Unusual morphology of the anterior arch of Atlas

Anomalies of anterior arch of atlas vertebra are seldom reported in the literature. Presence of inferior accessory ossicle is one of the reported anomalies of the anterior arch of atlas. In the present case, we report a rare case of unusual morphology of the atlas vertebra. It was observed in one of the bones macerated locally for the teaching purpose. There were two wide accessory bony laminae extending from the middle three fourth of the superior and inferior aspect of the anterior arch proper. Each bony lamina was measured 4 cm x 0.3 mm. Further, there were small foramina along the attached border of the each bony lamina. Anterior tubercle was situated at the lower edge of the anterior arch proper. Accessory bony lamina may interfere with rotatory movements of the atlas and may lead to degenerative changes of the dense. Reporting of unusual morphology of anterior arch of atlas vertebra is clinically important during diagnostic procedures of neck pain. Sometimes this extra growth of the anterior arch may be mistaken for the pathologic mass.