Study Design.
Plain lateral radiographs of the lumbar spines of 607 women (age range 20–87 years) and 633 men (age range 20–92 years) were studied.
Objective.
To study the radiographic changes in the lumbar intervertebral discs and lumbar vertebrae with age. To compile a database of reference values for the age-dependent height of lumbar discs and concavity index of lumbar vertebral bodies as well as prevalence of vertebral osteophytes by age and sex.
Summary of Background Data.
There is a general agreement that changes induced by aging lead to alterations in the thickness of the disc, but there are differences in the accounts of the effect of aging on the thickness of the lumbar discs. Published methods to measure disc height yield, except for some exceptional cases, inaccurate results. Reference values of disc height and concavity index of lumbar vertebral bodies, suitable for quantitative comparison with a given disc and lumbar vertebral body, have yet to be established.
Methods.
Using a new protocol with a precision of 3.9%, the anulus heights of lumbar discs were measured from sets of lateral radiographic views of 607 women and 633 men. The measurement of concavity index of vertebrae was established for each vertebral body by dividing the central vertebral height by the anterior vertebral height.
Results.
The heights of lumbar discs T12–L1, L1–L2, L2–L3, L3–L4, L4–L5, and L5–S1 of men and women within the age 20–69 years increased with increasing age (4.6–6.9% in men and 4.7–8.4% in women). The concavity index of vertebrae T12, L1, L2, L3, L4, and L5 of men within age 20–87 years and of women within age 20–92 years decreased linearly with increasing age (0.9–1.5% in men and 1.6–3.2% in women). In other words, the vertebral body endplates became more concave with age. The prevalence of osteophytes was greater in men than in women in lumbar spine and increased with age.
Conclusions.
Using the new procedure and the database of reference values, it is possible to measure the height of lumbar discs and concavity of vertebrae objectively and precisely and to compare the results quantitatively with reference values.
