Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication.

BACKGROUND: The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine. METHODS: The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members. RESULTS: Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided. CONCLUSIONS: The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

A nationwide multicenter study of the cost effectiveness of five leading drugs for pharmacological management of cervicobrachial symptoms.

BACKGROUND: Cervicobrachial pain frequently affects the quality of life (QOL) of the general public and has a significant economic impact on the health care systems of various countries. There are a number of treatment options for this disease, including widely-used drug therapy, but the effectiveness of each option is indeterminate, and there have been no published cost-effectiveness analysis studies so far. This prospective observational study aimed to examine the cost-effectiveness of drug treatment for cervicobrachial symptoms. METHODS: A 6-month medication regimen for each of five frequently-prescribed drugs for cervicobrachial symptoms was administered to 322 patients at 24 centers in Japan. Outcome measures, including of the EuroQol Group 5D, Short Form-8, and Visual Analog Scale (VAS), were investigated at baseline and every month thereafter. Incremental cost-effectiveness ratios (ICERs) of the drug cost to quality-adjusted life years (QALYs) were calculated. A stratified analysis of patient characteristics was also performed to identify baseline factors potentially affecting cost-effectiveness. RESULTS: The ICER of entire drug treatment for cervicobrachial symptoms was 7,491,640 yen. Compared with the reference willingness-to-pay, the ICER was assumed to not be cost-effective. A certain number of QALYs were gained during the first 3 months after the treatment intervention, but almost no QALYs were gained during the following 3 months. Stratified analysis showed that cost-effectiveness was extremely low for patients with high baseline VAS and high QOL. CONCLUSIONS: The available medications for cervicobrachial symptoms did not have excellent cost-effectiveness. Although a certain number of QALYs were gained during the first 3 months after medication, no QALYs were gained in the latter half of the study period, suggesting that it is not advisable to continue the medication needlessly. LEVEL OF EVIDENCE: II, prospective cohort study.

Supervised physical therapy versus surgery for patients with lumbar spinal stenosis: a propensity score-matched analysis.

BACKGROUND: Previous studies comparing surgical with nonsurgical treatment for lumbar spinal stenosis (LSS) reported that surgery is superior to nonsurgical treatments, but intensive and adequate volume of physical therapy were rarely performed. The purpose of this study was to compare the 1-year follow-up outcomes of patients with LSS treated with supervised physical therapy or surgery using propensity score-matched analysis. METHODS: A total of 224 patients with LSS who received supervised physical therapy (n = 38) or surgery (n = 186) were included, of which 66 were matched on baseline demographics, radiological findings, and patient-reported outcomes. The physical therapy group received supervised physical therapy twice weekly for 6 weeks. The physical therapy sessions included manual therapy, individually tailored exercises, cycling, and body-weight supported treadmill walking. The surgery group underwent decompression surgery with or without spinal fusion. A propensity score analysis was performed using a one-to-one nearest neighbor approach. RESULTS: The surgery group showed greater improvements in Zurich claudication questionnaire symptom severity and physical function, SF-36 physical functioning, bodily pain, and mental health, but had more severe stenosis and symptoms and mental health problems than the physical therapy group at baseline (P <  0.05). After propensity score matching, there were no significant differences in baseline characteristics, and all clinical outcomes at 1 year, except for a higher percentage of responders achieving minimum clinically important difference in the role-emotional subscale of SF-36 in the surgery group (P <  0.05). CONCLUSIONS: When baseline characteristics were considered, supervised physical therapy yielded similar effects to lumbar surgery. These results suggest that supervised physical therapy is preferred over surgery as first-choice treatment, to prevent complications and to minimize health care costs, especially in mild to moderate cases of LSS.

MRI grading of spinal stenosis is not associated with the severity of low back pain in patients with lumbar spinal stenosis.

BACKGROUND: Although lumbar spinal stenosis (LSS) often coexists with other degenerative conditions, few studies have fully assessed possible contributing factors for low back pain (LBP) in patients with LSS. The purpose of this study was to identify factors associated with the severity of LBP in patients with LSS. METHODS: The patients with neurogenic claudication caused by LSS, which was confirmed by magnetic resonance imaging (MRI) were included in this cross-sectional study. Data included ratings of LBP, buttock and leg pain, and numbness on a numerical rating scale (NRS), 36-item Short-Form Survey (SF-36) scores, muscle mass measured by bioelectrical impedance analysis, and radiographic measurements including lumbopelvic alignment and slippage. The severity of LSS, endplate defects, Modic endplate changes, intervertebral disc degeneration, and facet joint osteoarthritis were evaluated on MRI. Spearman correlation and multivariate linear regression analyses were used to examine the factors associated with the severity of LBP (NRS score). RESULTS: A total of 293 patients (135 male and 158 female, average age 72.6 years) were analyzed. LBP was moderately correlated with buttock and leg pain, and buttock and leg numbness. Significant but weak correlations were observed between LBP and body mass index, appendicular and trunk muscle mass, all domains of SF-36, pelvic tilt, total number of endplate defects and Modic endplate changes, and summary score of disc degeneration grading, but not severity or number of spinal stenoses. In the multivariate regression analysis, age, female sex, trunk muscle mass, diabetes, NRS buttock and leg pain, NRS buttock and leg numbness, SF-36 vitality, pelvic tilt, and total number of endplate defects were associated with the severity of LBP. CONCLUSIONS: Trunk muscle mass, lumbopelvic alignment, and endplate defects, but not severity of stenosis are partly associated with severity of LBP, but buttock and leg pain and buttock and leg numbness have strongest relationships with LBP in patients with LSS.

Formulation of Japanese Orthopaedic Association (JOA) clinical practice guideline for the management of low back pain- the revised 2019 edition.

BACKGROUND: The latest clinical guidelines are mandatory for physicians to follow when practicing evidence-based medicine in the treatment of low back pain. Those guidelines should target not only Japanese board-certified orthopaedic surgeons, but also primary physicians, and they should be prepared based entirely on evidence-based medicine. The Japanese Orthopaedic Association Low Back Pain guideline committee decided to update the guideline and launched the formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline with the latest data of evidence-based medicine. METHODS: The Japanese Orthopaedic Association Low Back Pain guideline formulation committee revised the previous guideline based on a method for preparing clinical guidelines in Japan proposed by Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Two key phrases, "body of evidence" and "benefit and harm balance" were focused on in the revised version. Background and clinical questions were determined, followed by literature search related to each question. Appropriate articles were selected from all the searched literature. Structured abstracts were prepared, and then meta-analyses were performed. The strength of both the body of evidence and the recommendation was decided by the committee members. RESULTS: Nine background and nine clinical qvuestions were determined. For each clinical question, outcomes from the literature were collected and meta-analysis was performed. Answers and explanations were described for each clinical question, and the strength of the recommendation was decided. For background questions, the recommendations were described based on previous literature. CONCLUSIONS: The 2019 clinical practice guideline for the management of low back pain was completed according to the latest evidence-based medicine. We strongly hope that this guideline serves as a benchmark for all physicians, as well as patients, in the management of low back pain.

Supervised physical therapy versus unsupervised exercise for patients with lumbar spinal stenosis: 1-year follow-up of a randomized controlled trial.

OBJECTIVE: To compare the 1-year outcomes of patients with lumbar spinal stenosis treated with supervised physical therapy or unsupervised exercise. DESIGN: A single-center randomized controlled trial with concealed allocation, blinded assessor and intention-to-treat analysis. SETTING: Spine care center. SUBJECTS: A total of 86 patients presenting with symptoms of neurogenic claudication caused by lumbar spinal stenosis. INTERVENTIONS: The physical therapy group received supervised physical therapy sessions twice a week for 6 weeks and home exercise program. The home exercise group received 6-week home exercise program only. MAIN MEASURES: The primary outcome was symptom severity on the Zurich claudication questionnaire at 1 year. Secondary outcomes included physical function, pain, health-related quality of life and the surgery rate after 1 year. RESULTS: At 1 year, more patients in the physical therapy group than in the home exercise group achieved minimum clinically important differences in Zurich claudication questionnaire symptom severity (60.5% vs 32.6%; adjusted odds ratio [AOR] 4.3, [95% CI [1.5-12.3], P = 0.01); Zurich claudication questionnaire physical function (55.8% vs 32.6%; AOR 3.0 [1.1-8.1], P = 0.03); SF-36 bodily pain (48.8% vs 25.6%; AOR 2.8 [1.1-7.3], P = 0.03), and SF-36 general health (20.9% vs 7.0%; AOR 6.1 [1.1-33.0], P = 0.04). The surgery rate at 1 year was lower in the physical therapy than in the home exercise group (7.0% vs 23.3%; AOR 0.2 [0.04-0.9] P = 0.04). CONCLUSIONS: Supervised physical therapy produced greater improvements in symptom severity and physical function than unsupervised exercise and was associated with lower likelihood of receiving surgery within 1 year.

Sagittal imbalance of the spine-pelvis-lower extremity axis associated with back-related disability.

BACKGROUND: The impact of sagittal imbalance in patients has been reported in LBP and LBP-related disabilities due to spinopelvic imbalance. However, no reports investigating the spine-pelvis-lower extremity axis using lateral images have been reported thus far. This study introduced a novel parameter of the spine-pelvis-lower extremity axis and evaluated whether this parameter was related to symptoms. METHODS: A total of 343 subjects were included in this cross-sectional study. Standing spine-pelvis and pelvis-lower extremity radiographs were obtained to assess the sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumbar lordosis, and thoracic kyphosis. The sacral-knee distance (SKD) (i.e., distance from the anterior femoral condyle to the vertical axis at the upper posterior edge of S1 body) was measured. Furthermore, the SVA/SKD ratio was calculated for global balance. Subjects were divided into leg compensated (LC; SVA/SKD ratio <0.8) and decompensated (LD; SVA/SKD ratio ≥0.8) groups. The SVA was divided into balanced spine (BS; SVA ≤40 mm) and imbalanced spine (IS; SVA >40 mm) groups. All individuals were classified into LC + BS, LC + IS, LD + BS, and LD + IS groups. The relationships among the four groups and low back pain (LBP), Oswestry Disability Index (ODI), and knee pain were examined. RESULTS: SKD was significantly correlated with SVA, SS, PI, PT, and knee-femoral angle. ODI was significantly higher in the LC + IS group than in the LD + BS group (p < 0.05). Knee pain prevalence was significantly higher in the LC + IS and LC + BS groups than in the LD + IS group (p < 0.05). CONCLUSION: SVA/SKD ratio is useful for evaluating global alignment. Our findings are significant because they highlight the importance of SKD with respect to knee pain, LBP, and LBP- related disabilities.

Impact of background factors on outcomes of pharmacological therapy for chronic low back pain: A nationwide multicenter prospective study.

BACKGROUND: Chronic low back pain (CLBP) is a major cause of chronic pain with nociceptive, neuropathic or both pain components, and a leading cause of disability. The objectives of this study were to determine the impact of background factors including previous use of drugs on outcomes of pharmacological therapy for CLBP in a nationwide multicenter prospective study. METHODS: The subjects were 474 patients (male: 41.9%, median age: 73.0) with CLBP. Background factors that could influence outcomes after pharmacological treatment for 6 months were examined: age, gender, body mass index (BMI), duration of CLBP, osteoporosis, history of spinal surgery, history of malignant tumor, smoking habit, employment status (yes or no), exercise habit (frequency), number of live-in family members, having something to do for pleasure, Center for Epidemiologic Studies depression scale (CES-D) score, and medication at baseline. Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) for LBP, JOA Back Pain Evaluation Questionnaire (JOABPEQ), Roland-Morris Disability Questionnaire (RDQ), Short-form 8-item health survey (SF-8), and EQ-5D were used for evaluation at baseline and after 6 months. Multivariate linear regression models were used in statistical analysis. RESULTS: Drugs for neuropathic pain at baseline (p < 0.001), Tramacet® at baseline (p < 0.05), weak opioids at baseline (p < 0.05), older age (p < 0.001), long disease duration (p < 0.005), history of spinal surgery (p < 0.001), and smoking habit (p < 0.001) had significant negative effects on outcomes. Employment (p < 0.05), exercise habit (p < 0.05), and CED-D at baseline (p < 0.001) had positive effects on outcomes. CONCLUSIONS: This is the first study to identify significant prognostic factors for outcomes of pharmacological treatment of CLBP. The neuropathic pain component of CLBP at baseline is a major significant negative factor for most outcomes involving improved pain, activities of daily life, and quality of life. Treatment strategies developed with consideration of these factors may be advantageous for recovery from CLBP.

Preoperative psychological factors affecting surgical satisfaction of elderly patients with lumbar spinal stenosis.

OBJECTIVE: The objective of this observational study was to investigate the effects of preoperative psychological factors on short-term patient satisfaction with surgery in elderly patients with lumbar spinal stenosis (LSS). METHODS: Surgery was performed on 90 elderly patients with clinically and radiologically defined LSS: mean age at surgery, 73 years; 46 men and 44 women. Patients completed questionnaires before surgery and 1 year postoperatively. They used a self-administered the Roland Morris Disability Questionnaire (RDQ), the Japanese Orthopaedic Association Back Pain Questionnaire (JOABPEQ), MOS 36-Item Short-Form Health Survey (SF-36), and satisfaction for surgery (VAS) were completed. At baseline, psychological factors were assessed using the Self-Rating Questionnaire for Depression (SRQ-D), Hospital Anxiety and Depression scale (HADS), Pain Catastrophizing Scale (PCS), Pain Anxiety Symptoms Scale-20, and Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP). At follow-up, patient satisfaction was evaluated using 2 items: (1) satisfaction with surgery and (2) Would you undergo the same surgery again?. RESULTS: Satisfaction item 1 correlated negatively with the VAS for low back pain, leg pain, numbness, JOABPEQ social life disturbance score, SF-36 physical function score, and HADS anxiety score (p < 0.05). Satisfaction 2 correlated negatively with age at surgery, VAS of leg pain, PCS magnification score, and BS-POP score (p < 0.05). Multiple regression analysis showed significant associations between satisfaction 1 and SF-36 physical function and HADS anxiety scores, and between satisfaction 2 and PCS magnification score (p < 0.05). STATISTICAL ANALYSIS: The preoperative factors independently associated with surgical satisfaction were analyzed utilizing Speaman's rank correlation coefficient and multiple regression analysis. CONCLUSION: Physical function and anxiety were identified as preoperative factors that affected patient satisfaction with surgery. Preoperative assessment of psychological factors and interventions for anxiety may help improve patient satisfaction after surgery for LSS.

Correction to: ISSLS PRIZE IN BASIC SCIENCE 2018: Growth differentiation factor-6 attenuated pro-inflammatory molecular changes in the rabbit anular-puncture model and degenerated disc-induced pain generation in the rat xenograft radiculopathy model.

The author "Ashish D. Diwan" receives educational consultant fees from Nuvasive Inc.

A comparative study of gait characteristics associated with and without degenerative lumbar spondylolisthesis in patients with lumbar spinal stenosis.

BACKGROUND: Reported characteristics of DS include forward slippage of the superior lumbar relative to the inferior lumbar, lumbar instability, increased lumbar lordotic angle, and high body mass index (BMI). However, to our knowledge, only static measurements were conducted in previous studies, and no dynamic observations exist. In this crosssectional study, the gait of patients with and without DS in LSS was compared, and their characteristics were examined using a three-dimensional motion analysis system. METHODS: In total, 42 patients with LSS were included. Lumbar lordosis angle, sacral tilt angle, lumbar slip rate determined from X-ray images, the Zurich Claudication Questionnaire (ZCQ), the visual analog scale (VAS), and BMI were evaluated. U-COM length was the distance between the upper center of mass (COM) and the body's COM, while L-COM length was the distance between the lower COM and the COM. Each DS and Non-DS group evaluation was compared using the Mann-Whitney U-test. Additionally, multivariate analysis was performed using factors with significant differences as explanatory variables and with or without DS as the target variable. RESULTS: Lumbar lordotic angle was significantly higher in the DS group and there was a significant difference between U-COM and L-COM lengths in the sagittal planes at heel contact (HC) and toe-off (TO). L-COM length at HC and TO was a significant variable when the lumbar lordotic angle was adjusted as a confounding factor in multivariate analysis. CONCLUSIONS: The U-COM and L-COM lengths in the DS group were both extended and the line connecting each COM was inclined backward on the sagittal plane at HC and TO during gait. Our study showed that L-COM length was associated with or without DS.

Japanese orthopaedic association cervical myelopathy evaluation questionnaire (JOACMEQ): Part 5. Determination of responsiveness.

BACKGROUND: In 1999, the Japanese Orthopaedic Association decided to develop a new Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). The final version of the JOACMEQ, comprising 24 questions and five domains (cervical spine function (CF); upper extremity function (UF); lower extremity function (LF); bladder function (BF); and quality of life (QOL)), was established after three nationwide investigations. The fourth investigation, reported in this paper, was performed to confirm the responsiveness of the questionnaire. METHODS: A total of 137 patients with cervical myelopathy were included in the study. Each patient was interviewed twice using the JOACMEQ before and after treatment. At the second interview, the patients self-rated their condition in five domains for "worse," "somewhat worse," "no change," "somewhat better," or "better," and these scores were defined as the external assessment rating. The difference of the points in five domains between the first and the second interview was calculated against each external assessment. Based on the results, substantial clinical benefit (SCB) thresholds for the JOACMEQ were determined. RESULTS: The statistically significant median values of the acquired points were 17.5 for CF, 16.0 and 21.0 for UF, 27.0 and 20.5 for LF, 13.0 for BF, and 29.0 for QOL. After consideration of the results, the committee decided that an acquired point ≥20 could be interpreted as representing an SCB threshold for the JOACMEQ. CONCLUSION: We have concluded that a treatment can be judged to be effective for a patient if 1) The patient give all answers for the questions necessary to calculate the functional score of a domain and an increase of ≥20 points is obtained for that score, or 2) The functional score after treatment is > 90 points even if the answer for the unanswered questions was supposed to be the worst possible choice.

Cost-effectiveness analysis of the pharmacological management of chronic low back pain with four leading drugs.

BACKGROUND: Chronic low back pain is a major health problem that has a substantial effect on people's quality of life and places a significant economic burden on healthcare systems. However, there has been little cost-effectiveness analysis of the treatments for it. Therefore, the purpose of this prospective observational study was to evaluate the cost-effectiveness of the pharmacological management of chronic low back pain. METHODS: A total of 474 patients received pharmacological management for chronic low back pain using four leading drugs for 6 months at 28 institutions in Japan. Outcome measures, including EQ-5D, the Japanese Orthopaedic Association (JOA) score, the JOA back pain evaluation questionnaire (BPEQ), the Roland-Morris Disability Questionnaire, the Medical Outcomes Study SF-8, and the visual analog scale, were investigated at baseline and every one month thereafter. The incremental cost-utility ratio (ICUR) was calculated as drug cost over the quality-adjusted life years. An economic estimation was performed from the perspective of a public healthcare payer in Japan. Stratified analysis based on patient characteristics was also performed to explore the characteristics that affect cost-effectiveness. RESULTS: The ICUR of pharmacological management for chronic low back pain was JPY 453,756. Stratified analysis based on patient characteristics suggested that the pharmacological treatments for patients with a history of spine surgery or cancer, low frequency of exercise, long disease period, low scores in lumbar spine dysfunction and gait disturbance of the JOA BPEQ, and low JOA score at baseline were not cost-effective. CONCLUSIONS: Pharmacological management for chronic low back pain is cost-effective from the reference willingness to pay. Further optimization based on patient characteristics is expected to contribute to the sustainable development of a universal insurance system in Japan.

Stress enhances gait disturbance induced by lumbar disc degeneration in rat.

PURPOSE: Although psychological factors are assumed to be the primary cause of stress-related back pain, there have been no studies of the relationships between stress and low back pain in an animal model. The purpose of this study was to examine the influence of specific alternation of rhythm in temperature (SART) stress on gait abnormality using the CatWalk method in a rat model of low back pain caused by lumbar facetectomy. METHODS: Sixty rats were divided into three groups: the control, sham and experimental groups. Each group was then divided into non-SART stress and SART stress subgroups. We evaluated the behavioral changes 7 weeks postoperatively using the von Frey test and the CatWalk method. RESULTS: Threshold values for the hind paw in the SART stress subgroups were significantly lower than those in the non-SART stress subgroups. In the experimental group, significant changes by CatWalk in step cycle, stand time and average speed were observed under non-SART stress conditions, but SART stress resulted in additional significant changes in not only these parameters, but in other parameters including the duty cycle and swing time, compared with those in the control and sham groups. CONCLUSIONS: The demonstration by CatWalk analysis may indicate that SART stress enhanced gait disturbance. In this animal model, we demonstrated for the first time that stress may be a factor involved in worsening of low back pain.

ISSLS PRIZE IN BASIC SCIENCE 2018: Growth differentiation factor-6 attenuated pro-inflammatory molecular changes in the rabbit anular-puncture model and degenerated disc-induced pain generation in the rat xenograft radiculopathy model.

PURPOSE: To elucidate the effects of growth differentiation factor-6 (GDF6) on: (i) gene expression of inflammatory/pain-related molecules and structural integrity in the rabbit intervertebral disc (IVD) degeneration model, and (ii) sensory dysfunction and changes in pain-marker expression in dorsal nerve ganglia (DRGs) in the rat xenograft radiculopathy model. METHODS: Forty-six adolescent rabbits received anular-puncture in two non-consecutive lumbar IVDs. Four weeks later, phosphate-buffered saline (PBS) or GDF6 (1, 10 or 100 µg) was injected into the nucleus pulposus (NP) of punctured discs and followed for 4 weeks for gene expression analysis and 12 weeks for structural analyses. For pain assessment, eight rabbits were sacrificed at 4 weeks post-injection and NP tissues of injected discs were transplanted onto L5 DRGs of 16 nude rats to examine mechanical allodynia. The rat DRGs were analyzed immunohistochemically. RESULTS: In GDF6-treated rabbit NPs, gene expressions of interleukin-6, tumor necrosis factor-α, vascular endothelial growth factor, prostaglandin-endoperoxide synthase 2, and nerve growth factor were significantly lower than those in the PBS group. GDF6 injections resulted in partial restoration of disc height and improvement of MRI disc degeneration grades with statistical significance in rabbit structural analyses. Allodynia induced by xenograft transplantation of rabbit degenerated NPs onto rat DRGs was significantly reduced by GDF6 injection. Staining intensities for ionized calcium-binding adaptor molecule-1 and calcitonin gene-related peptide in rat DRGs of the GDF6 group were significantly lower than those of the PBS group. CONCLUSION: GDF6 injection may change the pathological status of degenerative discs and attenuate degenerated IVD-induced pain.

A comparative study of 2-year follow-up outcomes in lumbar spinal stenosis patients treated with physical therapy alone and those with surgical intervention after less successful physical therapy.

BACKGROUND: The efficacy of physical therapy for patients with lumbar spinal stenosis (LSS) has been reported only for the short term, and few reports have compared outcomes of surgical treatment with nonsurgical treatment after physical therapy. The purpose of this study was to assess 2-year outcomes of LSS patients treated with surgery or under follow-up observation after physical therapy for 6 weeks. METHODS: Patients presenting with neurogenic claudication, radiologically-confirmed central LSS affecting both legs and refractory symptoms to pharmacotherapy of more than 3 months were enrolled. Patients were treated with manual therapy, stretching and strengthening exercises, and body weight-supported treadmill walking once a week for 6 weeks. Clinical outcomes were measured using the Zurich Claudication Questionnaire (ZCQ), visual analog scale of low back pain, leg pain, and numbness, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire and the SF-36. Two years after physical therapy, patients were classified into the observation group (Group I) or the surgery group (Group II), whose patients failed to respond to physical therapy and wanted to undergo surgery. RESULTS: Thirty-eight patients were enrolled; 28 had complete data at 2 years: 21 and 7 in Groups I and II, respectively. Group II had a higher body mass index (BMI) than Group I. There were no significant differences in clinical outcomes at baseline. Six weeks after physical therapy, Group I had significantly better outcomes for symptom severity and physical function on the ZCQ subscales, physical functioning and bodily pain on the SF-36 subscales. These outcomes in Group I were maintained or improved and did not differ significantly between groups at 2-years. However, the physical function on the ZCQ subscales was improved in Group II more than those in Group I (mean difference -0.6; 95% CI: -1.2 to -0.03, P < 0.05) at 2 years. CONCLUSIONS: At 2 years, the outcomes except for the change in physical function score in the ZCQ subscale did not differ significantly between patients who had undergone surgery and those who avoided surgery.

Reduced blood loss and operation time in lumbar posterolateral fusion using a bipolar sealer.

PURPOSE: A bipolar sealer using Transcollation® technology, a combination of radiofrequency energy and saline, can provide hemostasis at 100 °C, which is lower than that used in standard electrocautery. Previous studies of joint arthroplasty have shown that use of the bipolar sealer reduces blood loss and tissue damage during the operation. However, it is unknown whether a bipolar sealer reduces blood loss and tissue damage in lumbar posterolateral fusion (PLF) surgery. The purpose of this study was to analyze the efficacy of this device in limiting blood loss during exposure of the lumbar spine in the treatment of PLF and postoperative pain. METHODS: Fifty patients who underwent PLF were prospectively enrolled between October 2011 and March 2013. Twenty-five patients were randomized to the bipolar sealer group (BS group) and 25 patients to the standard electrocautery group (control group). Operative time and blood loss during exposure of posterior bony elements including the transverse process for PLF, visual analog scale (VAS) to quantify postoperative pain, and the interval from the surgery to hospital discharge were compared. RESULTS: Operative time and blood loss expressed per level of exposure were significantly lower in the BS group than in the control group. There was a tendency toward a lower VAS at postoperative week 1 in the BS group. The duration of hospitalization was 15 and 26 days in the BS and control groups, respectively. CONCLUSIONS: A large randomized control trial adjusted for the number of fusion levels and body mass index is required to confirm the novelty value of this new bipolar sealers.

Three-dimensional micro-computed tomography analysis for spinal instability after lumbar facetectomy in the rat.

PURPOSE: Intervertebral disc degeneration is thought to contribute to low back pain. However, the pathophysiological mechanisms remain controversial. In a previous study, we developed an animal model that showed delayed gait disturbance after lumbar facetectomy in the rat. We believe that this gait disturbance was caused by low back pain, although the mechanisms of this gait abnormality remain unknown. The purpose of this study was to evaluate structural changes of the lumbar spine after facetectomy in the rat utilizing three-dimensional micro-computed tomography (3DµCT) compared to histology. METHODS: Thirty male SD rats were divided into three groups. In the Sham group (n = 13), only exposure of bilateral facet joints at the L4-5 level was performed. In the Experimental group (n = 13), complete resection of bilateral L4-5 facet joints was achieved. Naïve rats (n = 4) were used for controls. At 7-week postoperative, 3DµCT and histological analyses were performed. RESULTS: On 3DµCT images, increased disc height and endplate irregularities at the L4-5 segment and decreased disc height at adjacent segments were observed in the Experimental group. Histological scores were also higher in the Experimental group than the Sham Group. CONCLUSIONS: Degenerative changes were observed at the facetectomy level. These may correspond with the previously reported delayed gait disturbance after facetectomy. This animal model may be useful to create mechanically induced disc degeneration without direct tissue damage to the disc.

Verification of the sensitivity of functional scores for treatment results - Substantial clinical benefit thresholds for the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ).

BACKGROUND: Validity and reliability of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) had already been verified as the patients' self-rating assessment of low back pain and lumbar spinal disease and, the present study demonstrated the responsiveness of this measure. METHODS: 192 subjects who were determined by medical instructors of the Japanese Society for Spine Surgery and Related Research were analyzed. They had completed a series of treatment and both surveys before and after the treatment. Authors investigated rates of concordance between assessment by physicians and subjective assessment by patients. The mean, standard deviation, minimum, 25th percentile, median, 75th percentile and maximum values for pre-treatment, post-treatment, and acquired points were calculated, and then, we also investigated the trend between subjective assessment by patients and mean acquired points for each JOABPEQ domain and substantial clinical benefit thresholds for the JOABPEQ. RESULTS: Symptom changes as assessed by physicians did not coincide with those by patients, and acquired points in each JOABPEQ domain were significantly increased with improved self-rating by patients. In addition, patients who rated symptom changes as "slightly improved" showed a mean acquired points of ≥20, and those reporting "improved" showed a 25th percentile points of the acquired points of ≥20 approximately. CONCLUSION: A significant correlation was noted between the self-rating of patients and acquired points JOABPEQ, suggesting that ≥20 acquired points can be interpreted as substantial clinical benefit thresholds for the JOABPEQ.

Gait abnormality due to spinal instability after lumbar facetectomy in the rat.

PURPOSE: Spinal instability of the lumbar spine causes various clinical symptoms. Among them, spinal instability is thought to contribute to low back pain, but the pathophysiological mechanisms are controversial. Although experimental animal models of spinal instability have been reported, it is unknown whether these models produce pain and whether spinal instability affects walking ability. We used the CatWalk system to investigate whether lumbar facetectomy causes gait abnormalities and low back pain. METHODS: Thirty male Sprague-Dawley rats were divided into three experimental groups. In the sham group, only the bilateral L4-L5 facet joints were exposed. In the experimental group, rats underwent complete resection of the bilateral L4-L5 facet joints without neural tissue injury. The control group comprised naïve rats. The CatWalk system was used to analyze gait in postoperative weeks 3, 4.5, 6, and 7. Radiological and histological analyses were also performed. RESULTS: At 7 weeks postoperatively, the rats in the experimental group showed the gait abnormalities seen in low back pain and neuropathic pain models. Radiological examination of the same rats revealed spinal instability with histological evidence of intervertebral disc degeneration. CONCLUSIONS: These results suggest that spinal instability and/or intervertebral disc degeneration induce gait abnormalities and low back pain. This experimental model may be useful for elucidating the mechanisms underlying clinical symptoms, such as low back pain, in patients with spinal instability.