Arcuate ForamenNCT07130461
Prevalence and Surgical Implications of the Arcuate Foramen: A 3D CT-Based Observational Study
An observational study of Arcuate Foramen and Anatomical Variations, run by Ondokuz Mayıs University at 1 site in Turkey (Türkiye).
Trial summary
This study aims to determine the prevalence and types of the arcuate foramen (AF), an anatomical variation of the first cervical vertebra (atlas), using three-dimensional computed tomography (3D CT). The arcuate foramen is formed when a bony bridge develops over the groove for the vertebral artery. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Arcuate Foramen, Anatomical Variations, Spine Surgery Complications
- How many people
- 200 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jul 2025to 31 Jul 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adult patients (≥18 years) who underwent head computed tomography (CT) or computed tomography angiography (CTA) at Giresun University Faculty of Medicine between January 2023 and July 2025, whose images included the atlas (C1) vertebra and met quality criteria for three-dimensional reconstruction.
Who may be able to join
- Age ≥ 18 years at the time of imaging
- High-quality CT or CTA images including the atlas (C1) vertebra and posterior arch
- Imaging obtained between January 2023 and July 2025 at Giresun University Faculty of Medicine
- Images suitable for 3D volume rendering analysis without significant artifacts
Who cannot join
- Motion or metallic artifact preventing adequate evaluation of atlas anatomy
- Prior cervical spine surgery or trauma affecting the atlas
- Congenital anomalies or severe deformity of the atlas obscuring posterior arch assessment
- Incomplete demographic or imaging data
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Giresun University Faculty of Medicine
Giresun, (506) 291 66 78
About this study
Official title: Three-Dimensional Computed Tomography Assessment of Arcuate Foramen Variants and Their Surgical Implications: A Retrospective Observational Study
This study aims to determine the prevalence and types of the arcuate foramen (AF), an anatomical variation of the first cervical vertebra (atlas), using three-dimensional computed tomography (3D CT). The arcuate foramen is formed when a bony bridge develops over the groove for the vertebral artery. Although often asymptomatic, it may increase the risk of vascular or nerve injury during surgery in the craniovertebral junction region.
In this retrospective observational study, 3D CT scans of 200 adult patients obtained between January 2023 and July 2025 at Giresun University Faculty of Medicine were reviewed. The presence of AF was classified as complete or incomplete, and also categorized according to its location (right, left, or bilateral). Associations with demographic variables (age, sex) were analyzed.
The results will help improve awareness of AF in preoperative planning for neurosurgical and spinal procedures, potentially reducing the risk of complications involving the vertebral artery and surrounding neurovascular structures.
Read the detailed description
The arcuate foramen (AF) is an anatomical variation of the atlas (C1 vertebra) that occurs when a bony bridge forms over the groove for the vertebral artery, creating a complete or partial tunnel. While frequently asymptomatic, its presence has been associated with conditions such as vertebrobasilar insufficiency, cervicogenic headache, and chronic neck pain. Importantly, AF may alter the course of the vertebral artery and suboccipital nerve, increasing the risk of injury during craniovertebral junction surgery, C1-C2 instrumentation, and posterior fossa approaches.
This retrospective cross-sectional study reviewed 3D computed tomography (CT) images of 200 adult patients obtained between January 2023 and July 2025 at Giresun University Faculty of Medicine. Images were reconstructed and analyzed using OsiriX MD software with a 3D volume rendering technique. AF was classified as complete or incomplete and further categorized by side (right, left, or bilateral). Associations with demographic variables, including age and sex, were examined.
Prevalence estimates were calculated with 95% confidence intervals. Interobserver agreement between two experienced neurosurgeons was assessed using Cohen's Kappa statistic. The findings aim to provide a clearer understanding of AF prevalence in the Turkish population and its potential surgical relevance. By identifying these variations preoperatively, surgeons can better plan instrumentation trajectories and minimize neurovascular complications in craniovertebral and upper cervical procedures.
- Keywords
- Arcuate Foramen, 3D Computed Tomography, Vertebral Artery, Volume Rendering, OsiriX
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| All Adults Undergoing Head CT/CTA (2023-2025) | Consecutive adult patients (≥18 years) whose high-quality 3D CT or CTA images included the atlas (C1) vertebra. Images were evaluated retrospectively for the presence, type (complete/incomplete), and laterality (right/left/bilateral) of the arcuate foramen. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Prevalence of Arcuate Foramen Variants
Proportion of participants with complete arcuate foramen identified on 3D computed tomography (CT).
Unit of Measure: Percentage (%) of participants.
Measurement Tool: High-resolution 3D reconstructed craniovertebral junction CT images, evaluated independently by two neuroradiologists.
Analysis: Proportion calculated with 95% confidence intervals (CI).
Measured: Baseline (single review of existing imaging data)
Secondary outcomes (1)
Association between Arcuate Foramen Type and Demographic Characteristics (Age and Sex)
Description: Relationship between arcuate foramen type (complete vs. incomplete) and patient demographics, including age and sex distribution.
Unit of Measure:
Age: Mean ± standard deviation (years)
Sex: Percentage (%) of male and female participants
Measurement Tool: Demographic data (age and sex) recorded from electronic medical records.
Analysis:
Age: Independent t-test or Mann-Whitney U test; effect size with 95% confidence interval (CI).
Sex: Chi-square test or Fisher's exact test; odds ratio (OR) with 95% CI.
Unit of Measure: Mean ± standard deviation (years).
Measurement Tool: Age recorded from electronic medical records.
Analysis: Independent t-test or Mann-Whitney U test; effect size with 95% CI.
Measured: Baseline.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Aug 2025
- Study start1 Jul 2025
- Primary completion31 Jul 2025
- Study completion31 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Arcuate ForamenStudies of the same condition, open and under way.
- More trials run by Ondokuz Mayıs UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 200 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ondokuz Mayıs University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ilke Tamdogan, Ondokuz Mayıs University
- Investigators
- Tamer Tamdogan, MD, Principal investigator, Giresun University Faculty of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07130461
- Sponsor's protocol ID
- E-53593568-771-250207806
- Status last verified
- Aug 2025
- First submitted
- 11 Aug 2025
- Last updated
- 19 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: This study involves retrospective analysis of de-identified radiological images. Individual participant data will not be shared to protect patient confidentiality.
Publications
Arslan D, Ozer MA, Govsa F, Kitis O. The Ponticulus Posticus as Risk Factor for Screw Insertion into the First Cervical Lateral Mass. World Neurosurg. 2018 May;113:e579-e585. doi: 10.1016/j.wneu.2018.02.100. Epub 2018 Feb 25.
PubMed 29486308Pekala PA, Henry BM, Pekala JR, Hsieh WC, Vikse J, Sanna B, Walocha JA, Tubbs RS, Tomaszewski KA. Prevalence of foramen arcuale and its clinical significance: a meta-analysis of 55,985 subjects. J Neurosurg Spine. 2017 Sep;27(3):276-290. doi: 10.3171/2017.1.SPINE161092. Epub 2017 Jun 16.
PubMed 28621616Elliott RE, Tanweer O. The prevalence of the ponticulus posticus (arcuate foramen) and its importance in the Goel-Harms procedure: meta-analysis and review of the literature. World Neurosurg. 2014 Jul-Aug;82(1-2):e335-43. doi: 10.1016/j.wneu.2013.09.014. Epub 2013 Sep 18.
PubMed 24055572
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Three-Dimensional Computed Tomography Assessment of Arcuate Foramen Variants and Their Surgical Implications: A Retrospective Observational Study
- ClinicalTrials.gov ID
- NCT07130461
- Acronym / sponsor ID
- E-53593568-771-250207806
- Keywords
- Arcuate Foramen, 3D Computed Tomography, Vertebral Artery, Volume Rendering, OsiriX
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 200 participants (actual)
- Lead sponsor
- Ondokuz Mayıs UniversityUniversity, hospital or other
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- 31 Jul 2025 (actual)
- Study completion
- 31 Jul 2025 (actual)
- First posted
- 19 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to determine the prevalence and types of the arcuate foramen (AF), an anatomical variation of the first cervical vertebra (atlas), using three-dimensional computed tomography (3D CT). The arcuate foramen is formed when a bony bridge develops over the groove for the vertebral artery. Although often asymptomatic, it may increase the risk of vascular or nerve injury during surgery in the craniovertebral junction region.
In this retrospective observational study, 3D CT scans of 200 adult patients obtained between January 2023 and July 2025 at Giresun University Faculty of Medicine were reviewed. The presence of AF was classified as complete or incomplete, and also categorized according to its location (right, left, or bilateral). Associations with demographic variables (age, sex) were analyzed.
The results will help improve awareness of AF in preoperative planning for neurosurgical and spinal procedures, potentially reducing the risk of complications involving the vertebral artery and surrounding neurovascular structures.
Detailed description
The arcuate foramen (AF) is an anatomical variation of the atlas (C1 vertebra) that occurs when a bony bridge forms over the groove for the vertebral artery, creating a complete or partial tunnel. While frequently asymptomatic, its presence has been associated with conditions such as vertebrobasilar insufficiency, cervicogenic headache, and chronic neck pain. Importantly, AF may alter the course of the vertebral artery and suboccipital nerve, increasing the risk of injury during craniovertebral junction surgery, C1-C2 instrumentation, and posterior fossa approaches.
This retrospective cross-sectional study reviewed 3D computed tomography (CT) images of 200 adult patients obtained between January 2023 and July 2025 at Giresun University Faculty of Medicine. Images were reconstructed and analyzed using OsiriX MD software with a 3D volume rendering technique. AF was classified as complete or incomplete and further categorized by side (right, left, or bilateral). Associations with demographic variables, including age and sex, were examined.
Prevalence estimates were calculated with 95% confidence intervals. Interobserver agreement between two experienced neurosurgeons was assessed using Cohen's Kappa statistic. The findings aim to provide a clearer understanding of AF prevalence in the Turkish population and its potential surgical relevance. By identifying these variations preoperatively, surgeons can better plan instrumentation trajectories and minimize neurovascular complications in craniovertebral and upper cervical procedures.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| All Adults Undergoing Head CT/CTA (2023-2025) | – | –Consecutive adult patients (≥18 years) whose high-quality 3D CT or CTA images included the atlas (C1) vertebra. Images were evaluated retrospectively for the presence, type (complete/incomplete), and laterality (right/left/bilateral) of the arcuate foramen. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients (≥18 years) who underwent head computed tomography (CT) or computed tomography angiography (CTA) at Giresun University Faculty of Medicine between January 2023 and July 2025, whose images included the atlas (C1) vertebra and met quality criteria for three-dimensional reconstruction.
Key inclusion criteria (4 listed)
- Age ≥ 18 years at the time of imaging
- High-quality CT or CTA images including the atlas (C1) vertebra and posterior arch
- Imaging obtained between January 2023 and July 2025 at Giresun University Faculty of Medicine
- Images suitable for 3D volume rendering analysis without significant artifacts
Key exclusion criteria (4 listed)
- Motion or metallic artifact preventing adequate evaluation of atlas anatomy
- Prior cervical spine surgery or trauma affecting the atlas
- Congenital anomalies or severe deformity of the atlas obscuring posterior arch assessment
- Incomplete demographic or imaging data
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Prevalence of Arcuate Foramen Variants
Time frame: Baseline (single review of existing imaging data)
Proportion of participants with complete arcuate foramen identified on 3D computed tomography (CT). Unit of Measure: Percentage (%) of participants. Measurement Tool: High-resolution 3D reconstructed craniovertebral junction CT images, evaluated independently by two neuroradiologists. Analysis: Proportion calculated with 95% confidence intervals (CI).
1 secondary outcome
Association between Arcuate Foramen Type and Demographic Characteristics (Age and Sex)
Time frame: Baseline.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Aug 2025.
- Results publication: PubMed 29486308Arslan D, Ozer MA, Govsa F, Kitis O. The Ponticulus Posticus as Risk Factor for Screw Insertion into the First Cervical Lateral Mass. World Neurosurg. 2018 May;113:e579-e585. doi: 10.1016/j.wneu.2018.02.100. Epub 2018 Feb 25.
- Results publication: PubMed 28621616Pekala PA, Henry BM, Pekala JR, Hsieh WC, Vikse J, Sanna B, Walocha JA, Tubbs RS, Tomaszewski KA. Prevalence of foramen arcuale and its clinical significance: a meta-analysis of 55,985 subjects. J Neurosurg Spine. 2017 Sep;27(3):276-290. doi: 10.3171/2017.1.SPINE161092. Epub 2017 Jun 16.
- Results publication: PubMed 24055572Elliott RE, Tanweer O. The prevalence of the ponticulus posticus (arcuate foramen) and its importance in the Goel-Harms procedure: meta-analysis and review of the literature. World Neurosurg. 2014 Jul-Aug;82(1-2):e335-43. doi: 10.1016/j.wneu.2013.09.014. Epub 2013 Sep 18.
- Individual participant dataSharing planned: No. This study involves retrospective analysis of de-identified radiological images. Individual participant data will not be shared to protect patient confidentiality.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tamer Tamdogan, MD principal investigator
Giresun University Faculty of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Arcuate Foramen and Anatomical Variations, run by Ondokuz Mayıs University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Prevalence of Arcuate Foramen Variants (time frame: Baseline (single review of existing imaging data)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07130461, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Aug 2025.