Anatomic Parameters for Diagnosing Congenital Cervical Stenosis via Computed Tomography

Introduction: Quantitative parameters for diagnosis of congenital cervical stenosis (CCS) have yet to be universally accepted. This study establishes parameters for CCS using computed tomography (CT), assessing the influences of patient sex, race, and ethnicity.

Methods: Measurements of anteroposterior diameter (APD), interpedicular distance (IPD) and neuroforaminal height, width, and area were performed using 1,000 patients between 18 and 35 years of age who were without spinal pathology. CCS was determined as described by Bajwa et al. whereby values two standard deviations below the mean of the measurements conducted in this study were defined as congenitally stenotic.

Results: Irrespective of vertebral level, mean anatomic APD, CNFD and IPD measurements were as follows: 14.94 ± 1.99 mm for APD, 6.58 ± 1.45 mm and 6.68 ± 1.45 mm for left and right widths, of 9.30 ± 2.30 mm and 9.25 ± 2.80 mm for left and right heights, 57.0 ± 19.2 mm2 and 59.5 ± 20.3 mm2 for left and right areas, and 25.4 ± 1.78 mm for IPD. Irrespective of vertebral level, threshold values for CCS were 10.96 mm for APD, 3.68 mm and 3.78 mm for left and right widths, of 4.70 mm and 3.65 mm for left and right heights, 20.6 mm2 and 19 mm2 for left and right areas, and 21.8 mm for IPD. Males demonstrated larger CCS threshold values compared to females for left and right CNFD area and APD at all vertebral levels. African American patients had smaller NFDs and APD, and subsequent CCS thresholds at every vertebral level compared to White patients.

Conclusion : This study reports measurements across bilateral cervical neuroforaminal measurements and interpedicular distance to establish quantitative thresholds for diagnosis of CCS. APD, CNFD, and IPD measurements, as well as CCS thresholds, were significantly influenced by patient sex, race, and ethnicity.