Morphometric evaluation of the sacrum and sacroiliac joint anatomy according to age and gender differences with computed tomography scanning in southeastern anatolia region

Nowadays, sacral and sacroiliac joint injuries caused by accidents of motor vehicles, falling from a height and gunshot wounding constitute serious risks in terms of death and complications. Well knowing the morphological structure of the sacrum and sacroiliac joint will guide in the treatment of such injuries and decrease the risks of death and complications which likely to happen. The pelvic tomography of 50 males (Group 1) and 50 females (Group 2) between the ages of 18 and 80, who for any reason took pelvic tomography at the Radiodiagnostic Department of Dicle University in 2015, have been included. The patients who have structural abnormality in their pelvic skeleton due to congenital abnormality, trauma, tumour or any other reason have not been included in the study. A total of 35 different measurements have been taken on sagittal, coronal and transverse sections obtained by computerized tomography and 3-dimensional computerized tomography of Picture Archiving and Communications System. Group I and Group II have been compared based on these parameters. Furthermore, the groups compared were divided into two types according to different age categories. Group IA consisted of the 28 cases aged 18-39 years. Group IB consisted of the 22 cases aged 40-80 years. Similarly, Group II was divided into two sub-categories namely; Group IIA (23 cases, aged 18-39) and Group IIB (27 cases, aged 40-80 ). When Group I and Group II are compared, there were statistically significant difference between the groups in terms of S1 vertebrae anterior-posterior diameters (P<0,001), S2 vertebrae anterior-posterior diameters (P<0,001), average inlet angles (P=0,013), S1 vertebrae distance between foramina (P=0,003), S2 vertebrae distance between foramina (P<0,001), S1 vertebrae anterior concavity angles (P=0,004), S1 vertebrae sacral canal anterior-posterior diameter (P=0,047), S1 vertebrae transiliac distance (P=0,038), S2 vertebrae anterior concavity angles (P=0,001), S2 vertebrae viii sacral canal anterior-posterior diameter (P=0,007), S2 vertebrae sagittal axis, sacroiliac joint angles (P=0,028). When Group IA and Group IB are compared there were statistically significant difference in terms of inlet anterior angles (P=0,023), S2 sacral canal anterior-posterior diameter (P=0,039), S2 vertebrae sacroiliac joint length (P=0,008), S2 vertebrae sagittal axis- sacroiliac joint angle (P=0,045). When Group IIA and Group IIB are compared there were statistically significantly difference in terms of inlet anterior angles (P=0,028), S2 vertebrae foramen diameter (P=0,026), sacral slope angle (P=0,014), S1 vertebrae sacroiliac joint length (P=0,001), S2 vertebrae iliac wing thickness (P=0,018). Sacrum, sacroiliac joints and understanding the relationship between these will be helpful for the surgical operations on this part and widen the horizons of surgeons. Key words: Anthropometry; os sacrum; sacroiliac joint; computed tomography; iliosacral screw application