Morphometric and Morphological Analysis of the Craniovertebral Junction in a Kenyan Population (a Cross Sectional, Retrospective Radiological Study)

Abstract

Background: The Craniovertebral junction (CVJ) is transition zone between the skull and cervical spine. It protects the neuroaxis, and is involved in moving the head on the neck. The compact anatomy of the CVJ and inherent variations renders surgery a daunting task. It also gives rise to various vascular and neurogenic compression syndromes that may be difficult to diagnose. Craniometric indices that aid in diagnosis and surgical approach have been developed, and they have been shown to have gender and population differences. Objective: To determine the morphometrical indices and morphology of the craniovertebral junction in a Kenyan population. Study set up: Kenyatta National Hospital Radiology Department Study design: Retrospective Cross-sectional study Methods: CT scans of the CVJ of patients undergoing routine treatment at Kenyatta National Hospital were analyzed to derive craniometric indices. These craniometric parameters were then used to create sex prediction model. The presence of select atlantal variations was also assessed. Data Management: SPSS software (Version 28.0, Chicago, Illinois) was used to analyze data. Descriptive and inferential statistics was generated, with gender-based comparison being done. Univariate discriminant analysis and logistic regression analysis was used to estimate the accuracy of predicting sex from the craniometric variables. Data was presented using photographs, tables and graphs. Results: The mean age of the participants was 38 ± 12 years. The mean diameter of the anterior-posterior dimension of the foramen magnum was 35.7±2.88mm, while the transverse diameter was 30.2±2.88mm. The mean distance between the Odontoid peg and the anterior-posterior diameter was 6.3 ±2.3mm, indicating that none of the pegs protruded into the foramen. The mean area of the foramen was 847 ± 83.4mm2, while the foramen magnum index was 1.19 ± 0.1. The difference in means between males and females was statistically significant for the anterior-posterior diameter, transverse diameter and the area (p<0.001). Rounded foramina dominated at 54.3. The prevalence of posterior ponticulus was 36.2%. A half of these ponticuli formed a complete arcuate foramen, and 76% of the total ponticuli were unilaterally placed. xii Only midline posterior arch defects of the atlas were discovered in the study population, with a general prevalence of 6.9%. There were no cases of atlantal occipitalization reported. Discriminant functional analysis yielded an accuracy of 69% in sex prediction, while the binary logistic regression analysis correctly predicted 70.7% of skulls as males and 67.2% as females. Conclusion: There are significant differences in craniometric indices of the foramen magnum within the Kenyan population. However, these differences have a relatively low sex prediction ability. rendering them only as secondary discriminators in sex determination forensically. Posterior ponticuli and arcuate foramens have high prevalence, necessitating low threshold of imaging the CVJ before surgical procedures