Comparing 3D and 2D Views in Biportal Spine Surgery: A Pilot Simulation Study

Felix Corr

Status: Not yet enrolling

Conditions: Simulation Training; Lumbar Vertebrae; Randomized Controlled Trial; Endoscopy Simulation; Three-Dimensional; Spinal Diseases

Treatments: Device: Two-Dimensional Endoscopic Visualization; Device: Three-Dimensional Endoscopic Visualization

Study type: Interventional

Funder types: Other

Identifiers

NCT07171801

V1

Details and patient eligibility

About

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.

Full 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.

Enrollment: 6 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Device Feasibility

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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6 participants in 2 patient groups

Three-Dimensional Endoscopy First, Then Two-Dimensional

Other group

Description:

Participants first perform standardized spinal endoscopic simulation tasks using a stereoscopic three-dimensional (3D) endoscopic system providing binocular depth perception via dual optical channels and polarized glasses. After completing all tasks under 3D visualization, the same participants subsequently repeat the identical tasks using conventional two-dimensional (2D) visualization on the same high-definition endoscopic platform

Treatment:

Device: Three-Dimensional Endoscopic Visualization

Device: Two-Dimensional Endoscopic Visualization

Two-Dimensional Endoscopy First, Then Three-Dimensional

Other group

Description:

Participants first perform standardized spinal endoscopic simulation tasks using conventional two-dimensional (2D) visualization, with stereoscopic capability deactivated, displaying a monoscopic high-definition image. After completing all tasks under 2D visualization, the same participants subsequently repeat the identical tasks using stereoscopic three-dimensional (3D) visualization on the same endoscopic platform, viewed with polarized glasses.

Treatment:

Device: Three-Dimensional Endoscopic Visualization

Device: Two-Dimensional Endoscopic Visualization