Torg ratio in normal ageing population: no risk of stenosis

Canal/body or Torg's ratio has been agreed as a reliable method to detect cervical spinal stenosis. Age changes of cervical canal diameter and the ratio have been seldom analyzed in the cohort of normal adults. Our objective is to undertake the age changes in decades from healthy young to the elderly subjects. Sagittal diameter (SD) of the spinal canal and anteroposterior diameter of the vertebral body (VB) were taken on the lateral cervical radiographs consisting of normal appearance from 104 males and 102 females. SD showed significant gender differences and insignificant age changes. VB changed with age significantly in both sex, and showed sex difference. Torg ratio was found above 0.9 and changed with age. The ratio also indicated no difference between sexes. The male/female difference declared previously might not be a consistent finding. The present study suggested that bone cervical canal might diminish in normal ageing persons without existence of the cervical stenosis and/or risk of myelopathy. Our findings might be peculiar to our subject group, which need to be confirmed by the further studies.