Type of Article:  Original

Volume 7; Issue 2.1 (April 2019)

Page No.: 6370-6376

DOI: https://dx.doi.org/10.16965/ijar.2019.120


Monika Lalit *1, Sanjay Piplani 2, Anupama Mahajan 3, Anuradha Dehiya 4.

*1 Associate Prof, Dept. of Anatomy, SGRDIMS&R, Amritsar, Punjab, India.

2 Professor, Dept. of Pathology, SGRDIMS&R, Amritsar, Punjab, India.

3 Professor & Head, Dept. of Anatomy, SGRDIMS&R, Amritsar, Punjab, India.

4 Lecturer, Dept. of Anatomy, Govt. Medical College, Amritsar, Punjab, India.

Corresponding Author: Dr. Monika Lalit, Associate Prof, Dept. of Anatomy, SGRDIMS&R, Amritsar, Punjab, India. Ph No.- 9814325454 E-Mail: monika.lalit@yahoo.com


Background: The lateral outgrowth from the superior articular facet(SAF) to the posterior root of the transverse process of the atlas forms the partial lateral bridge(PLB) and when complete forms the supratransverse foramen (STF). Presence of such bridges may predispose to vertebrobasilar insufficiency.  Since there are fewer studies on the lateral bridge therefore the present study was aimed to know the incidence of lateral bridges and STF and also to know the dimensions of STF as the knowledge about such dimensions helps in interpretation of radiological findings, provide guidance for neurosurgical intervention.

Materials and methods: A total of 80 undamaged, dry human atlas vertebrae were obtained from the Department of Anatomy, Government Medical College and SGRDIMSAR, Amritsar, Punjab, India. The Partial lateral bridge(PLB) and Supratransverse Foramen(STF) were identified following the criteria used by Mitchell (1998a, 1998b). Measurements were taken of the maximum dimensions of the STF in (Supero-inferior and Medio-lateral planes) and ipsilateral Foramen Transversarium (FT) in (Ventro-dorsal and Medio-lateral planes). The cross-sectional area of STF and ipsilateral FT was calculated.

Results:  Total 7 (8.75%) lateral bridges in atlas vertebrae occurred. 6 (7.5%) lateral bridges occurred in association with the posterior bridges and 1(1.25%) isolated partial lateral bridge occurred on the left side. Partial lateral bridges were found in 2 bones(2.5%) on right side and 4(2.5%)bones on left side. 1 (0.625%) Complete lateral bridges forming STF was observed on right side. Rt. Supra-Transverse Foramen Height (STFH) and Width (STFW) was found to be 5.4mm and 6.2mm. Ipsilateral Foramen Transversarium Length (FTL) and Width (FTW) was found to be 6.4mm and 5.9mm. The cross-sectional area of Rt. STF was 26.28mm2 and the cross-sectional area of ipsilateral FT was 29.64mm2 and ipsilateral FT area was smaller than STF.

Conclusion:  The findings in the present study indicate a higher prevalence of lateral bridges on the left side. Difference in the cross sectional area of STF and ipsilateral FT may lead to compression of V.A and this compression becomes evidently symptomatic in extreme manipulations of the neck. Patients presenting with vertebrobasilar insufficiency or  cervicogenic syndromes should be evaluated to explore the possibility of the presence of lateral atlas bridges as etiological factor

KEY WORDS:  Lateral Bridge, Supratransverse Foramen,  Foramen Transversarium, Vertebral Artery, Cross-Sectional Area.


  1. William M, Newell RLM, Collin P. The back: cervical vertebrae. In: Standring S, Ellis H, Haely JC, Johson D, Williams A (eds), Gray’s Anatomy. 39th Edinburg, London: Elsevier Churchill Livingstone;2005:742-746.
  2. Macalister A. Notes on the homologics and comparative anatomy of the atlas and axis. J Anat and Physiol 1869;3:54-64.
  3. MacAlister A. Notes on the development and variations of the atlas. Journal of Anatomy and Physiology 1893;27:518–542.
  4. Lamberty BG and Zivanovic S. The retro-articular vertebral artery ring of the atlas and its significance Acta Anat 1973;85:113-22.
  5. Saunders S R & Popovich F. A family study of two skeletal variants: atlas bridging and clinoid bridging. American Journal of Physical Anthropology 1978; 49:193–204.
  6. Taitz C, Nathan H. Some observations on the posterior and lateral bridge of atlas. ActaAnat1986;127(3):212-217.
  7. Mitchell J. The incidence and dimensions of the retroarticular canal of the atlas vertebra. Acta Anat 1998 a;163:113-120.
  8. Mitchell J. The incidence of the lateral bridge of atlas vertebra. Journal of Anatomy 1998 b;193:283-285.
  9. Pyo J & Lowman R M. The ponticulus posticus of the first cervical vertebra. Radiology 1959;72:850-854.
  10. Hasan M, Shukla S, Siddiqui MS, Singh D. Posterolateral tunnels and ponticuli in human atlas vertebrae. J Anat 2001;199(3):339-343.
  11. Unur, E, Erdogan N, Ülger H, Ekinci N & Oztürk O. Radiographic incidence of complete arcuate foramen in Turkish population. Erciyes Med J 2004; 26:50-54.
  12. Lalit M, Singla R K, Kullar J S. Bilateral Arcuate Foramen in a Human Atlas Vertebra – A Case Report. International Journal of Anatomy, Radiology and Surgery 2013;2(3):3-6.
  13. Warlow CP. Cerebrovascular disease. In Oxford Textbook of Medicine, 3rd edn. Weatherall DJ, Ledingham JGG, Warrell DA Oxford: Oxford University Pres;1996:3950.
  14. Park PJ, Wallis WE, Wilson JE. Vertebral artery occlusion following manipulation of the neck. N Z Med 1978; 88:441-43.
  15. Zambare BR, Reddy BB.The retro articular ring of the atlas and its clinical significance. Anatomica Karnatka 2011;5:74-76.
  16. Selecki BR. The effects of rotation of the atlas on the axis: experimental work. Medical Journal of Australia 1969;1:1012–1015.
  17. Krueger BR, Okazaki H. Vertebral basilar distribution infarction following chiropractic cervical manipulation. Mayo Clinic Proceedings. 1980;55:322-332.
  18. Cakmak O, Gurdal E, Ekinci G, Yildiz E, Cavdar S. Arcuate foramen and its clinical significance. Saudi Med J 2005;26:1409-13.
  19. Lalit M, Piplani S, Verma P. Study of dimensions of retroarticular bony rings in human atlas vertebrae: An Original Research article. Int J Anat Res (IJAR) 2016;4(3):2526-30.
  20. Dhall U, Chhabra S, Dhal JC. Bilateral asymmetry in bridges and superior articular facets of atlas vertebra. J Anat Soc.India 1993;42:23-27.
  21. Hasan M, Shukla S, Siddiqui MS, Singh D. Posterolateral tunnels and ponticuli in human atlas vertebrae. J Anat 2001;199(3):339-343.
  22. Paraskewas G and Papaziogas B. Gross morphology of the bridges over vertebral artery groove on the atlas. Surgical and radiological Anatomy 2005;27:129-136.
  23. Le Minor JM. The retrotransverse foramen of the human atlas vertebra – A distinctive variant within primates. Acta Anat 1997;160:208-212.
  24. Le double AF. Traiteu des variations de la colonne vertebrae de i’homme et de leur signification au point de vue de i’anthropologique zoologique. Paris: vigot frères.1912.
  25. Barge JAJ. Problems in kranio- vertebral Gebiet section. Verh K Akad Wetensch Amsterdam 1918;20(2):102-105.
  26. Hayek H. Untersuchungen u ber epistropheus, atlas und hinterhauptsbein. Gegenbaurs morphologisches jahrbuch 1927;58:269-347.
  27. Toro I, Szepe L. Untersuchungen u$ ber die frage der assimilation und manifestation des atlas. Zeitschrift fur anatomie und enwicklungsgeschichte 1942;111:186-200.
  28. Radojevic S and Negtovanovic B. La gouttiere et les Anneaux osseux de l’artere vertebrale de l’atlas. Acta anatomica 1963;55:189-194.
  29. Malhotra VK, Tewari SP, Bajpai RN. Study of vertebral artery foramen of atlas vertebra. Journal of anatomical society of india 1979; 28:103-105.
  30. Karau Bundi P, Ogengo JA, Hassanali J, Odula PO. Anatomy and Prevalence of Atlas Vertebrae Bridges in a Kenyan Population: An Osteological Study. Clinical Anatomy 2010;23:649–653
  31. Karau Bundi P, Ogengo JA, Hassanali J, Odula PO. Morphometry and variations of bony poticles of the atlas vertebrae in Kenyans. Int J Morphol 2010; 28(4):1019-1024.
  32. Tubbs RS, Shoja MM, Shokouhi G, Farahani RM, Loukas M, Oakes WJ. 2007a. Simultaneous lateral and posterior ponticles resulting in the formation of a vertebral artery tunnel of the atlas: Case report and review of the literature. Folia Neuropathol 45:43–46.
  33. Limousin CA. Foramen arcuale and syndrome of Barre-Lieou. Its surgical treatment. Int Orthop 1980; 4:19–23.
  34. Bolton PS, Stick PE, Lord RS. Failure of clinical tests to predict cerebral ischemia before neck manipulation. J Manipul Physiol Ther 1989;12:304–307.

Cite this article: Monika Lalit, Sanjay Piplani, Anupama Mahajan, Anuradha Dehiya. PARTIAL LATERAL BRIDGES AND SUPRATRANSVERSE FORAMEN IN HUMAN ATLAS VERTEBRAE: AN OSTEOLOGICAL STUDY IN PUNJAB. Int J Anat Res 2019;7(2.1):6370-6376. DOI: 10.16965/ijar.2019.120