Reliability and Reproducibility of CT-Based Facet Joint Measurements in Patients With AOSpine Type A2, A3, and A4 Thoracolumbar Fractures (REFACT)

July 13, 2026 updated by: Ivan Lvov, MD, PhD, Sklifosovsky Institute of Emergency Care

The Reliability Evaluation of Facet joint Assessment by Computed Tomography in thoracolumbar fractures (REFACT) study aims to evaluate how consistently different specialists assess thoracolumbar facet joints on computed tomography (CT) images in patients with AOSpine type A2, A3, or A4 thoracolumbar fractures.

The main questions are:

  • How consistently do different raters classify facet joint degeneration using the Pathria grading system?
  • How consistently do different raters measure facet joint angle and mean facet joint space width on CT images?
  • How reproducible are these assessments when the same rater repeats the measurements after a one-month interval?

The study will use anonymized retrospective CT DICOM datasets obtained from the institutional imaging archive. Six independent raters (three neurosurgeons and three radiology specialists) will evaluate the same CT datasets using a standardized measurement protocol. Each rater will perform two independent assessment rounds separated by a one-month washout period. The results will be used to determine the inter-rater and intra-rater reliability of qualitative and quantitative CT-based facet joint assessment methods.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

The Reliability Evaluation of Facet joint Assessment by Computed Tomography in thoracolumbar fractures (REFACT) study is an imaging-based, multirater reliability study designed to evaluate the reproducibility of computed tomography-based assessment of thoracolumbar facet joints.

The study represents the methodological stage of a broader research program investigating longitudinal degenerative changes in the facet joints after surgical or conservative treatment of thoracolumbar fractures. Before changes in facet joint morphology can be interpreted over time, the reliability of the imaging assessment methods must first be established in the target patient population.

Anonymized CT DICOM datasets will be selected from the institutional imaging archive of the Sklifosovsky Research Institute for Emergency Medicine. The datasets will include patients with AOSpine type A2, A3, or A4 thoracolumbar junction fractures and will cover the anatomical levels required for standardized facet joint assessment. No additional imaging, patient contact, study-specific treatment, or prospective clinical intervention will be performed.

Six independent raters will participate in the study: three neurosurgeons and three specialists in radiology or CT imaging. All raters will use the same standardized assessment protocol and the same DICOM viewing software.

Before the formal assessment, the raters will participate in a joint training session using one representative anonymized CT dataset that will not be included in the main analysis. The session will be used to demonstrate the assessment procedure, standardize image orientation and vertebral level identification, clarify the interpretation of the Pathria grading system, and review the procedures for measuring facet joint angle and facet joint space width. Any ambiguities in the assessment instructions will be resolved before the formal study begins.

During the first assessment round, each rater will independently evaluate the same anonymized CT datasets. The order of the datasets will be randomized separately for each rater. Raters will record the Pathria grade of facet joint degeneration and quantitative facet joint measurements according to the standardized protocol.

After a one-month washout interval, the same CT datasets will be re-randomized and reassessed independently by the same six raters during a second assessment round. The changed order and washout period are intended to reduce recall bias and allow evaluation of the reproducibility of repeated assessments by the same rater.

Throughout both assessment rounds, raters will be blinded to patient identifiers, clinical information, previous measurements, and the assessments of the other raters. Raters will not discuss individual study cases or measurement decisions until both rounds have been completed.

The study will evaluate agreement across different raters and the consistency of repeated assessments by the same rater. The assessment will include both ordinal grading of facet joint degeneration and continuous morphometric measurements. Exploratory analyses may examine whether reliability differs according to rater specialty, vertebral level, or anatomical side.

All study data will be entered into a standardized data collection form and stored in a restricted-access institutional database. Missing, technically inadequate, or non-evaluable assessments will not be imputed and will be reported descriptively.

Because the study uses only previously acquired, anonymized imaging data, participants will not undergo any study-related procedures and will not be exposed to additional radiation or treatment-related risk.

Study Type

Observational

Enrollment (Estimated)

12

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

Study Contact Backup

Study Locations

  • Russia
      • Moscow, Russia, 129090
        • Sklifosovsky Research Institute for Emergency Medicine
        • Principal Investigator:
          • Andrey Grin, MD, PhD
        • Contact:
        • Sub-Investigator:
          • Aleksandr Talypov, MD, PhD
        • Sub-Investigator:
          • Anton Kordonsky, MD, PhD
        • Sub-Investigator:
          • Vasily Karandze, MD, PhD
        • Sub-Investigator:
          • Ivan Lvov, MD, PhD
        • Sub-Investigator:
          • Mikhail Kucherov, MD
        • Sub-Investigator:
          • Rinat Abdrafiev, MD
        • Sub-Investigator:
          • Aleksandr Tupikin, MD
        • Sub-Investigator:
          • Ksenia Dmitrenko, MD
        • Sub-Investigator:
          • Maria Nanoyan, MD
        • Sub-Investigator:
          • Olga Minkina, MD
        • Sub-Investigator:
          • Layla Khamidova, MD, PhD
        • Sub-Investigator:
          • Roman Elokhovskiy, MD, PhD

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

No

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of patients aged 18 to 50 years with AOSpine type A2, A3, or A4 thoracolumbar fractures whose previously acquired CT examinations are available in the institutional imaging archive. Eligible CT datasets must cover vertebral levels T9 through L3 and be suitable for standardized facet joint assessment. The study will use anonymized retrospective imaging data only; there will be no direct patient recruitment, additional imaging, treatment allocation, or other study-specific intervention. CT datasets will be selected according to predefined eligibility criteria until at least 142 evaluable facet joints are available for analysis.

Description

Inclusion Criteria:

  • patient age from 18 to 50 years;
  • thoracolumbar fracture classified as AOSpine type A2, A3, or A4;
  • availability of CT images covering vertebral levels from Th9 to L3;
  • absence of imaging artifacts at the levels planned for assessment.

Exclusion Criteria:

  • bone density of the thoracolumbar junction vertebrae below 100 HU;
  • systemic bone or joint disorders associated with changes in the FJs or intervertebral discs, including diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, rheumatoid arthritis, or other comparable conditions;
  • previous spinal surgery, including procedures performed without implants;
  • fractures with distraction or translational injury of the posterior supporting column.

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
CT Image Review Cohort
Anonymized CT scans of the thoracolumbar spine (T9-L3) obtained from eligible patients aged 18 to 65 years and reviewed independently by six raters to assess inter-rater and intra-rater reproducibility of CT-based evaluation of facet joint and intervertebral disc degenerative changes
Diagnostic test: Computed Tomography Image Review
Independent review of anonymized thoracolumbar CT scans by six raters for assessment of degenerative changes in facet joints and intervertebral discs using the Pathria scale, as well as measurement of facet joint space width and angulation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Interobserver Reliability of CT-Based Pathria Grading Scale for Facet Joint Degenerative Changes
Time Frame: At baseline CT image review
Interobserver agreement for grading facet joint degenerative changes on thoracolumbar CT scans using the 4-grade Pathria classification, assessed by Fleiss' kappa across six raters.
At baseline CT image review
Interobserver reliability of facet joint angulation measurements
Time Frame: At baseline CT image review
Interobserver reliability of measurement of facet joint angulation in the axial plane on thoracolumbar CT scans, assessed using the intraclass correlation coefficient.
At baseline CT image review
Interobserver reliability of facet joint space width measurements
Time Frame: At baseline CT image review
Interobserver reliability of quantitative measurement of mean facet joint space width assessed using the intraclass correlation coefficient.
At baseline CT image review

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Intraobserver Reliability of CT-Based Pathria Grading Scale for Facet Joint Degenerative Changes
Time Frame: At baseline and 1 month later
Intraobserver agreement for grading facet joint degenerative changes on thoracolumbar CT scans using the 4-grade Pathria classification, assessed on repeated review.
At baseline and 1 month later
Intraobserver reliability of facet joint angulation measurements
Time Frame: At baseline and 1 month later
Intraobserver reliability of repeated measurement of facet joint angulation in the axial plane on thoracolumbar CT scans, assessed using the intraclass correlation coefficient.
At baseline and 1 month later
Intraobserver reliability of facet joint space width measurements
Time Frame: At baseline and 1 month later
Intraobserver reliability of repeated quantitative measurement of mean facet joint space width, assessed using the intraclass correlation coefficient.
At baseline and 1 month later

Collaborators and Investigators

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

Sponsor

Sklifosovsky Institute of Emergency Care

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)

August 1, 2026

Primary Completion (Estimated)

November 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

June 16, 2026

First Submitted That Met QC Criteria

June 22, 2026

First Posted (Actual)

June 25, 2026

Study Record Updates

Last Update Posted (Actual)

July 15, 2026

Last Update Submitted That Met QC Criteria

July 13, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SKL052026

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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