Ten-year trends in values of joint space width and osteophyte area of knee joints: Comparison of the baseline and fourth ROAD study surveys.

Objective: Considering the joint space width and osteophyte area (OPA) of the knee joints of Japanese adults, this study elucidated the ten-year trends in medial minimum joint space width (mJSW) and OPA using data of two independent cohorts from a population-based cohort study. Methods: The baseline survey of the Research on Osteoarthritis/Osteoporosis Against Disability study was conducted from 2005 to 2007; 2975 participants (1041 men, 1934 women) completed all knee osteoarthritis (OA) examinations. The fourth survey was performed from 2015 to 2016; distinct 2445 participants (764 men, 1681 women) completed identical examinations. The medial mJSW and medial tibial OPA were measured bilaterally using an automated system. Results: The mean medial mJSW (standard deviation) was 3.22 (0.96) mm and 2.65 (0.95) mm at baseline and 3.81 (1.20) mm and 3.13 (1.15) mm in the fourth survey for men and women, respectively. The mean medial mJSW in the fourth survey was significantly greater in both men and women in all age groups than at baseline (p â€‹< â€‹0.01). The mean OPAs in men aged 40-49 and 60-69 years and women aged 40-49, 50-59, 60-69, and 70-79 years were significantly smaller in the fourth survey (p â€‹< â€‹0.05). The trend in mJSW remained the same even after adjusting for confounding factors in the multivariate analysis, but the trend in OPA was weakened. Conclusions: A significant improvement in the medial mJSW within 10 years could decrease the incidence and progression of knee OA and prevent the risk of walking disability.

Factors associated with cam deformity in Japanese local residents.

Femoroacetabular impingement has increasingly been recognized as a cause of primary hip osteoarthritis; however, its epidemiological indications remain unclear. We aimed to clarify the epidemiological indications and factors associated with cam deformity in a large-scale population-based cohort in Japan. Overall, 1480 participants (2960 hips) (491 men, 989 women; mean age, 65.3 years) analyzed in the third survey of the Research on Osteoarthritis/Osteoporosis Against Disability study were included. The α angle and spinopelvic parameters (lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence) were radiographically measured. Cam deformity was defined as α angle ≥ 60°. Overall, the cam deformity prevalence was 147/2960 (5.0%). Cam deformity prevalence tended to increase with age; in the univariate analysis, a higher percentage of men was observed in the group with cam deformity than in the group without it. No relationship was observed between cam deformity and hip pain. Factors associated with α angle were examined via multiple regression analysis for each gender; α angle was significantly associated with age and BMI in each gender. The α angle and PT were correlated in women. Thus, α angle and cam deformity prevalence increase with age in Japanese individuals. Accordingly, cam deformity can be considered a developmental disease.

Trends in the prevalence of atrophic gastritis and Helicobacter pylori infection over a 10­year period in Japan: The ROAD study 2005­2015.

Few large population-based studies have examined the prevalence of atrophic gastritis (AG) and Helicobacter pylori infection in Japan. The purpose of the present study was to estimate the prevalence of AG and H. pylori infection by age, in addition to investigating their change rates from 2005 to 2016 in Japan using data from a large population-based cohort. A total of 3,596 participants [1,690 in the baseline survey (2005-2006) and 1,906 at the fourth survey (2015-2016)] aged 18 to 97 years were included in the cohort. The prevalence of AG and H. pylori infection were examined at baseline and in the fourth survey based on serological tests for the H. pylori antibody titer and pepsinogen levels. The prevalence of AG and H. pylori infection were 40.1% (men, 44.1%; women, 38.0%) and 52.2% (men, 54.8%; women, 50.8%), respectively, at baseline. AG seropositivity rates showed a significant decrease from 40.1 to 25.8% in 10 years. H. pylori seropositivity rates decreased significantly from 52.2 to 35.5% in 10 years. Stratified for age, the prevalence of AG showed an increasing trend with age, whereas the prevalence of H. pylori infection increased with aging, except for in the elderly group, showing an inverted U-shaped association. In this population-based, cross-sectional study with a 10-year interval survey, the prevalence of AG and H. pylori infection decreased significantly. This change may influence the prevalence of H. pylori-related diseases, including extra-gastric disorders associated with H. pylori-induced systemic subclinical inflammation and hypochlorhydria, such as colorectal neoplasia and arteriosclerosis.

A common variant rs2054564 in ADAMST17 is associated with susceptibility to lumbar spondylosis.

The molecular pathophysiology underlying lumbar spondylosis development remains unclear. To identify genetic factors associated with lumbar spondylosis, we conducted a genome-wide association study using 83 severe lumbar spondylosis cases and 182 healthy controls and identified 65 candidate disease-associated single nucleotide polymorphisms (SNPs). Replication analysis in 510 case and 911 control subjects from five independent Japanese cohorts identified rs2054564, located in intron 7 of ADAMTS17, as a disease-associated SNP with a genome-wide significance threshold (P = 1.17 × 10-11, odds ratio = 1.92). This association was significant even after adjustment of age, sex, and body mass index (P = 7.52 × 10-11). A replication study in a Korean cohort, including 123 case and 319 control subjects, also verified the significant association of this SNP with severe lumbar spondylosis. Immunohistochemistry revealed that fibrillin-1 (FBN1) and ADAMTS17 were co-expressed in the annulus fibrosus of intervertebral discs (IVDs). ADAMTS17 overexpression in MG63 cells promoted extracellular microfibrils biogenesis, suggesting the potential role of ADAMTS17 in IVD function through interaction with fibrillin fibers. Finally, we provided evidence of FBN1 involvement in IVD function by showing that lumbar IVDs in patients with Marfan syndrome, caused by heterozygous FBN1 gene mutation, were significantly more degenerated. We identified a common SNP variant, located in ADAMTS17, associated with susceptibility to lumbar spondylosis and demonstrated the potential role of the ADAMTS17-fibrillin network in IVDs in lumbar spondylosis development.

Trends in prevalence of hip osteoarthritis over a 10-year period in Japan: The ROAD study 2005-2015.

Objective: The trends in prevalence of hip osteoarthritis (OA) over a 10-year period among Japanese men and women were investigated using the data from the Research on Osteoarthritis/osteoporosis Against Disability study. Design: We analyzed the data of 2924 baseline survey participants (1026 men, 1898 women) aged 40-89 years (mean 70.7 years) residing in urban, mountainous, and coastal communities who were surveyed in 2005-2007. We compared these data with that of 2347 participants (726 men, 1621 women) aged 40-89 years (mean 69.2 years) from the fourth survey in 2015-2016. The fourth survey invited participants to attend follow-ups for baseline survey and recruited new participants. After scoring the radiographs using the Kellgren/Lawrence (K/L) grading system, hip OA was defined as a K/L score ≥2. Results: The prevalence of radiographic hip OA was 18.4% and 14.4% in the baseline survey, and 16.0% and 10.7% in the fourth survey among men and women, respectively. Among the participants aged 40-69 years, the prevalence of radiographic hip OA was significantly lower during the fourth survey than during the baseline survey. Whereas, among elderly men aged 70-79 years, radiographic hip OA was significantly less prevalent during the baseline survey than during the fourth survey. From the logistic regression analysis results, radiographic hip OA was significantly less prevalent during the fourth survey than during the baseline survey (odds ratio: 0.55, 95% confidence interval: 0.46-0.65). Conclusion: At a 10-year interval, the prevalence of radiographic hip OA shows an improving trend.

Trends in osteoporosis prevalence over a 10-year period in Japan: the ROAD study 2005-2015.

INTRODUCTION: This study aimed to clarify the trends in the prevalence of osteoporosis among general inhabitants using population-based cohort data of the baseline and the survey 10 years later. MATERIALS AND METHODS: The baseline survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted in 2005-2007; 1690 participants (596 men, 1094 women, mean age 65.2 years) completed all examinations of osteoporosis, including a questionnaire of medical information in the present/past and bone mineral density measurement using dual-energy absorptiometry. The fourth survey was performed in 2015-2016; 1906 individuals (637 men, 1269 women, 65.0 years) completed assessments identical to those at the baseline survey. Osteoporosis was defined using the World Health Organization criteria. RESULTS: The prevalence of lumbar spine (L2-L4) osteoporosis at the baseline survey was 13.6% (men, 3.4%; women, 19.2%) and that at the fourth survey was 9.7% (men, 1.4%; women, 13.9%), which decreased significantly (p < 0.01), while that of the femoral neck was not significantly different between the baseline and fourth surveys. Regarding the prevalence of osteoporosis of L2-L4 or the femoral neck, the prevalence of osteoporosis in women aged ≥ 70 was 38.8% at the fourth survey and 48.9% at the baseline study; thus, the prevalence at the fourth survey was significantly lower than that at the baseline survey (p < 0.01). CONCLUSIONS: In the population-based survey with a 10-year interval, the prevalence of osteoporosis at lumbar spine tended to decrease significantly. This preferable change in osteoporosis could contribute to the decrease in the occurrence of osteoporotic fracture in the future.

Association between acetabular dysplasia and sagittal spino-pelvic alignment in a population-based cohort in Japan.

The relationship between acetabular dysplasia and spino-pelvic alignment remains unclear. The aim of this study was to clarify the association between acetabular dysplasia and spino-pelvic alignment, based on a large-scale population-based cohort in Japan. From the third survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study, 1,481 participants (491 men and 990 women; mean age, 65.3 years) were analyzed. Center-edge (CE) angle and spino-pelvic parameters (lumbar lordosis, LL; sacral slope, SS; pelvic tilt, PT; pelvic incidence, PI) were measured radiographically. Acetabular dysplasia was defined as a CE angle < 20°, and associations between acetabular dysplasia and spino-pelvic parameters were assessed. The group with acetabular dysplasia had significantly higher age, higher percentage of female, higher SS and higher PI than the group without acetabular dysplasia in a univariate analysis. On the other hand, acetabular dysplasia was not significantly associated with spino-pelvic parameters in a multiple logistic regression analysis that include age, sex, SS and PI as explanatory variables; however, PI demonstrated a positive odds ratio (odds ratio, 1.02; 95% CI 1.00-1.04). In conclusion, acetabular dysplasia was not significantly associated with spino-pelvic parameters, but higher PI may be an associated factor for acetabular dysplasia.

Epidemiology of locomotive syndrome using updated clinical decision limits: 6-year follow-ups of the ROAD study.

INTRODUCTION: Locomotive syndrome (LOCOMO) is defined by the Japanese Orthopaedic Association (JOA) as a condition requiring nursing care due to a decline in mobility resulting from musculoskeletal disorders. In 2020, the JOA announced the new definition of LOCOMO stage 3 and revision of clinical decision limits in stages of LOCOMO. However, there are few reports on the epidemiological indices of LOCOMO. This prospective cohort study aimed to investigate the prevalence, incidence, and association of poor prognosis with LOCOMO stages. MATERIALS AND METHODS: The third survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted during 2012-2013, examining a population-based cohort of 1575 participants (513 men and 1062 women, mean age 65.6 years). Three LOCOMO risk tests were performed, and patients were classified into LOCOMO stages 0, 1, 2, and 3. They were followed up for 6 years, and identical examination of LOCOMO was performed in 3- and 6-year follow-ups. Data on patients' prognoses, including disability and death, were collected. RESULTS: The prevalence of LOCOMO stages 1, 2, and 3 was 41.3, 14.9, and 11.6%, respectively. The incidence of LOCOMO stages 1, 2, and 3 were 83.7, 23.0, and 18.6 per 1000 person-years, respectively. Compared with LOCOMO stage 0, logistic regression analysis showed that LOCOMO stage 3 significantly increased the risk of disability and mortality. In addition, each value of LOCOMO risk tests for LOCOMO stage 3 increased the risk of poor prognosis. CONCLUSION: LOCOMO stage 3 is a sensitive indicator of future disability and mortality.

A Prospective, 3-year Longitudinal Study of Modic Changes of the Lumbar Spine in a Population-based Cohort: The Wakayama Spine Study.

STUDY DESIGN: Large-scale, prospective, population-based, longitudinal observational study. OBJECTIVE: The aim of this study was to investigate the rate of incidence, transformation, and reverse transformation of Modic changes (MCs) using T1-weighted (T1W) and T2-weighted (T2W) lumbar magnetic resonance images (MRI) over a 3-year period. SUMMARY OF BACKGROUND DATA: Although MCs in populational study are considered significant, existing epidemiological evidence is based on cross-sectional studies only. METHODS: Overall, 678 subjects (208 men, 470 women, mean age 62.1 ± 12.8 years in 2013) in both 2013 and 2016 surveys were included. The rate of change in Modic Type I (T1W: low-intensity, T2W: high-intensity), Type II (T1W: high, T2W: high), and Type III (T1W: low, T2W: low) at five endplates was analyzed over a 3-year period. An incidence of MC at each level and in the lumbar region was defined as no MC at baseline with signal changes at follow-up. Transformation was defined as Type I or II MC at baseline with conversion at follow-up Type II from Type I or Type III MC from Type I and II. Furthermore, reverse transformation was defined as Type I, II, or III MC at baseline, with at least one endplate showing a reversion in Modic type (no MC for baseline Type I; no MC and Type I for baseline Type II; no MC, Type I or Type II for baseline Type III) at follow-up. RESULTS: Overall, 3390 endplates were included. For 3 years, the incidence, transformation, and reverse transformation of MCs were seen in 395 (11.7%), 84 (2.5%), and 11 (0.3%) endplates, respectively. The highest levels of incidence, transformation, and reverse transformation were at L2/3 (96 [14.2%] endplates), L5/S1 (32 [4.7%] endplates), and L2/3 (5 [0.7%] endplates), respectively. CONCLUSION: This study revealed a high incidence of MCs at the upper lumbar levels and transformation at the lower lumbar levels. Reverse transformation of MCs occurs but are rare.Level of Evidence: 2.

Is radiographic lumbar spinal stenosis associated with the quality of life?: The Wakayama Spine Study.

OBJECTIVES: This prospective study aimed to determine the association between radiographic lumbar spinal stenosis (LSS) and the quality of life (QOL) in the general Japanese population. METHODS: The severity of radiographic LSS was qualitatively graded on axial magnetic resonance images as follows: no stenosis, mild stenosis with ≤1/3 narrowing, moderate stenosis with a narrowing between 1/3 and 2/3, and severe stenosis with > 2/3 narrowing. Patients less than 40 years of age and those who had undergone previous lumbar spine surgery were excluded from the study. The Oswestry Disability Index (ODI), which includes 10 sections, was used to assess the QOL. One-way analysis of variance was performed to determine the statistical relationship between radiographic LSS and ODI. Further, logistic regression analysis adjusted for gender, age, and body mass index was performed to detect the relationship. RESULTS: Complete data were available for 907 patients (300 men and 607 women; mean age, 67.3±12.4 years). The prevalence of severe, moderate, and non-mild/non-radiographic were 30%, 48%, and 22%, respectively. In addition, the mean values of ODI in each group were 12.9%, 13.1%, and 11.7%, respectively, and there was no statistically significant difference between the three groups in logistic analysis (P = 0.55). In addition, no significant differences in any section of the ODI were observed among the groups. However, severe radiographic LSS was associated with low back pain in the "severe" group as determined by logistic analysis adjusted for gender, age, and body mass index (odds ratio: 1.53, confidence interval: 1.13-2.07) compared with the non-severe group. CONCLUSION: In this general population study, severe radiographic LSS was associated with low back pain (LBP), but did not affect ODI.

Detailed Subphenotyping of Lumbar Modic Changes and Their Association with Low Back Pain in a Large Population-Based Study: The Wakayama Spine Study.

INTRODUCTION: To examine the association between the five types of Modic changes and low back pain (LBP) in a large population-based cohort. METHODS: Of the 952 participants in the second Wakayama Spine Study, 814 (men, 246; women, 568; mean age, 63.6 years) were included in this study. Endplate changes on magnetic resonance imaging were classified according to the Modic classification system. Low back pain (LBP) was defined as continuous back pain for at least 48 h in the past month that is currently present. The prevalence of Modic changes in the lumbar region was assessed. Multivariate logistic regression analysis was conducted to determine the association between detailed subphenotype of Modic change and LBP comparing no Modic change in the lumbar spine and each level, respectively. RESULTS: Modic changes throughout the lumbar spine were noted in 63.5% (n = 516) of all participants, with types I, I/II, II, II/III, and III observed in 7.8% (n = 63), 10.8% (n = 88), 40.0% (n = 326), 2.1% (n = 17), and 2.7% (n = 22), respectively. Modic types I/II were associated with LBP [odds ratio (OR): 3.26; 95% confidence interval (CI) 1.9, 5.5]. Furthermore, Modic type I/II changes at L2/3 and L4/5 were significantly associated with LBP (odds ratio: 2.77; 95% CI 1.04, 7.39 at L2/3; odds ratio: 2.86; 95% CI 1.39, 5.90 at L4/5). CONCLUSIONS: Type I/II Modic changes in the lumbar region are significantly associated with LBP. To the best of our knowledge, this is the first large population-based study on the association between various Modic changes and LBP.

Relationship of sagittal spinal alignment with low back pain and physical performance in the general population.

Studies have suggested a relationship between sagittal spinal malalignment and low back pain (LBP). The current study investigated the relationship of spinal alignment with LBP and physical performance in 1491 individuals who attended the second follow-up visit of the Wakayama Spine Study. The sagittal vertical axis at C7 (C7 SVA) was measured by a spine surgeon. The occurrence of LBP within one month, pain intensity, Oswestry Disability Index (ODI), and physical performance (grip strength, 6-m walking time, chair stand test, one-leg standing test) were also evaluated. LBP in the previous month was determined using ODI, and indicators of physical performance were measured. The mean C7 SVA was 11.0 ± 42.7 mm and was significantly greater in older participants (p < 0.001). LBP was more prevalent in participants with a greater C7 SVA (< 40 mm, 35.7%; 40-95 mm, 47.3%; ≥ 95 mm, 59.4%; p < 0.001) and those with a higher ODI score (10.0%, 17.5%, and 29.4%, respectively; p < 0.001). Physical performance significantly decreased in participants with a greater C7 SVA (p < 0.001). Multiple linear regression analysis revealed that LBP and physical performance were significantly associated with C7 SVA (p < 0.001). Thus, sagittal spinal malalignment may lead to LBP and decreased physical performance.

Prevalence and associated factors of pistol grip deformity in Japanese local residents.

Pistol grip deformity (PGD) may be the main factor in femoroacetabular impingement development. This study aimed to clarify the epidemiological indices and factors related to PGD in Japanese people. This population-based cohort study included 1575 local Japanese residents. PGD, center edge angle, and joint space width were measured radiographically. We investigated the relationship between PGD and spino-pelvic parameters. Factors associated with PGD were examined using multiple logistic regression analysis, with the presence/absence of PGD as an objective variable, and sex, age, body mass index (BMI), and the presence/absence of hip pain or spino-pelvic parameters as explanatory variables. In the entire cohort, 4.9% (10.6% men, 2.1% women) had PGD on at least one side. A trend was observed between PGD and increasing age in both men and women (men: p < 0.0001, women: p = 0.0004). No relationship was observed between PGD and hip pain (risk ratio 1.0 [95% confidence interval 0.97-1.03]). Factors significantly associated with PGD were age, sex, and BMI in the multivariate model. Acquired factors may be related to PGD in Japanese people as the PGD prevalence increased with age and PGD was not significantly associated with hip pain. This study provides new insights into the etiology and clinical significance of PGD.

Association between types of Modic changes in the lumbar region and low back pain in a large cohort: the Wakayama spine study.

PURPOSE: The clinical significance of Modic changes in low back pain (LBP) is yet to be clarified. Thus, this study aimed to examine the association between Modic changes and LBP after adjustment for confounding factors. METHODS: We evaluated participants in the second Wakayama Spine Study. The degree of endplate changes as measured using magnetic resonance imaging was classified based on the Modic classification system. The prevalence of the types of Modic change in the lumbar region and at each level was assessed. Multivariate logistic regression analysis was conducted to determine the association between the types of Modic changes and LBP with adjustment for age, sex, body mass index, disc degeneration score, and disc displacement score. The LBP intensity was also compared according to the Visual Analogue Scale (VAS) score among the three types of Modic change. RESULTS: Overall, 814 subjects were evaluated. Type II Modic changes were the most prevalent (41.9%). Only type I Modic changes were significantly associated with LBP (odds ratio): 1.84, 95% confidence interval [CI]: 1.1-2.9). The LBP VAS score was significantly higher in subjects with type I Modic change than that in those with no Modic change (23.9 ± 26.3 vs. 9.9 ± 19.4, p < 0.05). CONCLUSION: Type I Modic changes in the lumbar region are significantly associated with LBP. Profiling Modic changes may be helpful to improve targeted treatment of LBP.

The incidence and risk factors for adjacent vertebral fractures in community-dwelling people with prevalent vertebral fracture: the 3rd and 4th survey of the ROAD study.

In this 3-year follow-up study of 66 community-dwelling adults with severely deformed vertebral fractures, the annual incidence of adjacent vertebral fracture (AVF) was 6.1%/year. Lower bone mineral density at the femoral neck and spinopelvic malalignment were risk factors for AVF. PURPOSE: This study aimed to clarify the incidence and risk factors of adjacent vertebral fractures (AVFs)-fractures adjacent to a prevalent vertebral fracture (VF)-using an established population-based cohort from the ROAD study. METHODS: Among the 1213 participants who underwent whole-spine radiography in ROAD's third (2012-2013, the baseline) and fourth surveys (2015-2016, the follow-up), 66 (12 men, 54 women) had at least one VF at the baseline. VF and AVF were determined radiographically using Genant's semi-quantitative (SQ) method, where VF was SQ ≥ 2 and AVF was a one-level cranial or caudal vertebra with an SQ grade one or more higher at the follow-up. An interviewer-administered questionnaire was applied, and anthropometric measurements and bone mineral density (BMD) measurements at the lumbar spine and femoral neck were performed. Sagittal imbalance of the spine was defined as a mismatch between pelvic incidence and lumbar lordosis (PI-LL) of > 20°. Multivariate logistic regression analyses were performed to identify risk factors for AVF. RESULTS: AVF occurred in 12 participants (1 man, 11 women). The annual incidence of AVF was estimated at 6.1%/year. Logistic regression analyses revealed that lower BMD at the femoral neck and PI-LL > 20° were risk factors for AVF. CONCLUSIONS: The annual incidence of AVF in a general population with prevalent VF was 6.1%/year. In addition, lower BMD at the femoral neck and PI-LL > 20° were risk factors for AVF.

Prevalence and co-existence of locomotive syndrome, sarcopenia, and frailty: the third survey of Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study.

This study aimed to estimate the prevalence of locomotive syndrome, sarcopenia, and frailty and clarify their co-existence in a population-based cohort. The third survey of Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted between 2012 and 2013, examining 963 subjects (aged ≥ 60 years; 321 men, 642 women). Locomotive syndrome, sarcopenia, and frailty were defined using three tests proposed by Japanese Orthopaedic Association, Asian Working Group for Sarcopenia criteria, and Fried's definition, respectively. Prevalence of locomotive syndrome stages 1 and 2 were 81.0% (men, 80.4%; women, 81.3%) and 34.1% (men, 30.5%; women, 35.8%), respectively, and those of sarcopenia and frailty were 8.7% (men, 9.7%; women, 8.3%) and 4.5% (men, 2.8%; women, 5.3%), respectively. Locomotive syndrome stage 1, sarcopenia, and frailty co-existed in 2.1%; 6.5% had locomotive syndrome stage 1 and sarcopenia, 2.4% had locomotive syndrome stage 1 and frailty, while none had sarcopenia and frailty. Locomotive syndrome stage 1 presented alone in 70.0%, sarcopenia in 0.1%, and no frailty. The remaining 18.9% had none of these conditions. Co-existence of locomotive syndrome stage 2, sarcopenia, and frailty was observed in 2.0%; 5.0% had locomotive syndrome stage 2 and sarcopenia, 2.2% had locomotive syndrome stage 2 and frailty, and 0.1% had sarcopenia and frailty. Locomotive syndrome stage 2, sarcopenia, and frailty alone, presented in 24.9%, 1.7%, and 0.2%, respectively. The remaining 64.0% had none of these conditions. Most subjects with sarcopenia and/or frailty also had locomotive syndrome. Preventing locomotive syndrome may help prevent frailty and sarcopenia and subsequent disability.

Differences in prevalence and associated factors between mild and severe vertebral fractures in Japanese men and women: the third survey of the ROAD study.

Vertebral fracture (VF) is a common osteoporotic fracture, while its epidemiology varies according to regions and ethnicities, little is known about it in Japan. Using whole-spine radiographs from a population-based cohort study, the Research on Osteoarthritis/Osteoporosis Against Disability study 3rd survey performed in 2012-2013, we estimated the sex- and age-specific prevalence of VF in the Japanese. Genant's semiquantitative method (SQ) was used to define VF; SQ ≥ 1 as VF, SQ = 1 as mild VF, SQ≥ 2 as severe VF. We also revealed accurate site-specific prevalence, and associated factors with mild and severe VF. The participants were 506 men [mean age 66.3 years, standard deviation (SD):13.0] and 1038 women (mean age 65.3 years, SD: 12.6). The prevalence of VF in participants aged under 40, in their 40s, 50s, 60s, 70s, and ≥ 80 years was 17.4, 7.9, 18.5, 25.6, 26.3, and 41.5%, respectively, in men, and 2.9%, 2.4%, 7,3, 10.3, 27.1, and 53.0%, respectively, in women. Men had a significantly higher prevalence of mild VF (21.2%) than women (10.0%, p < 0.001); whereas, severe VF was significantly more prevalent in women (9.1%) than in men (4.7%, p = 0.003). VF was distributed with 2 peaks regarding site; one large peak at the thoracolumbar region, and another at the middle thoracic lesion. Low back pain and decreased walking ability were independently associated with severe VF, but not with mild VF, after adjustment for participant characteristics. Decreased walking ability was associated with multiple VFs in women, but not in men.

Prevalence of Facet Effusion and Its Relationship with Lumbar Spondylolisthesis and Low Back Pain: The Wakayama Spine Study.

INTRODUCTION: Facet effusion represents a magnetic resonance imaging finding suggesting accumulation of fluid in the facet joint, potentially predictive of lumbar spondylolisthesis and low back pain. However, its prevalence and epidemiological characteristics in the general population remain unclear, because previous studies only included patients or volunteers. The aim of the present study was to investigate the prevalence of facet effusion in the general population and to describe its potential relationship with spondylolisthesis and low back pain. MATERIAL AND METHODS: Our study enrolled 808 participants from the Wakayama Spine Study who underwent magnetic resonance imaging investigations in supine position. Facet effusion was defined as a measurable, curvilinear, high-intensity signal within the facet joint, closely matching that of cerebrospinal fluid on the axial T2 images. We used standing lateral radiographs to diagnose L4 spondylolisthesis. RESULTS: We found that the prevalence of facet effusion in the lumbar spine was 34.3%, which did not differ significantly between men and women (p=0.13) and did not tend to increase with age, either in men (p=0.81) or in women (p=0.65). Additionally, we found no significant association between facet effusion and low back pain (odds ratio, 1.04-1.49; 95% confidence interval, 0.57-2.64; p=0.17-0.85), or between facet effusion and L4 spondylolisthesis (odds ratio, 1.55; 95% confidence interval, 0.80-2.86; p=0.17). In a subset of participants with L4 spondylolisthesis, we also noted that facet effusion was not significantly associated with low back pain (odds ratio, 1.26; 95% confidence interval, 0.37-4.27; p=0.70). DISCUSSION: This is the first study of facet effusion employing a population-based cohort, and the findings are thus expected to accurately describe the relationship between facet effusion and low back pain in the general population. We are planning a follow-up survey of the Wakayama Spine Study cohort to clarify the natural history of facet effusion and its relationship with clinical symptoms.

Intra-individual biomechanical effects of a non-microprocessor-controlled stance-yielding prosthetic knee during ramp descent in persons with unilateral transfemoral amputation.

BACKGROUND:: A stance-yielding mechanism for prosthetic knees may reduce lower limb loading during specific activities, but quantitative data are insufficient. OBJECTIVES:: To clarify the biomechanical effect of a non-microprocessor-controlled stance-yielding mechanism on ramp descent for individuals with unilateral transfemoral amputation. STUDY DESIGN:: Intra-subject intervention study. METHODS:: Seven individuals with unilateral transfemoral amputation underwent three-dimensional motion analysis of ramp descent with and without activating a stance-yielding mechanism. Regarding early-stance internal joint moment and ground reaction force, whole-group and subgroup analyses stratified by stance prosthetic knee flexion were performed to verify differences in prosthetic side and contralateral limb loading between conditions. RESULTS:: Whole-group analysis revealed significant reduction in early-stance prosthetic knee extension moment with stance-yielding mechanism activation. Changes in prosthetic side hip extension moment and contralateral limb loading were inconsistent between conditions. Subjects with prosthetic stance knee flexion walked slower with a smaller stride and greater increase in aft ground reaction force and ankle dorsiflexion moment when stance-yielding was activated. CONCLUSION:: Stance-yielding mechanism has a biomechanical potential to decrease excessive knee hyperextension. However, prosthetic side stance knee flexion induced by the stance-yielding mechanism might not necessarily reduce the mechanical load on residual hip or contralateral lower limb joints. CLINICAL RELEVANCE: This study showed individual variability in the possibility of reducing the load on the remaining lower limb when using a non-microprocessor-controlled stance-yielding knee. This suggests that individualized prosthetic management and monitoring the activities of individuals wearing a stance-yielding prosthetic knee are crucial to maximize the benefits of stance-yielding prosthetic knees.