Type of Article:  Original Research

Volume 5; Issue 1 (January 2017)

Page No.: 3367-3371

DOI: https://dx.doi.org/10.16965/ijar.2016.479


Santhi B 1, Dhanalakshmi V *2, Esther Yamuna N 3, Manoharan C 4.

1 Associate Professor, Govt. Medical College, Omanthurar Govt. Estate, Chennai, Tamilnadu, India.

*2 Associate Professor, Govt. Thoothukudi Medical College, Thoothukudi, Tamilnadu, India.

3 Assistant Professor, Govt. Thoothukudi Medical College, Thoothukudi, Tamilnadu, India.

4 Associate Professor, Govt. Tirunelveli Medical College, Tirunelveli, Tamilnadu, India.

Corresponding Author:  Dr.V.Dhanalakshmi.M.D. (Anatomy), Department of Anatomy, Government Thoothukudi Medical College, 3rd Mile, Thoothukudi – 628008, Tamilnadu, India. E-Mail: drlakshmidhana@gmail.com


Background: Variations in bone are common. Atlas vertebrae are especially subject to variation and are of clinical importance because of its close relation to vertebral artery. Bony spur can arise from the posterior margin for the groove of vertebral artery and form bridges known as ponticles. The bridges can be posterior, lateral or posterolateral. If the bridge is complete it is known as arcuate foramen. These variations can predispose to vertebrobasilar insufficiency.

Aim: To study the incidence of arcuate foramen and its various dimensions in the atlas vertebrae.

Materials and Methods: 58 human dry atlas vertebrae from Dept. of Anatomy, Govt. Thoothukudi Medical College, Tamilnadu were studied for the presence of arcuate foramen and ponticles and its dimensions were measured using digital vernier caliper.

Results: Arcuate foramen was found in 5 atlas vertebra (8.6%), one was bilateral and others were unilateral with equal incidence in right and left side. The mean length of the arcuate foramen was 6.09mm and the mean height of the arcuate foramen was 5.44mm. Ponticulus posterior was observed in 4 sides (3.45%) of atlas with higher incidence on left side (2.59%) and projection from superior articular facet posteriorly was found in 31.03% and also showed left side preponderance (17.24%). Exostosis from superior articular facet posterolaterally forming supratransverse foramen was observed in 4.31%.

Conclusion: Arcuate foramen can cause compression of vertebral artery during rotatory movements of neck and can result in vertebrobasilar insufficiency. It can also be a cause for vertigo. Having knowledge about this variation will be beneficial for the radiologist in interpreting and for neurosurgeons operating along the posterior arch.

KEY WORDS: Arcuate foramen, atlas, compression, ponticles, vertebrobasilar insufficiency.


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Cite this article: Santhi B, Dhanalakshmi V, Esther Yamuna N, Manoharan C. STUDY OF ARCUATE FORAMEN OF ATLAS VERTEBRAE. Int J Anat Res 2017;5(1):3367-3471. DOI: 10.16965/ijar.2016.479