Lumbar vertebral canal stenosis: concept of morphometric and radiometric study of the human lumbar vertebral canal

Objectives: Vertebral canal stenosis has attracted the attention of anatomists and clinician as an important structural change with significant radiological and clinical implications. Narrowing of all diameters of the vertebral foramen with age could be responsible as a factor which might produce back pain. The aim of the present study was to estimate the averages anatomical changes in the transverse and anteroposterior diameters of the lumbar vertebral canal in Egyptian population to establish a clue to the underlying some causes of the low-back pain of unknown etiology. Methods: The present study investigated the lumbar part of the vertebral column of 20 adult skeletons and 200 plain Xrays of normal living subjects (100 males and 100 females) for both morphometric and radiometric analyses. Results: The mean width of the body of vertebrae showed gradual increase with the exception at L4 in dry bones. In addition, the mean width and depth of the vertebral foramina showed a gradual increase with the exception of L3 in dry bones. The study recorded a positive relationship between the mean width of the vertebral foramen and that of the body. The mean vertebral foramen width/body ratio was 0.6 except at L3 and L5 where the ratio was 0.5. Conclusion: The present study has shown a narrower depth of the lumbar vertebral canal in Egyptian population. L3 remains the center point for transition in the dimensions and hence more susceptible to stenosis and spinal nerve compression. This study has also shown that the ratio between the width of body and foramen of lumbar vertebrae remains constant. By this ratio it may be possible to predict any lumbar vertebral anomalies or vertebral canal stenoses and to give some explanation about low-back pain of unknown etiology.