The terminologies of transient, migratory, or localized osteoporosis, and bone marrow edema syndrome: a scoping review.

There is no formally defined terminology for the related entities transient osteoporosis of the hip (TOH), localized or regional migratory osteoporosis (RMO) and bone marrow edema syndrome (BMES). This study aimed to map the diversity and frequency of diagnostic terms and vocabulary utilized in the literature. A comprehensive search of electronic databases and reference lists was conducted. Publications that reported on patients with TOH, RMO, BMES, or related variants were eligible for inclusion. The terminologies were categorized based on the wording of the titles, abstracts, or texts. We included 561 publications, of which 423 were case reports, involving 2921 patients. Overall, TOH was the most commonly used term, occurring in 257 (45.8%). RMO was used in 34 (6.1%) and BMES in 57 (10.2%). The remaining used various combinations of transient, migratory, and regional in conjunction with either osteoporosis or bone marrow edema. Localized osteoporosis was not used. We identified three different terms related to pregnancy. In 76.3% of the publications, the terminology was related to osteoporosis and in 18.2% to bone marrow edema, although terminology did not correspond to actual findings. Bone marrow edema occurred as often as osteoporosis, and osteoporosis was generally ascertained by visual inspection of radiographs, seldom by bone densitometry. Many publications used osteoporosis-related terms without evidence that osteoporosis had been detected. The terminology of these closely related entities is confusing and unstandardized. The lack of formal definitions impedes accurate diagnosis, research on disease mechanisms, and effective treatment.

Longitudinal Relationship Between Reduced Modic Change Edema and Disability and Pain in Patients With Chronic Low Back Pain.

STUDY DESIGN: Secondary analyses of a randomized trial [Antibiotics In Modic changes (MCs) study]. OBJECTIVE: To assess whether or not reduced MC edema over time is related to reduced disability and pain in patients with chronic low back pain (LBP). SUMMARY OF BACKGROUND DATA: It is not clear whether or not reduced MC edema implies improved clinical outcomes. PATIENTS AND METHODS: Linear regression was conducted separately in 2 subgroups with MC edema at baseline on short tau inversion recovery (STIR) or T1/T2-weighted magnetic resonance imaging, respectively. Independent variable: reduced edema (yes/no) at 1 year on STIR or T1/T2-series, respectively. Dependent variable: 1-year score on the Roland-Morris Disability Questionnaire (RMDQ), Oswestry Disability Index (ODI), or 0 to 10 numeric rating scale for LBP intensity, adjusted for the baseline score, age, smoking, body mass index, physical workload, and baseline edema on STIR (STIR analysis only). Post hoc, we, in addition, adjusted all analyses for baseline edema on STIR, treatment group (amoxicillin/placebo), and prior disc surgery-or for disc degeneration. RESULTS: Among patients with MC edema on STIR at baseline (n = 162), reduced edema on STIR was not significantly related to the RMDQ ( B : -1.0, 95% CI: -2.8, 0.8; P = 0.27), ODI ( B :-1.4, 95% CI: -5.4, 2.6; P = 0.50), or LBP intensity scores ( B : -0.05, 95% CI: -0.8, 0.7; P = 0.90) after 1 year. Among patients with MC edema on T1/T2-series at baseline (n = 116), reduced edema on T1/T2 ( i.e ., reduced volume of the type 1 part of MCs) was not significantly related to RMDQ ( B: -1.7, 95% CI: -3.8, 0.3; P = 0.10) or ODI score ( B : -2.3, 95% CI: -7.1, 2.5; P = 0.34) but was significantly related to LBP intensity at 1 year ( B : -0.9, 95% CI: -1.8, -0.04; P = 0.04; correlation coefficient: 0.24). The post hoc analyses supported these results. CONCLUSION: Reduced MC edema over 1 year was not significantly associated with pain-related disability but was (on T1/T2-series) significantly but weakly related to reduced LBP intensity. LEVEL OF EVIDENCE: Level 3.

Amoxicillin Did Not Reduce Modic Change Edema in Patients With Chronic Low Back Pain: Subgroup Analyses of a Randomised Trial (the AIM Study).

STUDY DESIGN: Exploratory subgroup analyses of a randomised trial [Antibiotics in Modic changes (AIM) study]. OBJECTIVE: The aim was to assess the effect of amoxicillin versus placebo in reducing Modic change (MC) edema in patients with chronic low back pain. SUMMARY OF BACKGROUND DATA: The AIM study showed a small, clinically insignificant effect of amoxicillin on pain-related disability in patients with chronic low back pain and MC type 1 (edema type) on magnetic resonance imaging (MRI). MATERIALS AND METHODS: A total of 180 patients were randomised to receive 100 days of amoxicillin or placebo. MC edema was assessed on MRI at baseline and one-year follow-up. Per-protocol analyses were conducted in subgroups with MC edema on short tau inversion recovery (STIR) or T1/T2-weighted MRI at baseline. MC edema reductions (yes/no) in STIR and T1/T2 series were analyzed separately. The effect of amoxicillin in reducing MC edema was analyzed using logistic regression adjusted for prior disk surgery. To assess the effect of amoxicillin versus placebo within the group with the most abundant MC edema on STIR at baseline ("STIR3" group), we added age, STIR3 (yes/no), and STIR3×treatment group (interaction term) as independent variables and compared the marginal means (probabilities of edema reduction). RESULTS: Compared to placebo, amoxicillin did not reduce MC edema on STIR (volume/intensity) in the total sample with edema on STIR at baseline (odds ratio 1.0, 95% CI: 0.5, 2.0; n=141) or within the STIR3 group (probability of edema reduction 0.69, 95% CI: 0.47, 0.92 with amoxicillin and 0.61, 95% CI: 0.43, 0.80 with placebo; n=41). Compared with placebo, amoxicillin did not reduce MC edema in T1/T2 series (volume of the type 1 part of MCs) (odds ratio: 1.0, 95% CI: 0.5, 2.3, n=104). Edema declined in >50% of patients in both treatment groups. CONCLUSIONS: From baseline to one-year follow-up, amoxicillin did not reduce MC edema compared with placebo. LEVEL OF EVIDENCE: 2.

Symptom descriptors and patterns in lumbar radicular pain caused by disc herniation: a 1-year longitudinal cohort study.

OBJECTIVE: The objective of the present study was to explore the diversity, quality, severity and distribution of symptoms in patients with radicular pain and a lumbar disc herniation. DESIGN: Longitudinal cohort study. SETTING: Hospital-based back clinic. PARTICIPANTS: Ninety patients referred to secondary healthcare with (a) low back-related leg pain, (b) age between 18 and 65 years and (c) MRI confirmed lumbar disc herniation at a relevant side and level. OUTCOME MEASURES: Neuropathic pain symptoms were assessed using the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) and the painDETECT Questionnaire. In a subsample classified with neuropathic pain, in-depth interviews were performed, and symptomatic areas were drawn on standardised body charts. RESULTS: At baseline, the most frequently used painDETECT symptom descriptor was numbness sensation, reported by 94%, followed by sudden pain attacks and tingling or prickling. The mean (SD) SF-MPQ-2 score (0-10) for aching pain was 5.9 (2.8); numbness 4.3 (3.3); tingling 4.0 (3.4); burning 2.6 (3.1); pain caused by light touch 1.5 (2.6). Leg pain was rated as extremely bothersome by 73%, numbness and tingling by 38%, weakness by 24% and back pain by 17%. In the subsample (n=52), deep-lying pain and non-painful abnormal sensations were frequent, at 71% and 85%. Drawings demonstrated substantial overlap between symptoms from compromised L5 and the S1 nerve roots. Painful and non-painful symptoms improved at approximately the same rate. At the 1-year follow-up, 45% (14/31) of patients who had received disc surgery, and 34% (18/53) of those who had received conservative treatment reported no bothersome back pain, leg pain, numbness/tingling or weakness. CONCLUSION: Patients reported several highly bothersome symptoms, but not all are described as painful. The overall symptom profile of lumbar disc-related radicular pain differs from other neuropathic pain conditions with limited allodynia and thermal hyperalgesia. Symptomatic areas for the L5 and S1 nerve roots have a large overlap.

Pinprick and Light Touch Are Adequate to Establish Sensory Dysfunction in Patients with Lumbar Radicular Pain and Disc Herniation.

BACKGROUND: The frequency with which sensory disturbances occur in patients with radicular leg pain and disc herniation is not well known, and the efficacy of tests to identify such changes are not firmly established. The presence of sensory disturbances is a key sign of nerve root involvement and may contribute to the diagnosis of a lumbar disc herniation, identify patients for referral to spinal imaging and surgery, and improve disease classification. QUESTIONS/PURPOSES: In this study, we sought: (1) to determine the frequency with which abnormal sensory findings occur in patients with lumbar disc herniation-related radicular pain, using a standard neurological sensory examination; (2) to determine what particular standard sensory test or combination of tests is most effective in establishing sensory dysfunction; and (3) to determine whether a more detailed in-depth sensory examination results in more patients being identified as having abnormal sensory findings. METHODS: Between October 2013 and April 2016, 115 patients aged 18 to 65 years referred to secondary health care with radicular leg pain and disc herniation were considered potentially eligible for inclusion in the study. Based on these inclusion criteria, 79% (91) were found eligible. Ten percent (11) were excluded because of other illness that interfered with the study purpose, 3% (3) because of cauda equina syndrome, 2% (2) because of spinal stenosis, 2% (2) because of prior surgery at the same disc level, and 2% (2) because of poor Norwegian language skills. Three percent (4) of the patients did not want to participate in the study. Of the 91 eligible patients, 56% (51) consented to undergo a comprehensive clinical examination and were used for analysis here. The sample for the purposes of the present study was predetermined at 50. These patients were first examined by a standard procedure, including sensory assessment of light touch, pinprick, vibration, and warmth and cold over the back and legs. Second, an in-depth semiquantitative sensory testing procedure was performed in the main pain area to assess sensory dysfunction and improve the detection of potential positive sensory signs, or sensory gain of function more precisely. Sensory loss was defined as sensations experienced as distinctly reduced in the painful side compared with the contralateral reference side. In contrast, sensory gain was defined as sensations experienced as abnormally strong, unpleasant, or painful and distinctly stronger than the contralateral side. Ambiguous test results were coded as a normal response to avoid inflating the findings. The proportions of abnormal findings were calculated for each sensory modality and for all combinations of the standard examination tests. RESULTS: The standard examination identified at least one abnormal finding in 88% (45 of 51) of patients. Sensory loss was present in 80% (41), while sensory gain was present in 35% (18). The combination of pinprick and light touch identified all patients who were classified as having abnormal findings by the full standard examination. The semiquantitative procedure identified an additional three patients with an abnormal finding. CONCLUSION: We suggest that the combination of pinprick and light touch assessment is an adequate minimal approach for diagnostic and classification purposes in patients with lumbar radicular pain. LEVEL OF EVIDENCE: Level I, diagnostic study.

Clinical effect modifiers of antibiotic treatment in patients with chronic low back pain and Modic changes - secondary analyses of a randomised, placebo-controlled trial (the AIM study).

BACKGROUND: Randomised trials on antibiotic treatment for patients with chronic low back pain and vertebral endplate changes visible on MRI (Modic changes) have shown mixed results. A possible explanation might be a real treatment effect in subgroups of the study populations. The purpose of the present study was to explore potential clinical effect modifiers of 3-months oral amoxicillin treatment in patients with chronic low back pain and type I or II Modic changes at the level of a previous lumbar disc herniation. METHODS: We performed analyses of effect modifiers on data from AIM, a double-blind parallel-group multicentre trial. One hundred eighty patients with chronic low back pain, previous disc herniation, Modic change type I (n = 118) or type II (n = 62) were randomised to 3-months oral treatment with 750 mg amoxicillin (n = 89) or placebo (n = 91) three times daily. The primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (possible values 0-24) at 1-year follow-up in the intention-to-treat population. The predefined minimal clinically important between-group mean difference was 4 RMDQ points (not reached in the primary analysis of AIM). Predefined baseline characteristics were analysed as potential effect modifiers, four primary (type I Modic changes, previous disc surgery, positive pain provocation test, high CRP) and five exploratory (disturbed sleep, constant low back pain, short duration of low back pain, younger age, and male) using ANCOVA with interaction terms. RESULTS: None of the four primary potential effect modifiers had strong evidence of modifying the treatment effect. In patients younger than 40 years the difference in mean RMDQ score between the treatment groups was - 4.0 (95%CI, - 6.9 to - 1.2), compared to - 0.5 (95%CI, - 2.3 to 1.3) in patients 40 years or older, both in favour of amoxicillin treatment (exploratory analysis). CONCLUSIONS: We did not find evidence for convincing clinical effect modifiers of antibiotic treatment in patients with chronic low back pain and Modic changes. Our results for younger age in these explorative analyses should not affect clinical treatment decisions without confirmation in future studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT02323412 , First registered 23 December 2014.

Cost-utility analysis of antibiotic treatment in patients with chronic low back pain and Modic changes: results from a randomised, placebo-controlled trial in Norway (the AIM study).

OBJECTIVE: To evaluate the cost-utility of 100 days of antibiotics in patients with chronic low back pain (LBP) and type I or II Modic changes included in the Antibiotic treatment In patients with chronic low back pain and Modic changes (AIM) study. DESIGN: A cost-utility analysis from a societal and healthcare perspective alongside a double-blinded, parallel group, placebo, multicentre trial. SETTING: Hospital outpatient clinics at six hospitals in Norway. The main results from the AIM study showed a small effect in back-related disability in favour of the antibiotics group, and slightly larger in those with type I Modic changes, but this effect was below the pre-defined threshold for clinically relevant effect. PARTICIPANTS: 180 patients with chronic LBP, previous disc herniation and Modic changes type I (n=118) or type II (n=62) were randomised to antibiotic treatment (n=89) or placebo-control (n=91). INTERVENTIONS: Oral treatment with either 750 mg amoxicillin or placebo three times daily for 100 days. MAIN OUTCOME MEASURES: Quality-adjusted life years (QALYs) by EuroQoL-5D over 12 months and costs for healthcare and productivity loss measured in Euro (€1=NOK 10), in the intention-to-treat population. Cost-utility was expressed in incremental cost-effectiveness ratio (ICER). RESULTS: Mean (SD) total cost was €21 046 (20 105) in the amoxicillin group and €19 076 (19 356) in the placebo group, mean difference €1970 (95% CI; -3835 to 7774). Cost per QALY gained was €24 625. In those with type I Modic changes, the amoxicillin group had higher healthcare consumption than the placebo group, resulting in €39 425 per QALY gained. Given these ICERs and a willingness-to-pay threshold of €27 500 (NOK 275 000), the probability of amoxicillin being cost-effective was 51%. Even when the willingness-to-pay threshold increased to €55 000, the probability of amoxicillin being cost-effective was never higher than 53%. CONCLUSIONS: Amoxicillin treatment showed no evidence of being cost-effective for people with chronic LBP and Modic changes during 1-year follow-up. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02323412.

Association of Modic change types and their short tau inversion recovery signals with clinical characteristics- a cross sectional study of chronic low back pain patients in the AIM-study.

BACKGROUND: Modic Changes (MCs, magnetic resonance imaging (MRI) signal changes in the vertebral bone marrow extending from the vertebral endplate) may represent a subgroup of nonspecific chronic low back pain that could benefit from a specific management. The primary aim was to compare clinical characteristics between patients with type 1 versus type 2 MCs. The secondary aim was to explore associations between clinical characteristics and MC related short tau inversion recovery (STIR) signals. METHODS: This cross-sectional study used baseline data prospectively collected between 2015 and 2017 on the 180 patients included in the AIM-study (Antibiotics In Modic changes), a randomized controlled trial in a Norwegian hospital out-patient setting of patients with chronic low back pain, a lumbar disc herniation within the last 2 years, low back pain intensity score ≥ 5 (on a 0-10 scale) and current type 1 or type 2 MCs at the previously herniated lumbar disc level. We used prespecified clinical characteristics including self-report measures, physiologic measures and functional measures from clinical history and examination. The diagnostic accuracy of various clinical characteristics to discriminate between patients with type 1 MCs (with or without additional type 2 MCs) and patents with type 2 MCs only (not type 1) were assessed by calculating the area under the receiver-operating curve. We assessed the correlations of clinical characteristics with details of MC related STIR signal increase. RESULTS: No clinical characteristic differed between patients with type 1 (n = 118) versus type 2 (but not type 1) (n = 62) MCs. The clinical characteristics showed no/minor differences or no/weak correlations with MC related STIR signal increase. Patients with a positive Springing test (at any lumbar level) had slightly less volume of STIR signal increase than those with a negative test (mean difference 1.3 on a 0-48 scale, 95% CI 0.3 to 2.3). CONCLUSION: Clinical characteristics were similar for patients with type 1 MCs and patients with type 2 MCs, and showed no clinically relevant correlations with MC related STIR signal increase. TRIAL REGISTRATION: ClinicalTrials.gov NCT02323412, First registered 23 December 2014.

New insight to the characteristics and clinical course of clusters of patients with imaging confirmed disc-related sciatica.

BACKGROUND: Referral to secondary care is common for a considerable proportion of patients with persistent sciatica symptoms. It is unclear if information from clinical assessment can further identify distinct subgroups of disc-related sciatica, with perhaps different clinical courses. AIMS: This study aims to identify and describe clusters of imaging confirmed disc-related sciatica patients using latent class analysis, and compare their clinical course. METHODS: The study population were 466 patients with disc-related sciatica. Variables from clinical assessment were included in the analysis. Characteristics of the identified clusters were described and their clinical course over 2 years was compared. RESULTS: A four-cluster solution was optimal. Cluster 1 (n = 110) had mild back and leg pain; cluster 2 (n = 59) had moderate back and leg pain; cluster 3 (n = 158) had mild back pain and severe leg pain; cluster 4 (n = 139) had severe back and leg pain. Patients in cluster 4 had the most severe profile in terms of disability, distress and comorbidity and the lowest reported global change and the smallest proportion of patients with a successful outcome at 2 years. Of the 135 patients who underwent surgery, 42% and 41% were in clusters 3 and 4, respectively. CONCLUSIONS: Using a strict diagnosis of sciatica, this work identified four clusters of patients primarily differentiated by back and leg pain severity. Patients with severe back and leg pain had the most severe profile at baseline and follow-up irrespective of intervention. This simple classification system may be useful when considering prognosis and management with sciatica patients. SIGNIFICANCE: Using data from a large observational prospective study, this work identifies four distinct clusters of patients with imaging confirmed disc-related sciatica. This classification could be used when considering prognosis and management with sciatica patients at their initial consultation.

Lumbar spine surgery across 15 years: trends, complications and reoperations in a longitudinal observational study from Norway.

BACKGROUND: Studies from different Western countries have reported a rapid increase in spinal surgery rates, an increase that exceeds by far the growing incidence rates of spinal disorders in the general population. There are few studies covering all lumbar spine surgery and no previous studies from Norway. OBJECTIVES: The purpose of this study was to investigate trends in all lumbar spine surgery in Norway over 15 years, including length of hospital stay, and rates of complications and reoperations. DESIGN: A longitudinal observational study over 15 years using hospital patient administrative data and sociodemographic data from the National Registry in Norway. SETTING AND PARTICIPANTS: Patients aged ≥18 years discharged from Norwegian public hospitals between 1999 and 2013. OUTCOME MEASURES: Annual rates of simple (microsurgical discectomy, decompression) and complex surgical procedures (fusion, disc prosthesis) in the lumbar spine. RESULTS: The rate of lumbar spine surgery increased by 54%, from 78 (95% CI (75 to 80)) to 120 (107 to 113) per 100 000, from 1999 to 2013. More men had simple surgery whereas more women had complex surgery. Among elderly people over 75 years, lumbar surgery increased by a factor of five during the 15-year period. The rates of complications were low, but increased from 0.7% in 1999 to 2.4% in 2013. CONCLUSIONS: There was a substantial increase in lumbar spine surgery in Norway from 1999 to 2013, similar to trends in other Western world countries. The rise in lumbar surgery among elderly people represents a significant workload and challenge for health services, given our aging population.

The Rates of LSS Surgery in Norwegian Public Hospitals: A Threefold Increase From 1999 to 2013.

STUDY DESIGN: Retrospective administrative database study. OBJECTIVE: To assess temporal and regional trends, and length of hospital stay, in lumbar spinal stenosis (LSS) surgery in Norwegian public hospitals from 1999 to 2013. SUMMARY OF BACKGROUND DATA: Studies from several countries have reported increasing rates of LSS surgery over the last decades. No such data have been presented from Norway. METHODS: A database consisting of discharges from all Norwegian public hospitals was established. Inclusion criteria were discharges including a surgical procedure of lumbar spinal decompression and/or fusion in combination with an International Statistical Classification of Diseases and Related Health Problems, 10th Revision diagnosis of Spinal Stenosis (M48.0) or Other Spondylosis with Radiculopathy (M47.2), and a patient age of 18 years or older. Discharges with diagnoses indicating deformity, that is, spondylolisthesis or scoliosis were not included. RESULTS: During the 15-year period, 19,543 discharges were identified. The annual rate of decompressions increased from 10.7 to 36.2 and fusions increased from 2.5 to 4.4 per 100,000 people of the general Norwegian population. The proportion of fusion surgery decreased from 19.3% to 10.9%. Among individuals older than 65 years, the annual rate of surgery per 10,000, including both decompressions and fusions, more than quadrupled from 40.2 to 170.3. The regional variation was modest, differing with a factor of 1.4 between the region with the highest and the lowest surgical rates. The mean length of hospital stay decreased from 11.0 (standard deviation 8.0) days in 1999 to 5.0 (4.6) days in 2013, but patients who received fusion surgery stayed on average 3.6 days longer than those who received decompression only. CONCLUSION: The rate of LSS surgery more than tripled in Norway from 1999 to 2013. The mean length of hospital stay was reduced from 11 to 5 days. LEVEL OF EVIDENCE: N/A.

Antibiotic treatment In patients with chronic low back pain and Modic changes (the AIM study): study protocol for a randomised controlled trial.

BACKGROUND: A previous randomised controlled trial (RCT) of patients with chronic low back pain (LBP) and vertebral bone marrow (Modic) changes (MCs) on magnetic resonance imaging (MRI), reported that a 3-month, high-dose course of antibiotics had a better effect than placebo at 12 months' follow-up. The present study examines the effects of antibiotic treatment in chronic LBP patients with MCs at the level of a lumbar disc herniation, similar to the previous study. It also aims to assess the cost-effectiveness of the treatment, refine the MRI assessment of MCs, and further evaluate the impact of the treatment and the pathogenesis of MCs by studying genetic variability and the gene and protein expression of inflammatory biomarkers. METHODS/DESIGN: A double-blinded RCT is conducted at six hospitals in Norway, comparing orally administered amoxicillin 750 mg, or placebo three times a day, over a period of 100 days in patients with chronic LBP and type I or II MCs at the level of a MRI-confirmed lumbar disc herniation within the preceding 2 years. The inclusion will be stopped when at least 80 patients are included in each of the two MC type groups. In each MC type group, the study is designed to detect (ß = 0.1, α = 0.05) a mean difference of 4 (standard deviation 5) in the Roland Morris Disability Questionnaire score between the two treatment groups (amoxicillin or placebo) at 1-year follow-up. The study includes cost-effectiveness measures. Blood samples are assessed for security measures and for possible inflammatory mediators and biomarkers at different time points. MCs are evaluated on MRI at baseline and after 12 months. A blinded intention-to-treat analysis of treatment effects will be performed in the total sample and in each MC type group. DISCUSSION: To ensure the appropriate use of antibiotic treatment, its effect in chronic LBP patients with MCs should be re-assessed. This study will investigate the effects and cost-effectiveness of amoxicillin in patients with chronic LBP and MCs at the level of a disc herniation. The study may also help to refine imaging and characterise the biomarkers of MCs. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02323412 . Registered on 21 November 2014.

Subjective health complaints in patients with lumbar radicular pain and disc herniation are associated with a sex - OPRM1 A118G polymorphism interaction: a prospective 1-year observational study.

BACKGROUND: Earlier observations show that development of persistent pain may be associated with the genetic variability in the gene encoding for the µ-opioid receptor 1, the OPRM1 A118G (rs1799971). The aim of this study was to investigate the association between OPRM1 genotype and subjective health complaints in patients with radicular pain and disc herniation. METHODS: A prospective, 1-year observational study was conducted at a hospital back clinic, including 118 Caucasian patients with lumbar radicular pain and MRI confirmed disc herniation. Single nucleotide polymorphism genotyping regarding the OPRM1 A118G was performed. The data of individuals with AA versus AG or GG were analysed separately by linear mixed models. The Subjective Health Complaints Inventory (0-81) including 27 common complaints experienced the previous month on a scale from not at all (0) to severe (3) was used as outcome. Pain, prior duration of leg pain, age, smoking status, and lumbar disc surgery were considered as covariates. RESULTS: In total 23 of 118 patients were carriers of the OPRM1 G-allele. All patients except female carriers of the G-allele reported a decrease in pain from baseline to 1 year. Female carriers of the G-allele reported significantly higher subjective health complaints score during the study time span than male carriers of the G-allele when controlling for pain and pain duration. CONCLUSION: The present data indicate that, when controlling for pain intensity and duration, subjective health complaints are associated with a sex - OPRM1 A118G polymorphism interaction in patients with radicular pain.

Prognostic factors for return to work in patients with sciatica.

BACKGROUND CONTEXT: Little is known about the prognostic factors for work-related outcomes of sciatica caused by disc herniation. PURPOSE: To identify the prognostic factors for return to work (RTW) during a 2-year follow-up among sciatica patients referred to secondary care. STUDY DESIGN/SETTING: Multicenter prospective cohort study including 466 patients. Administrative data from the National Sickness Benefit Register were accessed for 227 patients. PATIENT SAMPLE: Two samples were used. Sample A comprised patients who at the time of inclusion in the cohort reported being on partial sick leave or complete sick leave or were undergoing rehabilitation because of back pain/sciatica. Sample B comprised patients who, according to the sickness benefit register, at the time of inclusion received sickness benefits or rehabilitation allowances because of back pain/sciatica. OUTCOME MEASURES: In Sample A, the outcome was self-reported return to full-time work at the 2-year follow-up. In Sample B, the outcome was time to first sustained RTW, defined as the first period of more than 60 days without receiving benefits from the register. METHODS: Significant baseline predictors of self-reported RTW at 2 years (Analysis A) were identified by multivariate logistic regression. Significant predictors of time to sustained RTW (Analysis B) were identified by multivariate Cox proportional hazard modeling. Both analyses included adjustment for age and sex. To assess the effect of surgery on the probability of RTW, analyses similar to A and B were performed, including the variable surgery (yes/no). RESULTS: One-fourth of the patients were still out of work at the 2-year follow-up. In Sample A (n=237), younger age, better general health, lower baseline sciatica bothersomeness, less fear-avoidance work, and a negative straight-leg-raising test result were significantly associated with a higher probability of RTW at the 2-year follow-up. Surgery was not significantly associated with the outcome. In Sample B (n=125), history of sciatica, duration of the current sciatica episode more than 3 months, greater sciatica bothersomeness, fear-avoidance work, and back pain were significantly associated with a longer time to sustained RTW. Surgery was significantly negatively associated with time to sustained RTW both in univariate (hazard ratio [HR] 0.60; 95% confidence interval [CI] 0.39, 0.93; p=.02) and in multivariate (HR 0.49; 95% CI 0.31, 0.79; p=.003) analyses. CONCLUSIONS: The baseline factors associated with RTW identified in multivariate analysis were age, general health, history of sciatica, duration of the current episode, baseline sciatica bothersomeness, fear-avoidance work, back pain, and the straight-leg-raising test result. Surgical treatment was associated with slower RTW, but surgical patients were more severely affected than patients treated without surgery; so, this finding should be interpreted with caution.

Prognostic factors for non-success in patients with sciatica and disc herniation.

BACKGROUND: Few studies have investigated prognostic factors for patients with sciatica, especially for patients treated without surgery. The aim of this study was to identify factors associated with non-success after 1 and 2 years of follow-up and to test the prognostic value of surgical treatment for sciatica. METHODS: The study was a prospective multicentre observational study including 466 patients with sciatica and lumbar disc herniation. Potential prognostic factors were sociodemographic characteristics, back pain history, kinesiophobia, emotional distress, pain, comorbidity and clinical examination findings. Study participation did not alter treatment considerations for the patients in the clinics. Patients reported on the questionnaires if surgery of the disc herniation had been performed. Uni- and multivariate logistic regression analyses were used to evaluate factors associated with non-success, defined as Maine-Seattle Back Questionnaire score of ≥5 (0-12) (primary outcome) and Sciatica Bothersomeness Index ≥7 (0-24) (secondary outcome). RESULTS: Rates of non-success were at 1 and 2 years 44% and 39% for the main outcome and 47% and 42% for the secondary outcome. Approximately 1/3 of the patients were treated surgically. For the main outcome variable, in the final multivariate model non-success at 1 year was significantly associated with being male (OR 1.70 [95% CI; 1.06 - 2.73]), smoker (2.06 [1.31 - 3.25]), more back pain (1.0 [1.01 - 1.02]), more comorbid subjective health complaints (1.09 [1.03 - 1.15]), reduced tendon reflex (1.62 [1.03 - 2.56]), and not treated surgically (2.97 [1.75 - 5.04]). Further, factors significantly associated with non-success at 2 years were duration of back problems >; 1 year (1.92 [1.11 - 3.32]), duration of sciatica >; 3 months (2.30 [1.40 - 3.80]), more comorbid subjective health complaints (1.10 [1.03 - 1.17]) and kinesiophobia (1.04 [1.00 - 1.08]). For the secondary outcome variable, in the final multivariate model, more comorbid subjective health complaints, more back pain, muscular weakness at clinical examination, and not treated surgically, were independent prognostic factors for non-success at both 1 and 2 years. CONCLUSIONS: The results indicate that the prognosis for sciatica referred to secondary care is not that good and only slightly better after surgery and that comorbidity should be assessed in patients with sciatica. This calls for a broader assessment of patients with sciatica than the traditional clinical assessment in which mainly the physical symptoms and signs are investigated.