Female sex hormones play an important role in the etiology and pathophysiology of a variety of musculoskeletal degenerative diseases. Postmenopausal women show accelerated disc degeneration due to relative estrogen deficiency. This literature review aims to validate or falsify this hypothesis, i.e., while overall females have higher prevalence of low back pain (LBP) across all age groups, this male vs. female difference in LBP prevalence further increases after female menopause age. The literature search was performed on PubMed on January 2, 2016. The search word combination was (low back pain) AND prevalence AND [(males OR men) AND (females OR women)].The following criteria were taken to include the papers for synthetic analysis: (I) only English primary literatures on nonspecific pain; (II) only prospective studies on general population, but not population with occupational LBP causes, of both males and female subjects studied using the same LBP criterion, ages-specific information available, and males and female subjects were agematched; (III) studies without major quality flaws. In total 98 studies with 772,927 subjects were analyzed.According to the information in the literature, participant subjects were divided into four age groups: (I) school age children group: 6-19 years; (II) young and middle aged group: 20-50 years; (III) mixed age group: data from studies did not differentiate age groups; (IV) elderly group: ≥50 years old. When individual studies were not weighted by participant number and each individual study is represented as one entry regardless of their sample size, the median LBP prevalence ratio of female vs. males was 1.310, 1.140, 1.220, and 1.270 respectively for the four age groups. When individual studies were weighted by participant number, the LBP prevalence ratio of female vs. males was 1.360, 1.127, 1.185, and 1.280 respectively for the four groups.The higher LBP prevalence in school age girls than in school age boys is likely due to psychological factors, female hormone fluctuation, and menstruation. Compared with young and middle aged subjects, a further increased LBP prevalence in females than in males was noted after menopause age.

SummaryThe epidemiology of lumbar degenerative spondylolisthesis (DS) remains controversial. We performed a systematic review with the aim of gaining a better understanding of the prevalence of DS in the general population. The results showed that the prevalence of DS is very gender- and age-specific. Few women and men develop DS before they are 50 years old. After 50 years of age, both women and men begin to develop DS, with women having a faster rate of development than men. For elderly Chinese (≥ 65 years, mean age: 72.5 years), large population-based studies MsOS (Hong Kong, females: n = 2000) and MrOS (Hong Kong, males: n = 2000) showed DS prevalence was 25.0% in women and 19.1% in men. The female:male (F:M) prevalence ratio was 1.3:1. The published data for MsOS (USA) and MrOS (USA) studies seem to show that elderly Caucasian Americans have a higher DS prevalence, being approximately 60–70% higher than elderly Chinese; however, the F:M prevalence ratio was similar to the elderly Chinese population. Patient data showed that female patients more often received surgical treatment than male and preliminary data showed the ratio of female to male patients receiving surgical treatment did not differ between Northeast Asians (Chinese, Japanese, and Korean), Europeans, and American Caucasians, being around 2:1 in the elderly population. The existing data also suggest that menopause may be a contributing factor for the accelerated development of DS in postmenopausal women.The translational potential of this article: A better understanding of epidemiology of lumbar degenerative spondylolisthesis can support patient consultation and treatment planning.

Study Design: A population-based radiographic study with longitudinal follow-up.Objective: To develop a quantitative index for lumbar disc space narrowing (DSN) evaluation in elderly subjects; to determine how DSN in the elderly is influenced by osteoporosis and gender. Results: DAIL correlated with semi-quantitative grading, with sensitivity and specificity varying from 87.3% to 96.8% for grade-1 DSN (<30% reduction in disc height), and 92.9 % to 100% for grade-3 DSN (>60% reduction in disc height). The thoracolumbar disc area loss among men and women during 4-years' follow-up period varied between 1.32% and 3.56%, and it was greater for women (mean: 2.44%) than for men (mean: 1.90%, p=0.044). Majority of lumbar DSN progressions during 72 to 76 years old were progression from normal disc space to grade-1DSN . Summary of BackgroundOsteoporosis was associated with greater disc area decrease, both for thoracic and lumbar discs. Conclusion:Lumbar DSN can be quantified using DAIL. In elderly Chinese, intervertebral disc narrowing over a 4-year period was greater in women than men, and associated with the presence of osteoporosis.