Normal aging of the lumbar spine in women

BACKGROUND: Lumbar lordosis is required for bipedalism. OBJECTIVES: To investigate age-related changes in lumbar lordosis and to clarify the relationships between lumbar lordosis and vertebral wedging and disc degeneration. METHODS: A total of 300 women were included in this retrospective study, 50 in each of six age groups (20-, 30-, 40-, 50-, 60- and 70-year-olds). Patients with vertebral collapse, instable fracture or disc sequestration were excluded. In each patient, lumbar lordosis angle, posterior vertebral wedging, L5-S1 intervertebral disc angle, L5/L1 vertebral height ratio and L5-S1 intervertebral disc/L1-L2 intervertebral disc height ratio were examined. Significance level was set at p< 0.05 and two-sided tests were used. RESULTS: Significant differences were found in lumbar lordosis according to age group (p< 0.001). Lumbar lordosis correlated most strongly with L4 posterior vertebral wedging, L5 posterior vertebral wedging and L5-S1 intervertebral disc angle, in that order (r= 0.50, r= 0.40, r= 0.32, respectively; p< 0.001). CONCLUSION: In this cohort, strong spinal structure was maintained during physiological aging from 20 to 40 years of age; lumbar lordosis increased by 50 years of age. Increased lordosis correlated with increased posterior vertebral wedging and loss of posterior disc height.