Anatomic parameters for diagnosing congenital cervical stenosis via computed tomography

PURPOSE: To establish parameters for congenital cervical stenosis (CCS) using computed tomography (CT), assessing influences of patient sex, race, and ethnicity. METHODS: Measurements were collected of anteroposterior diameter (APD), interpedicular distance (IPD) and cervical intervertebral foramen dimensions (CIFD) from 1000 patients between 18 and 35 years of age without spinal pathology. CCS was determined as two standard deviations below the mean of the collected measurements. RESULTS: Irrespective of vertebral level, mean anatomic APD, CIFD 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 than females for left and right CIFD area and APD. African American patients had smaller CIFDs and APD, and subsequent CCS thresholds compared to White patients. CONCLUSIONS: This study reports measurements of CIFD, IPD, and APD to establish quantitative thresholds for diagnosis of CCS. CCS thresholds were significantly influenced by patient sex, race, and ethnicity.