Objective:

Evaluation of lumbar canal dimensions in a Chicago population born in two different decades.

Methods:

This is a retrospective chart review analyzing CT reconstruction from patients born between 1940 – 1949 and 1970 – 1979 and the cross-sectional area (CSA) and anterior-posterior diameter (APD) of the lumbar bony canal was measured at each lumbar level at the level of the pedicle.

Results:

Our study includes 918 patients, 372 in the young group and 546 in the older group. Older patients have significantly larger CSA and APD at all lumbar levels compared to younger patients. Further, CSA and APD comparisons between ethnicities demonstrate significant differences between Caucasians, Asians, Hispanics, African Americans, and Other ethnicities. Lastly, there were no differences in CSA or APD compared with factors known to affect bone health (smoking, steroid use, osteoporosis, cancer history).

Conclusions:

Like European cohorts, our data suggests that patients born in the 1940s have both larger canal area and larger anterior-posterior diameter compared to the younger generation. These data suggest that significant differences exist between ethnicities. These differences highlight the importance of studying normal anatomical dimensions within different geographical populations and the importance of studying non-modifiable factors as they relate to spinal dimensions and spine patients. Furthermore, spinal canal growth seems to be negatively influenced in younger generations, a rather unexpected but worrying finding.