Low back pain research – Future directions

High-resolution, three-dimensional magnetic resonance imaging axial load dynamic study improves diagnostics of the lumbar spine in clinical practice

BACKGROUND

The response to axial physiological pressure due to load transfer to the lumbar spine structures is among the various back pain mechanisms. Understanding the spine adaptation to cumulative compressive forces can influence the choice of personalized treatment strategies.

AIM

To analyze the impact of axial load on the spinal canal’s size, intervertebral foramina, ligamenta flava and lumbosacral alignment.

METHODS

We assessed 90 patients using three-dimensional isotropic magnetic resonance imaging acquisition in a supine position with or without applying an axial compression load. Anatomical structures were measured in the lumbosacral region from L1 to S1 in lying and axially-loaded magnetic resonance images. A paired t test at α = 0.05 was used to calculate the observed differences.

RESULTS

After axial loading, the dural sac area decreased significantly, by 5.2% on average (4.1%, 6.2%, P < 0.001). The intervertebral foramina decreased by 3.4% (2.7%, 4.1%, P < 0.001), except for L5-S1. Ligamenta flava increased by 3.8% (2.5%, 5.2%, P < 0.001), and the lumbosacral angle increased.

CONCLUSION

Axial load exacerbates the narrowing of the spinal canal and intervertebral foramina from L1-L2 to L4-L5. Cumulative compressive forces thicken ligamenta flava and exaggerate lumbar lordosis.

Identifying psychosocial characteristics that predict outcome to the UPLIFT programme for people with persistent back pain: protocol for a prospective cohort study

INTRODUCTION

Prognostic screening of people with low back pain (LBP) improves utilisation of primary healthcare resources. Whether this also applies to secondary healthcare remains unclear. Therefore, this study aims to develop prognostic models to determine at baseline which patients with persistent LBP are likely to have a good and poor outcome to a 5-week programme of combined education and exercise ('UPLIFT') delivered in a secondary healthcare setting.

METHODS AND ANALYSIS

A prospective cohort study of 246 people with persistent LBP will be conducted in a secondary healthcare outpatient setting. Patients will be recruited from a physiotherapy-led neurosurgical screening clinic. Demographic data, medical history and psychosocial characteristics will be recorded at baseline. Fear avoidance beliefs, pain self-efficacy, LBP treatment beliefs, pain catastrophising, perceived injustice, depression, anxiety and stress, disability level, pain intensity and interference, health status and social connectedness will be considered as potential prognostic variables, which will be assessed using self-reported questionnaires. Participants will attend the UPLIFT programme, consisting of weekly 90 min group sessions that combine interactive education sessions and a graded exercise programme. The outcome measure to identify good and poor outcome is the Global Rating of Change scale, assessed at completion of the UPLIFT programme and at 6 months follow-up. Multiple imputation analyses will be performed for missing values. Prognostic models will be developed using multivariable logistic regression analyses, with bootstrapping techniques for internal validation. We will calculate the explained variance of the models and the area under the receiver operating characteristic curve. Furthermore, we will determine whether participation in the UPLIFT programme is associated with changes in psychosocial characteristics.

ETHICS AND DISSEMINATION

Gold Coast Health Service Human Research Ethics Committee (HREC/18/QGC/41) and the Griffith University Human Research Ethics Committee (GU Ref No: 2018/408) approved the study. Dissemination of findings will occur via peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12618001525279.

Do sensorimotor cortex activity, an individual's capacity for neuroplasticity, and psychological features during an episode of acute low back pain predict outcome at 6 months: a protocol for an Australian, multisite prospective, longitudinal cohort study

INTRODUCTION

Low back pain (LBP) is the leading cause of disability worldwide, with prevalence doubling in the past 14 years. To date, prognostic screening tools display poor discrimination and offer no net benefit of screening over and above a 'treat all' approach. Characteristics of the primary sensory (S1) and motor (M1) cortices may predict the development of chronic LBP, yet the prognostic potential of these variables remains unknown. The Understanding persistent Pain Where it ResiDes (UPWaRD) study aims to determine whether sensorimotor cortex activity, an individual's capacity for plasticity and psychosocial factors in the acute stage of pain, predict LBP outcome at 6 months. This paper describes the methods and analysis plan for the development of the prediction model.

METHODS AND ANALYSIS

The study uses a multicentre prospective longitudinal cohort design with 6-month follow-up. 120 participants, aged 18 years or older, experiencing an acute episode of LBP (less than 6 weeks duration) will be included. Primary outcomes are pain and disability.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from Western Sydney University Human Research Ethics Committee (H10465) and from Neuroscience Research Australia (SSA: 16/002). Dissemination will occur through presentations at national and international conferences and publications in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12619000002189; Pre-results.

Prognosis of sciatica and back-related leg pain in primary care: the ATLAS cohort

BACKGROUND CONTEXT

Evidence is lacking on the prognosis and prognostic factors of back-related leg pain and sciatica in patients seeing their primary care physicians. This evidence could guide timely appropriate treatment and referral decisions.

PURPOSE

The present study aims to describe the prognosis and prognostic factors in primary care patients with low back-related leg pain and sciatica.

STUDY DESIGN

This is a prospective cohort study.

PATIENT SAMPLE

The present study included adults visiting their family doctor with back-related leg pain in the United Kingdom.

OUTCOME MEASURES

Information about pain, function, psychological, and clinical variables, was collected. Good outcome was defined as 30% or more reduction in disability (Roland-Morris Disability Questionnaire).

METHODS

Participants completed the questionnaires, underwent clinical assessments, received a magnetic resonance imaging scan, and were followed-up 12 months later. Mixed-effects logistic regression evaluated the prognostic value of six a priori defined variable sets (leg pain duration, pain intensity, neuropathic pain, psychological factors, clinical examination, and imaging variables). A combined model, including variables from all models, examined independent effects. The National Institute for Health Research funded the study. There are no conflicts of interest.

RESULTS

A total of 609 patients were included. At 12 months, 55% of patients improved in both the total sample and the sciatica group. For the whole cohort, longer leg pain duration (odds ratio [OR] 0.41; confidence interval [CI] 0.19-0.90), higher identity score (OR 0.70; CI 0.53-0.93), and patient's belief that the problem will last a long time (OR 0.27; CI 0.13-0.57) were the strongest independent prognostic factors negatively associated with improvement. These last two factors were similarly negatively associated with improvement in the sciatica subgroup.

CONCLUSIONS

The present study provides new evidence on the prognosis and prognostic factors of back-related leg pain and sciatica in primary care. Just over half of patients improved at 12 months. Patient's belief of recovery timescale and number of other symptoms attributed to the pain are independent prognostic factors. These factors can be used to inform and direct decisions about timing and intensity of available therapeutic options.

Association between intervertebral disc degeneration and the Oswestry Disability Index

BACKGROUND

Low back pain and lumbar intervertebral disc degeneration (IDD) are common findings. Valid data on correlation between clinical pain scores and grades of IDD are not available.

OBJECTIVE

To investigate the correlation of intervertebral disc degeneration (IDD) at lumbar levels L4/5 and L5/S1 and the Oswestry Disability Index (ODI).

METHODS

The lumbar discs L4/5 and L5/S1 of 591 patients were evaluated according to the 5-point (Grade I to Grade V) grading system as published by Pfirrmann et al. Functional status was assessed using the Oswestry Disability Index. Spearman's coefficient of rank correlation was used for statistical analysis (p < 0.05).

RESULTS

The majority of patients revealed lumbar discs with Pfirrmann grade II to grade IV changes (93.3% at level L4/5; 89.8% at level L5/S1), while a relatively low percentage of lumbar discs presented with grade I (level L4/5: 1.5%; level L5/S1: 2.0%) or grade V (level L4/5: 5.1%; level L5/S1: 8.1%) changes, respectively. Patients' ODI scores ranged between 0 and 91.11% (arithmetic mean of 32.77% ± 17.02%). The largest group of patients (48.39%) had moderate functional disability (ODI score between 21 and 40%). There was a weak, but statistically significant positive correlation between IDD and ODI for both evaluated lumbar levels.

CONCLUSIONS

Increased lumbar IDD in MRI goes along with an increased ODI. Thus, MRI is a strong indicator of a patient's clinical appearance. However, low back pain cannot be explained by imaging alone. Clinical correlation is imperative for an adequate diagnostic advance in patients with low back pain.

Can screening instruments accurately determine poor outcome risk in adults with recent onset low back pain? A systematic review and meta-analysis

BACKGROUND

Delivering efficient and effective healthcare is crucial for a condition as burdensome as low back pain (LBP). Stratified care strategies may be worthwhile, but rely on early and accurate patient screening using a valid and reliable instrument. The purpose of this study was to evaluate the performance of LBP screening instruments for determining risk of poor outcome in adults with LBP of less than 3 months duration.

METHODS

Medline, Embase, CINAHL, PsycINFO, PEDro, Web of Science, SciVerse SCOPUS, and Cochrane Central Register of Controlled Trials were searched from June 2014 to March 2016. Prospective cohort studies involving patients with acute and subacute LBP were included. Studies administered a prognostic screening instrument at inception and reported outcomes at least 12 weeks after screening. Two independent reviewers extracted relevant data using a standardised spreadsheet. We defined poor outcome for pain to be ≥ 3 on an 11-point numeric rating scale and poor outcome for disability to be scores of ≥ 30% disabled (on the study authors' chosen disability outcome measure).

RESULTS

We identified 18 eligible studies investigating seven instruments. Five studies investigated the STarT Back Tool: performance for discriminating pain outcomes at follow-up was 'non-informative' (pooled AUC = 0.59 (0.55-0.63), n = 1153) and 'acceptable' for discriminating disability outcomes (pooled AUC = 0.74 (0.66-0.82), n = 821). Seven studies investigated the Orebro Musculoskeletal Pain Screening Questionnaire: performance was 'poor' for discriminating pain outcomes (pooled AUC = 0.69 (0.62-0.76), n = 360), 'acceptable' for disability outcomes (pooled AUC = 0.75 (0.69-0.82), n = 512), and 'excellent' for absenteeism outcomes (pooled AUC = 0.83 (0.75-0.90), n = 243). Two studies investigated the Vermont Disability Prediction Questionnaire and four further instruments were investigated in single studies only.

CONCLUSIONS

LBP screening instruments administered in primary care perform poorly at assigning higher risk scores to individuals who develop chronic pain than to those who do not. Risks of a poor disability outcome and prolonged absenteeism are likely to be estimated with greater accuracy. It is important that clinicians who use screening tools to obtain prognostic information consider the potential for misclassification of patient risk and its consequences for care decisions based on screening. However, it needs to be acknowledged that the outcomes on which we evaluated these screening instruments in some cases had a different threshold, outcome, and time period than those they were designed to predict.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO international prospective register of systematic reviews registration number CRD42015015778 .

Proprioceptive use and sit-to-stand-to-sit after lumbar microdiscectomy: The effect of surgical approach and early physiotherapy

BACKGROUND

Individuals with non-specific low back pain show decreased reliance on lumbosacral proprioceptive signals and slower sit-to-stand-to-sit performance. However, little is known in patients after lumbar microdiscectomy.

METHODS

Patients were randomly assigned into transmuscular (n=12) or paramedian lumbar surgery (n=13). After surgery, the same patients were randomly assigned into individualized active physiotherapy starting 2 weeks after surgery (n=12) or usual care (n=13). Primary outcomes were center of pressure displacement during ankle and back muscles vibration (to evaluate proprioceptive use), and the duration of five sit-to-stand-to-sit movements, evaluated at 2 (baseline), 8 and 24 weeks after surgery.

FINDINGS

Two weeks after surgery, all patients showed smaller responses to back compared to ankle muscles vibration (P<0.05). Patients that underwent a transmuscular surgical procedure and patients that received physiotherapy switched to larger responses to back muscles vibration at 24 weeks, compared to 2 weeks after surgery (P<0.005), although not seen in the paramedian group and usual care group (P>0.05). Already 8 weeks after surgery, the physiotherapy group needed significantly less time to perform five sit-to-stand-to-sit movements compared to the usual care group (P<0.05).

INTERPRETATION

Shortly after lumbar microdiscectomy, patients favor reliance on ankle proprioceptive signals over lumbosacral proprioceptive reliance to maintain posture, which resembles the behavior of patients with non-specific low back pain. However, early active physiotherapy after lumbar microdiscectomy facilitated higher reliance on lumbosacral proprioceptive signals and early improvement of sit-to-stand-to-sit performance. Transmuscular lumbar surgery favoured recovery of lumbosacral proprioception 6 months after surgery.

CLINICAL TRIAL NUMBER

NCT01505595.

Rising prevalence of back pain in Austria: considering regional disparities

BACKGROUND

Back pain is the most common form of musculoskeletal conditions and leads to high health care costs. Information about geographic variations in highly prevalent diseases/disorders represents important implications for public health planning to face structural challenges. The present study aims to investigate regional trends in the prevalence of back pain and the role of obesity and social inequalities among Austrian adults.

METHODS

A secondary data analysis based on five nationally representative cross-sectional surveys (1973-2007) was carried out (N = 178,818). Back pain was measured as self-reported presence. Obesity (BMI ≥ 30 kg/m²) was adjusted for self-report bias. For the regional analyses, Austria was divided into Western, Central and Eastern Austria. A relative index of inequality (RII) was computed to quantify the extent of social inequality.

RESULTS

A continuous rise in back pain prevalence was observed in the three regions and among all investigated subgroups. In 2007 the age-standardised prevalence was similar in Central (36.9 %), Western (35.2 %) and Eastern Austria (34.3 %). The absolute change in back pain prevalence was highest among obese subjects in Central Austria (women: + 29.8 %, men: + 32.5 %). RIIs were unstable during the study period and in 2007 highest in Eastern Austria.

CONCLUSION

Variation and trends in back pain are not attributable to geographic variation in Austria: an assumed East-West gradient in Austria has not been confirmed. Nevertheless our study confirms that back pain dramatically increased in all Austrian regions and investigated subgroups. This worrying trend should be further monitored and public health interventions should be implemented increasingly, especially among obese women and men.

Chronic low back pain clinical outcomes present higher associations with the STarT Back Screening Tool than with physiologic measures: a 12-month cohort study

BACKGROUND

Stratification strategies based on identifying patient's prognosis in order to guide patient care constitute one of the most prominent and recent approach in low back pain research. The STarT Back Screening Tool (SBST) although promising, has not been studied in patients with chronic low back pain (cLBP). Considering how challenging it is to translate research into practice, the value of integrating a new tool should be thoroughly assessed. The purpose was therefore to assess associations between the short- and long-terms clinical status and two types of variables, physiologic measures and the SBST, in participants with cLBP. The ability of both types of variables to discriminate between participants with and without higher levels of disability, pain, fear of movement and patient's global impression of change was also investigated.

METHODS

Fifty-three volunteers with cLBP participated in an initial evaluation and follow-ups at 2-, 4-, 6- and 12-month. Physiologic measures (maximal voluntary contraction, maximal endurance and muscle activity evaluated during prone and lateral isometric tasks) and the SBST were assessed at baseline. Disability (Oswestry Disability Index, ODI), pain intensity (101-point Numerical Rating Scale, NRS), fear of movement (Tampa Scale for Kinesiophobia, TSK) and patient's global impression of change (7-point scale, PGIC) were evaluated at baseline and at each follow-up. Aside the use of correlation analyses to assess potential associations; ROC curves were performed to evaluate the discriminative ability of physiologic measures and the SBST.

RESULTS

The SBST allowed for the identification of participants presenting higher levels of disability (ODI ≥24 %), pain (NRS ≥37 %) or fear of movement (TSK ≥41/68) over a 12-month period (AUC = 0.71 to 0.84, ps < 0.05). The SBST score was also correlated with disability at each follow-up (τ = 0.22 to 0.33, ps < 0.05) and with pain intensity and fear of movement at follow-ups. Among physiologic measures, only maximal voluntary contraction was correlated to disability, pain intensity or fear of movement during the follow-up (|τ| = 0.26 to 0.32, ps < 0.05) and none was able to identify participants presenting higher levels of outcomes (AUC ps > 0.05).

CONCLUSION

Physiologic measures obtained during prone and lateral tests have limited associations with the clinical status over a 12-month period in patients with nonspecific chronic low back pain. On the other hand, the STarT Back Screening Tool is useful for the identification of patients who will present higher levels of disability, pain intensity and fear of movement over a year.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02226692.

Can experienced physiotherapists identify which patients are likely to succeed with physical therapy treatment?

Background

The purpose of the study was to determine if clinician predicted prognosis is associated with patient outcomes.

Methods

The study was a secondary analysis of data that were collected in 8 physiotherapy outpatient clinics. Nine physiotherapists with post-graduate training in manual therapy (mean 20.3 years of experience) were asked at baseline to project the outcome of the patients evaluated. In total, 112 patients with low back (74 %) or neck (26 %) pain were treated pragmatically with interventions consisting of manual therapy, strengthening, and patient-specific education. Outcomes measures consisted of percent change in disability (Oswestry or Neck Disability Index), self-reported rate of recovery (0–100 %), and percent change in pain (numerical pain rating scale). Hierarchical logistic regression determined potential factors (clinician predicted prognosis score (1–10) at baseline, dichotomised as poor (1–6) and good (7–10); symptom duration categorised as acute, subacute or chronic; same previous injury (yes/no); baseline pain and disability scores; within-session improvement at initial visit (yes/no); and presence of ≥ one psychological factor) associated with meaningful changes in each of the three outcomes at discharge (disability and pain > 50 % improvement, rate of recovery ≥82.5 % improvement).

Results

Clinician predicted prognosis (OR 4.15, 95%CI = 1.31, 13.19, p = 0.02) and duration of symptoms (OR subacute 0.24, 95%CI = 0.07, 0.89, p = 0.03; chronic 0.21, 95%CI = 0.05, 0.90, p = 0.04) were associated with rate of recovery, whereas only clinician predicted prognosis was associated with disability improvement (OR 4.28, 95 % CI 1.37, 13.37, p = 0.01). No variables were associated with pain improvement.

Conclusions

Clinician predicted prognosis is potentially valuable for patients, as a good predicted prognosis is associated with improvements in disability and rate of recovery.

Prevalence of neck and low back pain in community-dwelling adults in Spain: an updated population-based national study (2009/10-2011/12)

PURPOSE

To estimate time trends in the prevalence of neck (NP) and low back pain (LBP) from 2009 to 2012; and to determine the socio-demographic features, self-rated health status, co-morbidity, lifestyle-related habits, and health care service associated with NP and LBP in Spanish adults.

OUTCOME MEASURES

The European Health Interview Survey for Spain (2009) and the Spanish National Health Survey (2011).

METHODS

A total of 43,072 subjects were included. We analyzed data collected from the European Health Interview Survey for Spain conducted in 2009 (n = 22,188), and the Spanish National Health Survey in 2011 (n = 20,884). We considered the presence of isolated NP, LBP and both (NP&LBP). We analyzed socio-demographic features; self-perceived health status; lifestyle habits; comorbid diseases, and professional treatment using logistic regression models.

RESULTS

The prevalence of isolated NP, LBP and NP&LBP increased from 2008/9 to 2011/12 (7.86 vs. 8.56 %; 5.18 vs.5.44 %; 10.61 vs.11.12 %, respectively). Being female, increased the probability of isolated NP and NP&LBP, but decreased the probability of LBP. The prevalence of all pain localizations increased with older age, lower education level, poor self-rated health, smoker, comorbidities, psychological distress (anxiety or depression), hospital and physiotherapist visits and consumed drugs for pain, in 2008/9 as compared to 2011/12. Moreover, LBP, and NP&LBP were associated with obesity, whereas NP&LBP was associated with being married.

CONCLUSIONS

The prevalence of LBP, NP and NP&LBP had increased in the last 3 years in Spain.

A 35-year trend analysis for back pain in Austria: the role of obesity

Background

The prevalence of back pain is constantly increasing and a public health problem of high priority. In Austria there is a lack of empirical evidence for the development of back pain and its related factors. The present study aims to investigate trends in the prevalence of back pain across different subpopulations (sex, age, obesity).

Methods

A secondary data analysis based on five nationally representative cross-sectional health surveys (1973–2007) was carried out. Face-to-face interviews were conducted in private homes in Austria. Subjects aged 20 years and older were included in the study sample (n = 178,818). Obesity was defined as BMI≥30 kg/m² and adjusted for self-report bias. Back pain was measured as the self-reported presence of the disorder.

Results

The age-standardized prevalence of back pain was 32.9% in 2007; it was higher among women than men (p<0.001), higher in older than younger subjects (p<0.001) and higher in obese than non-obese individuals (p<0.001). During the investigation period the absolute change in the prevalence of back pain was +19.4%. Among all subpopulations the prevalence steadily increased. Obese men showed the highest increase of and the greatest risk for back pain.

Conclusion

These results help to understand the development of back pain in Austria and can be used to plan controlled promotion programs. Further monitoring is recommended in order to control risk groups and plan target group-specific prevention strategies. In Austria particular emphasis should be on obese individuals. We recommend conducting prospective studies to confirm our results and investigate causal relationships.

Relief from Back Pain Through Postural Adjustment: a Controlled Clinical Trial of the Immediate Effects of Muscular Chains Therapy (MCT)

Introduction

Back pain can be one of the most common health problems, causing suffering, disabilities, and financial losses. Postural models for pain treatment state that poor posture alters the joint position and causes pain, such as back pain. Muscular Chain Therapy (MCT) is a technique that is used to treat posture pathologies, among others.

Purpose

The aim of the present study was to assess the efficiency of a single session of Muscular Chain Therapy (MCT) on complaints of undiagnosed musculoskeletal spinal pain.

Setting

Physical therapy clinic of the University of Center-West (Guarapuava, Brazil).

Participants

100 subjects, aged between 20 and 39 years, with complaints of spinal musculoskeletal pain.

Research Design

Randomized controlled trial.

Intervention

The participants were randomly assigned by a non-care provider into two groups: The MCT Group that received Muscular Chain Treatment and the Control Group that received a placebo treatment of 15 minutes turned off ultrasound therapy. All volunteers were assessed before and after treatment using an analog pain scale. A score of 0 indicated no pain and 10 was the maximum degree of pain on the scale.

Main Outcome Measure

Degree of pain measured by analog scale

Results

The chi-square goodness of fit test was used to compare gender distribution among groups displayed a p value = .25. Subject age had differences analyzed using the unpaired t test (p = .44). Pain assessment for treatment and placebo control groups was analyzed using a paired t test and unpaired t test. The paired t test was used for intragroup before/after treatment comparison (MCT p = .00001; Control Group p = .0001). The unpaired t test was used for comparing the difference of the pain level before and after treatment between groups (p = .0001). A priori statistical significance was set a p = .05.

Conclusion

It is possible to conclude that one MCT session is an effective treatment of undiagnosed spinal musculoskeletal pain.