Nonoperative management of discogenic back pain: a systematic review

Modic Changes in the Lumbar Spine: Exploring Their Association with Abdominal Aortic Calcification as a Potential Indicator of Systemic Atherosclerosis

BACKGROUND

This was a cross-sectional study on the correlation between abdominal aortic calcification (AAC) and Modic changes (MC). Little is known regarding the etiology of MC in the lumbar spine. Currently, insufficient vascularization of the endplate has been proposed to contribute to the appearance of MC. Our objective was to investigate whether AAC, a marker for a poor vascular status, is associated with MC in patients suffering from degenerative disc disease.

METHODS

Radiologic images of patients (n = 130) suffering from degenerative lumbar disc disease were reviewed. Type and severity of MC were assessed using magnetic resonance images, and severity of AAC was evaluated using computed tomography images or fluoroscopy. Both items were dichotomized into minimal and relevant grades. The correlation between them was studied using Spearman's correlation test, with age as a covariate.

RESULTS

Of the patients, 113 (87%) demonstrated MC (31% type I, 63% type II, and 6% type III) (55% relevant grade), and 68% had AAC (44% relevant grade). Spearman statistical analysis revealed that AAC was correlated with age (P < 0.001), whereas MC were not (P = 0.142). AAC severity was significantly correlated with MC, remaining so after age adjustment (P < 0.05). While MC type I lacked correlation with AAC, MC type II were significantly correlated with AAC (0.288, P = 0.015); however, this association lost significance after adjusting for age (P = 0.057).

CONCLUSIONS

AAC and MC (mainly MC type II) are associated, indicating that reduced blood supply or even a poor systemic vascularization status due to atherosclerotic disease may play a role in the formation of MC. Future studies focusing on the etiology of MC should pay more attention to patients' vascular status and determinants of abdominal aorta calcification.

Comparative Analysis of Early and Long-Term Outcomes of Patients with Degenerative Lumbar Spine Disease Using the DIAM Stabilizer and Standard Rehabilitation Program: A Preliminary Prospective Randomized Controlled Trial with 1-Year Follow-Up

Low back pain (LBP) is a leading cause of disability and work absenteeism. The cause of LBP may be degeneration of the intervertebral disc. LBP is characterized by considerable variability and tends to develop into chronic pain. Treatment of LBP includes conservative and rehabilitative treatments, surgery, and so-called minimally invasive treatment. One of the most commonly performed procedures is interspinous stabilization using a dynamic interspinous DIAM (device for intervertebral assisted motion) stabilizer. There is still no clear, strong evidence for the effectiveness and superiority of surgical treatment over conservative treatment. This study aimed to compare the early and long-term outcomes of patients with LBP using the DIAM interspinous stabilizer in relation to patients treated conservatively. A group of 86 patients was prospectively randomized into two comparison groups: A (n = 43), treated with the DIAM dynamic stabilizer for degenerative lumbar spine disease (mean age = 43.4 years ± SD = 10.8 years), and B (n = 43), treated conservatively. Pain severity was assessed using the visual analog scale (VAS), whereas disability was assessed using the Oswestry disability index (ODI). The difference in preoperative and postoperative ODI scores ≥ 15 points was used as a criterion for treatment effectiveness, and the difference in VAS scores ≥ 1 point was used as a criterion for pain reduction. In patients under general anesthesia, the procedure only included implantation of the DIAM system. Patients in the control group underwent conservative treatment, which included rehabilitation, a bed regimen, analgesic drug treatment and periarticular spinal injections of anti-inflammatory drugs. It was found that all patients (n = 43) continued to experience LBP after DIAM implantation (mean VAS score of 4.2). Of the 36 patients who experienced LBP with sciatica before the procedure, 80.5% (n = 29) experienced a reduction in pain. As for the level of fitness, the average ODI score was 19.3 ± 10.3 points. As for the difference in ODI scores in the pre-treatment results vs. after treatment, the average score was 9.1 ± 10.6. None of the patients required reoperation at 12 months after surgery. There were no statistically significant differences between the two groups in either early (p = 0.45) or long-term outcomes (p = 0.37). In conclusion, neurosurgical treatment with the DIAM interspinous stabilizer was as effective as conservative treatment and rehabilitation during the one-year follow-up period.

Multifunctional annulus fibrosus matrix prevents disc-related pain via inhibiting neuroinflammation and sensitization

Chronic low back pain mainly attributed to intervertebral disc (IVD) degeneration. Endogenous damage-associated molecular patterns (DAMPs) in the injured IVD, particularly mitochondria-derived nucleic acid molecules (CpG DNA), play a primary role in the inflammatory responses in macrophages. M1-type macrophages form a chronic inflammatory microenvironment by releasing pro-inflammatory factors and nerve growth factor (NGF) that induce nerve growth into the inner annulus fibrosus, resulting in persistent hyperalgesia. We fabricated an amphiphilic polycarbonate that naturally forms cationic nanoparticles (cNP) in aqueous solutions, with the hydrophobic core loaded with TrkA-IN-1, an antagonist against the NGF receptor (TrkA). The drug delivery nanoparticles were denoted as TI-cNP. TrkA-IN-1 and TI-cNP were added to the decellularized annulus fibrosus matrix (DAF) hydrogel to form hybrid hydrogels, denoted as TI-DAF and TI-cNP-DAF, respectively. As a result, TrkA-IN-1 showed a delayed release profile both in TI-DAF and TI-cNP-DAF. Each mole of cNP could bind approximately 3 mol of CpG DNA to inhibit inflammation. cNP-DAF and TI-cNP-DAF significantly inhibited the M1 phenotype induced by CpG DNA. TI-DAF and TI-cNP-DAF reduced neurite branching and axon length, and inhibited the expression of neurogenic mediators (CGRP and substance P) in the presence of NGF. Besides, TI-cNP-DAF relieved mechanical hyperalgesia, reduced CGRP and substance P expression in the dorsal root ganglion, and downregulated GFAP and c-FOS signaling in the spinal cord in the rat disc herniation model. Summarily, TI-cNP-DAF, a novel composite IVD hydrogel, efficiently mediated the inflammatory environment, inhibited nerve ingrowth and sensitization, and could be clinically applied for treating discogenic pain. STATEMENT OF SIGNIFICANCE: Discogenic lower back pain, related to intervertebral disc degeneration (IDD), imposes a tremendous health and economic burden globally. M1-type macrophages release pro-inflammatory factors and nerve growth factor (NGF) that induce nerve growth into the inner annulus fibrosus, resulting in persistent hyperalgesia and discogenic pain. Reconstructing matrix integrity and modulating the inflammatory microenvironment are promising strategies for preventing the ingrowth and activation of neurites. The TI-cNP-DAF hydrogel recovers tissue integrity, alleviates inflammation, and delivers the TrkA antagonist to inhibit the activity of NGF, thus restraining hyperinnervation and nociceptive input. Due to its simple production process, injectability, and acellular strategy, the hydrogel is operable and holds great potential for treating discogenic lower back pain.

Nonviral overexpression of Scleraxis or Mohawk drives reprogramming of degenerate human annulus fibrosus cells from a diseased to a healthy phenotype

Background

Intervertebral disc (IVD) degeneration is a major contributor to low back pain (LBP), yet there are no clinical therapies targeting the underlying pathology. The annulus fibrosus (AF) plays a critical role in maintaining IVD structure/function and undergoes degenerative changes such as matrix catabolism and inflammation. Thus, therapies targeting the AF are crucial to fully restore IVD function. Previously, we have shown nonviral delivery of transcription factors to push diseased nucleus pulposus cells to a healthy phenotype. As a next step in a proof-of-concept study, we report the use of Scleraxis (SCX) and Mohawk (MKX), which are critical for the development, maintenance, and regeneration of the AF and may have therapeutic potential to induce a healthy, pro-anabolic phenotype in diseased AF cells.

Methods

MKX and SCX plasmids were delivered via electroporation into diseased human AF cells from autopsy specimens and patients undergoing surgery for LBP. Transfected cells were cultured over 14 days and assessed for cell morphology, viability, density, gene expression of key phenotypic, inflammatory, matrix, pain markers, and collagen accumulation.

Results

AF cells demonstrated a fibroblastic phenotype posttreatment. Moreover, transfection of SCX and MKX resulted in significant upregulation of the respective genes, as well as SOX9. Transfected autopsy cells demonstrated upregulation of core extracellular matrix markers; however, this was observed to a lesser effect in surgical cells. Matrix-degrading enzymes and inflammatory cytokines were downregulated, suggesting a push toward a pro-anabolic, anti-inflammatory phenotype. Similarly, pain markers were downregulated over time in autopsy cells. At the protein level, collagen content was increased in both MKX and SCX transfected cells compared to controls.

Conclusions

This exploratory study demonstrates the potential of MKX or SCX to drive reprogramming in mild to moderately degenerate AF cells from autopsy and severely degenerate AF cells from surgical patients toward a healthy phenotype and may be a potential nonviral gene therapy for LBP.

The clinical efficacy of ozone combined with steroid in the treatment of discogenic low back pain: a randomized, double-blinded clinical study

Objective

This randomized double-blinded clinical study is to investigate the clinical efficacy of per-paravertebral disk ozone injection combined with steroids in the treatment of patients with chronic discogenic low back pain (CDLBP).

Methods

Group A (N = 60) received a per-paravertebral injection of a steroid mixture of 10 mL with pure oxygen 20 mL, while group B (N = 60) received a per-paravertebral injection of a steroid mixture of 10 mL combined with ozone 20 mL (30 μg/mL). Injections were administered once a week for 3 weeks, with a follow-up of 6 months. Clinical outcomes were assessed at week 1, month 3, and month 6 with the help of Visual Analog Scale (VAS) scores and Macnab efficacy evaluation.

Results

The VAS score of both group A (1.65 vs. 6.87, p = 0.000) and group B (1.25 vs. 6.85, p = 0.000) at week 1 was significantly reduced compared to baseline. The effect was sustained at the 3- and 6-month follow-up periods (p < 0.05). Group B had significantly lower VAS scores at month 3 (1.53 vs. 3.82, p = 0.000) and month 6 (2.80 vs. 5.05, p = 0.000) compared to group A, respectively. Based on Macnab criteria, 95 and 96.7% of patients in groups A and B had good rates "excellent plus good" at week 1, respectively. Good rates were significantly higher in group B at month 3 (91.7 vs. 78.3%, p = 0.041) and month 6 (85.0 vs. 68.3%, p = 0.031) compared to group A, respectively. No serious adverse events were noted in both groups.

Conclusion

Per-paravertebral injection of steroid and ozone combination resulted in better relief of CDLBP compared to pure oxygen plus steroid.

Clinical Trial Registration

ChiCTR2100044434 https://www.chictr.org.cn/showproj.html?proj=121571.

Interventional surgery effectiveness in treatment of the cervical spine and shoulder joint chronic pain

Relevance. Degenerative diseases of the spine are among the most common pathologies that cause significant medical, social and economic losses. Thus, a retrospective analysis of the Humana database from 2008 to 2014 indicates a sharp increase in discogenic neurocompression lesions of the cervical spine, which is 42 %. Degenerative processes are characterized by metabolic and structural changes in the intervertebral discs (IVD), which lead to the loss of its properties. The aim of the study was to analyze the results of intervertebral disc nucleoplasty and radiofrequency denervation of the facet joints in patients with cervical joint hernias. Materials and Methods . Intervertebral disc nucleoplasty and radiofrequency denervation of the facet joints in patients with hernias of the cervical spine was performed in 55 patients aged 18 to 74 years (mean age 36.28 ± 2.19 years), of which 56.36 % (31 patients) were men and 43.64 % (24 people) were women. Results and Discussion. The results demonstrate a significant improvement (p0.001) in VAS and ODI in patients after treatment. The majority of patients (45.45 %) rated their health status as “good”, 41.82 % of respondents believe that after the intervention, their health status can be assessed as “excellent”. Only 3 patients (5.45 %) indicated an unsatisfactory condition, which may be due to individual psychological characteristics, comorbidities, or a reduced sensitivity threshold. Conclusion. Nucleoplasty of the intervertebral disc and radiofrequency denervation of the facet joints is an effective and safe method for the treatment of intervertebral hernias of the cervical spine.

Axial hypersensitivity is associated with aberrant nerve sprouting in a novel model of disc degeneration in female Sprague Dawley rats

Chronic low back pain is a global socioeconomic crisis and treatments are lacking in part due to inadequate models. Etiological research suggests that the predominant pathology associated with chronic low back pain is intervertebral disc degeneration. Various research teams have created rat models of disc degeneration, but the clinical translatability of these models has been limited by an absence of robust chronic pain‐like behavior. To address this deficit, disc degeneration was induced via an artificial annular tear in female Sprague Dawley rats. The subsequent degeneration, which was allowed to progress for 18‐weeks, caused a drastic reduction in disc volume. Furthermore, from week 10 till study conclusion, injured animals exhibited significant axial hypersensitivity. At study end, intervertebral discs were assessed for important characteristics of human degenerated discs: extracellular matrix breakdown, hypocellularity, inflammation, and nerve sprouting. All these aspects were significantly increased in injured animals compared to sham controls. Also of note, 20 significant correlations were detected between selected outcomes including a moderate and highly significant correlation (R = 0.59, p < 0.0004) between axial hypersensitivity and disc nerve sprouting. These data support this model as a rigorous platform to explore the pathobiology of disc‐associated low back pain and to screen treatments.

In vivo Mouse Intervertebral Disc Degeneration Models and Their Utility as Translational Models of Clinical Discogenic Back Pain: A Comparative Review

Low back pain is a leading cause of disability worldwide and studies have demonstrated intervertebral disc (IVD) degeneration as a major risk factor. While many in vitro models have been developed and used to study IVD pathophysiology and therapeutic strategies, the etiology of IVD degeneration is a complex multifactorial process involving crosstalk of nearby tissues and systemic effects. Thus, the use of appropriate in vivo models is necessary to fully understand the associated molecular, structural, and functional changes and how they relate to pain. Mouse models have been widely adopted due to accessibility and ease of genetic manipulation compared to other animal models. Despite their small size, mice lumbar discs demonstrate significant similarities to the human IVD in terms of geometry, structure, and mechanical properties. While several different mouse models of IVD degeneration exist, greater standardization of the methods for inducing degeneration and the development of a consistent set of output measurements could allow mouse models to become a stronger tool for clinical translation. This article reviews current mouse models of IVD degeneration in the context of clinical translation and highlights a critical set of output measurements for studying disease pathology or screening regenerative therapies with an emphasis on pain phenotyping. First, we summarized and categorized these models into genetic, age-related, and mechanically induced. Then, the outcome parameters assessed in these models are compared including, molecular, cellular, functional/structural, and pain assessments for both evoked and spontaneous pain. These comparisons highlight a set of potential key parameters that can be used to validate the model and inform its utility to screen potential therapies for IVD degeneration and their translation to the human condition. As treatment of symptomatic pain is important, this review provides an emphasis on critical pain-like behavior assessments in mice and explores current behavioral assessments relevant to discogenic back pain. Overall, the specific research question was determined to be essential to identify the relevant model with histological staining, imaging, extracellular matrix composition, mechanics, and pain as critical parameters for assessing degeneration and regenerative strategies.

Platelet-Rich Plasma Releasate versus Corticosteroid for the Treatment of Discogenic Low Back Pain: A Double-Blind Randomized Controlled Trial

Clinical application of platelet-rich plasma is gaining popularity in treating low back pain (LBP). This study investigated the efficacy and safety of platelet-rich plasma releasate (PRPr) injection into degenerated discs of patients with discogenic LBP. A randomized, double-blind, active-controlled clinical trial was conducted. Sixteen patients with discogenic LBP received an intradiscal injection of either autologous PRPr or corticosteroid (CS). Patients in both groups who wished to have PRPr treatment received an optional injection of PRPr eight weeks later. The primary outcome was change in VAS from baseline at eight weeks. Secondary outcomes were pain, disability, quality of life (QOL), image analyses of disc degeneration, and safety for up to 60 weeks. The VAS change at eight weeks did not significantly differ between the two groups. Fifteen patients received the optional injection. Compared to the CS group, the PRPr group had a significantly improved disability score at 26 weeks and walking ability scores at four and eight weeks. Radiographic disc height and MRI grading score were unchanged from baseline. PRPr caused no clinically important adverse events. PRPr injection showed clinically significant improvements in LBP intensity equal to that of CS. PRPr treatment relieved pain, and improved disability and QOL during 60 weeks of observation.

Placebo Effect of Sham Spine Procedures in Chronic Low Back Pain: A Systematic Review

Background

The literature lacks information about the characteristics of the placebo effect following sham spine procedures for chronic low back pain. We aim to evaluate the effect using pain score data from the sham arms of published trials.

Methods

Relevant trials were selected and reviewed. Baseline and post-procedure pain scores were collected. Each follow up pain score was considered an episode and compared to its baseline for significance. Patients and episodes were pooled and analyzed using three parameters: patient reported outcome measures (PROMs) (Oswestry Disability Index [ODI], Visual Analog Scale [VAS], Numerical Rating Scale [NRS] and Short Form-36 [SF]), anatomical targets (disc, facet, sacroiliac joint [SIJ], ramus communicans nerve [RCN], basivertebral nerve [BVN], and caudal) and follow up periods (early: 0–2, intermediate: >2–4 and late: >4–6) in months. The percentage of pooled patients in the episodes that had significant reduction in pain scores was termed placebo effect. The outcome was defining the magnitude of the placebo effect and determining if it was influenced by the three parameters.

Results

Seventeen studies that reported 535 patients and 55 pain scoring episodes were considered eligible. Significant reduction in pain scores was reported in 21 episodes. The overall placebo effect among the patients during the studied period was 53.2%. The rate ranged according to PROMs from 42.4% to 72.1%, anatomical targets from 11.1% to 100% and follow up periods from 47.9% to 59%. The placebo effect differed significantly between the various domains in the three parameters.

Conclusion

Placebo effect was observed in nearly half of the patients during the first 6 months following a sham spine procedure. The effect was influenced by utilized PROMs, anatomical target and follow up period. The findings should be considered in the design of new sham spine procedure trials. Further research is required to delineate the effect of bias on the findings.

Inversion Table Fall Injury, the Phantom Menace: Three Case Reports on Cervical Spinal Cord Injury

Background: An inversion device, which is used to suspend one’s body and perform traction therapy, was introduced as an inversion table under the name of “Geokkuri” in South Korea. Fall injuries while hanging on inversion tables are among the most devastating spine injuries, as the likelihood of severe neurological sequelae such as tetraplegia increases. However, its enormous danger has been overlooked and this devastating injury has become a common clinical entity over time. The limited number of studies reported imply the lack of interest of researchers in these injuries. We reviewed three cases of spinal cord injury sustained on inversion tables in different environments and report the potential danger associated with the use of inversion tables to facilitate a safer exercise environment.

Amniotic Umbilical Cord Particulate for Discogenic Pain

Context

Discogenic low back pain is the most common type of low back pain and is a major cause of morbidity worldwide. Current nonoperative treatment options are limited in efficacy and lack evidence of long-term pain relief; thus, there is an unmet clinical need for an effective treatment for patients with discogenic pain. Amniotic membrane and umbilical cord (AMUC) particulate may be useful in relieving pain and inhibiting the degenerative cascade in patients with discogenic pain by reducing inflammation.

Objective

To evaluate the effectiveness of AMUC particulate for discogenic pain.

Methods

Six months of conservative therapy failed in patients who had discogenic pain confirmed by magnetic resonance imaging and provocative discography. They subsequently received intradiskal injection of 50 to 100 mg of AMUC particulate for cervical, lumbar, and lumbosacral disks.

Results

A total of 11 patients with 20 disks were included. Before treatment, all patients reported severe pain, and 10 patients took opioids daily. After treatment, the median reported pain relief was 40%, 50%, and 75% at 1-month (n=6), 3 months (n=8), and 6 months (n=5), respectively. Complete pain relief was noted in 1 patient; however, 2 patients (18%) reported no pain relief at 1 and 3 months. No adverse events, repeated procedures, or complications occurred.

Conclusion

This preliminary evidence suggests that a single intradiskal injection of AMUC particulate is safe and may provide symptomatic pain relief in some patients with discogenic pain.

J-2156, a somatostatin receptor type 4 agonist, alleviates mechanical hyperalgesia in a rat model of chronic low back pain

Chronic low back pain (LBP) ranks among the most common reasons for patient visits to healthcare providers. Drug treatments often provide only partial pain relief and are associated with considerable side-effects. J-2156 [(1'S,2S)-4amino-N-(1'-carbamoyl-2'-phenylethyl)-2-(4"-methyl-1"-naphthalenesulfonylamino)butanamide] is an agonist that binds with nanomolar affinity to the rat and human somatostatin receptor type 4 (SST₄ receptor). Hence, our aim was to assess the efficacy of J-2156 for relief of chronic mechanical LBP in a rat model. Male Sprague Dawley rats were anaesthetised and their lumbar L4/L5 and L5/L6 intervertebral discs (IVDs) were punctured (0.5 mm outer diameter, 2 mm-deep) 10 times per disc. Sham-rats underwent similar surgery, but without disc puncture. For LBP-rats, noxious pressure hyperalgesia developed in the lumbar axial deep tissues from day 7 to day 21 post-surgery, which was maintained until study completion. Importantly, mechanical hyperalgesia did not develop in the lumbar axial deep tissues of sham-rats. In LBP-rats, single intraperitoneal (i.p.) injection of J-2156 (3, 10, 30 mg kg^-1) alleviated primary and secondary hyperalgesia in the lumbar axial deep tissues at L4/L5 and L1, respectively. This was accompanied by a reduction in the otherwise augmented lumbar (L4-L6) dorsal root ganglia expression levels of the pro-nociceptive mediators: phosphorylated p38 (pp38) mitogen-activated protein kinase (MAPK) and phosphorylated p44/p42 MAPK and a reduction in pp38 MAPK in the lumbar enlargement of the spinal cord. The SST₄ receptor is worthy of further investigation as a target for discovery of novel analgesics for the relief of chronic LBP.

Discogenic Back Pain: Literature Review of Definition, Diagnosis, and Treatment

Discogenic back pain is multifactorial; hence, physicians often struggle to identify the underlying source of the pain. As a result, discogenic back pain is often hard to treat—even more so when clinical treatment strategies are of questionable efficacy. Based on a broad literature review, our aim was to define discogenic back pain into a series of more specific and interacting pathologies, and to highlight the need to develop novel approaches and treatment strategies for this challenging and unmet clinical need. Discogenic pain involves degenerative changes of the intervertebral disc, including structural defects that result in biomechanical instability and inflammation. These degenerative changes in intervertebral discs closely intersect with the peripheral and central nervous systems to cause nerve sensitization and ingrowth; eventually central sensitization results in a chronic pain condition. Existing imaging modalities are nonspecific to pain symptoms, whereas discography methods that are more specific have known comorbidities based on intervertebral disc puncture and injection. As a result, alternative noninvasive and specific diagnostic methods are needed to better diagnose and identify specific conditions and sources of pain that can be more directly treated. Currently, there are many treatments/interventions for discogenic back pain. Nevertheless, many surgical approaches for discogenic pain have limited efficacy, thus accentuating the need for the development of novel treatments. Regenerative therapies, such as biologics, cell‐based therapy, intervertebral disc repair, and gene‐based therapy, offer the most promise and have many advantages over current therapies. © 2019 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research

Comparison of percutaneous intradiscal ozone injection with laser disc decompression in discogenic low back pain

Background

Intervertebral disc herniation with the pressure on the surrounding neural structures is one of the most important causes of chronic low back pain, which sometimes leads to open surgery. Reducing the pressure inside the disc with intradiscal intervention such as laser irradiation or ozone injection is a minimally invasive method and an alternative to surgery with satisfactory results. These two methods were compared with each other in this research.

Patients and methods

In this clinical trial, 40 patients with back pain radiating to lower limb due to lumbar intervertebral disc herniation were selected. These patients were randomly divided into two equal groups for percutaneous intradiscal intervention. The Laser Disc Decompression Group (LDG) (n=20) was exposed to 1500 J of laser irradiation into the disc center. In the Ozone Injection Group (OZG) patients (n=20), 6 mL of ozone 30 µg/mL was injected into the center of the disc. Considering the level of neural root involvement, both groups received 20 mg of triamcinolone injection via transforaminal epidural. Patients were followed up for 12 months regarding score on visual analogue scale and life performance improvement based on Oswestry Disability Index (ODI) and satisfaction level.

Results

According to the results, no difference was found between the two groups for ODI variable before intervention, whereas OZG showed better ODI scores in the measured time intervals. In LDG, only a significant difference in terms of ODI score was found between the times of before surgery and the first month.

Conclusion

Intradiscal ozone injection could be an effective and cost-effective method for treatment of patients with discogenic back pain.

Critical aspects and challenges for intervertebral disc repair and regeneration-Harnessing advances in tissue engineering

Low back pain represents the highest burden of musculoskeletal diseases worldwide and intervertebral disc degeneration is frequently associated with this painful condition. Even though it remains challenging to clearly recognize generators of discogenic pain, tissue regeneration has been accepted as an effective treatment option with significant potential. Tissue engineering and regenerative medicine offer a plethora of exploratory pathways for functional repair or prevention of tissue breakdown. However, the intervertebral disc has extraordinary biological and mechanical demands that must be met to assure sustained success. This concise perspective review highlights the role of the disc microenvironment, mechanical and clinical design considerations, function vs mimicry in biomaterial‐based and cell engineering strategies, and potential constraints for clinical translation of regenerative therapies for the intervertebral disc.

Inhibiting tumor necrosis factor-alpha at time of induced intervertebral disc injury limits long-term pain and degeneration in a rat model

Background

Painful intervertebral disc (IVD) degeneration has tremendous societal costs and few effective therapies. Intradiscal tumor necrosis factor‐alpha (TNFα) is commonly associated with low back pain, but the direct relationship remains unclear.

Purpose

Treatment strategies for low back pain require improved understanding of the complex relationships between pain, intradiscal pro‐inflammatory cytokines, and structural IVD degeneration. A rat in vivo lumbar IVD puncture model was used to 1) determine the role of TNFα in initiating painful IVD degeneration, and 2) identify statistical relationships between painful behavior, IVD degeneration, and intradiscal pro‐inflammatory cytokine expression.

Methods

Lumbar IVDs were punctured anteriorly and injected with TNFα, anti‐TNFα, or saline and compared with sham and naive controls. Hindpaw mechanical hyperalgesia was assayed weekly to determine pain over time. 6‐weeks post‐surgery, animals were sacrificed, and IVD degeneration, IVD height, and intradiscal TNFα and interleukin‐1 beta (IL‐1β) expressions were assayed.

Results

Intradiscal TNFα injection increased pain and IVD degeneration whereas anti‐TNFα alleviated pain to sham level. Multivariate step‐wise linear regression identified pain threshold was predicted by IVD degeneration and intradiscal TNFα expression. Pain threshold was also linearly associated with IVD height loss and IL‐1β.

Discussion

The significant associations between IVD degeneration, height loss, inflammation, and painful behavior highlight the multifactorial nature of painful IVD degeneration and the challenges to diagnose and treat a specific underlying factor. We concluded that TNFα is an initiator of painful IVD degeneration and its early inhibition can mitigate pain and degeneration. Intradiscal TNFα inhibition following IVD injury may warrant investigation for its potential to alter downstream painful IVD degeneration processes.

α2-Macroglobulin: Autologous Protease Inhibition Technology

α₂-Macroglobulin (A2M) is a plasma glycoprotein best known for its ability to inhibit a broad spectrum of serine, threonine, and metalloproteases as well as inflammatory cytokines by a unique bait-and-trap method. A2M has emerged as a unique potential treatment of cartilage-based pathology and inflammatory arthritides. This article describes the unique method by which A2M not only inhibits the associated inflammatory cascade but also disrupts the catabolic process of cartilage degeneration. Autologous concentrated A2M from plasma is currently in use to successfully treat various painful arthritides. Future directions will focus on recombinant variants that enhance its anti-inflammatory and disease-modifying potential.

Animal models for studying the etiology and treatment of low back pain

Chronic low back pain is a major cause of disability and health care costs. Effective treatments are inadequate for many patients. Animal models are essential to further understanding of the pain mechanism and testing potential therapies. Currently, a number of preclinical models have been developed attempting to mimic aspects of clinical conditions that contribute to low back pain (LBP). This review focused on describing these animal models and the main behavioral tests for assessing pain in each model. Animal models of LBP can be divided into the following five categories: Discogenic LBP, radicular back pain, facet joint osteoarthritis back pain, muscle-induced LBP, and spontaneous occurring LBP models. These models are important not only for enhancing our knowledge of how LBP is generated, but also for the development of novel therapeutic regimens to treat LBP in patients. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1305-1312, 2018.

Cell-Seeded Adhesive Biomaterial for Repair of Annulus Fibrosus Defects in Intervertebral Discs

Defects in the annulus fibrosus (AF) of intervertebral discs allow nucleus pulposus tissue to herniate causing painful disability. Microdiscectomy procedures remove herniated tissue fragments, but unrepaired defects remain allowing reherniation or progressive degeneration. Cell therapies show promise to enhance repair, but methods are undeveloped and carriers are required to prevent cell leakage. To address this challenge, this study developed and evaluated genipin-crosslinked fibrin (FibGen) as an adhesive cell carrier optimized for AF repair that can deliver cells, match AF material properties, and have low risk of extrusion during loading. Part 1 determined that feasibility of bovine AF cells encapsulated in high concentration FibGen (F140G6: 140 mg/mL fibrinogen; 6 mg/mL genipin) for 7 weeks could maintain high viability, but had little proliferation or matrix deposition. Part 2 screened tissue mechanics and in situ failure testing of nine FibGen formulations (fibrin: 35-140 mg/mL; genipin: 1-6 mg/mL). F140G6 formulation matched AF shear and compressive properties and significantly improved failure strength in situ. Formulations with reduced genipin also exhibited satisfactory material properties and failure behaviors warranting further biological screening. Part 3 screened AF cells encapsulated in four FibGen formulations for 1 week and found that reduced genipin concentrations increased cell viability and glycosaminoglycan production. F70G1 (70 mg/mL fibrinogen; 1 mg/mL genipin) demonstrated balanced biological and biomechanical performance warranting further testing. We conclude that FibGen has potential to serve as an adhesive cell carrier to repair AF defects with formulations that can be tuned to enhance biomechanical and biological performance; future studies are required to develop strategies to enhance matrix production.

The Association Between Atherosclerosis and Low Back Pain: A Systematic Review

OBJECTIVE

To assess the evidence of association between atherosclerosis and low back pain (LBP). TYPE: Focused systematic review.

LITERATURE SURVEY

PubMed, Web of Science, CINAHL, and EMBASE were searched for original research articles, not limited by language, from January 1, 1990, to October 31, 2016.

METHODOLOGY

Titles and then abstracts were identified using predefined search terms and excluded based on lack of relevancy. This was followed by full-text reviews. Two authors independently assessed methodological quality based on Cochrane Handbook for Systematic Reviews of Interventions.

SYNTHESIS

A total of 26 studies met the inclusion criteria. The quality of the studies was low to moderate. There was significant heterogeneity across articles with respect to methodology. There was insufficient evidence to support an association between ischemia and low back pain.

CONCLUSIONS

The cause of LBP remains poorly understood. Better insight into how intervertebral disk changes relate to LBP is needed to guide future research. High-quality prospective studies are needed to answer the question of whether atherosclerosis is a risk factor for LBP.

LEVEL OF EVIDENCE

II.

The Changing Face of Spine Care: The MU Comprehensive Spine Center

Back pain is extraordinarily common, and the current approach to treatment has yielded enormous financial burdens on health care systems and society in general. In addition, primary care providers and patients alike are often unsure where to seek further care, and what, if any, advanced tests or images are needed. As a result, spine surgeons often see a high percentage of non-operative patients when unnecessary, redundant, or incorrect imaging was obtained. At MU Health Care a team of physiatrists, orthopedic surgeons, neurosurgeons sought to address these issues by forming the MU Comprehensive Spine Center that offers a systematic, collaborative approach to spine care.

Randomized sham-controlled, double-blind, multicenter clinical trial on the effect of percutaneous radiofrequency at the ramus communicans for lumbar disc pain

Background

Investigate the effect of percutaneous radiofrequency compared to a sham procedure, applied to the ramus communicans for treatment of lumbar disc pain.

Methods

Randomized sham‐controlled, double‐blind, crossover, multicenter clinical trial. Multidisciplinary pain centres of two general hospitals. Sixty patients aged 18 or more with medical history and physical examination suggestive for lumbar disc pain and a reduction of two or more on a numerical rating scale (0–10) after a diagnostic ramus communicans test block. Treatment group: percutaneous radiofrequency treatment applied to the ramus communicans; sham: same procedure except radiofrequency treatment. Primary outcome measure: pain reduction. Secondary outcome measure: Global Perceived Effect.

Results

No statistically significant difference in pain level over time between the groups, as well as in the group was found; however, the factor period yielded a statistically significant result. In the crossover group, 11 out of 16 patients experienced a reduction in NRS of 2 or more at 1 month (no significant deviation from chance). No statistically significant difference in satisfaction over time between the groups was found. The independent factors group and period also showed no statistically significant effects. The same applies to recovery: no statistically significant effects were found.

Conclusions

The null hypothesis of no difference in pain reduction and in Global Perceived Effect between the treatment and sham group cannot be rejected. Post hoc analysis revealed that none of the investigated parameters contributed to the prediction of a significant pain reduction.

Significance

Interrupting signalling through the ramus communicans may interfere with the transition of painful information from the discs to the central nervous system. Methodological differences exist in studies evaluating the efficacy of radiofrequency treatment for lumbar disc pain. A randomized, sham‐controlled, double‐blind, multicenter clinical trial on the effect of radiofrequency at the ramus communicans for lumbar disc pain was conducted. The null hypothesis of no difference in pain reduction and in Global Perceived Effect between the treatment and sham group cannot be rejected.

Conservative Care in Lumbar Spine Surgery Trials: A Descriptive Literature Review

OBJECTIVE

To evaluate the degree to which conservative care and failure were specifically defined in studies comparing nonoperative treatment versus surgery for low back pain (LBP) conditions in adults.

DATA SOURCES

A comprehensive literature search was conducted by an experienced librarian using MEDLINE (PubMed), Embase, Google Scholar, and CENTRAL from January 2003 to June 2014. Endnote bibliographic management application was used to remove duplicates and organize the citations.

STUDY SELECTION

Prospective, randomized, or cohort trials comparing surgery versus conservative intervention for patients with LBP conditions. Study selection was conducted by 2 independent reviewers.

DATA EXTRACTION

Three independent reviewers extracted data from each article using a structured data extraction form. Data extracted included type of study, participant characteristics, sample size, description, and duration of conservative care and whether failed conservative care criterion was defined.

DATA SYNTHESIS

A total of 852 unique records were screened for eligibility; of those, 72 articles were identified for further full-text review. Thirty-four full texts were excluded based on the exclusion criteria, and 38 articles, representing 20 unique studies, were included for qualitative synthesis. Fifteen of the 20 studies defined the duration of conservative care. Only 3 studies defined the dosage of physical therapy sessions, including total number of visits and visit duration. Two studies described medication usage, including the duration and type. No studies specifically defined what constituted failed conservative therapy.

CONCLUSIONS

This literature review suggests conservative care is poorly defined in randomized trials, which can lead to ambiguity of research procedures and unclear guidelines for clinicians. Future studies should increase transparency and explicitly define conservative care.

Differences in myoelectric and body-powered upper-limb prostheses: Systematic literature review

The choice of a myoelectric or body-powered upper-limb prosthesis can be determined using factors including control, function, feedback, cosmesis, and rejection. Although body-powered and myoelectric control strategies offer unique functions, many prosthesis users must choose one. A systematic review was conducted to determine differences between myoelectric and body-powered prostheses to inform evidence-based clinical practice regarding prescription of these devices and training of users. A search of 9 databases identified 462 unique publications. Ultimately, 31 of them were included and 11 empirical evidence statements were developed. Conflicting evidence has been found in terms of the relative functional performance of body-powered and myoelectric prostheses. Body-powered prostheses have been shown to have advantages in durability, training time, frequency of adjustment, maintenance, and feedback; however, they could still benefit from improvements of control. Myoelectric prostheses have been shown to improve cosmesis and phantom-limb pain and are more accepted for light=intensity work. Currently, evidence is insufficient to conclude that either system provides a significant general advantage. Prosthetic selection should be based on a patient's individual needs and include personal preferences, prosthetic experience, and functional needs. This work demonstrates that there is a lack of empirical evidence regarding functional differences in upper-limb prostheses.

Local anesthetic injections with or without steroid for chronic non-cancer pain: a protocol for a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Steroids are often combined with local anesthetic (LA) and injected to reduce pain associated with various chronic non-cancer pain (CNCP) complaints. The biological rationale behind injection of a steroid solution is unclear, and it is uncertain whether the addition of steroids offers any additional benefits over injection of LA alone. We propose to conduct a systematic review and meta-analysis to summarize the evidence for using steroids and LA vs. LA alone in the treatment of CNCP.

METHODS

An experienced librarian will perform a comprehensive search of EMBASE, MEDLINE, and the Cochrane Central Registry of Controlled Trials (CENTRAL) databases with search terms for clinical indications, LA, and steroid agents. We will review bibliographies of all relevant published reviews in the last 5 years for additional studies. Eligible trials will be published in English and randomly allocate patients with CNCP to treatment with steroid and LA injection therapy or injection with LA alone. We will use the guidelines published by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to inform the outcomes that we collect and present. Teams of reviewers will independently and in duplicate assess trial eligibility, abstract data, and assess risk of bias among eligible trials. We will prioritize intention to treat analysis and, when possible, pool outcomes across trials using random effects models. We will report our findings as risk differences, weighted mean differences, or standardized mean differences for individual outcomes. Further, to ensure interpretability of our results, we will present risk differences and measures of relative effect for pain reduction based on anchor-based minimally important clinical differences. We will conduct a priori defined subgroup analyses and use the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to evaluate the certainty of the evidence on an outcome-by-outcome basis.

DISCUSSION

Our review will evaluate both the effectiveness and the adverse events associated with steroid plus LA vs. LA alone for CNCP, evaluate the quality of the evidence using the GRADE approach, and prioritize patient-important outcomes guided by IMMPACT recommendations. Our results will facilitate evidence-based management of patients with chronic non-cancer pain and identify key areas for future research.

TRIAL REGISTRATION

PROSPERO CRD42015020614.

Combined transforaminal lumbar interbody fusion with posterolateral instrumented fusion for degenerative disc disease can be a safe and effective treatment for lower back pain

BACKGROUND

Lumbar fusion is a proven treatment for chronic lower back pain (LBP) in the setting of symptomatic spondylolisthesis and degenerative scoliosis; however, fusion is controversial when the primary diagnosis is degenerative disc disease (DDD). Our objective was to evaluate the safety and effectiveness of lumbar fusion in the treatment of LBP due to DDD.

MATERIALS AND METHODS

Two-hundred and five consecutive patients with single or multi-level DDD underwent lumbar decompression and instrumented fusion for the treatment of chronic LBP between the years of 2008 and 2011. The primary outcome measures in this study were back and leg pain visual analogue scale (VAS), patient reported % resolution of preoperative back pain and leg pain, reoperation rate, perioperative complications, blood loss and hospital length of stay (LOS).

RESULTS

The average resolution of preoperative back pain per patient was 84% (n = 205) while the average resolution of preoperative leg pain was 90% (n = 190) while a mean follow-up period of 528 days (1.5 years). Average VAS for combined back and leg pain significantly improved from a preoperative value of 9.0 to a postoperative value of 1.1 (P ≤ 0.0001), a change of 7.9 points for the cohort. The average number of lumbar disc levels fused per patient was 2.3 (range 1-4). Median postoperative LOS in the hospital was 1.2 days. Average blood loss was 108 ml perfused level. Complications occurred in 5% of patients (n = 11) and the rate of reoperation for symptomatic adjacent segment disease was 2% (n = 4). Complications included reoperation at index level for symptomatic pseudoarthrosis with hardware failure (n = 3); surgical site infection (n = 7); repair of cerebrospinal fluid leak (n = 1), and one patient death at home 3 days after discharge.

CONCLUSION

Lumbar fusion for symptomatic DDD can be a safe and effective treatment for medically refractory LBP with or without leg pain.

An update on the management of chronic lumbar discogenic pain

Lumbar degenerative disc disease without disc herniation, also known as discogenic pain, is an elusive diagnosis of chronic low back pain. Lumbar provocation discography and fusion surgery have been frequently utilized for several decades as the gold standards for the diagnosis and treatment of symptomatic lumbar discogenic pain, though controversial, based on conjecture, rather than evidence. In addition to lumbar fusion, various other operative and nonoperative modalities of treatments are available in managing chronic lumbar discogenic pain. This review provides an updated assessment of the management of chronic lumbar discogenic pain with a critical look at the many modalities of treatments that are currently available.

What is the Role of Epidural Injections in the Treatment of Lumbar Discogenic Pain: A Systematic Review of Comparative Analysis with Fusion

Background

Lumbar discogenic pain without pain mediated by a disc herniation, facet joints, or the sacroiliac joints, is common and often results in chronic, persistent pain and disability. After conservative treatment failure, injection therapy, such as an epidural injection, is frequently the next step considered in managing discogenic pain. The objective of this systematic review is to determine the efficacy of lumbar epidural injections in managing discogenic pain without radiculopathy, and compare this approach to lumbar fusion or disc arthroplasty surgery.

Methods

A systematic review of randomized trials published from 1966 through October 2014 of all types of epidural injections and lumbar fusion or disc arthroplasty in managing lumbar discogenic pain was performed with methodological quality assessment and grading of evidence. The level of evidence was based on the grading of evidence criteria which, was conducted using 5 levels of evidence ranging from levels I to V.

Results

Based on a qualitative assessment of the evidence for both approaches, there is Level II evidence for epidural injections, either caudal or lumbar interlaminar.

Conclusions

The available evidence suggests fluoroscopically directed epidural injections provide long-term improvement in back and lower extremity pain for patients with lumbar discogenic pain. There is also limited evidence showing the potential effectiveness of surgical interventions compared to nonsurgical treatments.

Efficacy of intervertebral disc regeneration with stem cells - a systematic review and meta-analysis of animal controlled trials

Management of intervertebral disc (IVD) degenerative disease is challenging, as it is accompanied by irreversible loss of IVD cells. Stem cell transplantation to the disc has shown promise in decelerating or arresting the degenerative process. Multiple pre-clinical animal trials have been conducted, but with conflicting outcomes. To assess the effect of stem cell transplantation, a systematic review and meta-analysis was performed. A comprehensive literature search was conducted through Week 3, 2015. Inclusion criteria consisted of controlled animal trials. Two reviewers screened abstracts and full texts. Disagreements were resolved by a third reviewer. Random effects models were constructed to pool standardized mean difference (SMD). Twenty two studies were included; nine of which were randomized. Statistically significant differences were found with the stem cell group exhibiting increased disc height index (SMD=3.64, 95% confidence interval (CI): 2.49, 4.78; p<0.001), increased MRI T2 signal intensity (SMD=2.28, 95% CI: 1.48, 3.08; p<0.001), increased Type II collagen mRNA expression (SMD=3.68, 95% CI: 1.66, 5.70; p<0.001), and decreased histologic disc degeneration grade (SMD=-2.97, 95% CI: -3.97, -1.97; p<0.001). There was statistical heterogeneity between studies that could not be explained with pre-planned subgroup analyses based on animal species, study designs, and transplanted cell types. Stem cells transplanted to the IVD in quadruped animals decelerate or arrest the IVD degenerative process. Further studies in human clinical trials will be needed to understand if such benefit can be translated to bipedal humans.