Correlation between the Cervical Spine Angle and Disc Height of the Cervical Vertebrae: A Prospective Radiogrammetric Study

This study evaluated the relationship between the radiogrammetric linear and angular parameters of the cervical vertebrae of healthy adult male and female Nigerian subjects. The research was a cross-sectional study involving radiogrammetric dimensions of the cervical vertebrae obtained from plain film lateral radiographs of the cervical spine of one hundred (100; 62 males, 38 females) apparently normal volunteer subjects. The measurements; cervical spine angle (CSA) and disc height (CDH) were obtained using the PACS software, which managed in MS office excel sheet 2016. The data was stratified by sex and transferred to STATGRAPHICS centurion CVI version 16.1.11 (StatPoint Tech., Inc.) for analysis. SPSS Spearman Rho was used to test the relationship between CSA and CDH. From the analysis, the correlations between CSA and CDH were not significant (P>0.05); however, CSA was positively correlated with CDH of C2-C3 (r=0.090), but negatively correlated with lower vertebrae disc; C3-C4 (r=- 0.150), C4-C5 (r=-0.166), C5-C6 (r=-0.147), and C6-C7 (r=-0.101). The extent of variation in model fitting explained by sex ranged from 3.10 to 4.20% for CDH, which were not significant (P>0.05). Notably was the high sex-associated variance in the relationship between CSA and CDH: C2-C3. In conclusion, though the correlations between CSA and CDH of C2 to C7 were not significant, nevertheless, it is important to note when the relationship is inverted, it suggests an abnormality of clinical importance. The existing relationship could be observed to be slightly influenced by sex, especially for C2-C3. It would be useful if the relationship between these parameters is studied for a spectrum of clinical conditions.

Key Words: Cervical spine angle (CSA), cervical disc height (CDH), correlations, sex influence, Nigerian population