Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis.

BACKGROUND: In patients with lumbar spinal stenosis and degenerative spondylolisthesis, it is uncertain whether decompression surgery alone is noninferior to decompression with instrumented fusion. METHODS: We conducted an open-label, multicenter, noninferiority trial involving patients with symptomatic lumbar stenosis that had not responded to conservative management and who had single-level spondylolisthesis of 3 mm or more. Patients were randomly assigned in a 1:1 ratio to undergo decompression surgery (decompression-alone group) or decompression surgery with instrumented fusion (fusion group). The primary outcome was a reduction of at least 30% in the score on the Oswestry Disability Index (ODI; range, 0 to 100, with higher scores indicating more impairment) during the 2 years after surgery, with a noninferiority margin of -15 percentage points. Secondary outcomes included the mean change in the ODI score as well as scores on the Zurich Claudication Questionnaire, leg and back pain, the duration of surgery and length of hospital stay, and reoperation within 2 years. RESULTS: The mean age of patients was approximately 66 years. Approximately 75% of the patients had leg pain for more than a year, and more than 80% had back pain for more than a year. The mean change from baseline to 2 years in the ODI score was -20.6 in the decompression-alone group and -21.3 in the fusion group (mean difference, 0.7; 95% confidence interval [CI], -2.8 to 4.3). In the modified intention-to-treat analysis, 95 of 133 patients (71.4%) in the decompression-alone group and 94 of 129 patients (72.9%) in the fusion group had a reduction of at least 30% in the ODI score (difference, -1.4 percentage points; 95% CI, -12.2 to 9.4), showing the noninferiority of decompression alone. In the per-protocol analysis, 80 of 106 patients (75.5%) and 83 of 110 patients (75.5%), respectively, had a reduction of at least 30% in the ODI score (difference, 0.0 percentage points; 95% CI, -11.4 to 11.4), showing noninferiority. The results for the secondary outcomes were generally in the same direction as those for the primary outcome. Successful fusion was achieved with certainty in 86 of 100 patients (86.0%) who had imaging available at 2 years. Reoperation was performed in 15 of 120 patients (12.5%) in the decompression-alone group and in 11 of 121 patients (9.1%) in the fusion group. CONCLUSIONS: In this trial involving patients who underwent surgery for degenerative lumbar spondylolisthesis, most of whom had symptoms for more than a year, decompression alone was noninferior to decompression with instrumented fusion over a period of 2 years. Reoperation occurred somewhat more often in the decompression-alone group than in the fusion group. (NORDSTEN-DS ClinicalTrials.gov number, NCT02051374.).

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.

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.

Mechanisms of vocational interventions for return to work from musculoskeletal conditions: a mediation analysis of the MI-NAV trial.

OBJECTIVES: To investigate whether and to what extent, return to work (RTW) expectancy and workability mediate the effect of two vocational interventions on reducing sickness absence in workers on sick leave from a musculoskeletal condition. METHODS: This is a preplanned mediation analysis of a three-arm parallel randomised controlled trial which included 514 employed working adults with musculoskeletal conditions on sick leave for at least 50% of their contracted work hours for ≥7 weeks. Participants were randomly allocated (1:1:1) to one of three treatment arms; usual case management (UC) (n=174), UC plus motivational interviewing (MI) (n=170) and UC plus a stratified vocational advice intervention (SVAI) (n=170). The primary outcome was the number of sickness absence days over 6 months from randomisation. Hypothesised mediators included RTW expectancy and workability assessed 12 weeks after randomisation. RESULTS: The mediated effect of the MI arm compared with UC on sickness absence days through RTW expectancy was -4.98 days (-8.89 to -1.04), and workability was -3.17 days (-8.55 to 2.32). The mediated effect of the SVAI arm compared with UC on sickness absence days through RTW expectancy was -4.39 days (-7.60 to -1.47), and workability was -3.21 days (-7.90 to 1.50). The mediated effects for workability were not statistically significant. CONCLUSIONS: Our study provides new evidence for the mechanisms of vocational interventions to reduce sickness absence related to sick leave due to musculoskeletal conditions. Changing an individual's expectation that RTW is likely may result in meaningful reductions in sickness absence days. TRIAL REGISTRATION NUMBER: NCT03871712.

Effectiveness of adding motivational interviewing or a stratified vocational advice intervention to usual case management on return to work for people with musculoskeletal disorders: the MI-NAV randomised controlled trial.

OBJECTIVES: To evaluate if adding motivational interviewing (MI) or a stratified vocational advice intervention (SVAI) to usual case management (UC), reduced sickness absence over 6 months for workers on sick leave due to musculoskeletal disorders. METHODS: We conducted a three-arm parallel pragmatic randomised controlled trial including 514 employed workers (57% women, median age 49 (range 24-66)), on sick leave for at least 50% of their contracted work hours for ≥7 weeks. All participants received UC. In addition, those randomised to UC+MI were offered two MI sessions from social insurance caseworkers and those randomised to UC+SVAI were offered vocational advice from physiotherapists (participants with low/medium-risk for long-term sickness absence were offered one to two sessions, and those with high-risk were offered three to four sessions). RESULTS: Median sickness absence was 62 days, (95% CI 52 to 71) in the UC arm (n=171), 56 days (95% CI 43 to 70) in the UC+MI arm (n=169) and 49 days (95% CI 38 to 60) in the UC+SVAI arm (n=169). After adjusting for predefined potential confounding factors, the results showed seven fewer days in the UC+MI arm (95% CI -15 to 2) and the UC+SVAI arm (95% CI -16 to 1), compared with the UC arm. The adjusted differences were not statistically significant. CONCLUSIONS: The MI-NAV trial did not show effect on return to work of adding MI or SVAI to UC. The reduction in sickness absence over 6 months was smaller than anticipated, and uncertain due to wide CIs. TRIAL REGISTRATION NUMBER: NCT03871712.

Problematic alcohol use in young adults exposed to childhood trauma: The Trøndelag Health (HUNT) Study.

Problematic alcohol use (PAU) severely impacts the health, functioning, and long-term prospects of young people. Prior research indicates that childhood trauma exposure may be an important risk factor for PAU, but few longitudinal studies have looked at how specific trauma types influence this risk. The aim of this study was to investigate the association between childhood trauma exposure and PAU in a large, population-based cohort of young people. The study sample included 1,913 adolescents who participated in the Trøndelag Health Study (HUNT) between 2006 and 2008 (age range: 12-20) and completed follow-up 10 years later as young adults (age range: 22-32). The results revealed an increased risk of PAU in young adults exposed to childhood trauma, especially direct physical violence, OR = 2.38, [95% CI 1.56, 3.64]. Young adults who had witnessed violence, OR = 1.55, [95% CI 1.11, 2.17], or experienced an accident, disaster, or other traumatic event, OR = 1.60, [95% CI 1.19, 2.15], also had higher odds of PAU compared to those without such experiences. These associations remained consistent after adjusting for symptoms of headaches and pain as well as posttraumatic and general psychological distress as reported by the participants in adolescence. Future prevention efforts targeting PAU among adolescents and young adults should address violence and other trauma exposure as potential drivers of problematic drinking.

The Norwegian degenerative spondylolisthesis and spinal stenosis (NORDSTEN) study: study overview, organization structure and study population.

PURPOSE: To provide an overview of the The Norwegian Degenerative spondylolisthesis and spinal stenosis (NORDSTEN)-study and the organizational structure, and to evaluate the study population. METHODS: The NORDSTEN is a multicentre study with 10 year follow-up, conducted at 18 public hospitals. NORDSTEN includes three studies: (1) The randomized spinal stenosis trial comparing the impact of three different decompression techniques; (2) the randomized degenerative spondylolisthesis trial investigating whether decompression surgery alone is as good as decompression with instrumented fusion; (3) the observational cohort tracking the natural course of LSS in patients without planned surgical treatment. A range of clinical and radiological data are collected at defined time points. To administer, guide, monitor and assist the surgical units and the researchers involved, the NORDSTEN national project organization was established. Corresponding clinical data from the Norwegian Registry for Spine Surgery (NORspine) were used to assess if the randomized NORDSTEN-population at baseline was representative for LSS patients treated in routine surgical practice. RESULTS: A total of 988 LSS patients with or without spondylolistheses were included from 2014 to 2018. The clinical trials did not find any difference in the efficacy of the surgical methods evaluated. The NORDSTEN patients were similar to those being consecutively operated at the same hospitals and reported to the NORspine during the same time period. CONCLUSION: The NORDSTEN study provides opportunity to investigate clinical course of LSS with or without surgical interventions. The NORDSTEN-study population were similar to LSS patients treated in routine surgical practice, supporting the external validity of previously published results. TRIAL REGISTRATION: ClinicalTrials.gov; NCT02007083 10/12/2013, NCT02051374 31/01/2014 and NCT03562936 20/06/2018.

Menopausal hormone therapy, oral contraceptives and risk of chronic low back pain: the HUNT Study.

BACKGROUND: There are indications that use of menopausal hormone therapy (MHT) and oral contraceptives (OC) increases the risk of low back pain (LBP), with higher oestrogen levels involved in the underlying mechanisms. The purpose of the present study was to investigate associations between use of systemic MHT or OC and risk of chronic LBP in a large population-based data set. METHODS: Data were obtained from two surveys in the Trøndelag Health Study in Norway, HUNT2 (1995-1997) and HUNT3 (2006-2008). A cross-sectional study of association between use of systemic MHT and prevalence of chronic LBP comprised 12,974 women aged 40-69 years in HUNT2, with 4007 women reporting chronic LBP. A cohort study involving MHT comprised 6007 women without chronic LBP at baseline in HUNT2, and after 11 years 1245 women reported chronic LBP at follow-up in HUNT3. The cross-sectional study of association with use of OC included 23,593 women aged 20-69 years in HUNT2, with 6085 women reporting chronic LBP. The corresponding cohort study included 10,586 women without chronic LBP at baseline in HUNT2, of whom 2084 women reported chronic LBP in HUNT3. Risk of chronic LBP was examined in both study designs in generalised linear models with adjustment for potential confounders. RESULTS: In the cohort study, current users of systemic MHT at baseline showed a greater risk of chronic LBP (relative risk (RR) 1.30; 95% CI: 1.14-1.49; compared with never users). The risk increased according to duration of MHT use (P for linear trend = 0.003). Known users of systemic MHT based exclusively on oestrogen experienced the highest risk (RR 1.49; 95% CI: 1.16-1.91), but an increased risk was also seen among known users of oestrogen-progestin combination MHT (RR 1.35; 95% CI: 1.16-1.57). A slight increase in risk of chronic LBP was found in the cohort study among former users of OC (RR 1.17; 95% CI: 1.06-1.30; compared with never users). CONCLUSIONS: Long-lasting use of systemic MHT, in particular therapy based on oestrogen only, is associated with greater risk of chronic LBP. Having been a user of OC most likely entails a minor increase in risk.

Is the presence of foraminal stenosis associated with outcome in lumbar spinal stenosis patients treated with posterior microsurgical decompression.

BACKGROUND: We aim to investigate associations between preoperative radiological findings of lumbar foraminal stenosis with clinical outcomes after posterior microsurgical decompression in patients with predominantly central lumbar spinal stenosis (LSS). METHODS: The study was an additional analysis in the NORDSTEN Spinal Stenosis Trial. In total, 230 men and 207 women (mean age 66.8 (SD 8.3)) were included. All patients underwent an MRI including T1- and T2-weighted sequences. Grade of foraminal stenosis was dichotomized into none to moderate (0-1) and severe (2-3) category using Lee's classification system. The Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and numeric rating scale (NRS) for back and leg pain were collected at baseline and at 2-year follow-up. Primary outcome was a reduction of 30% or more on the ODI score. Secondary outcomes included the mean improvement on the ODI, ZCQ, and NRS scores. We performed multivariable regression analyses with the radiological variates foraminal stenosis, Pfirrmann grade, Schizas score, dural sac cross-sectional area, and the possible plausible confounders: patients' gender, age, smoking status, and BMI. RESULTS: The cohort of 437 patients presented a high degree of degenerative changes at baseline. Of 414 patients with adequate imaging of potential foraminal stenosis, 402 were labeled in the none to moderate category and 12 in the severe category. Of the patients with none to moderate foraminal stenosis, 71% achieved at least 30% improvement in ODI. Among the patients with severe foraminal stenosis, 36% achieved at least 30% improvement in ODI. A significant association between severe foraminal stenosis and less chance of reaching the target of 30% improvement in the ODI score after surgery was detected: OR 0.22 (95% CI 0.06, 0.83), p=0.03. When investigating outcome as continuous variables, a similar association between severe foraminal stenosis and less improved ODI with a mean difference of 9.28 points (95%CI 0.47, 18.09; p=0.04) was found. Significant association between severe foraminal stenosis and less improved NRS pain in the lumbar region was also detected with a mean difference of 1.89 (95% CI 0.30, 3.49; p=0.02). No significant association was suggested between severe foraminal stenosis and ZCQ or NRS leg pain. CONCLUSION: In patients operated with posterior microsurgical decompression for LSS, a preoperative severe lumbar foraminal stenosis was associated with higher proportion of patients with less than 30% improvement in ODI. TRIAL REGISTRATION: The study is registered at ClinicalTrials.gov (22.11.2013) under the identifier NCT02007083.

Killing pain?: a population-based registry study of the use of prescription analgesics, anxiolytics, and hypnotics among all children, adolescents and young adults in Norway from 2004 to 2019.

The ongoing opioid epidemic has been a global concern for years, increasingly due to its heavy toll on young people's lives and prospects. Few studies have investigated trends in use of the wider range of drugs prescribed to alleviate pain, psychological distress and insomnia in children, adolescents and young adults. Our aim was to study dispensation as a proxy for use of prescription analgesics, anxiolytics and hypnotics across age groups (0-29 years) and sex over the last 15 years in a large, representative general population. The study used data from a nationwide prescription database, which included information on all drugs dispensed from any pharmacy in Norway from 2004 through 2019. Age-specific trends revealed that the prevalence of use among children and adolescents up to age 14 was consistently low, with the exception of a substantial increase in use of melatonin from age 5. From age 15-29, adolescents and young adults used more prescription drugs with increasing age at all time points, especially analgesics and drugs with higher potential for misuse. Time trends also revealed that children from age 5 were increasingly dispensed melatonin over time, while adolescents from age 15 were increasingly dispensed analgesics, including opioids, gabapentinoids and paracetamol. In contrast, use of benzodiazepines and z-hypnotics slightly declined in young adults over time. Although trends were similar for both sexes, females used more prescription drugs than their male peers overall. The upsurge in use of prescription analgesics, anxiolytics and hypnotics among young people is alarming.Trial registration The study is part of the overarching Killing Pain project. The rationale behind the Killing Pain research was pre-registered through ClinicalTrials.gov on April 7, 2020. Registration number NCT04336605; https://clinicaltrials.gov/ct2/show/record/NCT04336605 .

Clinical and MRI findings in lumbar spinal stenosis: baseline data from the NORDSTEN study.

PURPOSE: The aim was to describe magnetic resonance imaging findings in patients planned for lumbar spinal stenosis surgery. Further, to describe possible associations between MRI findings and patient characteristics with patient reported disability or pain. METHODS: The NORDSTEN spinal stenosis trial included 437 patients planned for surgical decompression of LSS. The following MRI findings were evaluated before surgery: morphological (Schizas) and quantitative (cross-sectional area) grade of stenosis, disk degeneration (Pfirrmann), facet joint tropism and fatty infiltration of the multifidus muscle. Patients were dichotomized into a moderate or severe category for each radiological parameter classification. A multivariable linear regression analysis was performed to investigate the association between MRI findings and preoperative scores for Oswestry Disability Index, Zurich Claudication Questionnaire and Numeric rating scale for back and leg pain. The following patient characteristics were included in the analysis: gender, age, smoking and weight. RESULTS: The percentage of patients with severe scores was as follows: Schizas (C + D) 71.3%, cross-sectional area (< 75 mm2) 86.8%, Pfirrmann (4 + 5) 58.1%, tropism (≥ 15°) 11.9%, degeneration of multifidus muscle (2-4) 83.7%. Regression coefficients indicated minimal changes in severity of symptoms when comparing the groups with moderate and severe MRI findings. Only gender had a significant and clinically relevant association with ODI score. CONCLUSION: In this cross-sectional study, the majority of the patients had MRI findings classified as severe LSS changes, but the findings had no clinically relevant association with patient reported disability and pain at baseline. Patient characteristics have a larger impact on disability and pain than radiological findings. TRIAL REGISTRATION: www. CLINICALTRIALS: gov identifier: NCT02007083, registered December 2013.

The association between preoperative MRI findings and clinical improvement in patients included in the NORDSTEN spinal stenosis trial.

PURPOSE: To investigate potential associations between preoperative MRI findings and patient reported outcome measures (PROMs) after surgery for lumbar spinal stenosis (LSS). METHODS: The NORDSTEN trial included 437 patients. We investigated the association between preoperative MRI findings such as morphological grade of stenosis (Schizas grade), quantitative grade of stenosis (dural sac cross-sectional area), disc degeneration (Pfirrmann score), facet joint tropism and fatty infiltration of the multifidus muscle, and improvement in patient reported outcome measures (PROMs) 2 years after surgery. We dichotomized each radiological parameter into a moderate or severe category. PROMs i.e., Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) and Numeric rating scale (NRS) for back and leg pain were collected before surgery and at 2 year follow-up. In the primary analysis, we investigated the association between MRI findings and ODI score (dichotomized to ≥ 30% improvement or not). In the secondary analysis, we investigated the association between MRI findings and the mean improvement on the ODI-, ZCQ- and NRS scores. We used multivariable regression models adjusted for patients' gender, age, smoking status and BMI. RESULTS: The primary analysis showed that severe disc degeneration (Pfirrmann score 4-5) was significantly associated with less chance of achieving a 30% improvement on the ODI score (OR 0.54, 95% CI 0.34, 0.88). In the secondary analysis, we detected no clinical relevant associations. CONCLUSION: Severe disc degeneration preoperatively suggest lesser chance of achieving 30% improvement in ODI score after surgery for LSS. Other preoperative MRI findings were not associated with patient reported outcome.

Modifiable prognostic factors of high costs related to healthcare utilization among older people seeking primary care due to back pain: an identification and replication study.

BACKGROUND: Back pain is an extensive burden to our healthcare system, yet few studies have explored modifiable prognostic factors associated with high costs related to healthcare utilization, especially among older back pain patients. The aims of this study were to identify modifiable prognostic factors for high costs related to healthcare utilization among older people seeking primary care with a new episode of back pain; and to replicate the identified associations in a similar cohort, in a different country. METHODS: Data from two cohort studies within the BACE consortium were used, including 452 and 675 people aged ≥55 years seeking primary care with a new episode of back pain. High costs were defined as costs in the top 25th percentile. Healthcare utilization was self-reported, aggregated for one-year of follow-up and included: primary care consultations, medications, examinations, hospitalization, rehabilitation stay and operations. Costs were estimated based on unit costs collected from national pricelists. Nine potential modifiable prognostic factors were selected based on previous literature. Univariable and multivariable binary logistic regression models were used to identify and replicate associations (crude and adjusted for selected covariates) between each modifiable prognostic factor and high costs related to healthcare utilization. RESULTS: Four modifiable prognostic factors associated with high costs related to healthcare utilization were identified and replicated: a higher degree of pain severity, disability, depression, and a lower degree of physical health-related quality of life. Kinesiophobia and recovery expectations showed no prognostic value. There were inconsistent results across the two cohorts with regards to comorbidity, radiating pain below the knee and mental health-related quality of life. CONCLUSION: The factors identified in this study may be future targets for intervention with the potential to reduce high costs related to healthcare utilization among older back pain patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT04261309, 07 February 2020. Retrospectively registered.

Assessing physical workload among people with musculoskeletal disorders: validity and reliability of the physical workload questionnaire.

BACKGROUND: Demands of physical work are related to musculoskeletal disorders, and hence, important to assess. The Physical Workload Questionnaire (PWQ) is based on 26 items related to physical workload. The PWQ has been translated into Norwegian, but its psychometric properties have not yet been tested. The aim of this study was to assess the validity and reliability of the PWQ among patients with musculoskeletal disorders. METHODS: A cross-sectional study with a test-retest design was conducted to assess construct validity (structural validity and hypothesis testing) and reliability (internal consistency and test-retest reliability) among employed patients with musculoskeletal disorders. Exploratory factor analysis was performed to assess the structural validity and number of items to be included in the Norwegian version of the PWQ. Hypothesis testing was assessed by 14 a priori hypotheses ("known" group, convergent and discriminant validity). Internal consistency was evaluated using Cronbach's alpha and test-retest reliability by Intraclass Correlation Coefficient (ICC2.1), Standard Error of Measurement (SEMagreement) and Smallest Detectable Change (SDC95%ind). RESULTS: In total, 115 patients with a mean age (SD) of 46 (9) years were included, of which 48 were included in the reliability analyses. Exploratory factor analysis resulted in two subscales: "Heavy physical work" (15 items, range 0-100) and "Long-lasting postures and repetitive movements" (7 items, range 0-100). No floor or ceiling effects were seen in the subscales. Twelve of the 14 (85%) predefined hypotheses were confirmed. The internal consistency with Cronbach's alpha was 0.94 and 0.85 on subscales 1 and 2, respectively. Test-retest reliability analyses demonstrated an ICC2.1 of 0.96 (95% CI 0.88, 0.98) and 0.92 (95% CI 0.81, 0.96), SEM of 6.9 and 10.0 and SDC95%ind of 19.2 and 27.7 of subscales 1 and 2, respectively. CONCLUSIONS: The Norwegian version of the PWQ demonstrated good validity and reliability and can be used to evaluate physical workload in patients with musculoskeletal disorders.

Apparent diffusion coefficient values in Modic changes - interobserver reproducibility and relation to Modic type.

BACKGROUND: Modic Changes (MCs) in the vertebral bone marrow were related to back pain in some studies but have uncertain clinical relevance. Diffusion weighted MRI with apparent diffusion coefficient (ADC)-measurements can add information on bone marrow lesions. However, few have studied ADC measurements in MCs. Further studies require reproducible and valid measurements. We expect valid ADC values to be higher in MC type 1 (oedema type) vs type 3 (sclerotic type) vs type 2 (fatty type). Accordingly, the purpose of this study was to evaluate ADC values in MCs for interobserver reproducibility and relation to MC type. METHODS: We used ADC maps (b 50, 400, 800 s/mm2) from 1.5 T lumbar spine MRI of 90 chronic low back pain patients with MCs in the AIM (Antibiotics In Modic changes)-study. Two radiologists independently measured ADC in fixed-sized regions of interests. Variables were MC-ADC (ADC in MC), MC-ADC% (0% = vertebral body, 100% = cerebrospinal fluid) and MC-ADC-ratio (MC-ADC divided by vertebral body ADC). We calculated mean difference between observers ± limits of agreement (LoA) at separate endplates. The relation between ADC variables and MC type was assessed using linear mixed-effects models and by calculating the area under the receiver operating characteristic curve (AUC). RESULTS: The 90 patients (mean age 44 years; 54 women) had 224 MCs Th12-S1 comprising type 1 (n = 111), type 2 (n = 91) and type 3 MC groups (n = 22). All ADC variables had higher predicted mean for type 1 vs 3 vs 2 (p < 0.001 to 0.02): MC-ADC (10- 6 mm2/s) 1201/796/576, MC-ADC% 36/21/14, and MC-ADC-ratio 5.9/4.2/3.1. MC-ADC and MC-ADC% had moderate to high ability to discriminate between the MC type groups (AUC 0.73-0.91). MC-ADC-ratio had low to moderate ability (AUC 0.67-0.85). At L4-S1, widest/narrowest LoA were for MC-ADC 20 ± 407/12 ± 254, MC-ADC% 1.6 ± 18.8/1.4 ± 10.4, and MC-ADC-ratio 0.3 ± 4.3/0.2 ± 3.9. Difference between observers > 50% of their mean value was less frequent for MC-ADC (9% of MCs) vs MC-ADC% and MC-ADC-ratio (17-20%). CONCLUSIONS: The MC-ADC variable (highest mean ADC in the MC) had best interobserver reproducibility, discriminated between MC type groups, and may be used in further research. ADC values differed between MC types as expected from previously reported MC histology.

Low social acceptance among peers increases the risk of persistent musculoskeletal pain in adolescents. Prospective data from the Fit Futures Study.

BACKGROUND: Musculoskeletal pain has a high prevalence in adolescence and causes huge consequences for the individuals and the society. Little knowledge exists on social risk factors for musculoskeletal pain in adolescents. This study aimed to investigate if low social acceptance among peers during the first year of upper secondary school was associated with persistent and severe persistent musculoskeletal pain 2 years later and if psychological distress modified this association. METHODS: Longitudinal data from the Norwegian Fit Futures Study was used. Students in the first year of upper secondary school answered an electronic questionnaire, covering health status, pain, social acceptance among peers, and psychological distress. Persistent musculoskeletal pain was measured 2 years later. Multiple logistic regression analyses and moderation analyses were conducted adjusting for sex and chronic diseases. Main analyses were conducted on participants without persistent musculoskeletal pain at baseline, and secondary analyses were conducted on all participants with and without persistent musculoskeletal pain at baseline. RESULTS: Of 775 participants (52% females), 556 (71.7%) were pain-free at baseline and included in the main analyses. Significant associations between low social acceptance among peers and persistent musculoskeletal pain 2 years later were found in crude (Odds ratio (OR) = 1.8, 95%CI [1.0-3.1]) and adjusted analyses (OR = 1.8, 95%CI [1.0-3.2]). No statistically significant effect modification of psychological distress (p = 0.89) on this association was found. A significant association between low social acceptance and persistent musculoskeletal pain was found in adjusted secondary analyses of all the students (n = 692) (OR = 1.6, 95%CI [1.0-2.3]). CONCLUSIONS: Our results indicate that low social acceptance among peers increases the risk of future persistent musculoskeletal pain in adolescents. Thus, interventions strengthening adolescent's social arenas may be helpful to prevent persistent musculoskeletal pain. TRIAL REGISTRATION: Retrospective registered at clinicaltrials.org NCT04526522 .

Implementing a Stratified Vocational Advice Intervention for People on Sick Leave with Musculoskeletal Disorders: A Multimethod Process Evaluation.

Purpose To perform a process evaluation of a stratified vocational advice intervention (SVAI), delivered by physiotherapists in primary care, for people on sick leave with musculoskeletal disorders participating in a randomised controlled trial. The research questions concerned how the SVAI was delivered, the content of the SVAI and the physiotherapists' experiences from delivering the SVAI. Methods We used qualitative and quantitative data from 148 intervention logs documenting the follow-up provided to each participant, recordings of 18 intervention sessions and minutes from 20 meetings with the physiotherapists. The log data were analysed with descriptive statistics. A qualitative content analysis was performed of the recordings, and we identified facilitators and barriers for implementation from the minutes. Results Of 170 participants randomised to the SVAI 152 (89%) received the intervention and 148 logs were completed. According to the logs, 131 participants received the correct number of sessions (all by telephone) and 146 action plans were developed. The physiotherapists did not attend any workplace meetings but contacted stakeholders in 37 cases. The main themes from the recorded sessions were: 'symptom burden', 'managing symptoms', 'relations with the workplace' and 'fear of not being able to manage work'. The physiotherapists felt they were able to build rapport with most participants. However, case management was hindered by the restricted number of sessions permitted according to the protocol. Conclusion Overall, the SVAI was delivered in accordance with the protocol and is therefore likely to be implementable in primary care if it is effective in reducing sick leave.

Oedema on STIR modified the effect of amoxicillin as treatment for chronic low back pain with Modic changes-subgroup analysis of a randomized trial.

OBJECTIVE: To evaluate potential MRI-defined effect modifiers of amoxicillin treatment in patients with chronic low back pain and type 1 or 2 Modic changes (MCs) at the level of a previous lumbar disc herniation (index level). METHODS: In a prospective trial (AIM), 180 patients (25-64 years; mean age 45; 105 women) were randomised to receive amoxicillin or placebo for 3 months. Primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (0-24 scale) at 1 year. Mean RMDQ score difference between the groups at 1 year defined the treatment effect; 4 RMDQ points defined the minimal clinically important effect. Predefined baseline MRI features of MCs at the index level(s) were investigated as potential effect modifiers. The predefined primary hypothesis was a better effect of amoxicillin when short tau inversion recovery (STIR) shows more MC-related high signal. To evaluate this hypothesis, we pre-constructed a composite variable with three categories (STIR1/2/3). STIR3 implied MC-related STIR signal increases with volume ≥ 25% and height > 50% of vertebral body and maximum intensity increase ≥ 25% and presence on both sides of the disc. As pre-planned, interaction with treatment was analysed using ANCOVA in the per protocol population (n = 155). RESULTS: The STIR3 composite group (n = 41) and STIR signal volume ≥ 25% alone (n = 45) modified the treatment effect of amoxicillin. As hypothesised, STIR3 patients reported the largest effect (- 5.1 RMDQ points; 95% CI - 8.2 to - 1.9; p for interaction = 0.008). CONCLUSIONS: Predefined subgroups with abundant MC-related index-level oedema on STIR modified the effect of amoxicillin. This finding needs replication and further support. KEY POINTS: • In the primary analysis of the AIM trial, the effect of amoxicillin in patients with chronic low back pain and type 1 or 2 MCs did not reach the predefined cut-off for clinical importance. • In the present MRI subgroup analysis of AIM, predefined subgroups with abundant MC-related oedema on STIR reported an effect of amoxicillin. • This finding requires replication and further support.