Validación de test de flexión-relajación para definir un déficit lumbar con electrodos tetrapolares / Validation of the flexion-relaxation test to define a lumbar deficit with tetrapolar electrodes

Introducción y objetivo: Obtener un nuevo punto de corte (PC) para un test de flexión-relajación (FR) lumbar efectuado con electrodos (e.) tetrapolares, desde valores ya definidos con dispositivos bipolares.Materiales y métodosLa muestra del estudio consta de 47 pacientes en situación de incapacidad temporal por dolor lumbar (DL). Fueron evaluados mediante un test de dinamometría isométrica, una prueba cinemática y una valoración del fenómeno FR.Se plantean dos experimentos con curvas ROC. El primero, con 47 pacientes que efectuaron de modo consecutivo el test FR con ambos tipos de electrodos, utilizándose como variable de clasificación el punto de corte conocido para los e. bipolares (2,49uV). En el segundo, con los datos de la EMGs registrados con e. tetrapolares en 17 pacientes, se efectúa un test de DeLong que compara las 2 curvas ROC que construimos, por un lado, al clasificar la muestra desde pruebas de dinamometría y cinemática, y por el otro, al clasificarlos con los valores de la EMGs bipolar.ResultadosUn total de 34 pacientes completaron adecuadamente las valoraciones del primer experimento y 17 pacientes el segundo. El primer estudio arroja un punto de corte de 1,2uV, con un AUC del 87,7%; sensibilidad 84,2% y especificidad 80%. El segundo muestra un PC para los e. bipolares de 1,21uV (AUC 87,5%) y para los e. tetrapolares de 1,43 (AUC 82,5%) con un test de DeLong sin diferencias significativas entre ambas curvas (p>0,4065).ConclusionesLa metodología de validación con curvas ROC ha permitido obtener un nuevo PC para la prueba FR de modo práctico, simplemente simultaneando ambos test sobre el mismo grupo de pacientes hasta obtener una muestra significativa. (AU)

Introduction and objective: To obtain a new cut-off point (CP) for a lumbar flexion-relaxation (RF) test established with tetrapolar (e.) electrodes, from values already defined with bipolar devices.Materials and methodsThe study sample consists of 47 patients in a situation of temporary disability due to low back pain (DL). They were evaluated by means of an isometric dynamometry test, a kinematic test and an assessment of the FR phenomenon.Two experiments with ROC curves are proposed. The first, with 47 patients who consecutively performed the RF test with both types of electrodes, using the cut-off point (CP) known for the e. bipolar (2.49μV). In the second, with the EMG data recorded with e. tetrapolar in 17 patients, a DeLong test was performed that compares the 2 ROC curves that were constructed on the one hand, by classifying the sample from dynamometry and kinematic tests, and on the other, by classifying them with the bipolar EMG values.ResultsA total of 34 patients adequately completed the evaluations of the first experiment and 17 patients the second. The first study shows a cut-off point of 1.2μV, with an AUC of 87.7%; Sensitivity 84.2% and Specificity 80%. The second shows a PC for e. bipolars of 1.21μV (AUC 87.5%) and for e. tetrapolar values of 1.43 (AUC 82.5%) with a DeLong test without significant differences between both curves (p>0.4065).ConclusionsThe validation methodology with ROC curves has made it possible to obtain a new PC for the RF test in a practical way, simply by simultaneously performing both tests on the same group of patients until a significant sample is obtained. (AU)

Rehabilitation of back pain in the pediatric population: a mixed studies systematic review.

BACKGROUND: A significant proportion of children and adolescents experience back pain. However, a comprehensive systematic review on the effectiveness of rehabilitation interventions is lacking. OBJECTIVES: To evaluate benefits and harms of rehabilitation interventions for non-specific low back pain (LBP) or thoracic spine pain in the pediatric population. METHODS: Seven bibliographic electronic databases were searched from inception to June 16, 2023. Moreover, reference lists of relevant studies and systematic reviews, three targeted websites, and the WHO International Clinical Trials Registry Platform were searched. Paired reviewers independently conducted screening, assessed risk of bias, and extracted data related to study characteristics, methodology, subjects, and results. Certainty of evidence was evaluated based on the GRADE approach. RESULTS: We screened 8461 citations and 307 full-text articles. Ten quantitative studies (i.e., 8 RCTs, 2 non-randomized clinical trials) and one qualitative study were included. With very low to moderate certainty evidence, in adolescents with LBP, spinal manipulation (1-2 sessions/week over 12 weeks, 1 RCT) plus exercise may be associated with a greater likelihood of experiencing clinically important pain reduction versus exercise alone; and group-based exercise over 8 weeks (2 RCTs and 1 non-randomized trial) may reduce pain intensity. The qualitative study found information provided via education/advice and compliance of treatment were related to effective treatment. No economic studies or studies examining thoracic spine pain were identified. CONCLUSIONS: Spinal manipulation and group-based exercise may be beneficial in reducing LBP intensity in adolescents. Education should be provided as part of a care program. The overall evidence is sparse. Methodologically rigorous studies are needed. TRIAL REGISTRATION: CRD42019135009 (PROSPERO).

Efficacy of a Psychologically-Informed Physiotherapy Intervention in Patients with Chronic Low Back Pain at High Risk of Poor Prognosis: A Pilot and Feasibility Randomized Controlled Trial.

Purpose: To determine the feasibility of a randomized controlled trial (RCT) testing the efficacy of psychologically-informed physiotherapy (PIPT), which includes usual physiotherapy (UP) interventions, compared with UP, and to explore the preliminary effectiveness of the interventions. Method: People with chronic low back pain at high risk of poor prognosis (using the STarT Back screening tool) were recruited and allocated to PIPT or UP. Effectiveness of recruitment strategies, adherence to intervention, risk of contamination, and specific challenges were assessed. Functional capacity, pain, quality of life, kinesiophobia, catastrophization, central sensitization, and self-efficacy were measured at baseline, 6-, 12- and 24-week follow-ups. Results: Forty participants were recruited mainly by diffusing through Laval University's email list, and 10 physiotherapists treated the participants recruited. The retention rate of participants at 24 weeks was 72.5%. Adherence to treatment by participants and physiotherapists was very good. The risk of contamination was low, and the specific challenges identified were modifiable. Significant improvement over time in all clinical variables of interest, except self-efficacy, was observed with no difference between groups. Conclusions: As most success criteria were met, conducting an RCT evaluating PIPT and PU is feasible with modifications. PIPT and UP appear to be similarly effective.

Objectif: déterminer la faisabilité d'une étude randomisée et contrôlée (ÉRC) évaluant l'efficacité de la physiothérapie fondée sur la psychologie (PTFP), qui inclut les interventions de physiothérapie conventionelle (PC), par rapport à la PC, et explorer l'efficacité préliminaire des interventions. Méthodologie: les chercheurs ont recruté des personnes qui souffrent de douleurs lombaires chroniques, ayant une probabilité élevée de mauvais pronostic (au moyen de l'outil de dépistage STarT Back) et les ont réparties entre la PTFP et la PC. Ils ont évalué l'efficacité des stratégies de recrutement, l'adhésion à l'intervention, le risque de contamination et les difficultés particulières. Ils ont également mesuré la capacité fonctionnelle, la douleur, la qualité de vie, la kinésiophobie, la catastrophisation, la sensibilisation centrale et l'autoefficacité en début d'étude ainsi que lors des suivis à six, 12 et 24 semaines. Résultats: les chercheurs ont recruté 40 participants, principalement en diffusant le projet par courriel à la communauté de l'Université Laval, et dix physiothérapeutes les ont traités. Le taux de rétention des participants était de 72,5 % à 24 semaines. Les participants et les physiothérapeutes ont démontré une très bonne adhésion au traitement. Le risque de contamination était faible, et les difficultés particulières constatées pouvaient être modifiées. Les chercheurs ont observé une amélioration considérable au fil du temps pour toutes les variables cliniques d'intérêt, sauf l'autoefficacité, sans différence entre les groupes. Conclusions: puisque la plupart des critères de succès étaient respectés, il est faisable de réaliser une ÉRC pour évaluer la PTFP et la PU, sous réserve de modifications. La PTFP et la PC semblent avoir une efficacité similaire.

Cryoneurolysis versus radiofrequency ablation outcome on pain experience in chronic low back pain (COPE): a single-blinded randomised controlled trial.

OBJECTIVE: A comparison of cryoneurolysis or radio frequency (RF) with placebo in patients with facetogenic chronic low back pain (LBP) for patient global impression of change (PGIC), pain intensity, function and quality of life, with 1-year follow-up. DESIGN: Single-centre, single-blinded placebo-controlled randomised controlled trial. SETTING: Single-centre study. PARTICIPANTS: Inclusion from March 2020 to September 2022: consenting adults over 18 years of age, LBP>3 months, average Numeric Rating Scale LBP≥4 average last 14 days and a positive response to a diagnostic medial branch block (>50% pain reduction after 60 min). INTERVENTIONS: 120 patients were block randomised 1:1:1 to cryoneurolysis, RF or placebo of the medial branch nerves. Physical therapy was added after 4 weeks for all groups. MAIN OUTCOME MEASURES: Primary outcome was PGIC 4 weeks after the intervention. Secondary outcomes included pain intensity (Numeric Rating Scale, NRS), quality of life (Short Form 36, EQ-5D-5L), disability (Oswestry Disability Index), depression (Major Depression Inventory) and catastrophising (Pain Catastrophising Scale). Outcomes were measured at 4 weeks, 3, 6 and 12 months. RESULTS: There was no statistically significant difference in PGIC at 4 weeks between cryoneurolysis and placebo (risk ratio (RR) 2; 95% CI 0.75 to 5.33, p=0.17) and RF and placebo (RR 1.6; 95% CI 0.57 to 4.49, p=0.37), except PGIC for cryoneurolysis at 6-month follow-up (RR 5.1; 95% CI 1.20 to 22.03, p=0.03). No statistically significant differences were found in secondary follow-up endpoints. CONCLUSIONS: Denervation of the medial branch nerve by either cryoneurolysis or RF compared with placebo did not demonstrate significant improvement in PGIC, pain intensity, function and quality of life in patients with facetogenic chronic LBP at short-term or long-term follow-up. TRIAL REGISTRATION NUMBER: NCT04786145.

Implementation of an integrated primary care prevention and management program for chronic low back pain (LBP): patient-reported outcomes and predictors of pain interference after six months.

BACKGROUND: Integrated primary care programs for patients living with chronic pain which are accessible, interdisciplinary, and patient-centered are needed for preventing chronicity and improving outcomes. Evaluation of the implementation and impact of such programs supports further development of primary care chronic pain management. This study examined patient-reported outcomes among individuals with low back pain (LBP) receiving care in a novel interdisciplinary primary care program. METHODS: Patients were referred by primary care physicians in four regions of Quebec, Canada, and eligible patients received an evidence-based interdisciplinary pain management program over a six-month period. Patients were screened for risk of chronicity. Patient-reported outcome measures of pain interference and intensity, physical function, depression, and anxiety were evaluated at regular intervals over the six-month follow-up. A multilevel regression analysis was performed to evaluate the association between patient characteristics at baseline, including risk of chronicity, and change in pain outcomes. RESULTS: Four hundred and sixty-four individuals (mean age 55.4y, 63% female) completed the program. The majority (≥ 60%) experienced a clinically meaningful improvement in pain intensity and interference at six months. Patients with moderate (71%) or high risk (81%) of chronicity showed greater improvement in pain interference than those with low risk (51%). Significant predictors of improvement in pain interference included a higher risk of chronicity, younger age, female sex, and lower baseline disability. CONCLUSION: The outcomes of this novel LBP program will inform wider implementation considerations by identifying key components for further effectiveness, sustainability, and scale-up of the program.

Which patients with chronic low back pain respond favorably to multidisciplinary rehabilitation? A secondary analysis of a randomized controlled trial.

OBJECTIVES: The aim of this study was to identify prognostic variables at baseline associated with being responding favorably to multidisciplinary rehabilitation in patients with chronic low back pain (CLBP). METHODS: A responder analysis was conducted based on data from a randomized controlled trial with 26-week follow-up including 165 patients with CLBP treated at a Danish multidisciplinary rehabilitation center. Patients were dichotomized into responders and non-responders based on the outcome of a minimal clinically important difference of six points on the Oswestry Disability Index. The associations between prognostic variables and responders were analyzed using logistic regression. RESULTS: A total of 139 patients completed the study, of which 42% were classified as responders. Sex and employment status were statistically significant, with a decreased odds ratio (OR) of being a responder found for males compared to females (OR = 0.09, 95% CI = 0.02-0.48) and for being on temporary or permanent social benefits (OR = 0.28, 95% CI = 0.10-0.75) compared to being self-supporting or receiving retirement benefits. Statistically significant interaction (OR = 8.84, 95% CI = 1.11-70.12) was found between males and being on temporary or permanent social benefits. CONCLUSIONS: In patients with CLBP, female patients as well as patients who were self-supporting or receiving retirement benefits were significantly more likely than male patients or patients on temporary or permanent social benefits to be a responder to multidisciplinary rehabilitation.

Expression of cytokines at baseline correlate/predict in the disc the outcome of surgery after disc degeneration: A 12-month follow-up study.

BACKGROUND: Low back pain (LBP) is a highly prevalent condition that comprise a large portion of outpatient practice, challenging the diagnosis and treatment. However, the diagnostic tools are limited to clinical history, physical examination and imaging. Degenerative disc disease (DDD) is a significant cause of LBP, and emerging literature confirms the elevated levels of biomarkers in the discs. These biomarkers may serve as a tool for diagnosis, but may also be useful in predicting the treatment outcome. Here, we examine the expression of various cytokines on 1-year recovery from patients with LBP. METHODS: Patient-reported outcome (PRO) in terms of pain intensity (VAS), disability (ODI), and quality of life (Eq-5D) is collected from 44 patients at baseline and 12 months after surgery to study the influence of baseline TNF-α, IL-1ß, and IL-6 mRNA expression in both annulus fibrosus (AF) and nucleus pulposus (NP). RESULTS: Between baseline and follow-up, our cohort showed improvement in VAS back pain (p < 0.001), VAS leg pain (p < 0.001), ODI (p = 0.02), and Eq-5D (p = 0.01). Baseline levels of IL-1 ß was positively correlated with VAS back pain scores in AF (p = 0.05) and NP (p = 0.01) at 1-year follow-up. TNF-α expression at baseline was also positively correlated to ODI scores (p = 0.01) at follow-up and inversely correlated to improvements in ODI score between baseline and follow-up, suggesting that high TNF-α expression at baseline is associated with poor outcomes from surgery. CONCLUSION: The results from our study support that TNF-α expression at baseline can serve as a very important predictor of treatment response from lumbar fusion surgery.

Temporal relationships between pain, functioning, and human assumed central sensitization in patients with chronic low back pain; a single-case design.

BACKGROUND: Interdisciplinary pain rehabilitation (IPR) aims to improve functioning in people with chronic low back pain (CLBP), and is not primary aimed at pain reduction. Many patients however also report a decrease in pain. An explanation could be that IPR results in a decrease in Central Sensitization (CS). As CS is not directly assessable in humans the term Human Assumed Central Sensitization (HACS) is used in this study. It is unknown whether a decrease in HACS precedes a decrease in pain and improved functioning or vice versa. OBJECTIVES: This study aimed to gain understanding into the temporal relationships between changes in pain, functioning, and HACS in patients with CLBP during IPR. DESIGN: Longitudinal observational small-N-study. METHOD: Twelve patients filled in frequently repeated self-reports 1 week before, during the 12-week IPR program, and 2 weeks after IPR. Pain was assessed by Visual Analogue Scale for pain (daily), functioning by Pain Disability Index (weekly) and Work Ability Score (daily), and HACS by Central Sensitization Inventory part A (bi-weekly). Analyses were performed by visual inspection and time series cross-correlation analyses. RESULTS: Visual inspection showed large fluctuations within and between individual participants in patterns over time. Cross-correlation analyses showed that in most participants, relationships between pain, functioning, and HACS were strongest when analyzed at the same time (55% of comparisons). Strength and direction of (strongest) correlations showed high interindividual variability (neg: 0.33-0.97; pos: 0.22-0.99). CONCLUSION: Overall, relationships between pain, functioning, and HACS did not show consistent temporality in patients with CLBP.

Exosomes for the Management of Low Back Pain: A Review of Current Clinical Evidence.

Low back pain affects millions of people, creating an enormous financial burden on the global healthcare system. Traditional treatment modalities are short-lived and have shortcomings. Recently, orthobiologics, including extracellular vesicles or exosomes derived from mesenchymal stem cells, have markedly increased for managing musculoskeletal conditions. Here, the primary aim is to review the outcomes of clinical studies using extracellular vesicles or exosomes for treating low back pain. Numerous databases (Scopus, PubMed, Web of Science, Embase, and Google Scholar) were searched using terms for the intervention 'exosomes' and the treatment 'low back pain' for studies published in English to March 18, 2024. Articles utilizing exosomes for the management of low back pain were included. Articles not utilizing exosomes, not explicitly stating the presence of exosomes in their formulation, or not targeting low back pain were excluded. Two articles that met our pre-defined criteria were included in this review. The results showed that administering extracellular vesicles or exosomes is safe and potentially effective in patients suffering from low back pain. Yet, more sufficiently powered, multi-center, prospective, randomized, and non-randomized trials with longer follow-up are essential to assess the long-term safety and efficacy of extracellular vesicles or exosomes derived from various sources and to support its routine clinical use for managing low back pain.

Mediating effect of metabolic syndrome in the association of educational attainment with intervertebral disc degeneration and low back pain.

The causal association of educational attainment (EA) with intervertebral disc degeneration (IVDD) or low back pain (LBP), and the mediating effect of metabolic syndrome (MetS) in this association, is not studied to date. In this study, using summary statistics of genome-wide association studies primarily conducted in the individuals of European ancestry, Mendelian randomization (MR) analyses were performed to investigate: (1) the total and direct effects of EA on IVDD and LBP, (2) bidirectional associations of EA with MetS or the components of MetS, (3) causal effects of MetS or its components on IVDD and LBP, and (4) mediating effects of MetS or its components on the causal associations of EA with IVDD and LBP. Univariable MR analysis demonstrated that genetically proxied EA was inversely associated with IVDD (ORIVW: 0.90; 95 % CI: 0.87-0.92) and LBP (ORIVW: 0.86; 95 % CI: 0.84-0.89). Consistent results were obtained after adjusting for potential confounders (cognition, economic level, smoking traits, and metabolic factors). Mediation analysis proved that the effect of EA on IVDD mediated by MetS, waist circumference, and high-density lipoprotein cholesterol was 11.38 %, 9.22 %, and 2.17 %, respectively. Besides, MetS mediated 8.42 % and waist circumference mediated 5.81 % of the EA effects on LBP, respectively. Our findings provided support for MetS mediating the causal protective effects of EA on IVDD and LBP, which provided causal evidence to the etiology and intervention targets of IVDD and LBP.

A Novel Treatment of Fascial Pain With Glucopuncture: Three Clinical Cases.

The fascial system (FS) represents a sophisticated and intricate network within the human body, comprising both superficial and deep fascial layers. Disruptions or dysfunctions within this system have been implicated in a variety of musculoskeletal (MSK) disorders and pain syndromes. Specifically, fascial tightness has been associated with diminished range of motion and localized pain. Glucopuncture, a novel therapeutic approach, involves the administration of 5% dextrose injections directly into the fascial layers, such as the superficial fascia, to address these issues. This article presents a case series involving three patients who underwent palpation/ landmark-guided glucopuncture for the treatment of superficial fascial dysfunction. The first case involves a 45-year-old male with a nine-month history of left groin pain, who experienced significant pain relief following glucopuncture below the inguinal ligament, with complete resolution of symptoms within four weeks. The second case describes a 36-year-old female suffering from left arm and neck pain for two years, who reported gradual pain alleviation over six weeks after receiving multiple injections in the fasciae of the neck, scapula, and lateral aspect of the triceps muscle. The final case involves a 67-year-old female with a six-month history of low back and buttock pain, who showed improvement after four weeks following multiple injections in the fasciae of the low back, lumbar region, and buttocks. These cases highlight the potential of palpation-guided glucopuncture as a simple, cost-effective method for modulating regional pain caused by superficial fascial dysfunction. However, further research is necessary to fully ascertain the efficacy and safety of glucopuncture for treating fascial dysfunction.

Lower Limb Proprioception in Low Back Pain and Its Relationship With Voluntary Postural Control.

This study aimed to investigate whether patients with low back pain (LBP) had impaired lower limb proprioception and its association with somatosensory acuity. Thirty patients with LBP and 30 asymptomatic people volunteered, using Sway Discrimination Apparatus tests to assess somatosensory acuity during voluntary anteroposterior and mediolateral postural sway. Results showed significantly reduced somatosensory acuity in mediolateral sway in LBP patients (p = 0.005) with ankle, knee, and hip proprioception showing significantly impairment compared to asymptomatic controls (all p ≤ 0.012). Regression analysis showed that ankle and hip proprioception were significantly associated with somatosensory perception (0.001 ≤ p ≤ 0.026, 0.067 ≤ R2≤ 0.235). Overall, findings suggested a global deterioration of lower limb proprioception in LBP patients, with ankle and hip proprioception playing crucial role in somatosensory perception.

Body awareness disturbances in patients with low back pain: a systematic review.

BACKGROUND: The pain-neuroscience literature has recently emphasized body perception or awareness. Impaired body perception results have been reported in many different chronic pain problems. Studies have reported that individuals with low back pain (LBP) also have body perception disturbances related to the lumbar spine. OBJECTIVES: This review aimed to determine the evidence that body awareness alterations in individuals with LBP. DESIGN: Systematic review. METHOD: Studies were searched in PubMed, Cochrane Library, and Pedro databases up to January 2021. Each database was searched independently, according to a specific iteration research string. The protocol record of the systematic review was entered into the PROSPERO system. RESULTS: Nine studies were included in this research. We found evidence to support more perceptual impairments in patients with LBP than healthy counterparts. In addition, the results of the studies showed an association between disrupted body awareness and pain severity, pain catastrophizing, and disability. CONCLUSIONS: Body perception disturbances in LBP seem to be a promising path that needs to be further explored, with the ultimate goal of developing treatment contents targeting body awareness as a more comprehensive and valid evaluation and therapeutic method. TRIAL REGISTRATION: The registration number was CRD42021235934.

Biphasic Calcium Phosphate Bone Graft With a Unique Surface Topography: A Single-Center Ambispective Study for Degenerative Disease of the Lumbar Spine.

STUDY DESIGN: This study is an ambispective evaluation and analysis of a single-center cohort. OBJECTIVE: This study aimed to evaluate the performance of a novel biphasic calcium phosphate (BCP) bone graft with submicron-sized needle-shaped surface topography (BCP<µm) in interbody arthrodesis of the lumbar spine. METHODS: This study was a single-center ambispective assessment of adult patients receiving BCP<µm as part of their lumbar interbody fusion surgery. The primary outcome was a fusion status on computed tomography (CT) 12 months postoperative. The secondary outcomes included postoperative changes in the visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form 12 (SF-12), and length of stay (LOS). RESULTS: Sixty-three patients with one- to three-level anterior (48, 76%) and lateral (15, 24%) interbody fusions with posterior instrumentation were analyzed. Thirty-one participants (49%) had three or more comorbidities, including heart disease (43 participants, 68%), obesity (31 participants, 49%), and previous lumbar surgery (23 participants, 37%). The mean ODI decreased by 24. The mean SF-12 physical health and SF-12 mental health improved by a mean of 11.5 and 6.3, respectively. The mean VAS for the left leg, right leg, and back improved by a mean of 25.75, 22.07, and 37.87, respectively. Of 101 levels, 91 (90%) demonstrated complete bridging trabecular bone fusion with no evidence of supplemental fixation failure. CONCLUSION: The data of BCP<µm in interbody fusions for degenerative disease of the lumbar spine provides evidence of fusion in a complicated cohort of patients.

Understanding social determinants of health and physical therapy outcomes in patients with low back pain: A scoping review.

BACKGROUND: Low back pain (LBP) is the number one cause of disability worldwide; however, it is not clear how social determinants of health (SDOH) impact care management and outcomes related to physical therapy (PT) services for patients with LBP. OBJECTIVE: The purposes of this scoping review are to examine and assimilate the literature on how SDOH and PT care relate to non-specific LBP outcomes and identify gaps in the literature to target for future research. METHODS: Data were extracted from eight electronic databases from January 2011 to February 2022. Reviewers independently screened all studies using the PRISMA extension for scoping review guidelines. Data related to study design, type of PT, type of non-specific LBP, patient demographics, PT intervention, SDOH, and PT outcomes were extracted from the articles. RESULTS: A total of 30,523 studies were screened, with 1961 articles undergoing full text review. Ultimately, 76 articles were identified for inclusion. Sex and age were the most frequent SDOH examined (88% and 78% respectively) followed by education level (18%). Approximately half of the studies that examined age, sex, and education level identified no effect on outcomes. The number of studies examining other factors was small and the types of outcomes evaluated were variable, which limited the ability to pool results. CONCLUSIONS: Sex and age were the most frequent SDOH examined followed by education level. Other factors were evaluated less frequently, making it difficult to draw conclusions. Study design and heterogeneity of determinants and outcomes were barriers to examining the potential impact on patients with LBP.

Human and Porcine Lumbar Endplate Injury Risk in Repeated Flexion-Compression.

Low back pain (LBP) affects 50-80% of adults at some point in their lifetime, yet the etiology of injury is not well understood. Those exposed to repeated flexion-compression are at a higher risk for LBP, such as helicopter pilots and motor vehicle operators. Animal injury models offer insight into in vivo injury mechanisms, but interspecies scaling is needed to relate animal results to human. Human (n = 16) and porcine (n = 20) lumbar functional spinal units (FSUs) were loaded in repeated flexion-compression (1 Hz) to determine endplate fracture risk over long loading exposures. Flexion oscillated from 0 to 6° and peak applied compressive stress ranged from 0.65 to 2.38 MPa for human and 0.64 to 4.68 MPa for porcine specimens. Five human and twelve porcine injuries were observed. The confidence intervals for human and porcine 50% injury risk curves in terms of stress and cycles overlapped, indicating similar failure behavior for this loading configuration. However, porcine specimens were more tolerant to the applied loading compared to human, demonstrated by a longer time-to-failure for the same applied stress. Optimization revealed that time-to-failure in human specimens was approximately 25% that of porcine specimens at a given applied stress within 0.65-2.38 MPa. This study determined human and porcine lumbar endplate fracture risks in long-duration repeated flexion-compression that can be directly used for future equipment and vehicle design, injury prediction models, and safety standards. The interspecies scale factor produced in this study can be used for previous and future porcine lumbar injury studies to scale results to relevant human injury.

The effect of long-term alendronic acid treatment on Modic changes in the lumbar spine: a gender and age-matched study.

BACKGROUND: Low back pain (LBP) affects a significant proportion of the adult population. Potent anti-resorptive drugs such as intravenous zoledronic acid have been demonstrated to reduce Modic changes (MCs) upon magnetic resonance imaging (MRI) of the spine and concomitantly decrease associated LBP. It is uncertain whether oral alendronic acid has a similar effect. METHODS: 82 subjects were recruited in this case-control study. Treatment subjects (n = 41) received oral alendronic acid treatment for at least 1-year and were matched by gender and age (± 2) to control subjects (n = 41) not receiving any anti-osteoporotic medication. The prevalence, type, and extent of MCs were quantified upon T1 and T2-weighted MRIs of the lumbosacral spine. RESULTS: Treatment subjects received oral alendronic acid for 124.0 ± 62.1 weeks at the time of MRI assessment and exhibited a lower prevalence of MCs over the lumbosacral spine (18/41 vs. 30/41, p < 0.001) as compared to control subjects. Amongst both groups, type 2 MCs were predominant. Quantification of type 2 MCs in treatment subjects revealed a significant reduction in area (113 ± 106 mm2 vs. 231 ± 144 mm2, p < 0.01) and volume (453 ± 427 mm3 vs. 925 ± 575 mm3, p < 0.01) affected by type 2 MCs in comparison to matched controls. CONCLUSION: Oral alendronic acid may be useful in the treatment of MC-associated LBP in patients with concomitant osteoporosis.

Associations between pain intensity, pain sensitivity, demographics, psychological factors, disability, physical activity, pain phenotype and COVID-19 history in low back pain: An observational study.

BACKGROUND AND PURPOSE: Knowledge of the factors affecting pain intensity and pain sensitivity can inform treatment targets and strategies aimed at personalizing the intervention, conceivably increasing its positive impact on patients. Therefore, this study aimed to investigate the association between demographic factors (sex and age), body mass index (BMI), psychological factors (anxiety and depression, kinesiophobia and catastrophizing), self-reported physical activity, pain phenotype (symptoms of central sensitization, and nociceptive or neuropathic pain), history of COVID-19 and pain intensity and sensitivity in patients with chronic non-specific low back pain (LBP). METHODS: This was a cross-sectional secondary analysis with 83 participants with chronic non-specific LBP recruited from the community between August 2021 and April 2022. BMI, pain intensity (Visual Analog Scale), pain sensitivity at the lower back and at a distant point [pressure pain threshold], catastrophizing (Pain Catastrophizing Scale), kinesiophobia (Tampa Scale for Kinesiophobia), anxiety and depression (Hospital Anxiety and Depression Scale), pain phenotype (Central Sensitization Inventory and PainDetect Questionnaire), physical activity (International Physical Activity Questionnaire), and disability (Roland Morris Disability Questionnaire) were assessed. Multiple linear regression analyses with pain intensity and sensitivity as the dependent variables were used. RESULTS: The model for pain intensity explained 34% of its variance (Adjusted R2 = -0.343, p < 0.001), with depression and anxiety (p = 0.008) and disability (p = 0.035) reaching statistical significance. The model for pain sensitivity at the lower back, also explained 34% of its variance (Adjusted R2 = 0.344, p < 0.001) at the lower back with sex, BMI, and kinesiophobia reaching statistical significance (p < 0.05) and 15% of the variance at a distant body site (Adjusted R2 = 0.148, p = 0.018) with sex and BMI reaching statistical significance (p < 0.05). DISCUSSION: This study found that different factors are associated with pain intensity and pain sensitivity in individuals with LBP. Increased pain intensity was associated with higher levels of anxiety and depression and disability and increased pain sensitivity was associated with being a female, higher kinesiophobia, and lower BMI.

Assessing the causal relationship between blood metabolites and low back pain: a Mendelian randomization study.

AIM: Low back pain (LBP) is one of the most common health problems worldwide. This study aimed to determine whether blood metabolites were causally linked to the risk of LBP. METHODS: Based on summary-level genome-wide association studies, we designed a Mendelian randomization (MR) study. Instrumental variables were selected for each blood metabolite with the following criteria: genome-wide significance levels of < 5e-8 and independent clumping (r2 < 0.001, distance < 10,000 kb). Inverse-variance weighting (IVW) was used as the primary statistical method. The weighted median (WM) method and MR-Egger regression were implemented to complement IVW. Subsequently, sensitivity analyses were conducted, including Cochran's Q test, MR-Egger intercept analysis, scatter plots, leave-one-out analysis, and funnel plots. RESULTS: IVW revealed that higher levels of lactate (odds ratio [OR] = 0.974, 95% confidence interval [CI] 0.953-0.995, P = 0.017), medium low-density lipoprotein triglycerides (OR = 0.990, 95% CI 0.983-0.997, P = 0.005) and albumin (OR = 0.985, 95% CI 0.973-0.998, P = 0.019) had a causal effect on decreased risk of LBP, whereas positive causality was detected between genetic predisposition to tyrosine and LBP (OR = 1.016, 95% CI 1.001-1.032, P = 0.043). Estimates from WM and MR-Egger were consistent with the direction of the IVW method. Additionally, there was no evidence of heterogeneity or pleiotropy in this study. CONCLUSION: This MR study demonstrated that four blood metabolites were causally related to LBP. It is possible to enhance the diagnosis of LBP, prognostic outcome predictions, and the personalization of therapy by analyzing novel signatures of metabolites.