The authors made several measurements in the lower lumbar vertebrae of patients with and without low back pain. Our objective was to determine the allometric relationships between different dimensions of the lumbar canal, the effects on these from degenerative disease, and differences between the symptomatic and asymptomatic populations. We compared 119 patients suffering from low back and sciatic pain and 39 subjects without lumbar symptoms as determined by computed tomography (CT). The following measurements were made: sagittal diameter of the canal, interpedicular distance, interarticular distance, and anteroposterior diameter of lateral recess and foramen. With respect to the patients with lumbar pain, the asymptomatic group proved to have wider foramina from L3 to L5 and wider sagittal diameters in S1. The patients with canal stenosis revealed lower figures for all diameters of the central canal, lateral recess of L4, and foramina of L4 and L5. Patients with lumbarization showed smaller diameters of the central canal.
Conclusion: There is an allometric relationship between the dimensions of the central canals. This relationship is less evident with lateral canals. The patients without lumbar symptoms had wider foramina and sagittal diameters in S1 than those with lumbar symptoms. Of these, patients who developed symptoms of canal stenosis demonstrated smaller diameters in central and lateral canals. Of the developmental anomalies, lumbarization proved to be associated with canal stenosis due to smaller diameters of the central canals.