Radiographic evaluation of the variation in transverse processes of lumbar vertebrae according to age and gender

The lamina arcus vertebra contains seven projections. These projections consist of the processus spinosus, processus transversus, and processus articularis. The processus transversi, which extend laterally, are two in number. The length, thickness, and shape of the processus transversi in the lumbar region vary from individual to individual. One of the reasons for this variation is the morphometric characteristics of the processus transversi. The aim of our study is to radiographically investigate the changes in the length, height, and width of the processus transversus in the horizontal, sagittal, and koronal planes according to age and sex. In this study, a detailed morphometric analysis of the processus transversi in the lumbar vertebrae was conducted, and the obtained results were evaluated in terms of their clinical significance. The CT images of a total of 400 patients were retrospectively examined: 50 females aged 21–30, 50 females aged 31–40, 50 females aged 41–50, 50 females aged 51–60, 50 males aged 21–30, 50 males aged 31–40, 50 males aged 41–50, and 50 males aged 51–60. Morphometric measurements of the processus transversi were performed. Appropriate descriptive statistics of the data were calculated. The normality assumption of quantitative variables was examined using Kurtosis, Skewness coefficients, and the Shapiro-Wilk test. The homogeneity of group variances was checked with Levene's test. For comparisons between groups, One-Way ANOVA (post hoc Sidak test) was applied. To examine the effect of different factors on quantitative variables, Factorial ANOVA and Generalized Linear Modeling approaches (post hoc Sidak test) were used. For within-group comparisons of quantitative variables, the Paired Samples t-test was employed. Statistical analyses were performed using SPSS version 22 and custom macros. A p-value of <0.05 was considered statistically significant. In males, no significant difference was found between sides in terms of the length values of the processus transversi of L1, L2, L3, L4, and L5 vertebrae (p>0.05). Similar findings were also obtained for the width and height of the processus transversi (p>0.05). In females, no significant difference was found between sides in terms of the length values of the processus transversi of L1, L2, L3, L4, and L5 vertebrae (p>0.05). Similar findings were also obtained for the height of the processus transversi (p>0.05). Only in females, a statistically significant difference was observed between the right and left processus transversi of the L2 vertebra in terms of width values (p<0.05), whereas no significant differences were found in the others (L1, L3, L4, L5) (p>0.05). We believe that our study will contribute to specialists and researchers in a wide range of fields, from surgical interventions to treatment planning. In addition, it is thought that the results will be beneficial for researchers in the field of anthropometry and for forensic medicine cases, particularly in the identification of individuals based on skeletal remains. Keywords: Processus Transversus, Lumbal Vertebra, Morphometry, Computed Tomography