abnorMal sPicules on tHe inferior asPect of anterior arcH of atlas vertebra

Abstract

Anterior arch of the atlas vertebra is known to exhibit various developmental anomalies. Bony
outgrowths, osteophytes, clefts and aplasia of the anterior and posterior arches of the atlas have
received special attention by research workers. To the best of our knowledge, not many osteological
studies have defined the spicules on the anterior arch of the atlas. The present study describes an
abnormal atlas vertebra with 2 spicules on the inferior aspect, 2 additional facets inferior to the
superior articular facets and a peculiar facet to the left of the posterior tubercle. These abnormal
spicules may cause dysphagia or involve atlanto-occipital movements. Such anomalies may be
misinterpreted in routine X rays as a degenerative disease. However, asymptomatic cases remain
undetected throughout life. Such anomalies may be important in radiological, clinical, forensic
and anthropological studies.

Key Words: Atlas, Anterior Arch, Anomaly, Spicules, Vertebra.