Variation in the human cervical neural canal.

Abstract

The dimensions of the cervical spinal canal can impact the likelihood of an individual suffering longtime effects from a spinal neck injury as well as influence recovery time. Most studies have used radiographic studies to compare differences in the neural canal, but few have examined skeletal populations to determine variation in the neural canal dimensions without the presence of soft tissue. To analyze variation seen in the cervical neural canal (anterior-posterior and transverse diameters) with respect to sex and ancestry and to define cervical canal narrowing in the sample. Observational. Measurements of the anterior-posterior (sagittal) (CAP) and transverse (CTR) diameters were taken from 321 individual skeletons. Comparisons were made between males and females and individuals belonging to different ancestral (racial) groups. CAP was narrowest at the C4 level for African-Americans and at C6 for Caucasians. CTR was narrowest at the C2/C3 level for all groups. Statistical analyses indicated that significant differences in cervical canal dimensions are due first to sexual dimorphism and then to ancestry. Significant variation in cervical canal dimensions precludes usage of universal definitions to determine spinal stenosis in individuals; definitions should be according to sex and ancestry.