Anatomy of Alar Ligament Part III: Biomechanical Study

Iwanaga, Joe; Sardi, Juan Pablo; Laws, Tyler; Oskouian, Rod J.; Tubbs, R. Shane

doi:10.1016/j.wneu.2017.07.188

Cited by 8 publications

(13 citation statements)

References 20 publications

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“…Govender et al [12] reported that the mean difference of surface area between type-II and type-III fractures was 134.72 mm 2 , which might in uence healing after fracture. Iwanaga et al [21] and Heggeness et al [22] reported that the odontoid process was under destructive forces from the apical ligament, which can lead to nonunion of type II odontoid fracture. Crockard et al [23] and Moskovich et al [24] suggested that the occurrence of nonunion in type-II fractures as a consequence of the interposition of the transverse ligament at the site of the fracture.…”

Section: Resultsmentioning

confidence: 99%

One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture 

Dong¹,

Hu²,

Zhong³

et al. 2020

Preprint

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Background. To analyze the underlying causes of frequent occurrence and nonunion of type II odontoid fracture.Methods. CT scans along with 3D imaging software (Mimics software) were used to measure the bone density of the axis. The axis was divided into three parts, including the odontoid of the axis (the first part), the base of the odontoid (the second part) and the body of the axis (the third part). The CT value of the axis was measured and analyzed in different axial planes from top to bottom, followed by calculation and comparison of the mean CT value of the three parts of the axis.Results. The mean CT value of the odontoid (the first part), base of the odontoid (the second part) and body of the axis (the third part) was 651.35±188.32, 318.38±98.82 and 397.45±93.59, respectively. In addition, the interval variation of CT value of different axial planes was initially decreased and further increased with the change of axial planes from top to bottom.Conclusion. The mean CT value of the base of the odontoid was significantly lower than that of the odontoid or the body of the axis. Therefore, the base of the odontoid was the transition region of shape and bone density, which may be one possible cause for the frequent occurrence and nonunion in the type II odontoid fracture in axis fracture.

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Section: Resultsmentioning

confidence: 99%

One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture 

Dong¹,

Hu²,

Zhong³

et al. 2020

Preprint

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“…[14] To date, these ligaments including some accessory ligaments have been studied. [5678914] However, the SAAOL has not been studied. Quain[11] defined the SAAOL as a thick “accessory ligament” whose fibers reinforcing the AAOM.…”

Section: Discussionmentioning

confidence: 99%

“…[4] The ligaments of the CCJ, especially the transverse and alar ligaments, have been well studied. [56789] By contrast, there is a rarely discussed and nearly forgotten ligament on the CCJ, the superficial anterior atlanto-occipital ligament (SAAOL). [10] The ligament is described in antiquated anatomical texts as running vertically anterior to the anterior atlanto-occipital membrane (AAOM) (synonym for the anterior atlanto-occipital ligament).…”

Section: Introductionmentioning

confidence: 99%

Superficial anterior atlanto-occipital ligament: Anatomy of a forgotten structure with relevance to craniocervical stability

Kikuta

Iwanaga

Watanabe

et al. 2019

J Craniovert Jun Spine

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Introduction: The superficial anterior atlanto-occipital ligament (SAAOL) is a narrowband located anterior to the anterior atlanto-occipital membrane. Nearly forgotten, it has not been well described in older anatomical textbooks and is missing in the current anatomical literature. As all of the binding structures of the craniocervical junction (CCJ) are important in maintaining stability, this study aims to clarify the anatomy and potential function of the SAAOL. Materials and Methods: The CCJ from ten fresh-frozen cadavers was studied. These specimens were derived from three males and seven females, and the age at death ranged from 57 to 91 years (mean, 79.8 years). The length, width, and thickness of the SAAOL were measured. In five specimens, the force to failure was recorded. Results: The SAAOL was found between the anterior tubercle of the atlas and the occiput and located as central thick fibers in front of the anterior atlanto-occipital membrane in 9 (90%) specimens. In one specimen, the vertical band to the occipital bone did not attach to the anterior tubercle of the atlas, but extended to the anterior aspect of the axis. The mean length, width, and thickness of the SAAOL were 19.8, 6.2, and 0.6 mm, respectively. The force to failure for the ligament was 38.8 N. Conclusion: The SAAOL was a constant structure of the anterior atlanto-occipital joint. This ligament seems to be a secondary stabilizer of the CCJ by limiting the extension of CCJ. Knowledge of this ligament may help in further understanding of craniocervical stability.

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“…Several ligaments stabilize these joints, namely the transverse, alar, transverse occipital, accessory, lateral atlantooccipital, and apical ligaments [ 1 ]. The transverse and alar ligaments are the two strongest ligaments stabilizing the craniocervical junction with approximately 400 N and 200 N necessary until failure, respectively [ 1 - 2 ].…”

Section: Introductionmentioning

confidence: 99%

“…The alar ligaments are fibrous cords that attach to the dens bilaterally and insert on the base of the skull. They function to limit axial rotation and lateral bending on the contralateral side, and flexion secondarily [ 1 - 2 ]. These functions are a result of the specific attachment, insertion, and orientation of the fibers of the alar ligaments and variations in these can lead to altered biomechanics.…”

Section: Introductionmentioning

confidence: 99%

Duplication of the Alar Ligaments: A Case Report

Rizvi

Iwanaga

Oskouian

et al. 2018

Cureus

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The alar ligament is one of the two strongest ligaments stabilizing the craniocervical junction. The literature describes many variations of the attachment, insertion, shape, and orientation of the alar ligament and an understanding of these variations is vital as they can lead to altered biomechanics or misinterpretation on imaging. Herein, we report, to our knowledge, the first case of duplication of the alar ligaments and discuss the anatomical variations present in the literature.

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Anatomy of Alar Ligament Part III: Biomechanical Study

Cited by 8 publications

References 20 publications

One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture

One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture

Superficial anterior atlanto-occipital ligament: Anatomy of a forgotten structure with relevance to craniocervical stability

Duplication of the Alar Ligaments: A Case Report

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Anatomy of Alar Ligament Part III: Biomechanical Study

Cited by 8 publications

References 20 publications

One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture&nbsp;

One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture&nbsp;

Superficial anterior atlanto-occipital ligament: Anatomy of a forgotten structure with relevance to craniocervical stability

Duplication of the Alar Ligaments: A Case Report

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One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture

One Possible Cause for the Frequent Occurrence and Nonunion of Type II Odontoid Fracture