The association between inflammatory biomarkers and low back disorder: a systematic review and meta-analysis.

INTRODUCTION: Low back disorder (LBD) is a major cause of disability worldwide. Inflammation results in proliferation of cytokines or consequent degradation products (collectively known as inflammatory biomarkers) that activate pain pathways which can result in non-specific LBD. This systematic review and meta-analysis aim to evaluate the relationship between inflammatory biomarkers and clinical outcomes in patients with LBD. METHODS: The PRISMA guideline was followed for the systematic reivew. Three online databases were searched. Four RCTs and sixteen observational studies with 1142 LBD patients were analysed. The primary outcomes were back and leg pain scores, back-specific disability scores and expression of inflammatory biomarkers. Standardized mean difference (SMD) and their 95% confidence intervals (CI) were evaluated. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to summarize the strength of evidence. RESULTS: Four RCTs and sixteen observational studies were included in the analysis of 1142 patients with LBD. There was a statistically significant reduction in back pain score and IL-1 beta and increase in the expression of CTX-1 and IL-10 levels post treatment. There was a significant relationship between increase in the expression of MCP- and reduction in the expression of hsCRP with increase in back pain. Significant relationship was also observed between increase in the expression of MCP-1 and reduction in the expression of IL-6 with increase in leg pain. Increase in the expression of IL-8 and reduction in the expression of hsCRP was also associated with increased disability score. CONCLUSION: Inflammatory biomarkers play a significant role in the pathogenesis of LBD. CTX-1, IL-10 and IL-1 beta may be responsible for the decrease in back pain scores post treatment. There is a relationship between MCP-1, IL-6, IL-8 and hsCRP with clinical and functional assessments for LBD. Further studies will improve understanding of the pathogenesis of LBD and aid in targeted management strategies.

A confirmatory factor analysis of an electronic format painDETECT questionnaire for patients with low back pain.

BACKGROUND: The substantial burden of low back pain on patients and healthcare systems is exacerbated by unclear pathology and ineffective diagnostic methods, hindering effective management. The painDETECT questionnaire (PD-Q) has been used to facilitate the evaluation and categorization of low back pain. While preliminary validation and translations of the paper-based format of PD-Q into languages such as Spanish and Dutch have been accomplished, the underlying factor model inherent to the electronic format of the PD-Q remains to be established. OBJECTIVE: The objective of this study was to utilise confirmatory factor analysis (CFA) to investigate the factor structure of an electronic format PD-Q among patients with neuropathic low back pain. METHODS: This cross-sectional study was conducted at a Spinal Clinic in Sydney between November 2020 and October 2022. Eligible participants were adults over 18 with low back pain and no history of lumbar surgery or systemic co-morbidities. Participants completed the electronic format of the PD-Q, and CFA was employed to assess the validity of the suggested two-factor, nine-item structure. Recommended cut-offs for goodness-of-fit indices were used to evaluate the model fit. RESULTS: Of the 236 patients that visited the clinic during the data collection period, 142 (71, 50% female, mean age 51.26 ± 15.28 years) participated in the study. Median pain severity was 9/10 over 4 weeks. CFA indicated strong model fit, with goodness-of-fit and comparative fit indices over 0.9, and overall internal consistency was 0.77. Construct validity analysis demonstrated the PD-Q's effectiveness in distinguishing neuropathic, mixed, and nociceptive LBP, aiding neuropathic pain evaluation in low back pain patients. CONCLUSION: This study confirms the reliability and two-factor structure of the electronic PD-Q for neuropathic pain assessment in low back pain patients. To enhance comprehension of the clinical applicability of the electronic format PD-Q, future research should conduct clinimetric evaluations.

Early outcomes of oblique lateral interbody fusion with posterior fixation versus posterior interbody fusion with fixation for treating adult degenerative scoliosis.

OBJECTIVE: To compare the surgical trauma and outcomes between oblique lateral interbody fusion (OLIF) and posterior fixation and posterior lumbar interbody fusion (PLIF) with fixation for adult degenerative scoliosis (ADS). METHODS: We included ADS patients who underwent OLIF with fixation or PLIF with fixation treatment from June 2020 to December 2022. The preoperative and postoperative spinal pelvic parameters were measured using X-rays. Clinical symptoms were measured using the Oswestry Disability Index and a visual analog scale. We recorded operation time, intraoperative blood loss, blood transfusion, albumin infusion, surgical fixation segment, surgical osteotomy segment, time, and drainage volume. RESULTS: Forty patients with ADS were included: 20 with OLIF with posterior fixation and 20 with PLIF matched for age, sex, pelvic incidence, and Cobb angle with the OLIF group. There were no significant differences in age, gender, BMI, preoperative spinal parameters, or preoperative clinical symptoms between the groups (p > 0.05). There were no statistical differences in postoperative spinal parameters or clinical symptoms (p > 0.05). Patients in the OLIF group had less intraoperative blood loss (p < 0.01) and fewer intraoperative blood transfusions (p < 0.001) than the posterior surgery group. The number of fixed segments was fewer (p < 0.01), and there were fewer total osteotomy segments (p < 0.001). CONCLUSION: OLIF with posterior fixation surgery can achieve the same corrective effect and efficacy as a posterior internal fusion with fixation surgery for treating ADS. OLIF with posterior fixation surgery causes less trauma and reduces the number of fixation segments.

Deep Learning Model to Classify and Monitor Idiopathic Scoliosis in Adolescents Using a Single Smartphone Photograph.

Importance: Adolescent idiopathic scoliosis (AIS) is the most common pediatric spinal disorder. Routine physical examinations by trained personnel are critical to diagnose severity and monitor curve progression in AIS. In the presence of concerning malformation, radiographs are necessary for diagnosis or follow-up, guiding further management, such as bracing correction for moderate malformation and spine surgery for severe malformation. If left unattended, progressive deterioration occurs in two-thirds of patients, leading to significant health concerns for growing children. Objective: To assess the ability of an open platform application (app) using a validated deep learning model to classify AIS severity and curve type, as well as identify progression. Design, Setting, and Participants: This diagnostic study was performed with data from radiographs and smartphone photographs of the backs of adolescent patients at spine clinics. The ScolioNets deep learning model was developed and validated in a prospective training cohort, then incorporated and tested in the AlignProCARE open platform app in 2022. Ground truths (GTs) included severity, curve type, and progression as manually annotated by 2 experienced spine specialists based on the radiographic examinations of the participants' spines. The GTs and app results were blindly compared with another 2 spine surgeons' assessments of unclothed back appearance. Data were analyzed from October 2022 to February 2023. Exposure: Acquisitions of unclothed back photographs using a mobile app. Main Outcomes and Measures: Outcomes of interest were classification of AIS severity and progression. Quantitative statistical analyses were performed to assess the performance of the deep learning model in classifying the deformity as well as in distinguishing progression during 6-month follow-up. Results: The training data set consisted of 1780 patients (1295 [72.8%] female; mean [SD] age, 14.3 [3.3] years), and the prospective testing data sets consisted of 378 patients (279 [73.8%] female; mean [SD] age, 14.3 [3.8] years) and 376 follow-ups (294 [78.2%] female; mean [SD] age, 15.6 [2.9] years). The model recommended follow-up with an area under receiver operating characteristic curve (AUC) of 0.839 (95% CI, 0.789-0.882) and considering surgery with an AUC of 0.902 (95% CI, 0.859-0.936), while showing good ability to distinguish among thoracic (AUC, 0.777 [95% CI, 0.745-0.808]), thoracolumbar or lumbar (AUC, 0.760 [95% CI, 0.727-0.791]), or mixed (AUC, 0.860 [95% CI, 0.834-0.887]) curve types. For follow-ups, the model distinguished participants with or without curve progression with an AUC of 0.757 (95% CI, 0.630-0.858). Compared with both surgeons, the model could recognize severities and curve types with a higher sensitivity (eg, sensitivity for recommending follow-up: model, 84.88% [95% CI, 75.54%-91.70%]; senior surgeon, 44.19%; junior surgeon, 62.79%) and negative predictive values (NPVs; eg, NPV for recommending follow-up: model, 89.22% [95% CI, 84.25%-93.70%]; senior surgeon, 71.76%; junior surgeon, 79.35%). For distinguishing curve progression, the sensitivity and NPV were comparable with the senior surgeons (sensitivity, 63.33% [95% CI, 43.86%-80.87%] vs 77.42%; NPV, 68.57% [95% CI, 56.78%-78.37%] vs 72.00%). The junior surgeon reported an inability to identify curve types and progression by observing the unclothed back alone. Conclusions: This diagnostic study of adolescent patients screened for AIS found that the deep learning app had the potential for out-of-hospital accessible and radiation-free management of children with scoliosis, with comparable performance as spine surgeons experienced in AIS management.

Partial atlantooccipital assimilation causing atlantoaxial instability and early myelopathy in an adult treated with occipitocervical fusion: A case report.

INTRODUCTION & IMPORTANCE: Atlanto-occipital assimilation is a rare congenital abnormality which can cause atlantoaxial instability. Basilar invagination and instability can lead to cord compression and myelopathy in young individuals. CASE REPORT & DISCUSSION: A 37-year-old male presented with gradually worsening axial neck pain for four years duration His deep tendon reflexes are exaggerated in all four limbs but there is no weakness or imbalance. Following radiological evaluation, he was diagnosed to have partial atlantooccipital assimilation causing atlantoaxial instability, basilar invagination and early myelopathy. He was treated with occipital-cervical fusion after the closed reduction of the atlantoaxial joint. CONCLUSION: Atlanto-axial assimilation can lead to atlantoaxial instability and subsequently myelopathy. Dynamic radiographs and computed tomography are helpful in the diagnosis. Reducible atlantoaxial instability can be managed with closed reduction and occipitocervical fusion.

Smoking and tetramer tryptase accelerate intervertebral disc degeneration by inducing METTL14-mediated DIXDC1 m6 modification.

Although cigarette smoking (CS) and low back pain (LBP) are common worldwide, their correlations and the mechanisms of action remain unclear. We have shown that excessive activation of mast cells (MCs) and their proteases play key roles in CS-associated diseases, like asthma, chronic obstructive pulmonary disease (COPD), blood coagulation, and lung cancer. Previous studies have also shown that MCs and their proteases induce degenerative musculoskeletal disease. By using a custom-designed smoke-exposure mouse system, we demonstrated that CS results in intervertebral disc (IVD) degeneration and release of MC-restricted tetramer tryptases (TTs) in the IVDs. TTs were found to regulate the expression of methyltransferase 14 (METTL14) at the epigenetic level by inducing N6-methyladenosine (m6A) deposition in the 3' untranslated region (UTR) of the transcript that encodes dishevelled-axin (DIX) domain-containing 1 (DIXDC1). That reaction increases the mRNA stability and expression of Dixdc1. DIXDC1 functionally interacts with disrupted in schizophrenia 1 (DISC1) to accelerate the degeneration and senescence of nucleus pulposus (NP) cells by activating a canonical Wnt pathway. Our study demonstrates the association between CS, MC-derived TTs, and LBP. These findings raise the possibility that METTL14-medicated DIXDC1 m6A modification could serve as a potential therapeutic target to block the development of degeneration of the NP in LBP patients.

Measuring compressive loads on a 'smart' lumbar interbody fusion cage: Proof of concept.

There are several complications associated with lumbar interbody fusion surgery however, pseudarthrosis (non-union) presents a multifaceted challenge in the postoperative management of the patient. Rates of pseudarthrosis range from 3 to 20 % in patients with healthy bone and 20 to 30 % in patients with osteoporosis. The current methods in post-operative follow-up - radiographs and CT, have high false positive rates and poor agreement between them. The aim of this study was to develop and test a proof-of-concept load-sensing interbody cage that may be used to monitor fusion progression. Piezoresistive pressure sensors were calibrated and embedded within a polyether ether ketone (PEEK) interbody cage. Silicone and poly (methyl methacrylate) (PMMA) were inserted in the graft regions to simulate early and solid fusion. The load-sensing cage was subjected to distributed and eccentric compressive loads up to 900 N between synthetic lumbar vertebral bodies. Under maximum load, the anterior sensors recorded a 56-58 % reduction in pressure in the full fusion state compared to early fusion. Lateral regions measured a 36-37 % stress reduction while the central location reduced by 45 %. The two graft states were distinguishable by sensor-recorded pressure at lower loads. The sensors more effectively detected left and right eccentric loads compared to anterior and posterior. Further, the load-sensing cage was able to detect changes in endplate stiffness. The proof-of-concept 'smart' cage could detect differences in fusion state, endplate stiffness, and loading conditions in this in vitro experimental setup.

Clinicians' perceptions around discectomy surgery for lumbar disc herniation: a survey of orthopaedic and neuro-surgeons in Australia and New Zealand.

INTRODUCTION: Understanding practice-based differences in treatment of lumbar disc herniations (LDHs) is vital for reducing unwarranted variation in the delivery of spine surgical health care. Identifying factors that influence surgeons' decision-making will offer useful insights for developing the most cost-effective and safest surgical strategy as well as developing surgeon education materials for common lumbar pathologies. This study was to capture any variation in techniques used by surgeons in Australia and New Zealand (ANZ) region, and perceived complications of different surgical procedures for primary and recurrent LDH (rLDH). MATERIALS AND METHODS: Web-based survey study was emailed to orthopaedic and neurosurgeons who routinely performed spinal surgery in ANZ from Decmber 20, 2018 to February 20, 2020. The response data were analyzed to assess for differences based on geography, practice setting, speciality, practice experience, practice length, and operative volume. RESULTS: Invitations were sent to 150 surgeons; 96 (64%) responded. Most surgeons reported microdiscectomy as their surgical technique of choice for primary LDH (73%) and the first rLDH (72%). For the second rLDH, the preferred choice for most surgeons was fusion surgery (82%). A surgeon's practice setting (academic/private/hybrid) was a statistically significant factor in what surgical procedure was chosen for the first rLDH (P = 0.014). When stratifying based on surgeon experience, there were statisfically significant differences based on the annual volume of spine surgeries performed (perceived reherniation rates following primary discectomy, P = 0.013; perceived reherniation rates following revision surgeries, P = 0.017; perceived intraoperative complications rates following revision surgeries, P = 0.016) and based on the annual volume of lumbar discectomies performed (perceived reherniation rates following revision surgeries, P = 0.022; perceived intraoperative complications rates following revision surgeries, P = 0.036; perceived durotomy rates following primary discectomy, P = 0.023). CONCLUSIONS: Surgeons' annual practice volume and practice setting have significant influences in the selection of surgical procedures and the perception of surgical complications when treating LDHs.

Stand-alone anterior cervical decompression and fusion surgery: A cohort study evaluating a shaped cage without plates or screws.

Background: The anterior approach to the cervical spine is the most commonly used surgery with effective decompression and less surgical trauma. Anterior plate construct (APC) is considered a standard technique. However, it appears to cause implant failure and postoperative dysphagia. Due to these reasons, locking stand-alone cages (LSCs) without the addition of an anterior plate have been developed and gained popularity in the past decade. In theory, an LSC could provide immediate load-bearing support to the anterior column of the cervical spine and may enhance the rate of arthrodesis. However, screw skiving and backing off are known complications of LSC. Given the characteristic shape of cervical discs, we wondered whether there may be a role for a shape-conforming cage without screws and plates to achieve desired outcomes, i.e., a true stand-alone cage (TSC). A single surgeon cohort using the cage in a heterogenic set of indications was evaluated. Methods: A total of 45 patients with degenerative cervical conditions who underwent surgery using TSC using CoRoent Small Contoured peek cage (Nuvasive, San Diego, CA) and Orthoblend™ (Medtronics, Memphis, TN) were retrospectively reviewed. Comparisons between preoperative and postoperative Numeric Rating Scale (NRS), the modified AAOS-Modems disability outcome, Neck Disability Index (NDI) scores, and Short Form 36 were evaluated. Operative time, the occurrence rate of fusion, lordosis change of cervical spine, and occurrence rate of complications were evaluated. Results: There were one-level (n = 15), two-level (n = 24), and three-level (n = 6) cases making a total of 81 cages implanted and studied. The mean operative time was 132.7 min. The group demonstrated significant improvements in NRS, AAOS-Modems disability outcome, and NDI scores after surgery (mean follow-up 12 months). The cervical lordosis at pre- and last follow-up period was 8.7 ± 2.2° and 8.3 ± 3.2°, respectively. The complication rate was 21.2%. Conclusions: TSC yielded satisfactory long-term clinical and radiological outcomes; this preliminary report can form the basis of a cost-benefit analysis study either prospectively or by way of meta-modeling comparing APC, LSC to TSC.

Clinical and Research MRI Techniques for Assessing Spinal Cord Integrity in Degenerative Cervical Myelopathy-A Scoping Review.

BACKGROUND: Degenerative cervical myelopathy (DCM) manifests as the primary cause of spinal cord dysfunction and is non-traumatic, chronic and progressive in nature. Decompressive surgery is typically utilised to halt further disability and neurological dysfunction. The limitations of current diagnostic options surrounding assessment and prognostic potential render DCM still largely a clinical diagnosis. AIMS: To outline the limitations of current diagnostic techniques, present evidence behind novel quantitative MRI (qMRI) techniques for assessing spinal cord integrity in DCM and suggest future directions. METHOD: Articles published up to November 2021 were retrieved from Medline, EMBASE and EBM using key search terms: spinal cord, spine, neck, MRI, magnetic resonance imaging, qMRI, T1, T2, T2*, R2*, DTI, diffusion tensor imaging, MT, magnetisation transfer, SWI, susceptibility weighted imaging, BOLD, blood oxygen level dependent, fMRI, functional magnetic resonance imaging, functional MRI, MRS, magnetic resonance spectroscopy. RESULTS: A total of 2057 articles were retrieved with 68 articles included for analysis. The search yielded 2 articles on Quantitative T1 mapping which suggested higher T1 values in spinal cord of moderate-severe DCM; 43 articles on DTI which indicated a strong correlation of fractional anisotropy and modified Japanese Orthopaedic Association scores; 15 articles on fMRI (BOLD) which demonstrated positive correlation of functional connectivity and volume of activation of various connections in the brain with post-surgical recovery; 6 articles on MRS which suggested that Choline/N-acetylaspartate (Cho/NAA) ratio presents the best correlation with DCM severity; and 4 articles on MT which revealed a preliminary negative correlation of magnetisation transfer ratio with DCM severity. Notably, most studies were of low sample size with short timeframes within 6 months. CONCLUSIONS: Further longitudinal studies with higher sample sizes and longer time horizons are necessary to determine the full prognostic capacity of qMRI in DCM.

Interventions for promoting evidence-based guideline-consistent surgery in low back pain: a systematic review and meta-analysis of randomised controlled trials.

PURPOSE: Examine the effectiveness of interventions to approach guideline-adherent surgical referrals for low back pain assessed via systematic review and meta-analysis. METHODS: Five databases (10 September 2021), Google Scholar, reference lists of relevant systematic reviews were searched and forward and backward citation tracking of included studies were implemented. Randomised controlled/clinical trials in adults with low back pain of interventions to optimise surgery rates or referrals to surgery or secondary referral were included. Bias was assessed using the Cochrane ROB2 tool and evidence certainty via Grading of Recommendations Assessment, Development and Evaluation (GRADE). A random effects meta-analysis with a Paule Mandel estimator plus Hartung-Knapp-Sidik-Jonkman method was used to calculate the odds ratio and 95% confidence interval, respectively. RESULTS: Of 886 records, 6 studies were included (N = 258,329) participants; cluster sizes ranged from 4 to 54. Five studies were rated as low risk of bias and one as having some concerns. Two studies reporting spine surgery referral or rates could only be pooled via combination of p values and gave evidence for a reduction (p = 0.021, Fisher's method, risk of bias: low). This did not persist with sensitivity analysis (p = 0.053). For secondary referral, meta-analysis revealed a non-significant odds ratio of 1.07 (95% CI [0.55, 2.06], I2 = 73.0%, n = 4 studies, Grading of Recommendations Assessment, Development and Evaluation [GRADE] evidence certainty: very low). CONCLUSION: Few RCTs exist for interventions to improve guideline-adherent spine surgery rates or referral. Clinician education in isolation may not be effective. Future RCTs should consider organisational and/or policy level interventions. PROSPERO REGISTRATION: CRD42020215137.

Network meta-analysis for comparative effectiveness of treatments for chronic low back pain disorders: systematic review protocol.

INTRODUCTION: Chronic low back pain disorders (CLBDs) present a substantial societal burden; however, optimal treatment remains debated. To date, pairwise and network meta-analyses have evaluated individual treatment modes, yet a comparison of a wide range of common treatments is required to evaluate their relative effectiveness. Using network meta-analysis, we aim to evaluate the effectiveness of treatments (acupuncture, education or advice, electrophysical agents, exercise, manual therapies/manipulation, massage, the McKenzie method, pharmacotherapy, psychological therapies, surgery, epidural injections, percutaneous treatments, traction, physical therapy, multidisciplinary pain management, placebo, 'usual care' and/or no treatment) on pain intensity, disability and/or mental health in patients with CLBDs. METHODS AND ANALYSIS: Six electronic databases and reference lists of 285 prior systematic reviews were searched. Eligible studies will be randomised controlled/clinical trials (including cross-over and cluster designs) that examine individual treatments or treatment combinations in adult patients with CLBDs. Studies must be published in English, German or Chinese as a full-journal publication in a peer-reviewed journal. A narrative approach will be used to synthesise and report qualitative and quantitative data, and, where feasible, network meta-analyses will be performed. Reporting of the review will be informed by Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidance, including the network meta-analysis extension (PRISMA-NMA). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach for network meta-analysis will be implemented for assessing the quality of the findings. ETHICS AND DISSEMINATION: Ethical approval is not required for this systematic review of the published data. Findings will be disseminated via peer-reviewed publication. PROSPERO REGISTRATION NUMBER: PROSPERO registration number CRD42020182039.

The association between pain scores and disc height change following discectomy surgery in lumbar disc herniation patients: a systematic review and meta-analysis.

PURPOSE: To evaluate the impact of discectomy on disc height (DH) in lumbar disc herniation (LDH) patients following discectomy surgery and address the association of DH change with pain score change. METHODS: We searched three online databases for randomized controlled trials (RCTs) and observational studies. In LDH patients, eligible for discectomy surgery, the changes in pre- and post-operative back and/or leg pain score and DH and/or disc height index (DHI) were considered as primary outcomes. Standardize mean difference (SMD) and their 95% confidence intervals (CI) were evaluated. The GRADE approach was used to summarize the strength of evidence. RESULTS: Two RCTs and sixteen observational studies were included in the analysis of 893 LDH patients undergoing discectomy surgery. The mean overall follow-up was 211 weeks. There was a statistically significant reduction in DH (14.4% reduction: SMD = -0.74 (95% CI = -0.86 to -0.61)) and DHI (11.5% reduction: SMD = -0.81 (95% CI = -0.97 to -0.65)) following discectomy surgery. There was a significant relationship between the reduction in DH and decrease in back pain score (r = 0.68, (95% CI = 0.07-1.30), p = 0.034) after discectomy surgery. No significant relationship between DHI change and decrease in clinical pain scores (back and leg pain) could be established. CONCLUSION: Discectomy surgery produces significant and quantifiable reductions in DH and DHI. Additionally, the reduction in DH is responsible for the decrease in back pain scores post discectomy, but further studies will improve understanding and aid preoperative counselling.

Degenerative Cervical Myelopathy: Insights into Its Pathobiology and Molecular Mechanisms.

Degenerative cervical myelopathy (DCM), earlier referred to as cervical spondylotic myelopathy (CSM), is the most common and serious neurological disorder in the elderly population caused by chronic progressive compression or irritation of the spinal cord in the neck. The clinical features of DCM include localised neck pain and functional impairment of motor function in the arms, fingers and hands. If left untreated, this can lead to significant and permanent nerve damage including paralysis and death. Despite recent advancements in understanding the DCM pathology, prognosis remains poor and little is known about the molecular mechanisms underlying its pathogenesis. Moreover, there is scant evidence for the best treatment suitable for DCM patients. Decompressive surgery remains the most effective long-term treatment for this pathology, although the decision of when to perform such a procedure remains challenging. Given the fact that the aged population in the world is continuously increasing, DCM is posing a formidable challenge that needs urgent attention. Here, in this comprehensive review, we discuss the current knowledge of DCM pathology, including epidemiology, diagnosis, natural history, pathophysiology, risk factors, molecular features and treatment options. In addition to describing different scoring and classification systems used by clinicians in diagnosing DCM, we also highlight how advanced imaging techniques are being used to study the disease process. Last but not the least, we discuss several molecular underpinnings of DCM aetiology, including the cells involved and the pathways and molecules that are hallmarks of this disease.

Changes in Back Pain Scores after Bariatric Surgery in Obese Patients: A Systematic Review and Meta-Analysis.

Bariatric surgery produces significant and quantifiable reductions in back pain. However, there is a lack of information on the association of weight changes after bariatric surgery with changes in pain score. We aim to evaluate the impact of bariatric surgery on back pain in obese patients and to address the association between changes in body mass index (BMI) and pain score. In obese patients eligible for bariatric surgery, the changes in pre- and post-operative pain scores, assessed by the Numeric Rating Pain Scale (NPS) or Visual Analogue Scale (VAS), were considered as primary outcomes. Mean difference (MD) and their 95% confidence intervals (CI) were evaluated. Eight cohort studies were included in the analysis of 298 obese patients undergoing bariatric surgery. All studies showed a reduction in back pain, with a mean change of -2.9 points in NPS and of -3.8 cm in VAS. There was a significant reduction in back pain (NPS: (MD = -3.49) (95% CI = -3.86, -3.12); VAS: MD = -3.75, (95% CI = -4.13, -3.37)) and BMI (MD = -12.93, (95% CI = -13.61, -12.24)) following bariatric surgery. No significant relationship between BMI change and decrease in clinical scores could be established. However, it was evident that bariatric surgery had a significant effect on back pain scores in severely obese patients. Ideally, a prospective study including spinal imaging, inflammatory markers, a longer follow-up period, and larger study groups with a randomized control group needs to be performed.

Does the Use of Intraoperative Pressure Sensors for Knee Balancing in Total Knee Arthroplasty Improve Clinical Outcomes? A Comparative Study With a Minimum Two-Year Follow-Up.

BACKGROUND: It is undetermined whether using sensors for knee balancing in total knee arthroplasty (TKA) improves patient outcomes. The purpose of this study was to compare clinical outcomes of sensor balance (SB) with manual balance (MB) TKA with a minimum two-year follow-up. METHODS: A consecutive series of 207 MB TKAs was compared with 222 SB TKAs between April 2014 and April 2017. A single surgeon performed all surgeries, using the same prosthesis. The primary end point was the aggregated mean change in four subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS4) between preoperative and two-year time points. Secondary outcomes included mean differences between groups in all five KOOS subscales, proportions of knee balancing procedures, and rates of reoperations including revisions and manipulations for stiffness. RESULTS: The mean changes in the KOOS4 aggregated means for MB TKA (42.4; standard deviation, 29.1) and SB TKA (41.5; standard deviation, 25.0) were not significantly different (mean difference, 0.9; 95% confidence interval: -2.6 to 4.4, P = .62). There were significantly more balancing procedures in the SB group (55.9% versus 16.9%; P < .01). There were no significant differences in the number of reoperations (1.4% SB versus 1.4% MB; P = .71) or manipulations for stiffness (3.7% SB versus 4.4% MB; P = .69). CONCLUSION: The use of sensors in TKA to achieve knee balance did not result in improved clinical outcomes, despite significantly increasing the number of surgical interventions required to achieve a balanced knee. Sensors did not alter the rates of revision surgery or requirements for manipulation. It remains to be determined whether precise soft-tissue balancing improves prosthetic survivorship and joint biomechanics.

Surgeon-defined assessment is a poor predictor of knee balance in total knee arthroplasty: a prospective, multicenter study.

BACKGROUND: The accuracy of surgeon-defined assessment (SDA) of soft tissue balance in total knee arthroplasty (TKA) is poorly understood despite balance being considered a significant determinant of surgical success. The study's hypothesis was that intra-operative SDA is a poor predictor of coronal balance in TKA. METHODS: A prospective, multicenter study assessing accuracy of SDA of balance was conducted in 250 patients (285 TKAs). Eight surgeons and thirteen trainees participated, and all were blinded to sensor measurements. The primary outcome was test accuracy of SDA measured at 10°, 45° and 90° compared to sensor measures as the gold standard test. Cohen's kappa coefficient was calculated to determine chance-corrected agreement. Secondary outcomes include the relationship of SDA to level of surgical experience, analysis of between-surgeon differences, and the influence of patient and operative factors on SDA accuracy. RESULTS: Average accuracy of SDA was 58.3%, 61.2% and 66.5% at 10°, 45° and 90° respectively. Cohen's kappa coefficient was 0.18 at all angles and rated as "slight agreement". SDA sensitivities to correctly identify a balanced knee (76.2% at 10°; 82.6% at 45°; 83.2% at 90°) were approximately twice specificities to correctly identify an unbalanced knee (42.6% at 10°; 34.1% at 45°; 41.4% at 90°). Surgical experience (surgeon versus trainee) had no effect on capacity to determine balance. Considerable between-surgeon variability was found (33-65% at 10°, 41-73% at 45°, 55-89% at 90°). CONCLUSION: SDA was a poor predictor of balance, particularly when assessing the unbalanced TKA. Surgeon experience had no effect on test accuracy and considerable between-surgeon variability was recorded. These findings question the accuracy of SDA in TKA. TRIAL REGISTRATION NUMBER: ACTRN# 12618000817246.

Reliability, validity, and responsiveness of multidimensional pain assessment tools used in postoperative adult patients: a systematic review of measurement properties.

OBJECTIVE: The objective of this systematic review was to synthesize the best available evidence relating to the measurement properties of the multidimensional pain assessment tools used to assess postoperative pain in adults. INTRODUCTION: Pain is a common and poorly managed occurrence in patients during the postoperative period. Currently, postoperative pain is usually evaluated with assessment tools that measure one dimension of pain, namely pain intensity, resulting in inadequate management of postoperative pain. It is important to understand the complex nature of pain by considering all dimensions for optimal postoperative pain management. Systematic, robust evidence is lacking regarding the most psychometrically reliable and valid multidimensional pain assessment tool for adult postoperative patients. INCLUSION CRITERIA: This systematic review considered all study types for inclusion. Studies were considered if they assessed the measurement properties of a multidimensional pain assessment tool in adult postoperative patients within two weeks post-surgery. The outcomes included measurement of at least one of the psychometric properties, including reliability, validity, and responsiveness. METHODS: A three-step search strategy was undertaken, including a search of the MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL databases performed in October 2019. We also searched Dissertation Abstracts International, ProQuest Dissertations and Theses, MedNar, and ClinicalTrials.gov to identify unpublished studies. The title and abstracts of the studies were reviewed by two independent reviewers against the inclusion/exclusion criteria. The methodological quality of the potential studies was assessed independently by three reviewers using the COSMIN checklist. RESULTS: Seventeen studies involving five multidimensional postoperative pain assessment tools were included in the review: American Pain Society Pain Outcomes Questionnaire-Revised; Brief Pain Inventory; Houston Pain Outcome Instrument; McGill Pain Questionnaire; and the Quality Improvement in Postoperative Pain Management Postoperative Pain Questionnaire. The two most commonly used tools were the Brief Pain Inventory and the American Pain Society Pain Outcomes Questionnaire-Revised, which were assessed in six studies each. The included studies mainly reported internal consistency reliability, with four of the five identified tools demonstrating high Cronbach's alpha values ranging from 0.72 to 0.92. However, the Houston Pain Outcome Instrument demonstrated mixed findings, with eight of the nine subscales having moderate to high reliability while the expectations about pain subscale had poor reliability (α=0.003). CONCLUSIONS: This review provides much needed information about the current tools used in many clinical, educational, and research settings. Of the five tools included in this review, the Brief Pain Inventory demonstrated strong evidence of psychometric validity and is recommended for use in assessing postoperative pain. Further psychometric validation of multidimensional postoperative pain assessment tools with emphasis on responsiveness and measurement error is required in order to accurately assess the minimal clinically important difference in postoperative pain outcomes.

Do Markers of Inflammation and/or Muscle Regeneration in Lumbar Multifidus Muscle and Fat Differ Between Individuals with Good or Poor Outcome Following Microdiscectomy for Lumbar Disc Herniation?

STUDY DESIGN: Observational study. OBJECTIVE: The aim of this study was to evaluate whether inflammatory and/or muscle regeneration markers in paraspinal tissues (multifidus muscle/fat) during microdiscectomy surgery in patients with lumbar disc herniation (LDH) with radiculopathy, differ between individuals with good or poor outcome. SUMMARY OF BACKGROUND DATA: Structural back muscle changes, including fat infiltration, muscle atrophy, and fiber changes, are ubiquitous with LBP and are thought to be regulated by inflammatory and regeneration processes. Muscle changes might be relevant for recovery after microdiscectomy, but a link between expression of inflammatory and muscle regeneration genes in paraspinal tissues and clinical outcome has not been tested. METHOD: Paraspinal tissues from deep multifidus muscles and fat (intramuscular, sub-cutaneous, epidural) were harvested from twenty-one patients with LDH undergoing microdiscectomy surgery. Quantitative polymerase chain reaction (qPCR) measured expression of 10 genes. Outcome was defined as good (visual analogue scale (VAS) low back pain (LBP)+) or poor (VAS LBP-) by an improvement of >33% or ≤33% on the pain VAS, respectively. Good functional improvement was defined as 25% improvement on the physical functioning scale (PFS). RESULTS: Brain-derived neurotrophic factor expression in deep multifidus was 91% lower (P = 0.014) in the VAS LBP- than VAS LBP+ group. Expression of interleukin-1ß in subcutaneous fat was 48% higher (P = 0.026) in the VAS LBP- than VAS LBP+ group. No markers differed based on PFS. CONCLUSION: Results show a relationship between impaired muscle regeneration profile in multifidus muscle and poor outcome following microdiscectomy for LDH. Inflammatory dysregulation in subcutaneous fat overlying the back region might predict poor surgical outcome.Level of Evidence: 4.

Fat infiltration in the multifidus muscle is related to inflammatory cytokine expression in the muscle and epidural adipose tissue in individuals undergoing surgery for intervertebral disc herniation.

PURPOSE: Recent animal studies have discovered dysregulation of local inflammatory activity as a novel mechanism to explain fat and connective tissue accumulation in the multifidus muscle in association with intervertebral disc (IVD) degeneration/injury. This study aimed to test whether similar mechanisms are active in humans by investigation of whether expression of inflammatory genes in the multifidus muscle differed between individuals with low and high levels of intra-muscular fat in the muscle. The secondary aims were to compare inflammatory gene expression in the intra-muscular, subcutaneous and epidural fat between groups. METHODS: Muscle and fat were procured from 24 individuals undergoing spine surgery for IVD herniation. Gene expression was quantified using qPCR assays. Participants were allocated to high- and low-fat infiltration groups based on clinical assessment of multifidus fat using Kjaer grading of MRI. RESULTS: TNF expression in the multifidus muscle was greater in participants with high rather than low levels of fat infiltration. This group also had greater expression of leptin, but lower arginase-1 (marker of anti-inflammatory M2 macrophages) in intra-muscular and subcutaneous adipose tissue, and greater expression of TNF, adiponectin and nitric oxide synthase 2 (marker of pro-inflammatory M1 macrophages) in epidural fat. CONCLUSION: The results support the hypothesis that IVD degeneration is associated with dysregulation of the inflammatory state of the local multifidus muscle, which provides initial evidence for translation of some, but not all, observations from recent animal studies to humans. Discovery of inflammatory dysregulation in epidural adipose tissue has potential for broad impact on tissue health and LBP symptoms.