Evidence map›Paper›PMID 39951204›Full record

ArticleNeurosurgical review2025

The range of motion characteristics of atlantoaxial joints with the "sandwich" deformity: a human cadaveric biomechanical study.

Yinglun Tian, Nanfang Xu, Huijie Leng, Kan-Lin Hung, Xiangyu Hou, Jinguo Chen, Ming Yan, Weishi Li, Shenglin Wang

Abstract read
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In one paragraph

Article in Neurosurgical review, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. In vivo three-dimensional kinematics of the upper cervical spine during upright head rotation in patients with atlantoaxial dislocation.European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society · 2026
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Yinglun Tian *Department of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China.
Nanfang Xu *Department of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China.
Huijie LengDepartment of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China.
Kan-Lin HungDepartment of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China.
Xiangyu HouDepartment of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China.
Jinguo ChenDepartment of Minimal Invasive Spine Surgery, the First Hospital of Putian, Putian, 351100, China.
Ming YanDepartment of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China.
Weishi LiDepartment of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China.
Shenglin WangDepartment of Orthopaedics, Peking University Third Hospital, No 49. North Garden Road, HaiDian District, Beijing, 100191, China. pkuwsl@126.com.ORCID http://orcid.org/0000-0001-7361-9494

Funding

National Natural Science Foundation of China 82172377
6 · The paper itself

Abstract

During our clinical work, a special subtype of atlantoaxial dislocation(AAD) was identified, which was combined with atlas occipitalization and C2-3 fusion and was named as "sandwich" AAD.To explore if the biomechanical characteristics between atlantoaxial joints in "sandwich" deformity patients is particular and if there is a relationship between the AAD and the malformations (Chiari malformation and the formation of syringomyelia). A biomechanical study on the atlantoaxial joint by simulating "sandwich" deformity in cadaveric specimens was conducted. Five fresh frozen cadaver spinal specimens (from the occiput to C7) were selected from human donors with no history of spinal trauma and congenital malformations. The C0-1 and C2-3 (C1 pedicle screws combined with occipital titanium, C2 pedicle screws and C3 lateral mass screws) were fixed to develop congenital atlas occipitalization and C23 fusion deformities ("sandwich" deformity). Each specimen was tested two times, firstly under the normal condition and secondly under the "sandwich" condition. Then the range of motion(ROM) between C1 and C2 was measured under different conditions. The results showed that the relative range of flexion-extension motion between C1-2 in the "Sandwich" specimens was significantly greater than that in the normal specimens (P < 0.05). No significant difference in the relative range of other two motion modes (lateral bending and axial rotation) between C1-2 was observed for the normal and "Sandwich" specimens. The "clamp" mechanism of "sandwich" deformity during flexion and extension might be involved in the pathogenesis of AAD and secondary nervous system damage.

Indexed as

Atlanto-Axial JointJoint DislocationsRange of Motion, ArticularAdultAgedBiomechanical PhenomenaCadaverCervical VertebraeFemaleHumansMaleMiddle AgedSpinal FusionAtlantoaxial dislocationCadaveric biomechanical studyChiari malformationRange of motion“Sandwich” deformitySyringomyelia

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.