Congenital stenosis of the spine- A cross-sectional study of 1019 whole-spine CT scans to determine the prevalence and association between multi-level, tandem, and triple region stenosis.

BACKGOUND: Patients with Congenital stenosis of the spine (CSS) present with clinical symptoms at an early age, and with fewer degenerative hypertrophic changes than the more common degenerative cohort. Literature is lacking in the true prevalence of CSS affecting the three segments of the spine in isolation as well as in tandem in the Indian sub-continent.

METHODS: Anteroposterior spinal canal diameter in axial plane CT at the mid-vertebral level was measured in asymptomatic patients with whole spine CT. Spinal canal stenosis was defined as a diameter of less than 12 mm for the cervical region, less than 12 mm for the thoracic region, and less than 13 mm for the lumbar region. Single-level and multilevel stenosis as well as tandem and triple-region stenosis were evaluated.

RESULTS: The results show the prevalence of CSS as 16.6%, 11.5%, and 20.1% involving the cervical, thoracic, and lumbar spine respectively. Single-level stenosis affected 90.6%, 94%, and 79.8% of the patients with cervical, thoracic, and lumbar CSS respectively. Tandem stenosis affected 10.4% of the population (n=104), with cervicolumbar stenosis being the most prevalent (n=51, 5%). The presence of CSS in any one segment of the spine was significantly associated with the presence of stenosis at one of the other segments (p<0.05). Triple-region stenosis was seen in 0.3%(n=3) patients.

CONCLUSION: The prevalence of cervical, thoracic, lumbar and tandem stenosis from our study is established at 16.6%, 11.5%, 20.1%, and 10.4%. Additionally, our study demonstrates the association between stenosis of the different regions of the spine.