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

September 15, 2025 updated by: Felix Corr

3D vs. 2D Unilateral Biportal Endoscopic Spine Surgery: A Randomized Blinded Crossover Pilot Simulation Study

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.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Estimated)

6

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Device Feasibility
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Three-Dimensional Endoscopy First, Then Two-Dimensional
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
Device: Three-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.
Device: Two-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.
Other: Two-Dimensional Endoscopy First, Then Three-Dimensional
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.
Device: Three-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.
Device: Two-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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference in Task Completion Time (seconds) and Error Rate During Spinal Endoscopic Simulation, Assessed Immediately Post-Task
Time Frame: 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.
Immediately during each simulation session (within minutes of task performance).
Difference in Task Completion Time (seconds) and Error Rate During Spinal Endoscopic Simulation, Assessed Immediately Post-Task
Time Frame: 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 performanc
Immediately during each simulation session (within minutes of task performance).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Felix Corr

Investigators

  • Principal Investigator: Stefan Motov, MD, Kantonsspital St. Gallen, Health Ostschweiz

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2025

Primary Completion (Estimated)

November 1, 2025

Study Completion (Estimated)

December 1, 2025

Study Registration Dates

First Submitted

September 6, 2025

First Submitted That Met QC Criteria

September 6, 2025

First Posted (Estimated)

September 15, 2025

Study Record Updates

Last Update Posted (Estimated)

September 16, 2025

Last Update Submitted That Met QC Criteria

September 15, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • V1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The study generated only simulation performance and questionnaire data from healthy volunteer trainees. No clinical or patient-level data were collected. Individual-level data will not be shared, but summary results are available in the publication.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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