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ORIGINAL ARTICLE
To Determine the Incidence of Accessory ForamenTransversarium
Rachna Magotra, Shahnaz Choudhary, Ashwani K Sharma, Nusrat Jabeen
All seven cervical vertebrae have a foramen - theforamen transversarium in the transverse process.Anterior to the foramen is the bar of bone - the costalprocess - which projects laterally from the body to theend of anterior tubercle. The costal process correspondsto the ribs. Behind the foramen the true transverseprocess projects laterally from the junction of the pedicleand the lamina. It ends in the posterior tubercle. A bar ofbone the costotransvrese bar unites the anterior andposterior tubercle and completes the foramentransversarium. It is concave superiorly and has a ventralramus of the corresponding spinal nerve. The foramentransversarium transmits the vertebral artery (C1 to C6)only, vertebral veins and sympathetic plexus (1)
Presence of another foramen apart from foramentransversarium in the transverse process of cervicalvertebrae is called accessory foramen transversariumwhich is smaller in size than the primary foramen.Generally, it is found in the sixth cervical vertebra andless frequently in other typical cervical and 7th cervicalvertebrae. This accessory foramen transversarium liesposterior to the normal foramen transversarium (2)
Formation of foramen transversarium occurs due to
the fusion of costal element of developing cervicaltransverse process with the transverse element of thedeveloping vertebrae. During this interaction the vertebralvessels and nerve plexuses are caught between thesetwo bony parts. So the course of vertebral vesselsdetermines the formation of foramen transversarium.
The aim of this study is to find out the incidence ofaccessory foramen transversarium in cervical vertebrae.Material and Methods
The present study was conducted on 150 dried cervicalvertebrae obtained from the Postgraduate Departmentof Anatomy Government Medical College. Only completevertebrae, which were not broken, were included in thestudy. All the vertebrae were observed grossly, for thepresence of accessory foramen transversarium. A fineneedle was passed through these foramina to observetheir patency. All the vertebrae having accessory foramentransversarium were photographed and the findings weretabulated.Results
Out of 150, only 24 cervical vertebrae had accessoryforamen transversarium. Amongst them 14 (58%) hadbilateral accessory foramen transversarium (Fig-1) and
Introduction
AbstractTo find the incidence of accessory foramen transversarium in dried cervical vertebrae. 150 dried cervicalvertebrae were collected from Postgraduate department of Anatomy Government Medical College Jammuand examined for the accessory foramen transversarium.Out of 150 cervical vertebrae, only 24 hadaccessory foramen transversarium with preponderance in sixth cervical vertebrae. Amongst the vertebraewith accessory foramen transversarium, 14 were bilateral and 10 were unilateral. In the present study theincidence of accessory foramen transversarium was 16%. This is important for Radiologists to interpretComputed Tomography Images and Magnetic Resonance Imaging of cervical spine.
Key WordsCervical Vertebrae, Foramen Transversarium, Accessory Foramen Transversarium, Vertebral Artery
From the Deptt. of Anatomy, Govt. Medical College Jammu (J&K), IndiaCorrespondence to : Dr Shahnaz Choudhary, Assistant Professor, Dept. of Anatomy, Govt. Medical College Jammu, (J&K)
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9 (42%) had unilateral accessory foramentransversarium (6 on the right side and 4 on the left side)(Fig-2, 3) (Table-1). No accessory foramentransversarium was present in first, second and seventhcervical vertebrae (Atypical cervical vertebrae). It wasonly present in third, fourth, fifth and sixth cervicalvertebrae (Typical cervical vertebrae), . The incidenceof accessory foramen transversarium in 150 cervicalvertebrae was 16%. Amongst the vertebrae withaccessory foramen transversarium, 2 were C3 (8.34%),3 were C4 (12.5%), 5 were C5 (20.83%) and 14 wereC6 (58.33%)(Fig-3). Absence of foramentransversarium and double accessory foramentransversarium was not seen in our study.
DiscussionVariations in the foramen transversarium are important
as they depict variations in the vertebrate artery. In thepresent study we studied 150 cervical vertebrae and
Number of
Vertebrae
Vertebrae with
AFT
Bilateral AFT Unilateral
AFT Left
Unilateral
AFT Right
% Incidence
150 24 14 4 6 16%
Table1. Showing Number Vertebrae
Fig.1 Showing bilateral AFT
Fig.2 Showing unilateral AFT(R)
Fig.3 Showing unilateral AFT(L)
incidence of accessory foramen transversarium was 16%with bilateral preponderance. A number of studies havebeen done previously to show the incidence of accessoryforamen transversarium (Table-2).
Sharma et al 2010(4) studied 200 cervical vertebraeand only 16 had accessory foramen transversarium (8%).Out of 16 vertebrae, it was present unilaterally in 7 andbilaterally in 9. This is in accordance to our study.
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Table 2 Comparison of Various Studies
More bilateral incidence than unilateral was alsoobserved by Mishra et al, 2014 (5) and Patra et al,2015 (6). Murlimanju et al, 2011 (7) observed 373vertebrae and only 6 (1.6%) had accessory foramentransversarium. In this study the incidence was moreunilateral than bilateral.
More unilateral incidence was observed by manyauthors like Ratnakar et al, 2013 (8) and Gujar et al,2015 (9). Murlimanju et al, 2011 (7) also observed doubleaccessory foramen transversarium which was not foundin the present study.
The presence of accessory foramen transversariummay be correlated to variations in vertebral artery, theknowledge of which is important for clinicians as vertebralartery insufficiency may lead to headaches, migraine,vertigo and fainting attacks.
Moreover the presence of accessory foramentransversarium is related to duplication of vertebral arterywhich is a rare condition and seen in 1% of dissections,Oviya et al, 2016 (10).
It is also important for the radiologists to have theknowledge of this variation while reporting ComputedTomography and Magnetic Resonance Imaging of cervicalspine.Conculsion
We found accessory foramen transversarium in 16%of cervical vertebrae. It was more common bilaterally(58.33%) than unilaterally (41.67%). It is more prevalentin sixth cervical vertebrae (58%).
S.N.O Authors Unilateral Aft-Rt Unilateral Aft-Lt Bilateral Aft
1 Sharma et al 07 00 09
2 Murlimanju et al 04 01 01
3 Rathnakar et al 05 00 02
4 Mishra et al 10 00 18
5 Gujar et al 27 14 00
6 Patra et al 16 00 17
7 Oviya et al 02 04 05
8 PRESENT
STUDY
06 04 14
1. Koshi R. The Cervical Vertebrae. In Koshi R. Cunningham'smanual of practical anatomy, Head Neck and Brain. 16thedn, Vol.3, 16th edn., Vol.3. Oxford University Press. Greatclarendon street, Oxford, United Kingdom. 2018. Pp 9-18.
2. Esakkiammal N & Chauhan R. Clinical significance ofpresence of accessory foramen transversarium in typicalcervical vertebrae. Int J Res Med Sci. 2016, 4(12), 5231-36.
3. Das S, Suri R & Kapur B. Double foramen transversaria: anosteological study with clinical implications. Int med J.2005, 12, 311-13.
4. Sharma A, Singh K, Gupta V & Srivastava S. DoubleForamen Transversarium in Cervical Vertebra: AnOsteological Study. J Anat Soc Ind. 2010, 59(02), 229-31.
5. Mishra GP, Bhatnagar S, Singh B, Mishra PP & Mishra A.Anatomical Variations in Foramen Transversarium of TypicalCervical Vertebrae and Clinical Significance. Int J of BiomedRes. 2014, 05(06), 405-07.
6. Patra A, Kaur H, Chhabra U, Kaushal S & Kumar U. Doubleforamen transversarium in dried cervical vertebra: Anosteological study with its clinical implications. IndianJournal of Oral Sci, 2015; 06(01), 7-9.
7. Murlimanju BV, Prabhu LV, Shilpa K, Rai R, DhananjayaKV & Jiji PJ. Accessory transverse foramina in the cervicalspine. Incidence, embryological basis, morphology andsurgical importance. Turk Neurosurg. 2011, 21(03), 384-87.
8. Rathnakar P, Remya K & Swathi B. Study of accessoryforamen transversaria in cervical vertebra. Nitte Univ J HealthSci. 2013, 03(04), 97-99.
9. Gujar S M, Oza Sunil G & Shekhawat JP. A Study ofAccessory Foramen Transversarium in Dry CervicalVertebrae and its Clinical Implications. National J ofIntegrated Res in Med. 2015, 06(06), 27-30.
10. Oviya VJ & Thenmozhi MS. Accessory foramentransversarium and its incidence in South Indians driedcervical vertebrae. Journal Pharm Sci & Res. 2016, 08(10),1204-05.
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