Morphological Study of the Foramen Transversarium of the Typical Cervical Vertebrae with Clinical Correlation

The foramen transversarium (FT) is a distinctive anatomical structure in the cervical vertebrae for the passage of the vertebral artery, vein, and sympathetic plexus. The FT is a feature in all cervical vertebrae and is important for normal vertebral physiology. In this article, the anatomy of the FT is presented and discussed with respect to the variability of this foramen, its structural dimensions, and its clinical applications. The relevance for the contents of the FT are important because they contain nerves and blood vessels, and given its intimate relation with the neurovascular structures, even minor anatomical variations may cause potentially severe clinical implications. One potential danger is vertebral artery damage, occurring due to a blow or sudden twisting of the cervical spine. The injury could cause vertebrobasilar insufficiency, a temporary reduction of blood flow to the rear of the brain that causes dizziness, nausea, and even stroke.

The study aims to perform morphometric analysis of the variations in the appearance of the FT and the related accessory foramen.

An observational study was conducted in the Department of Anatomy. The present study utilized 97 cervical vertebrae (C3-C7) of unknown sex and age. Damaged vertebrae in the form of partial breakage or fusion were excluded from the study.

In the present study, the incidence of abnormal or accessory FT (AFT) is 12.37%. The unilateral variation in the AFT on the right side (5.15%) is more than on the left (4.12%). The incidence of double foramen transversion is only 3.09%. The maximum anteroposterior diameter of the FT ranges from 2.92 mm to 7.86 mm on the right side compared to 3.2 mm to 8.01 mm on the left side. The transverse diameter of the FT ranges from 3.49 mm to 8.12 mm on the right side compared to 2.12 mm to 8.20 mm on the left side. Various diameters were measured using the freely available ImageJ analysis software.

AFT turns out to be a fairly common anatomical variant in specimens studied. It tends to favor the right side slightly more often than the left. Double foramina, on the other hand, are noticeably rarer. When it comes to size, there is quite a bit of natural variation from one specimen to the next. Interestingly, the left side tends to show a slightly broader range than the right for both diameters measured. Understanding the variations in the FT is of utmost importance for the surgeons and radiologists, as the FT is closely associated with various neurovascular structures.