Epidemiology of low back pain in the elderly: correlation with lumbar lordosis.

We carried out an epidemiologic study to determine the prevalence of low back pain in elderly Japanese and to examine the correlation with lumbar lordosis in sagittal plane radiographs. Low back pain is an enormous clinical and public health problem. With the increasing use of spinal instrumentation, the measurement of lumbar lordosis is thought to be important. However, in elderly Japanese, the prevalence of low back pain and its correlation with lumbar lordosis is not clear. Five hundred and nine people, aged 50-85 years, were examined, and 489 subjects met our criteria. Clinical findings, physical status, and the visual analogue scale (VAS) of pain were examined in these subjects. Measurements and determination of total lordosis from L1-S1 were made from standing radiographs. Forty-eight percent of the subjects had experienced low back pain within the previous 3 months. Women had low back pain more frequently (P = 0.006). There was a significant difference in lumbar lordosis between the groups with and without low back pain (P = 0.0006). Lumbar lordosis was approximately 4 degrees less in the low back pain group and there was no relationship to age or sex in either group. VAS was significantly inversely correlated with lumbar lordosis (P = 0.025, at rest). The body mass index (BMI) of the low back pain group was higher in women, but the difference was not significant (P = 0.06). In conclusion, lumbar lordosis was defined and its prevalence in elderly Japanese was reported together with VAS and physical data used to compare the two groups.