fine motor control, or safe endoscope handling * Inability or unwillingness to complete the simulation protocol * Declined participation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in Task Completion Time (seconds) and Error Rate During Spinal Endoscopic Simulation, Assessed Immediately Post-Task | Immediately during each simulation session (within minutes of task performance). | Task performance was assessed during standardized spinal endoscopic simulation tasks under both three-dimensional (3D) and two-dimensional (2D) visualization. Task completion time was measured in seconds with a digital stopwatch from the start to the successful completion of each task. Task accuracy was assessed as the number of predefined errors, including deviations from the optimal trajectory or inadvertent contact with marked no-go zones on the simulation model. Both measures were collected immediately during each simulation session. Lower times and fewer errors indicate better performance. |
Contacts
Primary ContactFelix Corr, MD, MSc.
Outcome results
None listed