Prevalence of bifidity of the seventh cervical vertebral spinous process in southwestern Nigeria: a computed tomography based study.

Palpation of the seventh cervical vertebra (C7) is an important landmark for counting vertebrae for vertebral spine surgical instrumentation. However, studies have shown that the spinous process of C7 displays an anatomical deviation among individuals, which may mislead a surgeon who is not aware of this, and there have been no such studies among southwest Nigerians. The present study aimed to examine the incidence of bifidity in the C7 spinous process and their variation among 48 subjects with the aid of a three-dimensional (3D) computed tomography. The 48 subjects who had undergone cervical spine computed tomography studies comprised the pooled data of ages between 12 and 55 years of black race in southwest Nigeria from the radiology department of the Trauma and Surgical Centre, Ondo State, Nigeria. A series of multivariate and discriminant statistical tests were performed on the measurement data to determine the occurrence of bifid spinous processes at C7 in southwestern Nigeria. The results show about 10% bifidity in the C-7 vertebra and no bifidity in the first cervical vertebra and the highest rate in the C-6 vertebra in the study population. The incidence in this study is significantly higher than findings in previous works. Thus, there is a need for clinicians to pay more attention to this variation when using C7 as a landmark especially in the studied population.