Total aplasia of posterior arch of the atlas

Uppalapadu Solomon Krupanidhi,Raveendra Patil,Jayaprakash B R,Mallikarjun M

doi:10.7439/ijbr.v4i9.323

Abstract

Congenital anomaly-total aplasia of the posterior arch of the atlas vertebra is very rare, a developmental failure of chondrogenesis rather than the disturbance of ossification. Reported prevalence is 0.95-4%. In the present study the incidence of total aplasia of posterior arch of the atlas is 0.91% i.e., 1 in109 dried human adult atlas vertebrae. This atlas comes under the type E category according to the classification of congenital posterior arch defect proposed by currarino et al. This knowledge is essential for clinicians as new surgical techniques and instruments continue to evolve for the treatment of unstable cervical spine and also to avoid misdiagnosis among trauma victims and to provide information on its proper management.

Highlights

The atlas presents an anterior arch, a posterior arch and lateral masses
The onset of ossification of the posterior arch of the atlas occurs during seventh week of intrauterine life proceeding perichondrically from two centers located in the lateral masses
We found an atlas with total aplasia of posterior arch which is a very rare anomaly even well documented congenital anomaly

Summary

Introduction

The atlas presents an anterior arch, a posterior arch and lateral masses. The onset of ossification of the posterior arch of the atlas occurs during seventh week of intrauterine life proceeding perichondrically from two centers located in the lateral masses. Defect of posterior arch of atlas is believed to occur due to failure of local chondrogenesis rather than disturbance of ossification[4]. This has been agreed with the autopsy or intra operative findings[5]. We found an atlas with total aplasia of posterior arch which is a very rare anomaly even well documented congenital anomaly. Knowledge of congenital anomaly of atlas is essential for clinicians while treating patients with unstable cervical spine as new surgical techniques and instruments continue to evolve[6]

Materials and Methods

Findings

Discussion

Conclusion