Time Course of Asymptomatic Stenosis in Multiple Lumbar Spinal Stenosis-Five-Year Results of Selective Decompression of Symptomatic Levels.

Background: In the diagnosis of lumbar spinal stenosis (LSS), finding stenosis with magnetic resonance imaging (MRI) does not always correlate with symptoms such as sciatica or intermittent claudication. We perform decompression surgery only for cases where the levels diagnosed from neurological findings are symptomatic, even if multiple stenoses are observed on MRI. The objective of this study was to examine the time course of asymptomatic stenosis in patients with LSS after they underwent decompression surgery for symptomatic stenosis. Materials and Methods: The participants in this study comprised 137 LSS patients who underwent single-level L4-5 decompression surgery from 2003 to 2013. The dural sac cross-sectional area at the L3-4 disc level was calculated based on preoperative MRI. A cross-sectional area less than 50 mm2 was defined as stenosis. The patients were grouped, according to additional spinal stenosis at the L3-4 level, into a double group (16 cases) with L3-4 stenosis, and a single group (121 cases) without L3-4 stenosis. Incidences of new-onset symptoms originating from L3-4 and additional L3-4-level surgery were examined. Results: Five years after surgery, 98 cases (72%) completed follow-up. During follow-up, 2 of 12 patients in the double group (16.7%) and 9 of 86 patients in the single group (10.5%) presented with new-onset symptoms originating from L3-4, showing no significant difference between groups. Additional L3-4 surgery was performed for one patient (8.3%) in the double group and three patients (3.5%) in the single group; again, no significant difference was shown. Conclusion: Patients with asymptomatic L3-4 stenosis on preoperative MRI were not prone to develop new symptoms or need additional L3-4-level surgery within 5 years after surgery when compared to patients without preoperative L3-4 stenosis. These results indicate that prophylactic decompression for asymptomatic levels is unnecessary.

Lumbar spinal stenosis is a risk factor for the development of dementia: locomotive syndrome and health outcomes in the Aizu cohort study.

PURPOSE: It remains unclear whether musculoskeletal diseases are risk factors for dementia development. This prospective cohort study of community-dwelling residents aimed to clarify the impact of lumbar spinal stenosis (LSS) on dementia development. METHODS: We included participants aged ≥ 65 years from the Locomotive Syndrome and Health Outcomes in the Aizu cohort study. LSS was diagnosed using the validated LSS diagnostic support tool. Dementia development between 2008 and 2015 was investigated using official long-term care insurance certification data. We analysed the effects of LSS on dementia development after adjusting for potential confounders, like age, sex, diabetes, depressive symptoms, hip and knee joint osteoarthritis, daily activity, and smoking habit. RESULTS: We included 1220 patients in the final analysis. The incidence of dementia was significantly higher in the LSS group [48 of 444 (10.8%)] than in the control group [34 of 776 (4.4%)]. Multivariable analysis using multiple imputations revealed that the confidence interval for the adjusted odds ratio of LSS for dementia development was 1.87 (95% confidence interval; 1.14-3.07). CONCLUSION: We clarified that LSS is an independent risk factor for dementia development. Our findings suggest the importance of considering the risk of dementia in the decision-making process for the treatment of LSS.

Relationship between lumbar facet joint osteoarthritis and comorbidities: A cross-sectional study in the Japanese community.

BACKGROUND: Few epidemiological studies have evaluated associations between lumbar facet joint (LFJ) osteoarthritis (OA) and comorbidities. This study aimed to investigate the prevalence of LFJ OA in a Japanese community population and associations between LFJ OA and underlying diseases, including lower extremity OA. METHODS: This epidemiological cross-sectional study evaluated LFJ OA in 225 Japanese community residents (81 males, 144 females; median age, 66 years) using magnetic resonance imaging (MRI). LFJ OA from L1-L2 to L5-S1 was evaluated using a 4-grade classification. Associations between LFJ OA and comorbidities were examined using multiple logistic regression analyses adjusting for age, sex, and body mass index. RESULTS: Prevalences of LFJ OA were 28.6% at L1-L2, 36.4% at L2-L3, 48.0% at L3-L4, 57.3% at L4-L5, and 44.2% at L5-S1. Males were significantly more likely to have LFJ OA at several spinal levels (L1-L2 45.7% vs 18.9%, p < 0.001; L2-L3 46.9% vs 30.6%, p < 0.05; L4-L5 67.9% vs 51.4%, p < 0.05). LFJ OA was present in 50.0% of residents <50 years old, 68.4% at 50-59 years old, 86.3% at 60-69 years old, and 85.1% at ≥70 years old. Multiple logistic regression analysis showed no associations between LFJ OA and comorbidities. CONCLUSIONS: The prevalence of LFJ OA as evaluated by MRI was >85% at ≥60 years old and highest at the L4-L5 spinal level. Males were significantly more likely to have LFJ OA at several spinal levels. Comorbidities were not associated with LFJ OA.

Impact of low back pain experience on future occurrence of shoulder pain in adolescent baseball players: A 1-year prospective cohort study.

BACKGROUND: Low back pain can affect musculoskeletal problems of the upper limb in adolescent overhead athletes. However, few epidemiological studies have examined this causal relationship. This prospective cohort study aimed to investigate the relationship between baseline low back pain experience and the occurrence of future shoulder and elbow pain among high school baseball players. METHODS: Participants comprised 383 high school baseball players from 43 high school baseball teams who had undergone baseline medical evaluations (a self-completed questionnaire and physical examination). The occurrence of shoulder and elbow pain during a 1-year follow-up and associations with baseline low back pain (positive subjective symptom during the last year at baseline) adjusted for flexibility of the scapulo-thoracic region, shoulder, and lower extremities, such as straight-leg raise angle (hamstring tightness), Thomas test (iliopsoas tightness), heel-buttock-distance (quadriceps tightness) and passive range of motion of the hip were investigated using multivariable analysis. RESULTS: A total of 307 players (80.2%) participated in the 1-year follow-up survey, with shoulder and elbow pain reported in 75 players (24.4%) and 119 players (38.8%), respectively, during follow-up. After adjusting for factors associated with shoulder pain using logistic regression modeling, significant associations between LBP experienced during the last year at baseline (odds ratio, 2.18; 95% confidence interval, 1.23-3.87; P = 0.0078) and new-onset of shoulder pain were noted. CONCLUSIONS: Baseline low back pain impacted future shoulder pain in high school baseball players during the 1-year follow-up. Management of shoulder pain warrants careful attention to low back pain.

Generalization of a clinical diagnosis support tool for lumbar spinal stenosis: Can the ankle brachial pressure index be replaced by palpation of the posterior tibial artery in the lumbar spinal stenosis diagnostic support tool? (DISTO project).

BACKGROUND: The Japanese Society for Spine Surgery and Related Research previously developed a diagnostic support tool for lumbar spinal stenosis (LSS-DST). Using the LSS-DST, general physicians can identify potential cases of LSS. However, in the LSS-DST, measurement of the ankle brachial pressure index (ABI) is required to exclude peripheral artery lesions in the lower limbs. We can expect further application of the LSS-DST if we can identify a simpler and easier method than ABI measurement. Therefore, in this large-scale, multicenter, cross-sectional study, we verified whether palpation of the posterior tibial (PT) artery could be used instead of ABI in the LSS-DST. METHODS: This survey was conducted at 2177 hospitals and included 28,883 participants. The sensitivity and specificity of the original LSS-DST method using the ABI and that of the LSS-DST ver2.0 with PT artery palpation were assessed to screen their ability for diagnosing LSS, using the physicians' final diagnosis based on the patients' history, physical examination and radiographic findings as the gold standard. RESULTS: The sensitivity and specificity [95%CI] of the LSS-DST were 88.2% [87.5, 88.8] and 83.9% [83.4, 84.5], respectively, whereas the sensitivity and specificity of the LSS-DST ver2.0 were 87.7% [87.0, 88.3] and 78.3% [77.7, 78.9], respectively, indicating that LSS-DST ver2.0 is a useful screening tool for LSS with good sensitivity. CONCLUSION: When the item of ABI in the LSS-DST is replaced by palpation of the PT artery (LSS-DST ver2.0), its sensitivity is maintained as a screening tool for LSS. LEVEL OF EVIDENCE: Level 3.

Clinical characteristics of early-stage lumbar spondylolysis detected by magnetic resonance imaging in male adolescent baseball players.

BACKGROUND: Many adolescent athletes experience low back pain; the most common cause is lumbar spondylolysis. Although early identification of lumbar spondylolysis in adolescent athletes is critical, few studies have focused on identifying the early stages of spondylolysis in baseball players. This study aimed to investigate the clinical characteristics of early-stage spondylolysis in male adolescent baseball players. METHODS: The participants comprised male junior and high school baseball players. Before magnetic resonance imaging, we recorded their demographic data, low back pain characteristics, and physical findings (lumbar flexion, extension, Kemp's test and the provocative tenderness of a spinous process). After the imaging evaluation, the association among low back pain characteristics, physical findings and the final diagnosis (early-stage spondylolysis or not) were investigated using univariate and multivariable analyses. RESULTS: A total of 171 players were included in this study. Univariate analyses indicated that the characteristics associated with early-stage spondylolysis were longer duration of low back pain (P = 0.0085), low back pain-related interference while running (P = 0.0022), low back pain starting with laterality (P = 0.0001), lumbar extension (P = 0.022), positive Kemp's test (P = 0.020), and the tenderness of a spinous process (P = 0.0003). After adjusting for confounding factors (age and position), we found that early-stage spondylolysis was significantly associated with low back pain duration ≥4 weeks (odds ratio 3.13, 95% confidence interval 1.42-6.92; P = 0.0048), low back pain-related interference while running (odds ratio 2.89, 95% confidence interval 1.30-6.46; P = 0.0094), low back pain starting with laterality (odds ratio 2.78, 95% confidence interval 1.24-6.27; P = 0.0133), and the tenderness of a spinous process (odds ratio 3.00, 95% confidence interval 1.36-6.57; P = 0.0062). CONCLUSIONS: Male adolescent baseball players with early-stage spondylolysis might have low back pain duration of more than four weeks, low back pain-related interference while running, and a history of low back pain starting with laterality. The tenderness of a spinous process might be helpful in the diagnosis of early-stage spondylolysis in male adolescent baseball players.

Influences of limited flexibility of the lower extremities and occurrence of low back pain in adolescent baseball players: A prospective cohort study.

BACKGROUND: Limited flexibility of the lower extremities, such as hamstring tightness, has long been suggested as a physical risk factor for low back pain among adolescent athletes. However, few prospective cohort studies have examined the direction of causality for this relationship. This prospective cohort study investigated the relationship between limited flexibility of the lower extremities and the occurrence of low back pain among high school baseball players. METHODS: Participants comprised 335 high school baseball players from 43 high school baseball teams who had undergone baseline medical evaluations (a self-completed questionnaire and physical examination). Occurrence of low back pain during a 1-year follow up, and associations with measurements of flexibility of the lower extremities such as straight-leg-raising angle (hamstring tightness), Thomas test (iliopsoas tightness), heel-buttock-distance (quadriceps tightness), and passive range of motion of the hip were investigated. RESULTS: In total, 296 players (88.4%) participated in the 1-year follow-up survey, with 147 of the 296 players (49.7%) reporting the occurrence of low back pain during follow-up. The number of players with low back pain during follow-up peaked in November, then decreased and was lowest in June. After adjusting for factors associated with low back pain using logistic regression modeling, a significant association between hamstring tightness on the non-throwing arm side and low back pain (odds ratio 2.86, 95% confidence interval 1.17-6.94; P = 0.018) was found. CONCLUSIONS: Hamstring tightness on the non-throwing arm side was identified as a potential risk factor for low back pain in high school baseball players. These results may provide guidance in the development of future prevention programs.

The prevalence and clinical characteristics of sacroiliac joint dysfunction in adolescent baseball players.

BACKGROUND: Sacroiliac joint (SIJ) dysfunction is a potential source of low back pain (LBP) in baseball players, who are more likely to be affected by loading of the SIJ in the throwing motion. However, the prevalence and characteristics of this condition have not been studied thoroughly. This study aimed to investigate the prevalence and clinical characteristics of SIJ dysfunction among high school baseball players. METHODS: Participants comprised 891 high school baseball players who had undergone annual medical evaluations (a self-completed questionnaire and physical examination). The prevalence of SIJ dysfunction and associations with the measurements of the flexibility of the spine and lower extremities such as finger-floor-distance, straight-leg-raising angle, heel-buttock-distance, Thomas test, and passive range of motion of the hip were investigated. RESULTS: Twenty-two of 891 subjects (2.5%) met our criteria for SIJ dysfunction. Twelve subjects (55%) exhibited throwing arm side symptoms more commonly than in the non-throwing arm side (n = 3, 15%) or bilateral side (n = 7, 32%). Previous episodes of LBP were experienced significantly more frequently among subjects with SIJ dysfunction (n = 19, 86.4%) than among those without (n = 501, 57.7%; P = 0.015). The prevalence of present LBP that interfered with play was significantly higher among subjects with SIJ dysfunction (n = 9, 42.9%) than among those without (n = 118, 21.2%; P = 0.038). The prevalence of SIJ dysfunction as a source of LBP was estimated at 7.1% (9 of 127 subjects). After adjustment for associated factors using a logistic regression model, we observed a significant association between a limitation in hip internal rotation on the throwing arm side and SIJ dysfunction (odds ratio 3.11 [1.30-7.71]; P = 0.0109). CONCLUSIONS: According to our criteria, the estimated prevalence of SIJ dysfunction among high school baseball players is 2.5%. There was a significant association between a limitation in hip internal rotation on the throwing arm side and SIJ dysfunction.

Associations between core stability and low back pain in high school baseball players: A cross-sectional study.

BACKGROUND: Reduced core stability is a potential risk factor for low back pain in athletes. However, the association between core stability and low back pain in high school baseball players has not been thoroughly studied. The purpose of this study was to investigate the relationship between core stability and low back pain and its clinical characteristics in high school baseball players. METHODS: Participants comprised 812 high school baseball players who had undergone annual medical evaluations, comprising a self-completed questionnaire and a physical examination. We investigated the relationships between low back pain during the season and on the day of medical evaluations and core stability using a cross-sectional study design. Core stability was assessed using the Sahrmann core stability test. RESULTS: Reduced core stability was confirmed in 358 (44.1%) of all players, 98 (49.5%) pitchers, and 260 (42.3%) fielders. In total, 352 players (43.3%) reported incidents of seasonal low back pain during the previous year. Thirty-five pitchers (17.7%) and 153 fielders (24.9%) reported low back pain on the day of the medical evaluations. No significant associations were seen between low back pain throughout the season and reduced core stability. After adjusting for confounding factors (total amount of practice per week, hamstring tightness and quadriceps tightness) using logistic regression modeling, a significant association between presence of low back pain during lumbar extension movement and reduced core stability was found (odds ratio, 2.57; 95% confidence interval, 1.08-6.62; P = 0.033) in pitchers. CONCLUSIONS: High school baseball pitchers with reduced core stability showed a higher probability of reporting low back pain during lumbar extension movement. Evaluation of core stability should be considered in high school baseball players, especially in pitchers.

Usefulness of Lateral Lumbar Interbody Fusion Combined with Indirect Decompression for Degenerative Lumbar Spondylolisthesis: A Systematic Review.

Background and Objective: The aim of this review was to analyze the existing literature and investigate the outcomes or complications of lateral lumbar interbody fusion (LLIF) combined with indirect decompression for degenerative lumbar spondylolisthesis (DS). Materials and Methods: A database search algorithm was used to query MEDLINE, COCHRANE, and EMBASE to identify the literature reporting LLIF with indirect decompression for DS between January 2010 and December 2021. Improvements in outcome measures and complication rates were pooled and tested for significance. Results: A total of 412 publications were assessed, and 12 studies satisfied the inclusion criteria after full review. The pooled data available in the included studies showed that 438 patients with lumbar spondylolisthesis (mean age 65.2 years; mean body mass index (BMI) 38.1 kg/m2) underwent LLIF. A total of 546 disc spaces were operated on. The most frequently treated levels were L4-L5 and L3-L4. Clinically, the average improvement was 32.5% in ODI, 46.3 mm in low back pain, and 48.3 mm in leg pain estimated from the studies included. SF-36 PCS improved by 51.5% and MCS improved by 19.5%. For radiological outcomes, a reduction in slippage was seen in 6.3%. Disc height increased by 55%, foraminal height increased by 21.1%, the foraminal area on the approach side increased by 21.9%, and on the opposite side it increased by 26.1%. The cross-sectional spinal canal area increased by 20.6% after surgery. Post-operative complications occurred in 5-40% of patients with thigh symptoms, such as anterior thigh numbness, dysesthesia, discomfort, pain, and sensory deficits. Conclusions: Indirect decompression by LLIF for DS is an effective method for improving pain and dysfunction with less surgical invasion. In addition, it has the effect of significantly improving disc height, foraminal height and area, and segmental lordosis on radiological outcomes compared to the posterior approach.

Pregnancy and Lactation-Associated Osteoporosis Successfully Treated with Romosozumab: A Case Report.

Pregnancy- and lactation-associated osteoporosis (PLO) is a rare type of premenopausal osteoporosis that occurs mainly in the third trimester or immediately after delivery; one of its most common symptoms is back pain caused by a vertebral fracture. The pathogenesis of PLO is unclear, and there is no accepted consensus regarding the treatment of PLO. Although treatments with drugs such as bisphosphonate, strontium ranelate, denosumab, and teriparatide were reported, there is no report of a patient with PLO treated with romosozumab. We present the first case of a patient with PLO treated with romosozumab following 4-month teriparatide treatment. A 34-year-old primiparous and breastfeeding Japanese woman experienced severe low back pain 1 month postdelivery. She was diagnosed with PLO on the basis of low bone marrow density (BMD) and multiple vertebral fractures with no identified cause of secondary osteoporosis. She was treated with teriparatide injection for 4 months, but the treatment was discontinued because of the patient feeling severe nausea after every teriparatide injection and the appearance of new vertebral fractures. Thereafter, we used romosozumab for 12 months. After the romosozumab treatment, her BMD was increased from the baseline by 23.6% at L1-L4, 6.2% at the femoral neck, and 11.2% at the total hip. Treating PLO with 12-month romosozumab after 4 months of teriparatide injection remarkably increased the BMD of the lumbar spine, femoral neck, and total hip without subsequent fracture. Romosozumab has potential as a therapeutic option to improve the BMD and reduce the subsequent fracture risk of patients with PLO.

Dose-response relationship between spino-pelvic alignment determined by sagittal modifiers and back pain-specific quality of life.

PURPOSE: To determine whether abnormalities of the sagittal modifiers (SMs) of the Scoliosis Research Society (SRS)-Schwab classification truly reflect back pain (BP)-specific quality of life (QOL), it is necessary to examine their dose-response relationships and to determine clinically impactful thresholds for declines in BP-specific QOL. This study aimed to analyse the continuous dose-response relationship between each SM and BP-specific QOL. METHODS: This cross-sectional study, using data from a Japanese population-based cohort study, included 519 community-dwelling residents aged ≥ 50 years who participated in the annual health examination. The participants completed the Roland-Morris Disability Questionnaire (RDQ) on BP-specific QOL. Spino-pelvic alignment based on SMs was assessed by whole-spine X-ray examinations. We fitted general linear models with or without nonlinear terms to estimate the dose-response relationship between each SM and BP-specific QOL. RESULTS: Pelvic tilt, pelvic incidence minus lumbar lordosis (PI-LL), and sagittal vertical axis showed dose-response relationships with BP-specific QOL measured as the RDQ score. PI-LL was most likely to predict a minimally clinically important RDQ score when its value exceeded the 90th percentile. A nonlinear relationship between PI-LL and the BP-specific QOL score was found. RDQ increased when PI-LL exceeded 10°. CONCLUSION: PI-LL might be the most sensitive of the three modifiers of the SRS-Schwab classification for determining BP-specific QOL. Moreover, BP-specific QOL worsens rapidly when the compensatory mechanism against malalignment exceeds a critical value. Therefore, we suggest that traditional classifications and surgical strategies should be re-examined regarding the dose-dependent abnormalities of the SMs to develop a more reliable classification strategy.

Sagittal imbalance and symptoms of depression in adults: Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study (LOHAS).

PURPOSE: With spinal deformities, mental health can deteriorate due to sagittal imbalance of the spine. The purpose of this study was to clarify the relationship between sagittal imbalance and symptoms of depression among local residents in the community. METHODS: This study used data from the Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS) in 2010. The sagittal vertical axis (SVA) was identified as an indicator of sagittal imbalance. Symptoms of depression were assessed using the 5-item version of the Mental Health Inventory. Participants were classified into three categories based on the SVA balance as normal (< 40 mm), moderate imbalance (40-95 mm), and severe imbalance (> 95 mm). To evaluate the relationship between sagittal imbalance of the spine and symptoms of depression, the adjusted risk ratio (RR) and the 95% confidence interval (CI) were calculated using a generalized linear model with Poisson link. RESULTS: There were 786 participants included in the statistical analysis. Overall, the mean age was 68.1 y (standard deviation, 8.8 y), and 39.4% were men. The prevalence of symptoms of depression by SVA category was 18.6% for normal, 23.8% for moderate, and 40.6% for severe. On multivariate analysis, the RR of SVA for symptoms of depression compared to the normal category was 1.12 (95% CI 0.7-1.70) for the moderate category and 2.29 (95% CI 1.01-5.17) for the severe category. CONCLUSION: In local community residents, sagittal imbalance had a significant association with symptoms of depression.

Development of a severity discrimination scale based on physical quality of life for patients with chronic pain.

BACKGROUND: Deterioration of quality of life in patients with chronic pain is difficult to treat. Chronic pain in patients with low quality of life may be "severe" and require multidisciplinary treatments. This study aimed to develop an objective severity discrimination scale based on quality of life measurements to identify patients with "severely disabling" chronic pain. METHODS: Subjects were 156 patients with chronic pain whose numerical rating pain score was ≥1 and who had pain for ≥3 months. Diseases associated with chronic pain included spinal diseases, joint diseases, concomitant diseases, complex regional pain syndromes, and other musculoskeletal diseases. Patients were divided into low, middle, and high groups based on physical quality of life summary scores on the Short Form-36. The mental component summary, painDETECT, Japanese version of the Pain Catastrophizing Scale, Brief Scale for Psychiatric Problems in Orthopaedic Patients, and factors related to degree/quality of pain during the past 4 weeks were analyzed to identify components in the low group. The score weighting factor for discriminating between the high and low groups was determined by discriminant analysis. RESULTS: Factor analysis identified 4 factors representing features of chronic pain patients with low QOL: enhanced perception of pain, pain catastrophic thoughts, depressive sleep disorder, and pain intensity. For discriminant analysis, patients were defined as those with low physical quality of life if each factor's total score multiplied by a factor plus a constant value of 2.6 was ≥0, and high quality of life if it was <0. The receiver operating characteristic curve area used to determine the cut-off value was 0.71, with 67.3% sensitivity and specificity. CONCLUSIONS: We developed a 33-question severity discrimination scale to define "severely disabling" chronic pain based on physical quality of life. "Severely disabling" patients identified on this scale could represent chronic pain patients needing focused multidisciplinary treatment.

The Change of Lumbar Spinal Stenosis Symptoms over a Six-Year Period in Community-Dwelling People.

Background and Objectives: The high prevalence of lumbar spinal stenosis (LSS) and its negative impact on quality of life in the elderly is well known. However, the longitudinal time course of LSS symptoms remains unclear. The purpose of this study was to clarify the longitudinal time course and associated factors of LSS symptoms over a period of six years in a community. Materials and Methods: This study was conducted with data prospectively collected in 2004 and 2010 under a retrospective design. In 2004, 1578 subjects (age range: 40 to 79 years) were interviewed on LSS symptoms using a specially designed and validated questionnaire. In 2010, a follow-up study was performed by mail, to which 789 subjects of the 2004 study population responded. Considering that the presence of osteoarthritis (OA) of the knee or hip may influence the participants' answers in the questionnaire, analysis was performed in all 789 subjects with and 513 subjects without either knee or hip OA. Changes in LSS symptoms between the initial and the 6-year survey were investigated. Multiple logistic regression analysis was used for detecting the risk factors for LSS symptom presence at the six-year follow-up. Results: 1. At the six-year follow-up, more than half of the subjects who showed LSS symptoms at the initial analysis became LSS-negative, and 12-15% of those who were LSS-negative became LSS-positive. 2. From the multiple logistic regression analysis, a lower Roland-Morris Disability Questionnaire (RDQ) score and a positive LSS symptom at the initial analysis were detected as predictive factors of the presence of LSS symptoms at the six-year follow-up in the total number of subjects, as well as just in those who did not have either knee or hip OA. Conclusions: More than half of the subjects who were LSS-positive at their initial assessment still experienced improvement in their symptoms even after 6 years. This means that both LSS symptoms and their time course vary from person to person. Predictive factors for the presence of LSS symptoms during the six-year follow-up period were RDQ score and positive LSS symptoms.

Involvement between social defeat stress and pain-related behavior in a rat lumbar disk herniation model.

INTRODUCTION: Psychological and social factors are involved in the disability and chronicity of pain. Our study aim was to investigate whether social defeat stress (SDS) as a psychophysical stress affected mechanical withdrawal thresholds in the lumbar disk herniation (LDH) rat model. Changes in microglia and astrocytes, which play important roles in neuropathic pain states, were also investigated. MATERIALS AND METHODS: For the LDH model, nucleus pulposus (NP) was applied to the L5 dorsal root ganglion (DRG) in adult female Sprague-Dawley rats. SDS was performed 15 min daily for 8 days. Mechanical withdrawal thresholds were measured, and immunoreactive cells of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule-1 (Iba-1), which were used as markers of microglia, satellite glial cells, and astrocytes, were assessed in the DRG, spinal cord (SC), and ventrolateral periaqueductal gray matter (VLPAG). RESULTS: Mechanical withdrawal thresholds decreased in the NP group for 21 days and for 35 days in the NP + SDS group. Expression of GFAP and Iba-1 in the DRG and SC increased up to day 21 in the NP and NP + SDS groups. In the sham + SDS and NP + SDS groups, expression of GFAP in the VLPAG decreased until day 35. CONCLUSION: SDS prolongs mechanical allodynia induced by NP. Changes of GFAP expression in the VLPAG were associated with mechanical allodynia of the NP + SDS group during the late phase. These results suggest that psychological chronic stress might delay recovery from mechanical allodynia induced by the LDH model.

Acetaminophen combined with tramadol is more effective than acetaminophen or tramadol to reduce neuropathic root pain: an experimental study with application of nucleus pulposus in a rat model.

INTRODUCTION: Various drugs are used to treat patients with neuropathic pain; however, optimal treatment using acetaminophen (A) and/or tramadol (T) remains unclear. The evidence supporting the drug choice and the timing of administration is insufficient. Therefore, the objective of the present study was to investigate the effect of T and/or A on pain-related behavior in a nucleus pulposus (NP) rat model. MATERIALS AND METHODS: Sprague-Dawley rats (n = 180) were divided into NP-A (52 mg/kg), NP-T (6 mg/kg), NP-AT (combined A and T), NP-S (saline), and sham groups (n = 36 per group). The rats received 0.2 mL of treatment solution orally once daily for 7 days after application of NP on the left L5 dorsal root ganglion (DRG). Behavioral testing and immunohistochemistry analysis for some markers' expressions in DRGs and the spinal cord were performed. RESULTS: Pain thresholds in the NP-AT group did not significantly differ from the sham at all time points, while those were significantly lower in the NP-A and in the NP-T groups at D7 and/or D14 (p < 0.05). Tumor necrosis factor-α in the NP-S group was significantly higher at D2 and D7 (p < 0.05). Among the three treatment groups, activating transcriptional factor 3 and growth-associated protein 43 showed a tendency toward an increase at D7-D21. CONCLUSION: Combined administration of acetaminophen and tramadol maintained in the pain threshold in the rat NP model. These findings suggest that the combination of acetaminophen and tramadol might be a potential therapeutic modality for patients with lumbar disc herniation. These slides can be retrieved under Electronic Supplementary Material.

Talipes Equinus Deformity Caused by Fibrous Gastrocnemius Muscle Contracture After Direct Contusion in Football Players: Report of Two Cases.

Two main causes of gastrocnemius contracture have been considered: 1) congenital deformities in pediatric patients, such as limb-length discrepancy, cerebral palsy, flatfoot, and clubfoot; and 2) secondary conditions such as immobilization for trauma or a nonfunctional limb. Talipes equinus deformity caused by fibrous gastrocnemius contracture after a direct muscle contusion is extremely rare. We describe 2 cases of talipes equinus deformity caused by fibrous gastrocnemius muscle contracture after a direct contusion in football players. Both of the players had a talipes equinus deformity with a severe restriction of ankle dorsiflexion, and a cord-like structure was observed at the proximal part of the lateral gastrocnemius head. Both patients' histological examinations revealed fibrous tendon-like tissue within the structure. After discission of the cord-like structures, the restriction of ankle dorsiflexion was completely resolved, and the patients were able to fully return to playing football without any discomfort in their calves.

An Open-Label, 52-Week, Phase III Trial of Duloxetine in Japanese Patients with Chronic Low Back Pain.

OBJECTIVE: To evaluate the safety and efficacy of duloxetine treatment for 52 weeks. DESIGN: Multicenter, open-label, phase III clinical study. SETTING: Forty-one medical institutions in Japan. SUBJECTS: Japanese patients with chronic low back pain (CLBP). METHODS: Duloxetine 60 mg once-daily was administered for 52 weeks. Safety was evaluated based on adverse events (AEs), vital signs, laboratory test values, electrocardiogram, Columbia-Suicide Severity Rating Scale, and occurrence of falls. The efficacy outcome measures were the Brief Pain Inventory (BPI; average pain, worst pain, least pain, and pain right now), BPI Interference, Patient's Global Impression of Improvement (PGI-I), Clinical Global Impressions of Severity (CGI-S), Roland-Morris Disability Questionnaire-24 (RDQ-24), 36-Item Short-Form Health Survey (SF-36), and European Quality of Life-5 Dimensions Questionnaire (EQ-5D). RESULTS: In total, 151 patients (83 who completed a 14-week placebo-controlled superiority trial and 68 newly registered patients) were enrolled. The incidence rates of AEs and adverse drug reactions (ADRs) were 86.1% and 50.3%, respectively. ADRs with an incidence of ≥5% were somnolence, constipation, nausea, and dry mouth. Treatment discontinuation for AEs occurred in 16 patients. A significant reduction in the BPI average pain score (mean ± SD) was observed at all assessment time points from week 2 (-1.02 ± 1.37) to week 50 (-2.26 ± 1.63), compared with baseline. BPI pain severity (worst pain, least pain, and pain right now), BPI Interference, PGI-I, CGI-S, RDQ-24, SF-36, and EQ-5D showed significant improvement. CONCLUSION: Japanese patients with CLBP had significant pain reduction over 52 weeks without new safety concerns.

Level of Low Back Pain-Related Disability Is Associated with Risk of Subsequent Falls in an Older Population: Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS).

OBJECTIVES: To examine the longitudinal association between baseline disability due to low back pain (LBP) and future risk of falls, particularly significant falls requiring treatment, in a community-dwelling older population. METHODS: This was a prospective population-based cohort study using data from the Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS; 2008-2010). A total of 2,738 residents aged ≥60 years were enrolled. LBP was assessed using the Roland-Morris Disability Questionnaire (RMDQ), and the level of LBP-related disability was divided into three categories (none, low, and medium to high). Incidence of falls over the following year was determined using a self-reported questionnaire after the one-year follow-up period. The risk ratio (RR) for LBP-related disability associated with any fall and any fall requiring treatment was estimated using log binomial regression models. RESULTS: Data were analyzed for 1,358 subjects. The prevalence of LBP at baseline was 16.4%, whereas 122 (8.9%) participants reported a low level of LBP-related disability and 101 (7.4%) reported medium to high levels of LBP-related disability. Incidence of any fall and falls requiring treatment was reported by 22.1% and 4.6% of participants, respectively. Subjects with medium to high levels of disability were more likely to experience subsequent falls (adjusted RR = 1.53, 95% confidence interval [CI] = 1.21-1.95) and falls requiring treatment (adjusted RR = 2.55, 95% CI = 1.41-4.60) than those with no LBP-related disability. CONCLUSIONS: Level of LBP-related disability was associated with an increased risk of serious falls in a general population of community-living older adults. These findings can alert health care providers involved in fall prevention efforts to the important issue of activity-related disability due to LBP.