Morphology and morphometry of the transverse foramina of cervical vertebrae in an adult Kenyan population: a radiological study

Background: Transverse foramina are canals in cervical transverse processes transmitting the vertebral vessels and the accompanying sympathetic plexus. These foramina exhibit side, sex and population specific variations such as those of size, shape and number. Knowledge of these variations is important for cervical surgical procedures and prediction of vertebral artery variations. Objective: To describe the morphology and morphometry of cervical transverse foramina in an adult Kenyan population. Methods: Ninety-four neck CT scan images of 2 mm slice thickness in axial view were used to assess presence, number, completeness and shape of transverse foramina. Antero-posterior and transverse lengths were measured using NeusoftTM software. Paired and independent t-tests were used to compare morphometric parameters for side and sex respectively. One-way ANOVA was used to determine differences in foramina down the cervical spine. A p-value of ≤ 0.05 was considered significant. Results: Transverse foramina had a prevalence of 98.78% with 3.64% being duplicated. They were identified as type 1 (circular), type 2 (elongated antero-posteriorly), type 3 (elongated transversely), type 4 (oblique left-right elongation) and type 5 (oblique right-left elongation) in 69.62%, 3.62%, 13.38%, 7.23% and 6.15% respectively. 0.46% foramina were incomplete and 3.19% constricted. Diameters on the right were larger than left. C1 foramina were the largest and C7 smallest. The diameters decreased from C2 to C3 then increased to C6. Conclusion: Transverse foramina display side and level dependent variations. This is of clinical importance to spine surgeons to prevent intraoperative damage of vertebral vessels when operating in the cervical region. Keywords: Morphology and morphometry; transverse foramina; cervical vertebrae; in Kenyan Population; a radiological study.