Summary of background data: Tandem stenosis of the cervical and lumbar spine is known to occur in 5% of individuals with symptomatic neural compression in one region. However, the prevalence of concurrent cervical and thoracic stenosis is not known. Whether this relationship is due to an increased risk of degenerative disease in these individuals, or whether this finding is due to the tandem presence of a congenitally small cervical and thoracic canal is unknown.
Objectives: To determine the prevalence of concurrent thoracic and cervical stenosis and whether the presence of stenosis in the cervical spine is associated with stenosis in the thoracic spine.
Study design: A morphoanatomic study of the cervical and thoracic cadaveric spines.
Methods: A total of 1072 adult skeletal specimens from the Hamann-Todd Collection in the Cleveland Museum of Natural History were selected. Canal area at each level was also calculated using a geometric formula. A standard distribution for each level was created, and values that were 2 SD below mean were considered as being congenitally stenotic. Linear regression analysis was used to determine the association between the additive canal areas at all levels in the cervical and thoracic spine and to determine the association between the number of stenotic levels in the cervical and thoracic spine. Logistic regression was used to calculate odds ratios for concurrent cervical and thoracic stenosis.
Results: The prevalence of concurrent cervical and thoracic stenosis is 1%. A positive association was found between the additive areas of all cervical and thoracic levels (P<0.01). No association, however, was found between the number of stenotic thoracic and cervical levels (P=0.689). Log regression demonstrated no significant association (odds ratio <1) between stenosis in the thoracic and cervical spine.
Conclusions: The area changes in the cervical spine correlate with area variations in the thoracic spine and the severity of stenosis in the thoracic spine increases as the levels of stenosis increase in the cervical spine. The presence of tandem cervical and thoracic stenosis does seem to be, in part, related to the tandem presence of a congenitally small cervical and thoracic canal.