During extensive osteological study of 150 dry skulls in the Department of Anatomy, Vardhman Mahavir Medical college, an unusual Paramedian Occipital (POC) condyle was detected in the occipital bone of a cadaveric skull. The anatomical details of this unusual occipital condyle were carefully studied and its morphometric measurements taken. A coronal multiplanner reformatted image and a volume rendered image were taken to study radiological details and establish significant clinical correlation. Precise understanding of anatomy of craniovertebral junction and its anomalies have become immensely important for the present day surgeon during orthopaedic and neurosurgical procedures of this region . Technical advancements in imaging modalities such as CT and MRI scans further signify the importance of these anatomical variations ,which are often missed in routine examination. Osteological study combined with radiological details of the paramedian occipital condyle in the present case aims to emphasize the importance of bony anomalies in the craniovertebral region and their role in diagnosis and appropriate treatment of neurovascular compression syndromes of craniovertebral junction. The present study highlights anatomical details, clinical relevance and embryological basis of such a rare unusual paramedian occipital condyle.
The occipital sinus (OS) lies in the attached margin of the faix cerebelli in the internal occipital crest of the occipital bone. The OS extends from the foramen magnum to the confluence of sinuses. Standard textbooks and research reports do not describe in detail any variation in the groove for the occipital sinus.