Radiological anatomy of the C7 vertebra: clinical implications in spine surgery

Context: This study was designed to understand and define the special radio-anatomic morphometry of C7 vertebra by using multidetector computed tomography (MDCT). Aims: The major aim of the study was to detect the gender- and side-related morphometric differences of C7 vertebra among subjects. Setting and design: Our radiology unit database scanned for MDCT sections of the C7 vertebra. Materials and Methods: A total of 214 patients (134 men, 80 women) were selected. A detailed morphometric evaluation of C7 was done. Statistical analysis used: T test, ANOVA. Lamina length (P < 0.001), pedicle length (P < 0.001), outer cortical (P = 0.01) and inner cancellous pedicle (P < 0.001) width, pedicle angle to sagittal plane (P < 0.001) values were statistically significantly different on the right versus left side. When the results were stratified by gender, lamina length, inner cancellous lamina height, pedicle length, inner cancellous pedicle height, outer cortical pedicle width, lateral mass anteroposterior length, anteroposterior length of C7 corpus, height of C7 corpus (P < 0.001), C6-7 (P = 0.013) and C7-T1disc height (P = 0.04), transverse foramina perpendicular width at C7 (P = 0.046) values were found to be statistically significantly different. Vertebral artery most commonly enters into the transverse foramina at C6 level. Conclusions: Gender and side differences are important factors for preoperative planning and showed significant differences among subjects. MDCT is a practical option for investigating the exact anatomical features of osseous structures