Prevalence and risk of psychiatric disorders in young people: prospective cohort study exploring the role of childhood trauma (the HUNT study).

BACKGROUND: Better knowledge about childhood trauma as a risk factor for psychiatric disorders in young people could help strengthen the timeliness and effectiveness of prevention and treatment efforts. AIMS: To estimate the prevalence and risk of psychiatric disorders in young people following exposure to childhood trauma, including interpersonal violence. METHOD: This prospective cohort study followed 8199 adolescents (age range 12-20 years) over 13-15 years, into young adulthood (age range 25-35 years). Data about childhood trauma exposure from adolescents participating in the Trøndelag Health Study (HUNT, 2006-2008) were linked to data about subsequent development of psychiatric disorders from the Norwegian Patient Registry (2008-2021). RESULTS: One in four (24.3%) adolescents were diagnosed with a psychiatric disorder by young adulthood. Regression analyses showed consistent and significant relationships between childhood exposure to both interpersonal violence and other potentially traumatic events, and subsequent psychiatric disorders and psychiatric comorbidity. The highest estimates were observed for childhood exposure to two or more types of interpersonal violence (polyvictimisation), and development of psychotic disorders (odds ratio 3.41, 95% CI 1.93-5.72), stress and adjustment disorders (odds ratio 4.20, 95% CI 3.05-5.71), personality disorders (odds ratio 3.98, 95% CI 2.70-5.76), alcohol-related disorders (odds ratio 3.28, 95% CI 2.06-5.04) and drug-related disorders (odds ratio 4.67, 95% CI 2.87-7.33). CONCLUSIONS: These findings emphasise the importance of integrating knowledge about childhood trauma as a potent risk factor for psychopathology into the planning and implementation of services for children, adolescents and young adults.

Dural Sac Cross-sectional area change from preoperatively and up to 2 years after decompressive surgery for central lumbar spinal stenosis: investigation of operated levels, data from the NORDSTEN study.

PURPOSE: The aim of the present study was to investigate how canal area size changed from before surgery and up to 2 years after decompressive lumbar surgery lumbar spinal stenosis. Further, to investigate if an area change postoperatively (between 3 months to 2 years) was associated with any preoperative demographic, clinical or MRI variables or surgical method used. METHODS: The present study is analysis of data from the NORDSTEN- SST trial where 437 patients were randomized to one of three mini-invasive surgical methods for lumbar spinal stenosis. The patients underwent MRI examination of the lumbar spine before surgery, and 3 and 24 months after surgery. For all operated segments the dural sac cross-sectional area (DSCA) was measured in mm2. Baseline factors collected included age, gender, BMI and smoking habits. Furthermore, surgical method, index level, number of levels operated, all levels operated on and baseline Schizas grade were also included in the analysis. RESULTS: 437 patients were enrolled in the NORDSTEN-SST trial, whereof 310 (71%) had MRI at 3 months and 2 years. Mean DSCA at index level was 52.0 mm2 (SD 21.2) at baseline, at 3 months it increased to 117.2 mm2 (SD 43.0) and after 2 years the area was 127.7 mm2 (SD 52.5). Surgical method, level operated on or Schizas did not influence change in DSCA from 3 to 24 months follow-up. CONCLUSION: The spinal canal area after lumbar decompressive surgery for lumbar spinal stenosis increased from baseline to 3 months after surgery and remained thereafter unchanged 2 years postoperatively.

The association between lumbar lordosis preoperatively and changes in PROMs for lumbar spinal stenosis patients 2 years after spinal surgery: radiological and clinical results from the NORDSTEN-spinal stenosis trial.

BACKGROUND: Patients with lumbar spinal stenosis (LSS) sometimes have lower lumbar lordosis (LL), and the incidence of LSS correlates closely with the loss of LL. The few studies that have evaluated the association between LL and clinical outcomes after non-instrumented surgery for LSS show conflicting results. This study investigates the association between preoperative LL and changes in PROMs 2 years after decompressive surgery. METHOD: This prospective cohort study obtained preoperative and postoperative data for 401 patients from the multicenter randomized controlled spinal stenosis trial as part of the NORwegian degenerative spondylolisthesis and spinal STENosis (NORDSTEN) study. Before surgery, the radiological sagittal alignment parameter LL was measured using standing X-rays. The association between LL and 2-year postoperative changes was analyzed using the oswestry disability index (ODI), a numeric rating scale (NRS) for low back and leg pain, the Zurich claudication questionnaire (ZCQ), and the global perceived effect (GPE) score. The changes in PROMs 2 years after surgery for quintiles of lumbar lordosis were adjusted for the respective baseline PROMs: age, sex, smoking, and BMI. The Schizas index and the Pfirrmann index were used to analyze multiple regressions for changes in PROMs. RESULTS: There were no associations in the adjusted and unadjusted analyses between preoperative LL and changes in ODI, ZCQ, GPE, and NRS for back and leg pain 2 years after surgery. CONCLUSION: LL before surgery was not associated with changes in PROMs 2 years after surgery. Lumbar lordosis should not be a factor when considering decompressive surgery for LSS.

Preoperative fatty infiltration of paraspinal muscles assessed by MRI is associated with less improvement of leg pain 2 years after surgery for lumbar spinal stenosis.

PURPOSE: Fatty infiltration (FI) of the paraspinal muscles may associate with pain and surgical complications in patients with lumbar spinal stenosis (LSS). We evaluated the prognostic influence of MRI-assessed paraspinal muscles' FI on pain or disability 2 years after surgery for LSS. METHODS: A muscle fat index (MFI) was calculated (by dividing signal intensity of psoas to multifidus and erector spinae) on preoperative axial T2-weighted MRI of patients with LSS. Pain and disability 2 years after surgery were assessed using the Oswestry disability index, the Zurich claudication questionnaire and numeric rating scales for leg and back pain. Multivariate linear and logistic regression analyses (adjusted for preoperative outcome scores, age, body mass index, sex, smoking status, grade of spinal stenosis, disc degeneration and facet joint osteoarthritis) were used to assess the associations between MFI and patient-reported clinical outcomes. In the logistic regression models, odds ratios (OR) and 95% confidence intervals (CI) were calculated for associations between the MFI and ≥ 30% improvement of the outcomes (dichotomised into yes/no). RESULTS: A total of 243 patients were evaluated (mean age 66.6 ± 8.5 years), 49% females (119). Preoperative MFI and postoperative leg pain were significantly associated, both with leg pain as continuous (coefficient - 3.20, 95% CI - 5.61, - 0.80) and dichotomised (OR 1.51, 95% CI 1.17, 1.95) scores. Associations between the MFI and the other outcome measures were not statistically significant. CONCLUSION: Preoperative FI of the paraspinal muscles on MRI showed statistically significant association with postoperative NRS leg pain but not with ODI or ZCQ.

Responsiveness of the Oswestry Disability Index and Zurich Claudication Questionnaire in patients with lumbar spinal stenosis: evaluation of surgically treated patients from the NORDSTEN study.

PURPOSE: To evaluate the responsiveness of the original low back pain specific Oswestry Disability Index (ODI) and the spinal stenosis specific Zürich Claudication Questionnaire (ZCQ), and to investigate cut-off values for clinical "success" for ODI and ZCQ in surgically treated patients with lumbar spinal stenosis (LSS). METHODS: We included 601 LSS patients (218 with, 383 without degenerative spondylolisthesis) from the NORDSTEN trials. Outcome measures included ODI and ZCQ (symptom severity and physical function scales) with three alternative response parameters: scores at follow-up, absolute and relative changes from baseline to two-year follow-up. Effect size and standardised response mean evaluated internal responsiveness. External responsiveness was assessed by the Spearman rank correlation between patient-reported global perceived effect scale (GPE) and ODI and ZCQ, and receiver operating characteristics (ROC). We evaluated which cut-off values could maximise the percentage of correctly classified patients according to the GPE-anchor "completely recovered" / "much improved" for each parameter. RESULTS: Internal and external responsiveness were high for all three indices with effect sizes, standardized response means, ROC and corresponding area under the curve > 0.8. Correlations with GPE responses were moderate (> 0.50) for absolute change and strong (> 0.67) for relative change and follow-up scores. The 30% ODI relative change cut-off correctly classified 81% of patients to "success", within a range of accurate cut-offs according to the GPE-anchor. CONCLUSION: ODI and ZCQ demonstrate comparable responsiveness in evaluating outcomes for surgically treated LSS patients. The 30% ODI threshold was consistent with treatment "success" in NORDSTEN trials. TRIAL REGISTRATION: ClinicalTrials.gov; NCT02007083 10/12/2013, NCT02051374 31/01/2014 and NCT03562936 20/06/2018.

Identifying latent subgroups in the older population seeking primary health care for a new episode of back pain - findings from the BACE-N cohort.

BACKGROUND: Back pain is the number one condition contributing to years lived with disability worldwide, and one of the most common reasons for seeking primary care. Research on this condition in the ageing population is sparse. Further, the heterogeneity of patients with back pain complicates the management in clinical care. It is possible that subgrouping people with similar characteristics would improve management. This paper aimed to identify latent classes based on demographics, pain characteristics, psychosocial behavior, and beliefs and attitudes about back pain, among older patients seeking primary care with a new episode of back pain, and to examine if there were differences regarding the classes' first point-of-contact. METHODS: The study was part of the international BACE (Back complaints in elders) consortium and included 435 patients aged ≥ 55 years seeking primary care (general practitioners, physiotherapists, and chiropractors) in Norway from April 2015 to March 2020. A latent class analysis was performed to identify latent classes. The classes were described in terms of baseline characteristics and first point-of-contact in primary care. RESULTS: Four latent classes were identified. The mean age was similar across groups, as were high expectations towards improvement. Class 1 (n = 169, 39%), the "positive" class, had more positive attitudes and beliefs, less pain catastrophizing and shorter duration of current pain episode. Class 2 (n = 31, 7%), the "fearful" class, exhibited the most fear avoidance behavior, and had higher mean pain intensity. Class 3 (n = 33, 8%), the "distressed" class, had the highest scores on depression, disability, and catastrophizing. Finally, class 4 (n = 202, 46%), the "hopeful" class, showed the highest expectations for recovery, although having high pain intensity. The identified four classes showed high internal homogeneity, sufficient between-group heterogeneity and were considered clinically meaningful. The distribution of first point-of-contact was similar across classes, except for the positive class where significantly more patients visited chiropractors compared to general practitioners and physiotherapists. CONCLUSIONS: The identified classes may contribute to targeting clinical management of these patients. Longitudinal research on these latent classes is needed to explore whether the latent classes have prognostic value. Validation studies are needed to evaluate external validity. TRIAL REGISTRATION: Clinicaltrials.gov NCT04261309.

Predictive validity of the STarT Back screening tool among older adults with back pain.

BACKGROUND: The predictive validity of the STarT Back screening tool among older adults is uncertain. This study aimed to assess the predictive validity of the SBT among older adults in primary care. METHODS: This prospective cohort study included 452 patients aged ≥55 years seeking Norwegian primary care with a new episode of back pain. A poor outcome (persistent disabling back pain) was defined as a score of ≥7/24 on the Roland-Morris Disability Questionnaire (RMDQ) at 3, 6 or 12 months of follow-up. The ability of the SBT risk groups to identify persistent disabling back pain was assessed with multivariable logistic regression, area under receiver operating characteristics curve (AUC), and with the accuracy measures sensitivity, specificity, predictive values and likelihood ratios. RESULTS: The adjusted odds ratios (95% CI) for persistent disabling back pain were 2.40 (1.34-4.30) at 3 months, 3.42 (1.76-6.67) at 6 months and 2.81 (1.47-5.38) at 12 months for the medium-risk group (n = 118), and 8.90 (1.83-43.24), 2.66 (0.81-8.67) and 4.53 (1.24-16.46) for the high-risk group (n = 27), compared to the low-risk group (n = 282). There were no statistically significant differences in odds between the medium- and high-risk groups at any time point. AUC values (95% CI) were 0.65 (0.59-0.71), 0.67 (0.60-0.73) and 0.65 (0.58-0.71) at 3, 6 and 12 months. Accuracy measures were poor at all time points, with particularly poor sensitivity and negative likelihood ratio values. CONCLUSION: The predictive validity of the SBT risk groups in predicting persistent disabling back pain in older adults was poor. SIGNIFICANCE STATEMENT: This study found that the STarT Back screening tool had poor predictive validity among older adults and that it may need recalibration or extension before widespread implementation among older adults. Having valid tools for this population may aid clinicians with allocating scarce healthcare resources, which is especially important considering the rapidly ageing population and its expected challenge to the healthcare systems.

Primary care seeking among adults with chronic neck and low back pain in Norway: A prospective study from the HUNT study linked to Norwegian primary healthcare registry.

BACKGROUND: To describe the frequency of primary care seeking for neck or back-related conditions among people with chronic neck and low back pain and to develop prediction models of primary care seeking and frequent visits. METHODS: We included participants of the Trøndelag Health Study (HUNT4, 2017-19) in Norway who self-reported chronic neck and/or low back pain in the preceding year, and extracted data of primary care visits from the Norwegian primary healthcare registry. We investigated a total of 23 potential predictors and used multivariable logistic regression models to predict primary care seeking for neck or back-related conditions and frequent visits by healthcare provider (i.e., the highest quartile of number of visits). RESULTS: Among the 15,352 HUNT4 participants with chronic neck and/or low back pain, 6231 participants (40.6%) sought primary care for neck or back-related conditions (median = 5 visits, IQR 2-15) within 2 years after the study. Participants who consulted physical therapists sought care the most frequently (median = 10 visits, IQR 3-26). Discrimination of the best-fit prediction model of primary care seeking and frequent visits by healthcare provider, assessed by C-statistic, ranged from 0.66-0.76. Participants who made frequent primary care visits in the preceding year were highly likely to continue frequent care seeking in the following 2 years. CONCLUSIONS: Around 40% of people seek primary care for chronic neck and low back pain, and frequent care seeking may continue for years. Future studies should investigate strategies to reduce recurrent primary care visits, especially seeking physical therapist care, and promote self-management of chronic pain. SIGNIFICANCE: People with chronic neck and low back pain who seek physical therapist care had the highest frequency of care seeking, underscoring the significant burden on healthcare systems. The high frequency of visits and associated healthcare expenditures highlight the critical need for effective and valuable primary care for chronic pain management. To mitigate recurrent visits and reduce costs, it is essential to provide patients with evidence-based treatments and self-management interventions.

Machine Learning Models for Predicting Disability and Pain Following Lumbar Disc Herniation Surgery.

Importance: Lumber disc herniation surgery can reduce pain and disability. However, a sizable minority of individuals experience minimal benefit, necessitating the development of accurate prediction models. Objective: To develop and validate prediction models for disability and pain 12 months after lumbar disc herniation surgery. Design, Setting, and Participants: A prospective, multicenter, registry-based prognostic study was conducted on a cohort of individuals undergoing lumbar disc herniation surgery from January 1, 2007, to May 31, 2021. Patients in the Norwegian Registry for Spine Surgery from all public and private hospitals in Norway performing spine surgery were included. Data analysis was performed from January to June 2023. Exposures: Microdiscectomy or open discectomy. Main Outcomes and Measures: Treatment success at 12 months, defined as improvement in Oswestry Disability Index (ODI) of 22 points or more; Numeric Rating Scale (NRS) back pain improvement of 2 or more points, and NRS leg pain improvement of 4 or more points. Machine learning models were trained for model development and internal-external cross-validation applied over geographic regions to validate the models. Model performance was assessed through discrimination (C statistic) and calibration (slope and intercept). Results: Analysis included 22 707 surgical cases (21 161 patients) (ODI model) (mean [SD] age, 47.0 [14.0] years; 12 952 [57.0%] males). Treatment nonsuccess was experienced by 33% (ODI), 27% (NRS back pain), and 31% (NRS leg pain) of the patients. In internal-external cross-validation, the selected machine learning models showed consistent discrimination and calibration across all 5 regions. The C statistic ranged from 0.81 to 0.84 (pooled random-effects meta-analysis estimate, 0.82; 95% CI, 0.81-0.84) for the ODI model. Calibration slopes (point estimates, 0.94-1.03; pooled estimate, 0.99; 95% CI, 0.93-1.06) and calibration intercepts (point estimates, -0.05 to 0.11; pooled estimate, 0.01; 95% CI, -0.07 to 0.10) were also consistent across regions. For NRS back pain, the C statistic ranged from 0.75 to 0.80 (pooled estimate, 0.77; 95% CI, 0.75-0.79); for NRS leg pain, the C statistic ranged from 0.74 to 0.77 (pooled estimate, 0.75; 95% CI, 0.74-0.76). Only minor heterogeneity was found in calibration slopes and intercepts. Conclusion: The findings of this study suggest that the models developed can inform patients and clinicians about individual prognosis and aid in surgical decision-making.

Childhood trauma and the use of opioids and other prescription analgesics in adolescence and young adulthood: The HUNT Study.

ABSTRACT: Opioid and nonopioid analgesics are commonly prescribed to young people to alleviate pain. Even short-term prescriptions increase the risk of persistent use and future misuse of potent analgesics, such as opioids. Childhood trauma exposure has been found to be related to pain conditions and to using more prescription analgesics. This large, prospective cohort study aimed to investigate the association of a broad range of childhood trauma exposures with prescription rates for opioid and nonopioid analgesics in adolescence and young adulthood. Self-reported data on childhood trauma exposures from adolescents (aged 13-19 years) who participated in the Young-HUNT3 Study (2006-2008, n = 8199) were linked to data from the Norwegian Prescription Database (NorPD, 2004-2021). We found that exposure to childhood trauma was consistently associated with higher prescription rates for opioids throughout adolescence and young adulthood. The highest incidence rate ratio (IRR) in adolescence was observed for sexual abuse (IRR 1.63, confidence interval [CI] 1.19-2.23). In young adulthood, the highest IRR was observed for physical violence (2.66, CI 2.27-3.12). The same overall pattern was observed for nonopioid analgesics. The more frequent prescriptions of opioid and nonopioid analgesics to participants exposed to childhood trauma suggests a higher symptom load of pain causing them to seek professional help with pain relief. Receiving potent analgesics is not without risk, and the likelihood of misuse may be elevated among trauma-exposed individuals. A trauma-informed approach to pain could be vital for guiding clinicians to the most effective and least harmful treatment for each patient.

Change in Lumbar Lordosis after Decompressive Surgery in Lumbar Spinal Stenosis Patients and Associations with Patient Related Outcomes 2 Years after Surgery. Radiological and Clinical Results from the NORDSTEN Spinal Stenosis Trial.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: The aim was to investigate changes in lumbar lordosis (LL) and its association to changes in patient reported outcome measures (PROMs) after decompressive surgery for lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND: Few studies have addressed change in LL after decompression surgery for LSS in relation to outcomes. METHOD: Pre- and postoperative data from 310 patients having standing x-ray both before and 2 years after surgery were included. The patients were grouped based on the change in LL preoperatively to 2 years after surgery; group 1: <5 degrees (n=196), group 2: ≥5 <10 degrees (n=55) or group 3: ≥10 degrees (n=59) of change in LL. The changes in function, disability and pain were assessed by the Oswestry Disability Index (ODI), Numeric Rating Scale (NRS), and the Zurich claudication questionnaire (ZCQ). The three groups were compared regarding baseline variables using the ANOVA test for continuous variables and the chi-square test for categorical variables. The groups were further compared with a likelihood ratio test in relation to changes in PROMs 2 year after surgery and outcomes were adjusted for respective baseline PROMs, age, sex, smoking, BMI, Schizas and Pfirrmann scores. RESULTS: LL was significantly changed at group level 2 years after surgery with a mean difference of 2.2 (SD 9.4) degrees ( P =0.001). The three LL change groups did not show any significant differences in patient characteristics, function, disability, and pain at baseline. The two groups with a change of more than 5 degrees in LL 2 year after surgery (group 2 and 3) had significantly greater improvements in ODI ( P =0.022) and ZCQ function ( P =0.016) in the adjusted analyses, but was not significant for back and leg pain. CONCLUSION: Changed LL after decompressive surgery for LSS was associated with improved ODI and physical function.

Comparison of Patients Operated for Lumbar Spinal Stenosis with and without Spondylolisthesis - A Secondary Analysis of the NORDSTEN Trials.

STUDY DESIGN: Observational cohort study (secondary analysis of two randomized trials). OBJECTIVE: To investigate whether function, disability, pain and quality of life before surgery and patient-reported outcome as well as complication and reoperation rates up to two years after surgery differ between lumbar spinal stenosis patients with and without spondylolisthesis. SUMMARY OF BACKGROUND DATA: Lumbar spinal stenosis is a degenerative condition of the spine, which appears with or without degenerative spondylolisthesis often presenting similar signs and symptoms. METHOD: This study is a secondary analysis of two randomized trials on patients with lumbar spinal stenosis with and without spondylolisthesis conducted at 16 public Norwegian hospitals. Disability, function, back pain, leg pain, quality of life, complication and reoperation rates up to two years after surgery were compared between the two cohorts. RESULTS: A total of 704 patients were included in this study, 267 patients with spondylolisthesis (median age 67.0 years [IQR 61.0-72.0]; 68.7% female) and 437 patients without spondylolisthesis (median age 68.0 years IQR 62.0-73.0]; 52.9% female). In the linear mixed model analysis there were no significant differences in disability, function, back pain, leg pain and quality of life scores between the two cohorts of patient with and without spondylolisthesis before surgery or at two years follow-up. The complication rate was 22.9% in patients with spondylolisthesis and 12.1% in patients without spondylolisthesis (P<0.001). There were no significant differences in reoperation rates. CONCLUSION: In patients with lumbar spinal stenosis the symptom burden before surgery and the clinical outcome up to two years after surgery were similar independently of a concomitant spondylolisthesis.

Do patients with lumbar spinal stenosis benefit from decompression of levels with adjacent moderate stenosis? A prospective cohort study from the NORDSTEN study.

BACKGROUND: Lumbar spinal stenosis (LSS) is characterized by pain that radiates to the buttocks and/or legs, aggravated by walking and relieved by forward flexion. There is poor correlation between clinical symptoms and severity of stenosis on MRI, and multilevel stenosis has not been described to present worse symptoms or treatment outcomes, compared with patients with single-level stenosis. In patients with one level with severe stenosis combined with an adjacent level with moderate stenosis, the surgeon must decide whether to decompress only the narrowest level or both, to achieve the best possible outcome. The potential benefits of performing surgery on an adjacent moderate stenosis is debated, and the scientific evidence in scarce. PURPOSE: The aim of the present study was to investigate whether patients with a level of adjacent moderate stenosis, along with an index stenosis, benefitted from a dual-level decompression (DLD) compared with a single-level decompression (SLD). Furthermore, to investigate whether DLD patients had longer duration of surgery and hospital stay, higher rates of complications and/or lower rate of reoperations compared with SLD patients. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: We analyzed data from the Norwegian Degenerative Spondylisthesis and Spinal Stenosis study- Spinal Stenosis Trial (NORDSTEN-SST). In this randomized multicenter study, 437 patients were included, evaluating clinical outcomes of three different surgical treatment options for LSS. Patients with degenerative spondylolisthesis were excluded. METHOD: Based on preoperative MRI, the present analysis included all patients who had a moderate stenosis (defined as Schizas B or C) in addition to a predefined index stenosis (the level with the smallest cross-sectional area). We compared patients who, based on the surgeons` choice, received a dual-level decompression, with those receiving a single-level decompression. OUTCOME MEASURES: The primary outcome was mean change in the Oswestry Disability Index (ODI) score from baseline to 2-year follow up. Secondary outcomes were proportion of success (30% reduction in ODI score), the Numeric Rating Scales for back and leg pain (NRS), the EuroQol 5-dimensional questionnaire utility index (EQ-5D), the Zurich Claudication Questionnaire (ZCQ), the Global Perceived Effect (GPE)-scale, duration of surgery, duration of hospital stay, perioperative complications and reoperation rates. RESULTS: Among the 222 patients, included in the analysis, 108 underwent DLD and 114 underwent SLD. There was no difference in change scores for any of the investigated patient-reported outcomes between the groups after 2 years. However, the DLD group had longer duration of surgery and longer length of hospital stay. There was no difference in reoperation rates or perioperative complications. CONCLUSION: This study, alongside the NORDSTEN-LSS trial on patients with adjacent moderate stenosis as well as an index stenosis, showed no superior clinical effectiveness for dual-level surgery compared with single-level surgery.

Decompression alone or with fusion for degenerative lumbar spondylolisthesis (Nordsten-DS): five year follow-up of a randomised, multicentre, non-inferiority trial.

OBJECTIVE: To assess whether decompression alone is non-inferior to decompression with instrumented fusion five years after primary surgery in patients with degenerative lumbar spondylolisthesis. DESIGN: Five year follow-up of a randomised, multicentre, non-inferiority trial (Nordsten-DS). SETTING: 16 public orthopaedic and neurosurgical clinics in Norway. PARTICIPANTS: Patients aged 18-80 years with symptomatic lumbar spinal stenosis and a spondylolisthesis of 3 mm or more at the stenotic level. INTERVENTIONS: Decompression surgery alone and decompression with additional instrumented fusion (1:1). MAIN OUTCOME MEASURES: The primary outcome was a 30% or more reduction in Oswestry disability index from baseline to five year follow-up. The predefined non-inferiority margin was a -15 percentage point difference in the proportion of patients who met the primary outcome. Secondary outcomes included the mean change in Oswestry disability index, Zurich claudication questionnaire, numeric rating scale for leg and back pain, and EuroQol Group 5-Dimension (EQ-5D-3L) questionnaire. RESULTS: From 12 February 2014 to 18 December 2017, 267 participants were randomly assigned to decompression alone (n=134) and decompression with instrumented fusion (n=133). Of these, 230 (88%) responded to the five year questionnaire: 121 in the decompression group and 109 in the fusion group. Mean age at baseline was 66.2 years (SD 7.6), and 69% were women. In the modified intention-to-treat analysis with multiple imputation of missing data, 84 (63%) of 133 people in the decompression alone group and 81 (63%) of 129 people in the fusion group had a at least a 30% reduction in Oswestry disability index, a difference of 0.4 percentage points. (95% confidence interval (CI) -11.2 to 11.9). The respective results of the per protocol analysis were 65 (65%) of 100 in the decompression alone group and 59 (66%) of 89 in the fusion group, a difference of -1.3 percentage points (95% CI -14.5 to 12.2). Both 95% CIs were higher than the predefined non-inferiority margin of -15%. The mean change in Oswestry disability index from baseline to five years was -17.8 in both groups (mean difference 0.02 (95% CI -3.8 to 3.9)). Results of the other secondary outcomes were in the same direction as the primary outcome. From two to five year follow-up, a new lumbar operation occurred in six (5%) of 123 people in the decompression group and 11 (10%) of 113 people in the fusion group, with a total from baseline to five years of 21 (16%) of 129 people and 23 (18%) of 125, respectively. CONCLUSIONS: In participants with degenerative spondylolisthesis, decompression alone was non-inferior to decompression with instrumented fusion five years after primary surgery. Proportions of subsequent surgeries at the index level or an adjacent lumbar level were no different between the groups. TRIAL REGISTRATION: ClinicalTrials.gov NCT02051374.

Bacterial growth in patients with low back pain and Modic changes: protocol of a multicentre, case-control biopsy study.

INTRODUCTION: Bacterial infection and Modic changes (MCs) as causes of low back pain (LBP) are debated. Results diverged between two randomised controlled trials examining the effect of amoxicillin with and without clavulanic acid versus placebo on patients with chronic LBP (cLBP) and MCs. Previous biopsy studies have been criticised with regard to methods, few patients and controls, and insufficient measures to minimise perioperative contamination. In this study, we minimise contamination risk, include a control group and optimise statistical power. The main aim is to compare bacterial growth between patients with and without MCs. METHODS AND ANALYSIS: This multicentre, case-control study examines disc and vertebral body biopsies of patients with cLBP. Cases have MCs at the level of tissue sampling, controls do not. Previously operated patients are included as a subgroup. Tissue is sampled before antibiotic prophylaxis with separate instruments. We will apply microbiological methods and histology on biopsies, and predefine criteria for significant bacterial growth, possible contamination and no growth. Microbiologists, surgeons and pathologist are blinded to allocation of case or control. Primary analysis assesses significant growth in MC1 versus controls and MC2 versus controls separately. Bacterial disc growth in previously operated patients, patients with large MCs and growth from the vertebral body in the fusion group are all considered exploratory analyses. ETHICS AND DISSEMINATION: The Regional Committees for Medical and Health Research Ethics in Norway (REC South East, reference number 2015/697) has approved the study. Study participation requires written informed consent. The study is registered at ClinicalTrials.gov (NCT03406624). Results will be disseminated in peer-reviewed journals, scientific conferences and patient fora. TRIAL REGISTRATION NUMBER: NCT03406624.