Analgesics and ASH medications in workers increase the risk of disability pension and mortality: prospective cohort.

BACKGROUND: Relying on medication for musculoskeletal and mental disorders are common, but may have long-term consequences. This study investigates whether use of analgesics and anxiolytic/sedative/hypnotic (ASH) medication increases the risk of disability pension and mortality. METHODS: After completing a survey in 2005, 7773 female eldercare workers were followed for 11 years in a national register. We estimated hazard ratios (HRs) for disability pension and mortality from using analgesics and ASH. RESULTS: During follow-up, 10.3% obtained disability pension and 2.4% died. For use of analgesics, a frequency-response association for the risk of disability pension existed with HR's (95% confidence interval) of 1.30 (1.07-1.57), 2.00 (1.62-2.46) and 3.47 (2.69-4.47) for monthly, weekly and daily use, respectively. For ASH, an increased risk of disability pension also existed (HR's between 1.51 and 1.64). For mortality risk, only daily use of analgesics and ASH remained significant. Population attributable fractions of analgesics and ASH, respectively, were 30% and 3% for disability pension and 5% and 3% for mortality. CONCLUSIONS: Frequent use of analgesics and ASH medication in workers increase the risk of disability pension and early death. Better management of musculoskeletal and mental health conditions, without excessive medication use, is necessary.

Prognostic value of the clinical and imaging arm of the ASAS criteria for progression of structural sacroiliac joint lesions.

OBJECTIVE: To investigate the prognostic value of the two arms of the Assessment of SpondyloArthritis international Society (ASAS) criteria regarding the progression of structural lesions in the sacroiliac joints (SIJ). METHODS: Information on baseline fulfilment of the ASAS criteria and baseline and follow-up magnetic resonance imaging of the SIJ in 603 patients aged 18-40 years, referred with low back pain to an outpatient spine were collected. MRI-positivity was defined as bone marrow oedema (BMO) in ≥2 consecutive slices or ≥2 lesions in 1 slice, as described in ASAS definition of sacroiliitis. RESULTS: Of 71 participants fulfilling the ASAS criteria at baseline, 66(93%) fulfilled the 'imaging arm' and 14(20%) the 'clinical arm'. The 'clinical arm' predicted progression of erosions with an odds ratio of 55 (compared with not fulfilling the ASAS criteria), while the 'imaging arm' predicted progression of erosions with an odds ratio of 8. Moreover, in 24% of patients in the 'imaging arm', all having BMO at the SIJ at baseline, the BMO disappeared without neither erosions nor ankylosis emerging. CONCLUSION: We found that the 'clinical arm' was a strong predictor for progression of sacroiliac joint erosion, while the 'imaging arm' had a more modest prognostic value for structural progression.

Prevalence of long-term opioid therapy in spine center outpatients the spinal pain opioid cohort (SPOC).

PURPOSE: No reference material exists on the scope of long-term problems in novel spinal pain opioid users. In this study, we evaluate the prevalence and long-term use of prescribed opioids in patients of the Spinal Pain Opioid Cohort. METHODS: The setting was an outpatient healthcare entity (Spine Center). Prospective variables include demographics, clinical data collected in SpineData, and The Danish National Prescription Registry. Patients with a new spinal pain episode lasting for more than two months, aged between 18 and 65 years, who had their first outpatient visit. Based on the prescription of opioids from 4 years before the first spine center visit to 5 years after, six or more opioid prescriptions in a single 1-year interval fulfilled the main outcome criteria Long-Term Opioid Therapy (LTOT). RESULTS: Overall, of 8356 patients included in the cohort, 4409 (53%) had one or more opioid prescriptions in the registered nine years period. Of opioid users, 2261 (27%) were NaiveStarters receiving their first opioid prescription after a new acute pain episode; 2148(26%) PreStarters had previously received opioids. The prevalence of LTOT in PreStarters/NaiveStarters was 17.2%/11.2% in their first outpatient year. Similar differences between groups were seen in all follow-up intervals. In the last follow-up year, LTOT prevalence in Prestarters/NaiveStarters was 12.5%/7.0%. CONCLUSIONS: Previous opioid treatment-i.e., before a new acute spinal pain episode and referral to a Spine Center-doubled the risk of LTOT 5 years later. The results underscore clinicians' obligation to carefully and individually weigh the benefits against the risks of prescribing opioid therapy. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Is pseudarthrosis after spinal instrumentation caused by a chronic infection?

HYPOTHESIS: To assess whether a chronic bacterial infection is present in a subset of patients with pseudarthrosis after instrumented spinal fusion. METHODS: This was a prospective diagnostic study including adult patients with previous instrumented spinal fusion. Patients underwent revision surgery for either pseudarthrosis or other causes (e.g. implant removal, curve progression or junctional kyphosis) (control group). Five separate biopsies were randomly collected, intraoperatively, from the pseudarthrosis site and cultivated under both aerobic (5 days) and anaerobic (14 days) conditions. If cultivation was positive in at least 2/5 tissue samples, the biopsy was sectioned and stained using peptide nucleic acid fluorescence in situ hybridization (PNA-FISH). Confocal laser scanning microscopy was used to examine the sections and visualize bacterial aggregates. RESULTS: The study included 32 pseudarthrosis and 32 control patients. Cultivation yielded bacteria in at least 1/5 biopsies in 52% of patients with no difference between the groups (p = 1.0). Bacteria of the same species was found in at least 2/5 samples in seven pseudarthrosis patients and four controls (p = 0.509). Propionibacterium acnes was found in 8 of these 11 samples. Microscopy demonstrated tissue-embedded bacterial aggregates in two of these patients but with no inflammatory cells indicating an active infection. The presence of bacteria was not associated with the number of previous spinal procedures or the pre-revision fusion length (p ≥ 0.503). CONCLUSIONS: Pseudarthrosis after instrumented spinal surgery was not significantly associated with the presence of bacteria at the pseudarthrosis site. Positive cultivation results are common after spinal instrumentation, but our results indicate that they rarely represent an organized infection. These slides can be retrieved under Electronic Supplementary Material.

Somatic experiencing® for patients with low back pain and comorbid posttraumatic stress disorder - protocol of a randomized controlled trial.

BACKGROUND: Research has almost exclusively focused on the neck in order to explain the mechanisms of persistent pain after motor vehicle collisions (MVC). However, studies have shown that low back pain after MVC is as common as neck pain. Also, posttraumatic stress disorder (PTSD) is common after MVCs, and evidence indicate that PTSD may be linked to the development of pain and disability. PTSD has even been proposed as "the missing link" for some in the development of chronic low back pain. Unfortunately, PTSD often goes unattended in low back pain rehabilitation and very few randomized controlled studies exists targeting both conditions. Hence, the aim of the present study is to investigate the potential additional effect of the trauma therapy "Somatic Experiencing®" (SE) in addition to physiotherapy (PT) compared to PT alone for patients with chronic low back pain and comorbid PTSD. METHODS: The study is a two-group randomized controlled clinical trial in which participants (n = 140) are recruited consecutively from a large Danish spine center in the Region of Southern Denmark, between January 2016 and December 2017. Patients are randomly allocated to one of the two conditions: SE + PT or PT alone. Measurements of effect are carried out at baseline before randomization, post-intervention, 6 and 12 months post-randomization. The primary outcome is a 20% reduction in disability (Rolland Morris Disability Questionnaire) at 6 months post-randomization. Secondary outcomes are: PTSD symptoms, pain intensity, pain-catastrophizing, fear of movement, anxiety and depression. DISCUSSION: Comorbid PTSD is currently not targeted in back pain rehabilitation although highly prevalent. If the SE intervention shows to have an additional effect on disability and pain, the study is likely to have a positive impact on the management of chronic low back pain and will have immediate clinical applicability. TRIAL REGISTRATION: Current Controlled Trials Registration August 4, 2017: NCT03244046 . Retrospectively registered.

Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain.

OBJECTIVE: To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. METHODS: Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. RESULTS: Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. CONCLUSION: The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. KEY POINTS: • The location of vertebral endplate signal changes supports a mechanical aetiology. • Several sacroiliac joint findings were associated with female gender and pregnancy-related back pain. • Sacroiliac joint bone marrow oedema was frequent and age-associated, indicating a possible degenerative aetiology. • More knowledge of the clinical importance of sacroiliac joint MRI findings is needed.

Patient preferences for treatment of low back pain-a discrete choice experiment.

BACKGROUND: Back pain imposes a substantial economic and social burden, and treatment decisions are distorted by conflicting evidence. Thus, it is important to include patient preferences in decision making and policy making. OBJECTIVE: To contribute to the understanding of patient preferences in relation to the choice of treatment for low back pain. METHODS: A discrete choice experiment was conducted with consecutive patients referred to a regional spine center. The respondents (n = 348) were invited to respond to a choice of two hypothetical treatment options and an opt-out option. The treatment attributes included the treatment modality, the risk of relapse, the reduction in pain, and the expected increase in the ability to perform activities of daily living. In addition, the wait time to achieve the treatment effect was used as a payment vehicle. Mixed logit models were created to perform analysis. Subgroup analysis, dividing respondents into sociodemographic and disease-related categories, further explored the willingness to wait. RESULTS: Respondents assigned positive utilities to positive treatment outcomes and disutility to higher risks and longer waits for effects of treatment and to surgical interventions. The model captured significant heterogeneity within the sample for the outcomes of pain reduction and the ability to pursue activities of daily living and for the treatment modality. The subgroup analysis revealed differences in the willingness to wait, especially with regard to treatment modality, the level of pain experienced at the time of data collection, and the respondents' preferences for surgery. CONCLUSIONS: The majority of the respondents prefer nonsurgical interventions, but patients are willing to wait for more ideal outcomes and preferred interventions. The results show that health care professionals have a very important task in communicating clearly about the expected results of treatment and the basis of their treatment decisions, as patients' preferences are highly individual.

The predictive ability of the STarT Back Screening Tool in a Danish secondary care setting.

INTRODUCTION: The predictive ability of the STarT Back Tool (SBT) in secondary care settings has not been investigated. The aim of this study was to determine the SBT's predictive ability in a Danish secondary care setting and compare this to a Danish primary care setting. METHODS: Poor clinical outcome at 6 months (>30 points on a 0-100 Roland Morris Disability Scale) was calculated in secondary care (n = 960) and primary care (n = 172) cohorts. The cohorts were stratified into SBT subgroups and estimates of additional risk for poor outcome were calculated [relative risk (RR), unadjusted and adjusted odds ratios]. The discriminative ability was determined using the area under the curve statistic. RESULTS: In secondary care 69.0 % and in primary care 40.2 % had poor outcome on activity limitation. Although significant, the predictive ability of the SBT in secondary care (medium-risk RR 1.5, high-risk RR 1.7) was not as strong as in primary care (medium-risk RR 2.3, high-risk RR 3.5). Adjusting for episode duration and pain intensity only changed the predictive ability marginally in secondary care. The discriminative ability of the SBT was similar in both cohorts despite differences in the predictive ability. CONCLUSION: The SBT had less predictive ability in a Danish secondary care setting compared to a Danish primary care setting for persistent activity limitation at 6 months follow-up. SBT-targeted treatment implications in secondary care were not investigated in this study.

Antibiotic treatment in patients with chronic low back pain and vertebral bone edema (Modic type 1 changes): a double-blind randomized clinical controlled trial of efficacy.

PURPOSE: Modic type 1 changes/bone edema in the vertebrae are present in 6 % of the general population and 35-40 % of the low back pain population. It is strongly associated with low back pain. The aim was to test the efficacy of antibiotic treatment in patients with chronic low back pain (>6 months) and Modic type 1 changes (bone edema). METHODS: The study was a double-blind RCT with 162 patients whose only known illness was chronic LBP of greater than 6 months duration occurring after a previous disc herniation and who also had bone edema demonstrated as Modic type 1 changes in the vertebrae adjacent to the previous herniation. Patients were randomized to either 100 days of antibiotic treatment (Bioclavid) or placebo and were blindly evaluated at baseline, end of treatment and at 1-year follow-up. OUTCOME MEASURES: Primary outcome, disease-specific disability, lumbar pain. Secondary outcome leg pain, number of hours with pain last 4 weeks, global perceived health, EQ-5D thermometer, days with sick leave, bothersomeness, constant pain, magnetic resonance image (MRI). RESULTS: 144 of the 162 original patients were evaluated at 1-year follow-up. The two groups were similar at baseline. The antibiotic group improved highly statistically significantly on all outcome measures and improvement continued from 100 days follow-up until 1-year follow-up. At baseline, 100 days follow-up, 1-year follow-up the disease-specific disability-RMDQ changed: antibiotic 15, 11, 5.7; placebo 15, 14, 14. Leg pain: antibiotics 5.3, 3.0, 1.4; placebo 4.0, 4.3, 4.3. Lumbar pain: antibiotics 6.7, 5.0, 3.7; placebo 6.3, 6.3, 6.3. For the outcome measures, where a clinically important effect size was defined, improvements exceeded the thresholds, and a trend towards a dose-response relationship with double dose antibiotics being more efficacious. CONCLUSIONS: The antibiotic protocol in this study was significantly more effective for this group of patients (CLBP associated with Modic I) than placebo in all the primary and secondary outcomes.

The predictive and external validity of the STarT Back Tool in Danish primary care.

PURPOSE: The STarT Back Tool (SBT) was recently translated into Danish and its concurrent validity described. This study tested the predictive validity of the Danish SBT. METHODS: Danish primary care patients (n = 344) were compared to a UK cohort. SBT subgroup validity for predicting high activity limitation at 3 months' follow-up was assessed using descriptive proportions, relative risks, AUC and odds ratios. RESULTS: The SBT had a statistically similar predictive ability in Danish primary care as in UK primary care. Unadjusted relative risks for poor clinical outcome on activity limitation in the Danish cohort were 2.4 (1.7-3.4) for the medium-risk subgroup and 2.8 (1.8-3.8) for the high-risk subgroup versus 3.1 (2.5-3.9) and 4.5 (3.6-5.6) for the UK cohort. Adjusting for confounders appeared to explain the lower predictive ability of the Danish high-risk group. CONCLUSIONS: The Danish SBT distinguished between low- and medium-risk subgroups with a similar predictive ability of the UK SBT. That distinction is useful information for informing patients about their expected prognosis and may help guiding clinicians' choice of treatment. However, cross-cultural differences in the SBT psychosocial subscale may reduce the predictive ability of the high-risk subgroup in Danish primary care.

Does nuclear tissue infected with bacteria following disc herniations lead to Modic changes in the adjacent vertebrae?

PURPOSE: To investigate the prevalence of infected herniated nucleus material in lumbar disc herniations and to determine if patients with an anaerobic infected disc are more likely to develop Modic change (MC) (bone oedema) in the adjacent vertebrae after the disc herniation. MCs (bone oedema) in vertebrae are observed in 6 % of the general population and in 35-40 % of people with low back pain. These changes are strongly associated with low back pain. There are probably a mechanical cause and an infective cause that causes MC. Several studies on nuclear tissue from herniated discs have demonstrated the presence of low virulent anaerobic microorganisms, predominantly Propionibacterium acnes, in 7-53 % of patients. At the time of a herniation these low virulent anaerobic bacteria may enter the disc and give rise to an insidious infection. Local inflammation in the adjacent bone may be a secondary effect due to cytokine and propionic acid production. METHODS: Patients undergoing primary surgery at a single spinal level for lumbar disc herniation with an MRI-confirmed lumbar disc herniation, where the annular fibres were penetrated by visible nuclear tissue, had the nucleus material removed. Stringent antiseptic sterile protocols were followed. RESULTS: Sixty-one patients were included, mean age 46.4 years (SD 9.7), 27 % female. All patients were immunocompetent. No patient had received a previous epidural steroid injection or undergone previous back surgery. In total, microbiological cultures were positive in 28 (46 %) patients. Anaerobic cultures were positive in 26 (43 %) patients, and of these 4 (7 %) had dual microbial infections, containing both one aerobic and one anaerobic culture. No tissue specimens had more than two types of bacteria identified. Two (3 %) cultures only had aerobic bacteria isolated. In the discs with a nucleus with anaerobic bacteria, 80 % developed new MC in the vertebrae adjacent to the previous disc herniation. In contrast, none of those with aerobic bacteria and only 44 % of patients with negative cultures developed new MC. The association between an anaerobic culture and new MCs is highly statistically significant (P = 0.0038), with an odds ratio of 5.60 (95 % CI 1.51-21.95). CONCLUSION: These findings support the theory that the occurrence of MCs Type 1 in the vertebrae adjacent to a previously herniated disc may be due to oedema surrounding an infected disc. The discs infected with anaerobic bacteria were more likely (P < 0.0038) to develop MCs in the adjacent vertebrae than those in which no bacteria were found or those in which aerobic bacteria were found.

Vitamin D levels appear to be normal in Danish patients attending secondary care for low back pain and a weak positive correlation between serum level Vitamin D and Modic changes was demonstrated: a cross-sectional cohort study of consecutive patients with non-specific low back pain.

BACKGROUND: Hypovitaminosis D has previously been reported in both the general population, in people with chronic musculoskeletal pain, and in people with low back pain (LBP). Myopathy-related symptoms such as diffuse bone and muscle pain, weakness and paresthesia in the legs, have also been observed in people with non-specific LBP and associations with low levels of Vitamin D have been suggested. The objectives of this study were to investigate (1) Vitamin D levels in patients seeking care for LBP in a Danish out-patient secondary care setting, and (2) their possible relationship with myopathy-related symptoms, Body Mass Index (BMI), and Modic changes. METHODS: A total of 152 consecutive patients with non-specific LBP participated in a cross-sectional study. Participants were recruited at The Spine Centre of Southern Denmark during springtime 2011. Individual serum levels of 25-Hydroxyvitamin-D were determined using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Information about symptoms, height, and weight were collected from electronic questionnaires completed by the participants. All patients had an MRI from which Modic changes were identified. Correlations between Vitamin D level and pain, paresthesia, weakness in the legs, BMI or Modic changes were described using correlation coefficients and odds ratios obtained from logistic regression. RESULTS: Two-thirds of the included patients with LBP had normal Vitamin D levels of >50 nmol/L. No correlations were seen between Vitamin D deficiency and gender, age, back pain intensity, leg pain intensity, and duration of pain. Statistically significant, but low, correlation coefficients were found between Vitamin D levels and BMI as well as Modic changes. Low Vitamin D levels and Modic changes were statistically significantly associated with an odds ratio of 0.30 (95% CI 0.12; 0.75) while weakness, paresthesia and widespread pain were not. CONCLUSIONS: In patients seeking care for low back pain in a Danish outpatient clinic, Vitamin D deficiency was not common. Whether patients who are overweight or who have Modic changes might represent subgroups of people for whom their LBP may be associated with Vitamin D levels, needs further investigation.

Prognostic implications of the Quebec Task Force classification of back-related leg pain: an analysis of longitudinal routine clinical data.

BACKGROUND: Low back pain (LBP) patients with related leg pain have a more severe profile than those with local LBP and a worse prognosis. Pain location above or below the knee and the presence of neurological signs differentiate patients with different profiles, but knowledge about the prognostic value of these subgroups is sparse. The objectives of this study were (1) to investigate whether subgroups consisting of patients with Local LBP only, LBP + leg pain above the knee, LBP + leg pain below the knee, and LBP + leg pain and neurological signs had different prognoses, and (2) to determine if this was explained by measured baseline factors. METHODS: Routine clinical data were collected during the first visit to an outpatient department and follow-ups were performed after 3 and 12 months. Patients were divided into the four subgroups and associations between subgroups and the outcomes of activity limitation, global perceived effect (GPE) after 3 months, and sick leave after 3 months were tested by means of generalised estimating equations. Models were univariate (I), adjusted for duration (II), and adjusted for all baseline differences (III). RESULTS: A total of 1,752 patients were included, with a 76% 3-month and 70% 12-month follow-up. Subgroups were associated with activity limitation in all models (p < 0.001). Local LBP had the least and LBP + neurological signs the most severe limitations at all time-points, although patients with neurological signs improved the most. Associations with GPE after 3 months were only significant in Model I. Subgroups were associated with sick leave after 3 months in model I and II, with sick leave being most frequent in the subgroup with neurological signs. No significant differences were found in any pairwise comparisons of patients with leg pain above or below the knee. CONCLUSIONS: Subgrouping LBP patients, based on pain location and neurological signs, was associated with activity limitation and sick leave, but not with GPE. The presence of neurological signs and pain in the leg both have prognostic implications but whether that leg pain without neurological signs is above or below the knee does not.

Spondyloarthritis-related and degenerative MRI changes in the axial skeleton--an inter- and intra-observer agreement study.

BACKGROUND: The Back Pain Cohort of Southern Denmark (BaPa Cohort) was initiated with the aim of evaluating the clinical relevance of magnetic resonance imaging (MRI) in the diagnosis of early spondyloarthritis (SpA). In order to facilitate the collection of MRI data for this study, an electronic evaluation form was developed including both SpA-related and degenerative axial changes. The objective of the current study was to assess the intra- and inter-observer agreement of the MRI changes assessed. METHODS: Three radiologists evaluated 48 MRI scans of the whole spine and the sacroiliac joints from a subsample of the BaPa Cohort, consisting of patients with non-specific low back pain and patients with different stages of SpA features. The spine was evaluated for SpA-related and degenerative MRI changes and the SIJ for SpA-related changes. Inter- and intra-observer agreements were calculated with kappa statistics. In the interpretation of the kappa coefficient, the standards for strength of agreement reported by Landis and Koch were followed. RESULTS: A total of 48 patients, 40% men and mean age of 31 years (range 18-40 years), were evaluated once by all three readers and re-evaluated by two of the readers after 4-12 weeks. For MRI changes in the spine, substantial to almost perfect observer agreement was found for the location and the size of vertebral signal changes and for disc degeneration and disc contour. For the sacroiliac joints, substantial or almost perfect observer agreement was found for the grading of bone marrow oedema and fatty marrow deposition, the depth of bone marrow oedema and for subchondral sclerosis. Global assessment of the SpA diagnosis had substantial to almost perfect observer agreements. CONCLUSION: The acceptable agreement for key MRI changes in the spine and sacroiliac joints makes it possible to use these MRI changes in the BaPa Cohort study and other studies investigating MRI changes in patients with non-specific low back pain and suspected SpA.

Rest versus exercise as treatment for patients with low back pain and Modic changes. A randomized controlled clinical trial.

BACKGROUND: Clinical experience suggests that many patients with Modic changes have relatively severe and persistent low back pain (LBP), which typically appears to be resistant to treatment. Exercise therapy is the recommended treatment for chronic LBP, however, due to their underlying pathology, Modic changes might be a diagnostic subgroup that does not benefit from exercise. The objective of this study was to compare the current state-of-the art treatment approach (exercise and staying active) with a new approach (load reduction and daily rest) for people with Modic changes using a randomized controlled trial design. METHODS: Participants were patients from an outpatient clinic with persistent LBP and Modic changes. They were allocated using minimization to either rest therapy for 10 weeks with a recommendation to rest for two hours daily and the option of using a flexible lumbar belt or exercise therapy once a week for 10 weeks. Follow-up was at 10 weeks after recruitment and 52 weeks after intervention and the clinical outcome measures were pain, disability, general health and global assessment, supplemented by weekly information on low back problems and sick leave measured by short text message (SMS) tracking. RESULTS: In total, 100 patients were included in the study. Data on 87 patients at 10 weeks and 96 patients at one-year follow-up were available and were used in the intention-to-treat analysis. No statistically significant differences were found between the two intervention groups on any outcome. CONCLUSIONS: No differences were found between the two treatment approaches, 'rest and reduced load' and 'exercise and staying active', in patients with persistent LBP and Modic changes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00454792.

Centralization in patients with sciatica: are pain responses to repeated movement and positioning associated with outcome or types of disc lesions?

AIM: To determine the frequency of different patterns of centralization and their association with outcomes and MRI findings in patients experiencing sciatica. METHODS: A prospective longitudinal cohort study of 176 patients with radicular pain below the knee, who all had an MDT clinical assessment. Based on their pain response, patients were divided into five groups: abolition centralization, reduction centralization, unstable centralization, peripheralization, and "no effect". Patients had an MRI. RESULTS: Overall, 84.8% of patients reported experiencing centralization, 7.3% peripheralized and 7.9% reported "no effect". The median reduction in RMQ scores across all the three centralization groups was 9.5 points at 3 months, and 12.0 points at 12 months. The peripheralization group improved similarly. The 'no effect' group improved significantly lower (p < 0.001), by 3.0 at both time points. Patients who centralized, and peripheralized had a significantly reduction in leg pain, the "no effect" group demonstrated a less favorable outcome (p < 0.02). There was no association between pain responses and the type of disc lesion. CONCLUSION: In patients with sciatica, centralization was common and associated with improvement in activity limitation and leg pain. Centralization was very common in ruptured disc therefore the study does not support the theory, that centralization only occurs if the intra-discal hydrostatic mechanism is functional.

Is the development of Modic changes associated with clinical symptoms? A 14-month cohort study with MRI.

PURPOSE: Modic changes (MCs) have been suggested to be a diagnostic subgroup of low back pain (LBP). However, the clinical implications of MCs remain unclear. For this reason, the aims of this study were to investigate how MCs developed over a 14-month period and if changes in the size and/or the pathological type of MCs were associated with changes in clinical symptoms in a cohort of patients with persistent LBP and MCs. METHODS: Information on LBP intensity and detailed information from MRI on the presence, type and size of MCs was collected at baseline and follow-up. Changes in type (type I, II, III and mixed types) and size of MCs were quantified at both time points according to a standardised evaluation protocol. The associations between change in type, change in size and change in LBP intensity were calculated using odds ratios (ORs). RESULTS: Approximately 40% of the MCs followed the expected developmental path from type I (here type I or I/II) to type II (here type II or II/III) or type I to type I/II. In general, the bigger the size of the MC at baseline, the more likely it was that it remained unchanged in size after 14 months. Patients who had MC type I at both baseline and 14-month follow-up were less likely to experience an improvement in their LBP intensity as compared to patients who did not have type I changes at both time points (OR 7.2, CI 1.3-37). There was no association between change in size of MCs type I and change in LBP intensity. CONCLUSIONS: The presence of MCs type I at both baseline and follow-up is associated with a poor outcome in patients with persistent LBP and MCs.

Patients with low back pain differ from those who also have leg pain or signs of nerve root involvement - a cross-sectional study.

BACKGROUND: Leg pain associated with low back pain (LBP) is recognized as a risk factor for a poor prognosis, and is included as a component in most LBP classification systems. The location of leg pain relative to the knee and the presence of a positive straight leg raise test have been suggested to have clinical implications. To understand differences between such leg pain subgroups, and whether differences include potentially modifiable characteristics, the purpose of this paper was to describe characteristics of patients classified into the Quebec Task Force (QTF) subgroups of: 1) LBP only, 2) LBP and pain above the knee, 3) LBP and pain below the knee, and 4) LBP and signs of nerve root involvement. METHODS: Analysis of routine clinical data from an outpatient department. Based on patient reported data and clinical findings, patients were allocated to the QTF subgroups and described according to the domains of pain, activity limitation, work participation, psychology, general health and clinical examination findings. RESULTS: A total of 2,673 patients aged 18-95 years (median 47) who were referred for assessment of LBP were included. Increasing severity was consistently observed across the subgroups from LBP only to LBP with signs of nerve root involvement although subgroup differences were small. LBP patients with leg pain differed from those with LBP only on a wide variety of parameters, and patients with signs of nerve root involvement had a more severe profile on almost all measures compared with other patients with back-related leg pain. CONCLUSION: LBP patients with pain referral to the legs were more severely affected than those with local LBP, and patients with signs of nerve root involvement were the ones most severily affected. These findings underpin the concurrent validity of the Quebec Task Force Classification. However, the small size of many between-subgroup differences amid the large variability in this sample of cross-sectional data also underlines that the heterogeneity of patients with LBP is more complex than that which can be explained by leg pain patterns alone. The implications of the observed differences also require investigation in longitudinal studies.

Trajectories of disability in low back pain.

INTRODUCTION: Low back pain (LBP) is the leading course of years lived with disability. Unfortunately, not much knowledge exists about distinct trajectories of recovery from disability after LBP and their potential psychological predictors. OBJECTIVES: Hence, the aim of the present study was to identify trajectories of functional disability in LBP and their potential baseline psychological predictors. METHODS: A 1-year consecutive cohort (N = 1048) of patients with LBP referred to the Spine Centre if they have not improved satisfactorily from a course of treatment in primary care after 1 to 2 months were assessed by self-report questionnaires at their first visit and at 6- and 12-month follow-up. Data from patients who responded to the Roland Morris Disability Questionnaire at least twice (N = 747) were used to assess trajectories of functional disability by Latent Growth Mixture Modeling. The following measures were used as baseline predictors of the trajectories: Pain Intensity Numerical Rating Scales, Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and Hospital Anxiety and Depression Scale. RESULTS: Four distinct trajectories were identified: high-stable (22.0%), high-decreasing (20.4%), medium-stable (29.7%), and low-decreasing (27.9%). Using the low-decreasing trajectory as reference, baseline pain intensity, depressive symptoms, and pain-catastrophizing predicted membership of all 3 symptomatic trajectories. However, using the high-decreasing trajectory as reference, age, baseline pain intensity, and depression were predictors of the high-stable trajectory. CONCLUSION: In particular, the finding of a high-stable trajectory characterized by high levels of baseline psychological distress is of potential clinical importance because psychological distress may be targeted by cognitive behavioral therapeutic approaches.

Translation and discriminative validation of the STarT Back Screening Tool into Danish.

OBJECTIVE: The STarT Back Screening Tool (STarT) is a nine-item patient self-report questionnaire that classifies low back pain patients into low, medium or high risk of poor prognosis. When assessed by GPs, these subgroups can be used to triage patients into different evidence-based treatment pathways. The objective of this study was to translate the English version of STarT into Danish (STarT-dk) and test its discriminative validity. METHODS: Translation was performed using methods recommended by best practice translation guidelines. Psychometric validation of the discriminative ability was performed using the Area Under the Curve statistic. The Area Under the Curve was calculated for seven of the nine items where reference standards were available and compared with the original English version. RESULTS: The linguistic translation required minor semantic and layout alterations. The response options were changed from "agree/disagree" to "yes/no" for four items. No patients reported item ambiguity using the final version. The Area Under the Curve ranged from 0.735 to 0.855 (CI95% 0.678-0.897) in a Danish cohort (n = 311) and 0.840 to 0.925 (CI95% 0.772-0.948) in the original English cohort (n = 500). On four items, the Area Under the Curve was statistically similar between the two cohorts but lower on three psychosocial sub-score items. CONCLUSIONS: The translation was linguistically accurate and the discriminative validity broadly similar, with some differences probably due to differences in severity between the cohorts and the Danish reference standard questionnaires not having been validated. Despite those differences, we believe the results show that the STarT-dk has sufficient patient acceptability and discriminative validity to be used in Denmark.