Congenital cervical and lumbar stenosis occurs when the bony anatomy of the spinal canal is smaller than expected, predisposing an individual to symptomatic neural compression. While tandem stenosis is known to occur in 5%-25% of individuals, it 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 lumbar canal. The purpose of the present study was to determine if the presence of congenital cervical stenosis is associated with congenital lumbar stenosis.

One thousand seventy-two adult skeletal specimens from the Hamann-Todd Collection in the Cleveland Museum of Natural History were selected. The canal area at each level was calculated using a formula that was verified by computerized measurements. Values that were 2 standard deviations below the mean were considered to represent congenitally stenotic regions. Linear regression analysis was used to determine the association between the sum of canal areas at all levels in the cervical and lumbar spine. Logistic regression was used to calculate odds ratios for congenital stenosis in one area if congenital stenosis was present in the other.

A positive association was found between the additive area of all cervical (that is, the sum of C3-7) and lumbar (that is, the sum of L1-5) levels (p < 0.01). A positive association was also found between the number of cervical and lumbar levels affected by congenital stenosis (p < 0.01). Logistic regression also demonstrated a significant association between congenital stenosis in the cervical and lumbar spine, with an odds ratio of 0.2 (p < 0.05).

Based on the authors' findings in a large population of adult skeletal specimens, it appears that congenital stenosis of the cervical spine is associated with congenital stenosis of the lumbar spine. Thus, the presence of tandem stenosis appears to be, at least in part, related to the tandem presence of a congenitally small cervical and lumbar canal.