NJCA
  • Users Online: 365
  • Print this page
  • Email this page
  • Email this page
  • Facebook
  • Twitter


 
 Table of Contents  
CASE REPORT
Year : 2012  |  Volume : 1  |  Issue : 2  |  Page : 99-101

Spinabifida of atlas


1 Assistant Professor of Anatomy, ESIC Medical College, Rajajinagar, Bengaluru, India
2 Associate professor, Dr. B R Ambedkar Medical College, K G Halli, Bengaluru, India
3 Assistant Professor of Anatomy, Dr. B R Ambedkar Medical College, K G Halli, Bengaluru, India
4 Assistant Professor of Anatomy, Hassan Institute of Medical Sciences, Hassan, Karnataka, India

Date of Web Publication23-Jan-2020

Correspondence Address:
K Padmalatha
Assistant Professor of Anatomy, ESIC Medical College & PGIMSR, Rajaji Nagar, Bengaluru - 560 010
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


Rights and PermissionsRights and Permissions
  Abstract 


During the routine osteology demonstration for the first year MBBS students, the authors came across the presence of incomplete posterior arch in one of the atlas. Congenital clefts and other developmental anomalies of the atlas are rarely encountered. They are incidental findings discovered while investigating the cervical spine following trauma. Differentiation of developmental variants of the atlas from the Burst fracture of Jefferson is essential to prevent unnecessary medical intervention. Posterior midline cleft of atlas/ rachischisis/spinabifida occulta are well recognized and attributed to the defect /absent development of cartilaginous preformation of the arch and not to the disturbance of the ossification.

Keywords: Atlas, Spinabifida, Midline cleft


How to cite this article:
Padmalatha K, Prakash B S, Balachandra N, Mamatha Y. Spinabifida of atlas. Natl J Clin Anat 2012;1:99-101

How to cite this URL:
Padmalatha K, Prakash B S, Balachandra N, Mamatha Y. Spinabifida of atlas. Natl J Clin Anat [serial online] 2012 [cited 2021 Mar 7];1:99-101. Available from: http://www.njca.info/text.asp?2012/1/2/99/298014




  Introduction Top


Cervical vertebra anomalies are classified into two main categories, posterior arch deficiencies and fusions. Posterior arch deficiencies include spinabifida and Dehiscence. Fusions include fusion, Block fusion, assimilation and occipitalization[1]. Congenital anomalies of the posterior arch of atlas are rare. They range from partial clefts to total agenesis of posterior arch of atlas[2]. Congenital clefts and other malformations of atlas are incidental findings which are identified while investigating the cervical spine following trauma[3].


  Case Report Top


During the routine osteology demonstration for the first year MBBS students at Dr. B. R. Ambedkar Medical College, Bengaluru, the authors came across the presence of incomplete posterior arch in one of the atlas, with the tapering ends. [Figure 1] and [Figure 2].
Figure 1: Superior surface of atlas.

Click here to view
Figure 2: Inferior surface of atlas.
A- Anterior arch; P- Posterior arch; The gap in the posterior arch of atlas measured 0.65mm.


Click here to view



  Discussion Top


Atlas usually ossifies in three centres, one appears for centrum during 8th week, one centre each for lateral mass/neural arch during 7th week. At birth, the anterior arch is fibrocartilaginous and separate centre appears at the end of first year and unites with the lateral masses between 6th & 8th year. The centre for posterior arch appears during second year and they unite between third and fourth year[4].

The defects of posterior arch of atlas are commonly believed to be due to a local mesenchymal defect leading to lack of chondrification[5].

Posterior midline clefts of atlas are attributed to the defective development of cartilaginous preformation of arch & NOT due to the disturbance of ossification[6].

The basic defect in agenesis of posterior arch of atlas is the lack of a cartilage template on which the ossification process builds[7]. [Figure 3].
Figure 3: Classification of posterior arch defects of the atlas (reproduced from Currarino et al[8])
A. Failure of posterior midline fusion of the two hemiarches. Sometimes a small separate ossicle is seen within the gap; B. Unilateral cleft, ranging from a small gap to a complete absence of the hemiarch and posterior tubercle; C. Bilateral clefts of the lateral aspects of the arches with preservation of the most dorsal part of the arch ; D. Complete absence of the posterior arch with a persistent isolated tubercle. This anomaly is conceivably a more extensive form of bilateral clefts. The lateral parts of the posterior arch are absent except for the posterior tubercle; E. Absence of the entire posterior arch including the Tubercle[8].


Click here to view


High incidence of both anterior and posterior spinabifida Atlas is associated with certain diseases such as mucopolysaccharidiasis, Down’s syndrome and Morquio’s syndrome[9].

Clinical implications of posterior arch defects of atlas include acute neurologic deficits such as transient quadriparesis, paraparesis, Lhermitt’s sign, chronic neck pain & headache[10].

Cervical vertebra anomalies are usually associated with cleft Hp, cleft palate, the common pathogenesis most probably relates to simultaneous embryogenesis of both structures.

Congenital anomaly of posterior arch of atlas leads to cervical canal stenosis and that may cause cervical myelopathy.


  Conclusions Top


Defects of the posterior arch of atlas are very rare. The basic defect is due to local mesenchymal defect leading to lack of a cartilage template and not due to disturbance in ossification. Congenital clefts and other malformations of atlas are incidental findings which are identified while investigating the cervical spine following trauma.

Acknowledgement

The authors express heartfelt thanks to Non teaching staff and students of Dr. B R Ambedkar Medical College, KG Halli, Bengaluru for their support.



 
  References Top

1.
Ugar DA, Gunvor Semb. The prevalence of anomalies of the upper cervical vertebrae in subjects with cleft lip, cleft palate or both. Cleft Palate-Craniofac J. 2001; 38(5): 498-503.  Back to cited text no. 1
    
2.
Phan, Nicolas MD, Marras, Connie MD, Midha, Rajiv MD et al. Cervical Myelopathy caused by Hypoplasia of the atlas: Two case reports and review of the literature. Neurosurgery. 1998; 43(3): 629-633.  Back to cited text no. 2
    
3.
Kaissi AA , Ben F, Garbi H, Ben M, Grill F, Varga F. Persistent Torticollis, facial asymmetry, grooved tongue and dolico-odontoid process in connection with atlas malformation complex in three family subjects. Spine. 2000; 25(22): 2913-2915.  Back to cited text no. 3
    
4.
Standring S, Ellis H, Healy JC, Johnson D, Williams A, Collins P. et al. Gray’s anatomy - the anatomical basis of clinical practice. 39th edn. Elsevier; Churchill Livingstone, London, 2005 : 794-795.  Back to cited text no. 4
    
5.
Schrodel MH, Braun V, Stolpe E, Hertlien H. Coincidental deficiency of the posterior arch of atlas and thalassemia minor, possible pitfalls in a trauma victim. Emerg Med J. 2005; 22: 526-528.  Back to cited text no. 5
    
6.
Prempeh RC , Gibson JC, Bhattacharya J J . Midline clefts of the atlas :a diagnostic dilemma. Spinal cord. 2002; 40: 92-93.  Back to cited text no. 6
    
7.
YochumTR. Partial agenesis of the Cj posterior arch, www.theamericanchiropractor.com. Last accessed on 30.04.12.  Back to cited text no. 7
    
8.
Currarino G, Rollins N, Diehl J T. Congenital defects of the posterior arch of atlas: a report of seven cases including an affected mother and son. Am J Neuroradiol. 1994; 15: 249-254.  Back to cited text no. 8
    
9.
Benzel EC. Craniocervical developmental anatomy and its implications. Clin Neurosurg. 2008; 55:63-70.  Back to cited text no. 9
    
10.
KwonJK, Kim MS, Lee GJ. The incidence and clinical implications of congenital defects of atlantal arch. J Korean Neurosurg Soc. 2009; 46: 522-527.  Back to cited text no. 10
    


    Figures

  [Figure 1], [Figure 2], [Figure 3]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Case Report
Discussion
Conclusions
References
Article Figures

 Article Access Statistics
    Viewed119    
    Printed4    
    Emailed0    
    PDF Downloaded11    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]