Atlantoaxial DislocationNCT05754554
Clinical Study of the Treatment of Chiari Malformation Combined With Type II Skull Base Depression
A study testing Atlas occipital decompression lateral joint release combined with occipital-neck fusion and Simple FMD with Outer Dural Delamination in people with Atlantoaxial Dislocation and Chiari Malformation, run by Southern Medical University, China at 1 site in China.
Trial summary
The research background of this study is that Chiari malformation (CM) is a congenital malformation in the foramen magnum region, often associated with syringomyelia, basilar depression, odontoid dislocation and other craniocervical junction deformities. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Atlantoaxial Dislocation, Chiari Malformation, Basilar Invagination
- What is being tested?
- Atlas occipital decompression lateral joint release combined with occipital-neck fusion and Simple FMD with Outer Dural Delamination
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 64 participants
- Where
- 1 siteChina
- Study dates
- 1 Mar 2023to 16 Dec 2024
- Phase
- Interventional
- 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 to 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Clinical diagnosis of Chiari malformation
- Combined with type II skull base depression
- Clinical symptoms related to the disease
- Complete clinical imaging data
- Must be the first surgery
Who cannot join
- Secondary cerebellar tonsillar hernia
- Severe atlantoaxial dislocation
- Osteochondroplastica
- Rheumatoid arthritis
- Down syndrome
- Refurbished case reoperation
Trial locations and contacts
1 site in 1 country.
China1 site
Nan fang hospital, Southern medical university
Guangzhou, Guangdong, 510515
About this study
Official title: Clinical Study of Atlanto-occipital Decompression Lateral Joint Release Combined With Occipital-neck Fusion in the Treatment of Chiari Malformation Combined With Type II Skull Base Depression
The research background of this study is that Chiari malformation (CM) is a congenital malformation in the foramen magnum region, often associated with syringomyelia, basilar depression, odontoid dislocation and other craniocervical junction deformities. The traditional surgical method for Chiari malformation with skull basilar depression is simple decompression without fixation, so it cannot effectively maintain the stability of the cervical spine and reduce the compression of the brainstem and cervical cord, often resulting in poor curative effect and aggravated symptoms. The cervical spine is the most flexible and most mobile part of the spine, and the instability of the cervical spine will directly affect the quality of life of patients after surgery. Subsequently, with the continuous advancement of technology and the continuous development and improvement of surgical methods, Investigators can relieve spinal cord compression by using atlanto-occipital decompression and dissection followed by C1/2 lateral arthrolysis combined with occipitocervical fusion. So, is this surgical combination the most effective surgery for patients with Chiari malformation and type II skull basilar depression? How should doctors adjust to the best surgical approach to treat patients with Chiari malformation and type II skull basilar depression? These questions have long puzzled neurosurgeons. By conducting this research, investigators hope that participants can participate in it, and work with them to answer this question, and jointly promote the development and progress of doctors' careers, while benefiting more patients.
- Being tested
- Atlas occipital decompression lateral joint release combined with occipital-neck fusion, Simple FMD with Outer Dural Delamination
- Medical subject headings
- Arnold-Chiari Malformation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Atlas occipital decompression lateral joint release combined with occipital-neck fusionProcedure or surgery
- Chiari malformation combined with type II Basilar invagination showed that the slope spinal canal angle decreased, and the position of the dentition moved up. The yellow fusion device in the picture is C1/2 lateral inter-articular Cage (the patent granted by the applicant for this project); B. After atlanto-occipital decompression, C1/2 lateral inter-articular release is performed, and a fusion device is implanted to move down the position of the tip of the tooth process to reduce the compression of the cervical medulla oblongata; C. Implantation of the posterior neck nail rod system; D. Improve the angle of the sloped spinal canal by posterior compression rod technique (Cantilever) to further reduce the compression on the superior cervical medulla oblongata.
Simple FMD with Outer Dural DelaminationProcedure or surgery
This arm utilizes the traditional standard strategy, distinct from the comprehensive fusion in the experimental arm. The specific distinguishing details are: Performing strictly anatomical decompression ONLY. This involves bony foramen magnum decompression combined with outer dural delamination (without opening the inner layer of the dura mater). This arm specifically EXCLUDES C1/2 facet joint release, cage implantation, and any form of occipitocervical internal fixation or biomechanical reconstruction.
| Study group | Role | What they receive |
|---|---|---|
| Experimental: FMD + C1/2 Facet Release + OCF | Experimental | All patients underwent preoperative dynamic CT scans in flexion, neutral, and extension positions, and all were treated surgically with atlanto-occipital decompression, CI/2 lateral articular release, combined with occipital-cervical fusion. Receives: Procedure: Atlas occipital decompression lateral joint release combined with occipital-neck fusion |
| Active Comparator: Simple FMD + Outer Dural Delamination | Active comparator | Patients in this arm will receive the traditional standard procedure, which consists of simple bony foramen magnum decompression combined with outer dural delamination (without opening the inner layer of the dura mater to reduce complications). Receives: Procedure: Simple FMD with Outer Dural Delamination |
What is being measured
The primary outcome is the main question the study is designed to answer.
Chang of Chicago Chiari outcome score
The Chicago Chiari Malformation Prognosis Scale (CCOS) is a comprehensive quantitative scoring criterion for surgical prognosis in patients with Chiari malformations, first proposed by the Department of Neurosurgery of the University of Chicago School of Medicine. CCOS covered four scoring criteria, including improvement in pain symptoms, improvement in non-pain symptoms, ability to live, and surgery-related complications, with a single score of 1-4 for a total score of 4 to 16, and at the last follow-up, the higher the patient's score indicated the better the patient's postoperative prognosis.
Measured: through study completion, an average of 1 year
Secondary outcomes (5)
Occurrence of complications
1)Minor complications such as pain, neck stiffness, and poor wound healing. 2)Serious complications such as vertebral artery injury, dyspnea, cerebrospinal fluid leakage, and severe intracranial infection.
Measured: The second week after surgery
Chang of Magnetic Resonance Imaging
Measurements of radiographic improvement, such as cerebellar tonsillar hernia length.
Measured: through study completion, an average of 1 year
Chang of Visual Analog Score for pain
Visual Analog Score stands for visual analogue scoring method and is one of the commonly used pain scoring criteria. The main thing is to draw a 10cm horizontal line on the paper, the beginning end is 0, the other end is 10, the middle part represents different degrees of pain, let the patient choose the degree of pain by himself. A score below 3 represents mild pain; 4-6 are divided into pain that interferes with sleep, but is tolerable; A score of 7-10 indicates unbearable pain.
Measured: through study completion, an average of 1 year
Chang of Japanese Orthopaedic Association Scores
The patient's lumbar spine function and improvement were mainly evaluated from four aspects: subjective symptoms, daily activity ability, clinical signs, and bladder function. The scoring range is 0~29 points, and the higher the total score, the milder the patient's condition.
Measured: through study completion, an average of 1 year
Chang of Neck Disability Index
Neck Disability Index consists of 10 items, including: neck pain and related symptoms (pain intensity, headache, concentration and sleep) and activities of daily living (personal care, lifting heavy objects, reading, work, driving and playing). Each item has a minimum score of 0 and a maximum score of 5, with higher scores indicating greater levels of dysfunction.
Measured: through study completion, an average of 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2023
- Study start1 Mar 2023
- Primary completion12 Dec 2024
- Study completion16 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atlantoaxial DislocationStudies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 64 participants (actual)
Sponsor and investigators
- Lead sponsor
- Southern Medical University, China
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Yuntao Lu, Southern Medical University, China
- Investigators
- yutao lu, Study chair, 2Nanfang Neurology Research Institution, Nanfang Hospital, Southern Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05754554
- Sponsor's protocol ID
- NFEC-2022-440
- Status last verified
- Apr 2026
- First submitted
- 28 Jan 2023
- Last updated
- 28 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Clinical Study of Atlanto-occipital Decompression Lateral Joint Release Combined With Occipital-neck Fusion in the Treatment of Chiari Malformation Combined With Type II Skull Base Depression
- ClinicalTrials.gov ID
- NCT05754554
- Acronym / sponsor ID
- NFEC-2022-440
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 64 participants (actual)
- Lead sponsor
- Southern Medical University, ChinaUniversity, hospital or other
- Study start
- 1 Mar 2023 (actual)
- Primary completion
- 12 Dec 2024 (actual)
- Study completion
- 16 Dec 2024 (actual)
- First posted
- 6 Mar 2023 (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.
The research background of this study is that Chiari malformation (CM) is a congenital malformation in the foramen magnum region, often associated with syringomyelia, basilar depression, odontoid dislocation and other craniocervical junction deformities. The traditional surgical method for Chiari malformation with skull basilar depression is simple decompression without fixation, so it cannot effectively maintain the stability of the cervical spine and reduce the compression of the brainstem and cervical cord, often resulting in poor curative effect and aggravated symptoms. The cervical spine is the most flexible and most mobile part of the spine, and the instability of the cervical spine will directly affect the quality of life of patients after surgery. Subsequently, with the continuous advancement of technology and the continuous development and improvement of surgical methods, Investigators can relieve spinal cord compression by using atlanto-occipital decompression and dissection followed by C1/2 lateral arthrolysis combined with occipitocervical fusion. So, is this surgical combination the most effective surgery for patients with Chiari malformation and type II skull basilar depression? How should doctors adjust to the best surgical approach to treat patients with Chiari malformation and type II skull basilar depression? These questions have long puzzled neurosurgeons. By conducting this research, investigators hope that participants can participate in it, and work with them to answer this question, and jointly promote the development and progress of doctors' careers, while benefiting more patients.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Experimental: FMD + C1/2 Facet Release + OCF | Experimental | Procedure: Atlas occipital decompression lateral joint release combined with occipital-neck fusionAll patients underwent preoperative dynamic CT scans in flexion, neutral, and extension positions, and all were treated surgically with atlanto-occipital decompression, CI/2 lateral articular release, combined with occipital-cervical fusion. |
| Active Comparator: Simple FMD + Outer Dural Delamination | Active comparator | Procedure: Simple FMD with Outer Dural DelaminationPatients in this arm will receive the traditional standard procedure, which consists of simple bony foramen magnum decompression combined with outer dural delamination (without opening the inner layer of the dura mater to reduce complications). |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Clinical diagnosis of Chiari malformation
- Combined with type II skull base depression
- Clinical symptoms related to the disease
- Complete clinical imaging data
- Must be the first surgery
Key exclusion criteria (6 listed)
- Secondary cerebellar tonsillar hernia
- Severe atlantoaxial dislocation
- Osteochondroplastica
- Rheumatoid arthritis
- Down syndrome
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Atlas occipital decompression lateral joint release combined with occipital-neck fusionA. Chiari malformation combined with type II Basilar invagination showed that the slope spinal canal angle decreased, and the position of the dentition moved up. The yellow fusion device in the picture is C1/2 lateral inter-articular Cage (the patent granted by the applicant for this project); B. After atlanto-occipital decompression, C1/2 lateral inter-articular release is performed, and a fusion device is implanted to move down the position of the tip of the tooth process to reduce the compression of the cervical medulla oblongata; C. Implantation of the posterior neck nail rod system; D. Improve the angle of the sloped spinal canal by posterior compression rod technique (Cantilever) to further reduce the compression on the superior cervical medulla oblongata. | Procedure or surgery | Experimental: FMD + C1/2 Facet Release + OCF |
| Simple FMD with Outer Dural DelaminationThis arm utilizes the traditional standard strategy, distinct from the comprehensive fusion in the experimental arm. The specific distinguishing details are: Performing strictly anatomical decompression ONLY. This involves bony foramen magnum decompression combined with outer dural delamination (without opening the inner layer of the dura mater). This arm specifically EXCLUDES C1/2 facet joint release, cage implantation, and any form of occipitocervical internal fixation or biomechanical reconstruction. | Procedure or surgery | Active Comparator: Simple FMD + Outer Dural Delamination |
Primary outcome
Chang of Chicago Chiari outcome score
Time frame: through study completion, an average of 1 year
The Chicago Chiari Malformation Prognosis Scale (CCOS) is a comprehensive quantitative scoring criterion for surgical prognosis in patients with Chiari malformations, first proposed by the Department of Neurosurgery of the University of Chicago School of Medicine. CCOS covered four scoring criteria, including improvement in pain symptoms, improvement in non-pain symptoms, ability to live, and surgery-related complications, with a single score of 1-4 for a total score of 4 to 16, and at the last follow-up, the higher the patient's score indicated the better the patient's postoperative prognosis.
5 secondary outcomes
Occurrence of complications
Time frame: The second week after surgery
Chang of Magnetic Resonance Imaging
Time frame: through study completion, an average of 1 year
Chang of Visual Analog Score for pain
Time frame: through study completion, an average of 1 year
Chang of Japanese Orthopaedic Association Scores
Time frame: through study completion, an average of 1 year
Chang of Neck Disability Index
Time frame: through study completion, an average of 1 year
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 28 Apr 2026.
- Individual participant dataSharing planned: No
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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.
yutao lu study chair
2Nanfang Neurology Research Institution, Nanfang Hospital, Southern Medical University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Atlas occipital decompression lateral joint release combined with occipital-neck fusion and Simple FMD with Outer Dural Delamination in people with Atlantoaxial Dislocation and Chiari Malformation, run by Southern Medical University, China at 1 site in China.
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 5 inclusion and 6 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 28 Apr 2026. 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 China. 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?
Chang of Chicago Chiari outcome score (time frame: through study completion, an average of 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 28 Apr 2026.