We aimed to study generational changes in the dimensions of cervical and lumbar bony spinal canals in Western Switzerland.
A total of 254 patients were retrospectively included, 144 of whom were born during 1940-1949 and 110 during 1970-1979. Cervical spine CTs were performed as part of the spinal clearance procedure following trauma (n = 135) or while investigating neurological symptoms (CT angiography, n = 119). Three independent observers digitally measured the cross-sectional area (CSA) at pedicle levels from C0 to C7 and the anteroposterior diameter (APD) at C3, C5, and C7. In addition, lumbar spine CSAs and APDs were measured on whole body trauma or abdominal CTs, which were also available for 134 patients.
Mean CSAs at pedicle levels were numerically smaller in the younger patient group in both cervical and lumbar spine, with the difference reaching statistical significance at all lumbar levels (p ≤ 0.024) except L5. Cervical APDs showed no difference between groups. Subgroup analysis revealed that younger CT angiography patients had a significantly smaller CSA at C1 (p = 0.018) and a similar trend at C4 (p = 0.053). There was moderate positive correlation between cervical and lumbar CSAs, taking C4 and L3 as reference (r = 0.509, p < 0.01).
Younger generation patients have smaller bony spinal canals also in the cervical spine even though this difference is less marked than at the lumbar level. There is, nevertheless, moderate positive correlation between these two anatomical regions. Perinatal factors that adversely influence spinal growth, such as increased maternal age and smoking, could explain these generational changes, given that body height has increased during the same time period. The lesser difference observed in the cervical spine could be due to later closure of the neurocentral synchondrosis at this level.