Correlation between inflammatory cytokines released from the lumbar facet joint tissue and symptoms in degenerative lumbar spinal disorders

Ligamentum flavum analysis in patients with lumbar discus hernia and lumbar spinal stenosis

The normal ligamentum flavum (LF) is a well-defined elastic structure with specific innervation. Several studies investigated LF in patients with lumbar spinal stenosis (LSS) and used lumbar discus hernia (LDH) patients as control group, only on the presumed thesis that LF in this patients have normal morphology. In patients with LSS thickening of the LF is the main cause of stenosis, which is most often presented with neurogenic claudication, whose pathophysiological mechanism is not completely understood. We conducted observational cohort study of 60 operated patients divided into two groups. The first group of 30 patients underwent micro-discectomy (LSH group), and second group with 30 patients underwent decompression, after which analysis of harvested LF was performed. Patients from the LDH group and LSS group differed significantly in the frequencies of chief complaints, duration of symptoms, physical examination, and specific morphological/radiological parameters. The LF analysis showed that the groups differed significantly in the amount of collagen and elastic fibers, as well as in the histological appearance/architectonics of elastic fibers. Also, groups differ in the presence of LF nerve fibers. Our findings speak in favor of the recently postulated inflammatory theory in the origin of spinal neurogenic claudication's.

Facet overhang: A novel parameter in the pathophysiology of multifidus muscle atrophy

The relationship between degenerative zygapophysial joint (facet) arthropathy and multifidus muscle atrophy has not been rigorously evaluated. The purpose of this study was to determine if specific morphological features of degenerative facet arthropathy are correlated with multifidus muscle atrophy. We retrospectively reviewed medical records and imaging studies of patients with lumbar spinal stenosis. Facet overhang, bridging osteophyte formation, facet effusion, and facet angles were evaluated by univariable and multivariable regression to identify independent associations with deep and superficial parts of the multifidus total cross-sectional area (tCSA), functional cross-sectional area (fnCSA), and fatty infiltration (FI). Facet overhang was classified as severe in 50 females (53.2%) versus 56 males (36.9%) (p = 0.030). Severity of facet overhang and female sex were independently associated with smaller deep part of the multifidus tCSA and fnCSA as well as higher FI, reflecting greater atrophy of the deep region compared to total muscle mass. In comparison, severe facet overhang (p < 0.001; OR = 3.47, 95% CI = 2.13-5.66) and female sex (p < 0.001; OR = 4.19, 95% CI = 2.58-6.79) were independently associated only with higher superficial part of the multifidus FI, reflecting muscle steatosis without significant lean muscle atrophy. In patients with degenerative lumbar spinal stenosis, facet overhang is an independent risk factor for deep part of the multifidus atrophy. Bridging osteophyte formation, facet effusion, and facet angles were not independently associated with deep part of the multifidus atrophy.

Retrodural space of Okada in the posterior ligamentous complex region: clinical and anatomical findings relevant to lumbar interlaminar epidural injection

Background

The retrodural space of Okada is a potential space posterior to the ligamentum flavum that allows communication with the bilateral facet joints. However, the actual anatomy of this space has not been clearly visualized to date. We sought to investigate the characteristics of patients showing contrast spreading to the facet joint space during epidural injection and to clarify the anatomical structures of the retrodural space and adjacent ligamentous tissues in cadaveric specimens.

Methods

Fluoroscopic images of patients who underwent fluoroscopy-guided lumbar interlaminar epidural injection were assessed for contrast flow to the facet joints. Patient demographics, preprocedural imaging study findings, and epidural approaches were analyzed. The anatomical study included the sectional dissection, micro-CT imaging, and histological evaluation of lumbar spine specimens from 16 embalmed cadavers.

Results

Fluoroscopic images of 605 epidural injections were analyzed. Among them, 36 with inadvertent spread into the facet joints (5.9%) were identified. Multivariate analysis revealed that facet joint pathologies were significantly associated with inadvertent spread into the facet joints (OR 4.382; 95% CI 1.160 to 16.558; p=0.029). Micro-CT and histological findings consistently showed a retrodural space between the ligamentum flavum and interspinous ligament. Various anatomical communication routes in the posterior ligamentous complex leading to this space were observed in specimens with degenerative and pathological changes.

Conclusion

Degenerative and pathological facet joint changes were associated with a higher incidence of spread into the retrodural space during epidural injection. Our findings confirm anatomical evidence for a false loss of resistance before the needle enters the epidural space.

Whiplash injuries associated with experienced pain and disability can be visualized with [11C]-D-deprenyl positron emission tomography and computed tomography

ABSTRACT

Knowledge of etiological mechanisms underlying whiplash-associated disorders is incomplete. Localisation and quantification of peripheral musculoskeletal injury and inflammation in whiplash-associated disorders would facilitate diagnosis, strengthen patients' subjective pain reports, and aid clinical decisions, all of which could lead to improved treatment. In this longitudinal observational study, we evaluated combined [11C]-D-deprenyl positron emission tomography and computed tomography after acute whiplash injury and at 6-month follow-up. Sixteen adult patients (mean age 33 years) with whiplash injury grade II were recruited at the emergency department. [11C]-D-deprenyl positron emission tomography and computed tomography, subjective pain levels, self-rated neck disability, and active cervical range of motion were recorded within 7 days after injury and again at 6-month follow-up. Imaging results showed possible tissue injuries after acute whiplash with an altered [11C]-D-deprenyl uptake in the cervical bone structures and facet joints, associated with subjective pain locale and levels, as well as self-rated disability. At follow-up, some patients had recovered and some showed persistent symptoms and reductions in [11C]-D-deprenyl uptake correlated to reductions in pain levels. These findings help identify affected peripheral structures in whiplash injury and strengthen the idea that positron emission tomography and computed tomography detectable organic lesions in peripheral tissue are relevant for the development of persistent pain and disability in whiplash injury.

The association between clinical symptoms of lumbar spinal stenosis and MRI axial imaging findings

Purpose:

In diagnosing lumbar spinal stenosis (LSS), Magnetic Resonance Imaging (MRI) is appropriate to confirm the presence of anatomical stenosis of the spinal canal or compression of the nerve roots. However, it is known that morphological LSS is often present in asymptomatic subjects. There is still controversy about the relationship between anatomical LSS and symptomatic LSS. The aim of this study was to assess the association between qualitative imaging findings on MRI of the lumbar spine and symptomatic LSS.

Patients and methods:

This was a cross-sectional study of 239 volunteers from an epidemiological survey that included 1,862 participants in total. MRI of the lumbar spine was evaluated in four categories: morphological grading of central stenosis and lateral recess stenosis, presence of the sedimentation sign, and severity of facet joint effusion. The relationship between these morphological evaluations and typical LSS symptoms as assessed by the self-administered, self-reported history questionnaire for lumbar spinal stenosis (LSS-SSHQ) was investigated by multiple logistic regression analysis.

Results:

The odds ratio of the most severe central stenosis to no stenosis was 15.5 (95%CI: 1.4-164.9). Only the most severe central stenosis was associated with typical LSS symptoms, but not all cases with typical LSS symptoms were due to severe central stenosis.

Conclusion:

Extreme severe central stenosis was strongly related to typical LSS symptoms. However, although subjects with severe central stenosis showed symptoms suggestive of LSS, these subjects did not always show typical LSS symptoms.

The Clinical Application of Pulsed Radiofrequency Induces Inflammatory Pain via MAPKs Activation: A Novel Hint for Pulsed Radiofrequency Treatment

Pulsed radiofrequency (PRF) works by delivering short bursts of radiofrequency to a target nerve, thereby affecting nerve signal transduction to reduce pain. Although preliminary clinical investigations have shown that PRF treatment can be used safely as an alternative interventional treatment in patients with refractory pain conditions, unexpected damage to a normal nerve/ganglion is still one of the possible complications of using the PRF strategy. Noxious pain may also be triggered if PRF treatment accidentally damages an intact nerve. However, few studies in the literature have described the intracellular modifications that occur in neuronal cells after PRF stimulation. Therefore, in this study, we evaluated the effects of PRF on unimpaired nerve function and investigated the potential mechanisms of PRF-induced pain. Wistar rats were stimulated with 30-60 V of PRF for 6 min, and mechanical allodynia, cold hypersensitivity, cytokine and matrix metalloproteinase (MMP) production, and mitogen-activated protein kinase activity (p38 MAPK, ERK1/2, JNK/SAPK) were analyzed. The results indicated that PRF stimulation induced a significant algesic effect and nociceptive response. In addition, the protein array and Western blotting analyses showed that the clinical application of 60 V of PRF can induce the activation of MAPKs and the production of inflammatory cytokines and MMPs in the lumbar dorsal horn, which is necessary for nerve inflammation, and it can be suppressed by MAPK antagonist treatment. These results indicate that PRF stimulation may induce inflammation of the intact nerve, which in turn causes inflammatory pain. This conclusion can also serve as a reminder for PRF treatment of refractory pain.

Correlation of Tumor Necrosis Factor-α Expression with Pain Level in Degenerative Lumbar Canal Stenosis Patients

Introduction: Pain in degenerative lumbar canal stenosis is caused by osteoarthritis of a facet joint and intervertebral disc degeneration. Some inflammatory mediators such as tumor necrosis factor (TNF)-α are present in degenerative lumbar canal stenosis. This study aimed to evaluate the correlation of pain and functional pre-operative scores with the expression of TNF-α in nucleus pulposus, annulus fibrosus, and facet joint. Methods: Patients diagnosed with degenerative lumbar canal stenosis and planned for surgical treatment were included in this study. Patients with history of fracture, neoplasm, and/or infection of the spine were excluded. Tissue samples were collected from the nucleus pulposus, annulus fibrosus, facet joint, flavum ligament and paraspinal muscles of the spine during the surgery. TNF-α expression was examined semi-quantitively and correlated with the axial and radicular pain that were measured using Visual Analog Score (VAS) score. The result was then statistically analyzed. Results: The expression of TNF-α in the paraspinal muscle (6.30±14.20) was significantly higher compared to other locations. TNF-α expression in the facet joint group was significantly correlated with the intensity of low back pain measured by VAS score (r=0.893, p < 0.001), and pre-operative functional outcome based on Oswestry Disability Index (ODI) (r=0.948, p < 0.001). Conclusion: TNF-α expression, especially in the facet joint, is significantly associated with the pain intensity and pre-operative ODI that allow pain reduction with less invasive treatment in lumbar canal stenosis patients.  

Effects of Dorsal Column Spinal Cord Stimulation on Neuroinflammation: Revisiting Molecular Mechanisms and Clinical Outcomes on Chronic Lumbar/Leg Pain and Failed Back Surgery Syndrome

OBJECTIVE

In this narrative review, we reviewed and discussed current literature describing the molecular mechanisms leading to neuroinflammation and its role in the onset and progression of chronic neuropathic lumbar and leg pain in patients with persistent spinal pain syndrome. In addition, we reviewed the proposed mechanisms and impact of spinal cord stimulation (SCS) on neuroinflammation.

METHODS

A broad search of current literature in PubMed, Embase, Scopus, Cochrane library, Medline/Ovid, and Web of Science was performed using the following terms and their combinations: "biomarkers", "chronic back and leg pain", "cytokines", "neuroinflammation", "spinal cord stimulation (scs)," and "spinal cord modulation". We selected: 1) articles published in the English language between January 2000 and July 2020 2) preclinical and clinical data 3) case reports 4) meta-analysis and systematic reviews and 5) conference abstracts. Manuscripts not disclosing methodology or without full-text availability were excluded.

DISCUSSION

SCS techniques have gradually evolved since inception to include novel methods such as burst-SCS, high frequency SCS, and differential targeted multiplexed SCS. The incidence of chronic pain after spine surgery is highly variable, with at least one third of patients developing persistent spinal pain syndrome. Novel SCS techniques have been associated with improved clinical and functional outcomes thus increasing patient quality of life.

CONCLUSION

Currently, health care providers rely on different options and methods for SCS when treating patients with refractory chronic lumbar pain and persistent spinal pain syndrome. Nevertheless, compelling clinical trials remain necessary to elucidate the long-term benefits and mechanisms of neuromodulation of all different types of SCS.

Association between Serum Levels of Interleukin-6 on Pain and Disability in Lumbar Disc Herniation Surgery

Context:

Many inflammatory cytokines are also elevated in degenerated or herniated intervertebral discs. Among biomarkers, interleukin-6 (IL-6) plays an essential role in the inflammatory process of disc herniation. Some studies have suggested that an increase in serum IL-6 levels occurs in sustained radicular pain.

Aims:

The aim of this study was to determine the relationship between changes in IL-6 serum level and pain and disability index in patients with radicular pain in acute herniated lumbar disc before and after lumbar disc surgery.

Settings and Design:

This is a descriptive-analytic prospective study to examine the association between IL-6 serum levels on pain and disability before and after the surgery in patients admitted with acute herniated lumbar intervertebral discs from 2015 to 2018 in Imam Khomeini Hospital, Sari, Mazandaran, Iran.

Subjects and Methods:

The blood level of IL-6, the severity of pain based on visual analog score, and disability based on the Oswestry disability index were measured before and 3 months after surgery.

Statistical Analysis Used:

All data were analyzed using SPSS version 24.

Results:

Thirty-two patients were enrolled in the study. Seventeen patients were male. The mean age was 39.53 ± 8.89 years. IL-6 concentration, 4.36 and 1.16 pg/ml were determined as cutoff before and after the surgery.

Conclusions:

The acceptable sensitivity and specificity of IL were obtained in this study. Our findings revealed that IL-6 could be used as a biomarker for predicting postoperative pain relief and disability improvement.

Ligamentum flavum fibrosis and hypertrophy: Molecular pathways, cellular mechanisms, and future directions

Hypertrophy of ligamentum flavum (LF), along with disk protrusion and facet joints degeneration, is associated with the development of lumbar spinal canal stenosis (LSCS). Of note, LF hypertrophy is deemed as an important cause of LSCS. Histologically, fibrosis is proved to be the main pathology of LF hypertrophy. Despite the numerous studies explored the mechanisms of LF fibrosis at the molecular and cellular levels, the exact mechanism remains unknown. It is suggested that pathophysiologic stimuli such as mechanical stress, aging, obesity, and some diseases are the causative factors. Then, many cytokines and growth factors secreted by LF cells and its surrounding tissues play different roles in activating the fibrotic response. Here, we summarize the current status of detailed knowledge available regarding the causative factors, pathology, molecular and cellular mechanisms implicated in LF fibrosis and hypertrophy, also focusing on the possible avenues for anti-fibrotic strategies.

Inflammatory biomarkers in sera of patients with intervertebral disc degeneration

Objective:

To evaluate intervertebral disc levels of inflammatory factor (interleukin 6) and proteinase activity (cathepsin B) in patients with a degenerative disease and serum levels of interleukin 6, serum cathepsin B activity and hyaluronic acid biomarkers.

Methods:

We conducted immunohistochemistry studies of intervertebral discs to analyze interleukin 6 and cathepsin B levels of patients with degenerative disease and spine fracture (Control Group) and to measure hyaluronic acid, interleukin 6 and cathepsin B activity from sera of intervertebral disc degeneration patients, fracture patients, and healthy individuals.

Results:

Interleukin 6 and cathepsin B seem to be related with physiopathology of intervertebral disc degeneration, since the levels of both were higher in discs of patients with intervertebral disc degeneration. Interleukin 6 and cathepsin B do not represent good biomarkers of degenerative intervertebral disc disease, since the level of such compounds is increased in the plasma of patients with fractures.

Conclusion:

Hyaluronic acid can be a biomarker for intervertebral disc degeneration, because hyaluronic acid levels were higher only in sera of patients with intervertebral disc degeneration.

Controlled immobilization-traction based on intervertebral stability is conducive to the regeneration or repair of the degenerative disc: an in vivo study on the rat coccygeal model

BACKGROUND CONTEXT

Previous studies have shown the potential for intervertebral disc tissue regeneration is very limited. While in vivo and in vitro studies have shown that traction can restore disc height and internal pressure, in many clinical studies it was shown that axial mechanical traction for the treatment of low back pain is ineffective.

PURPOSE

The aim of this study was to identify how the disc could be distracted, how to define the state of traction, and to further examine the feasibility of regenerating or restoring the degenerative disc by means of traction.

STUDY DESIGN

A macro- and microlevel structural analysis of degenerative discs of rat tail before and after controlled immobilization-traction.

METHODS

In this study, 49 6-month-old male Sprague-Dawley rats were randomly assigned to one of seven groups. Group A was the sham control group in which caudal vertebrae were instrumented with K-wires only. In Group B (model group), caudal vertebrae were immobilized using a custom-made external device to fix four caudal vertebrae (Co7-Co10) and Co8-Co9 underwent 4 weeks of compression to induce moderate disc degeneration. In Group C, vertebrae Co8-Co9 underwent 4 weeks of compression to induce moderate disc degeneration, followed by removal of the external apparatus. Rats in the other four groups (Groups D-G), Co8-Co9 underwent 4 weeks of compression to induce moderate disc degeneration followed by 2 weeks, 4 weeks, 6 weeks, and 8 weeks of distraction, respectively. Caudal vertebrae were harvested and disc height, T2 signal intensity of the discs, disc morphology, total glycosaminoglycan content of the nucleus pulposus and the structure of the Co8-Co9 end plate were evaluated.

RESULTS

After 4 weeks of compression, the intervertebral height and T2 signal intensity of Co8-Co9 vertebrae of rats in Groups B to G were significantly reduced compared with Group A (sham group, all p<.0001). Histological scores of rats in Group B averaged 10.14 and the total glycosaminoglycan (GAG) of nucleus pulposus averaged 238.21μg GAG/ng DNA. The bony end plate structure showed significant changes in comparison with the control Group. After 2 weeks to 8 weeks of traction, the disc space and T2 signal intensity of Co8-Co9 vertebrae in Group E were significantly recovered compared to that of rats in Group B (p<.0001), and the intervertebral height of the Co8-Co9 in Group D, Group F, and Group G when compared with Group B (p<.0001). Meanwhile, the T2 signal intensity of Co8-Co9 in Group D, F, and G when compared with Group B (p<.001). Histological scores dropped from an average of 10.14 in Group B to 5.57 in Group E, and 5.86 in Group F (all p<.0001). Furthermore, the total GAG content of the nucleus pulposus increased from an average of 238.21μg GAG/ng DNA in Group B to 601.02μg GAG/ng DNA in Group E (p<.0001). The number of pores of end plates in rats in Groups D and E both were significantly increased when compared to that of rats in Group B (Groups D vs Groups B, p<.05; Groups E vs Groups B, p<.0001).

CONCLUSIONS

A mechanical degenerative model was successfully established by using a custom-made device. We demonstrated that disc degeneration is a cascade of biochemical, mechanical, and structural changes mediated by cells in an abnormal mechanical environment. Not all levels of disc degeneration can be regenerated or repaired. Regeneration or recovery of disc degeneration requires specific conditions. Based on the immobilization-traction mode, the cascade cycle of disc degeneration is interrupted. Traction of 2 to 6 weeks is a sensitive period for regeneration of the degenerative disc. Moreover, the duration and extent of the traction loading must be moderately controllable, and beyond the limits that can lead to significant degeneration. These data may help improve our understanding of the pathogenesis of clinical disc degeneration and how to optimize the use of traction devices for possible regeneration.

Physiologic facet capsule stretch can induce pain & upregulate matrix metalloproteinase-3 in the dorsal root ganglia when preceded by a physiological mechanical or nonpainful chemical exposure

BACKGROUND

Neck pain from cervical facet loading is common and induces inflammation and upregulation of nerve growth factor (NGF) that can sensitize the joint afferents. Yet, the mechanisms by which these occur and whether afferents can be pre-conditioned by certain nonpainful stimuli are unknown. This study tested the hypothesis that a nonpainful mechanical or chemical insult predisposes a facet joint to generate pain after a later exposure to typically nonpainful distraction.

METHODS

Rats were exposed to either a nonpainful distraction or an intra-articular subthreshold dose of NGF followed by a nonpainful distraction two days later. Mechanical hyperalgesia was measured daily and C6 dorsal root ganglia (DRG) tissue was assayed for NGF and matrix metalloproteinase-3 (MMP-3) expression on day 7.

FINDINGS

The second distraction increased joint displacement and strains compared to its first application (p = 0.0011). None of the initial exposures altered behavioral sensitivity in either of the groups being pre-conditioned or in controls; but, sensitivity was established in both groups receiving a second distraction within one day that lasted until day 7 (p < 0.024). NGF expression in the DRG was increased in both groups undergoing a pre-conditioning exposure (p < 0.0232). Similar findings were observed for MMP-3 expression, with a pre-conditioning exposure increasing levels after an otherwise nonpainful facet distraction.

INTERPRETATION

These findings suggest that nonpainful insults to the facet joint, when combined, can generate painful outcomes, possibly mediated by upregulation of MMP-3 and mature NGF.

Angiopoietin-Like Protein 2 Induces Synovial Inflammation in the Facet Joint Leading to Degenerative Changes via Interleukin-6 Secretion

Study Design

Experimental human study.

Purpose

To determine whether angiopoietin-like protein 2 (ANGPTL2) is highly expressed in the hyperplastic facet joint (FJ) synovium and whether it activates interleukin-6 (IL-6) secretion in FJ synoviocytes.

Overview of Literature

Mechanical stress-induced synovitis is partially, but significantly, responsible for degenerative and subsequently osteoarthritic changes in the FJ tissues in patients with lumbar spinal stenosis (LSS). However, the underlying molecular mechanism remains unclear. IL-6 is highly expressed in degenerative FJ synovial tissue and is responsible for local chronic inflammation. ANGPTL2, an inflammatory and mechanically induced mediator, promotes the expression of IL-6 in many cells.

Methods

FJ tissues were harvested from five patients who had undergone lumbar surgery. Immunohistochemistry for ANGPTL2, IL-6, and cell markers was performed in the FJ tissue samples. After cultured synoviocytes from the FJ tissues were subjected to mechanical stress, ANGPTL2 expression and secretion were measured quantitatively using real-time quantitative reverse-transcription–polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. Following ANGPTL2 administration in the FJ synoviocytes, anti-nuclear factor-κB (NF-κB) activation was investigated using immunocytochemistry, and IL-6 expression and secretion were assayed quantitatively with or without NF-κB inhibitor. Moreover, we assessed whether ANGPTL2-induced IL-6 modulates leucocyte recruitment in the degenerative process by focusing on the monocyte chemoattractant protein-1 (MCP-1) expression.

Results

ANGPTL2 and IL-6 were highly expressed in the hyperplastic FJ synovium samples. ANGPTL2 was co-expressed in both, fibroblast-like and macrophage-like synoviocytes. Further, the expression and secretion of ANGPTL2 in the FJ synoviocytes increased in response to stimulation by mechanical stretching. ANGPTL2 protein promoted the nuclear translocation of NF-κB and induced IL-6 expression and secretion in the FJ synoviocytes. This effect was reversed following treatment with NF-κB inhibitor. Furthermore, ANGPTL2-induced IL-6 upregulated the MCP-1 expression in the FJ synoviocytes.

Conclusions

Mechanical stress-induced ANGPTL2 promotes chronic inflammation in the FJ synovium by activating IL-6 secretion, leading to FJ degeneration and subsequent LSS.

The roles of IL-19 and IL-20 in the inflammation of degenerative lumbar spondylolisthesis

Background

Degenerative lumbar spondylolisthesis (DLS) is a major cause of spinal canal stenosis and is often related to lower back pain. IL-20 is emerging as a potent angiogenic, chemotactic, and proinflammatory cytokine related to several chronic inflammatory bone disorders likes intervertebral disc herniation, rheumatoid arthritis (RA), osteoporosis, and bone fracture. IL-19 also acts as a proinflammatory cytokine in RA. The aim of the present study was to investigate whether IL-19 and IL-20 are involved in DLS and compare three different tissues including disc, facet joint, and ligamentum flavum of patients with DLS to verify which tissue is affected more by inflammation.

Methods

Disc, facet joint and ligamentum flavum from 13 patients with DLS was retrieved, and the expression pattern of IL-19, IL-20, IL-20R1, IL-20R2, TNF-α, IL-1β, and MCP-1 was evaluated using immunohistochemical staining with specific antibodies. The disc cells were isolated and incubated with IL-19 and IL-20 under CoCl₂-mimicked hypoxic conditions to analyze the proinflammatory cytokine expression pattern using real-time quantitative PCR with specific primers.

Results

IL-19 and IL-20 were positively stained and accompanied by abundant expression of TNF-α, IL-1β, and MCP-1 in facet joints of DLS patients. IL-19 and IL-20's receptors (IL-20R1 and IL-20R2) were expressed on chondrocytes and fibrocytes/fibroblasts in facet joint and ligamentum flavum tissues from patients with DLS. There was a significant correlation between the expression of IL-20 and IL-1β in facet joint. In vitro assay, IL-19 and IL-20 upregulated the expression of IL-1β, IL-6, TNF-α, IL-8, VEGF, and MCP-1 in primary cultured DLS disc cells under CoCl₂-mimicked hypoxic conditions.

Conclusions

IL-19, IL-20, and their receptors as well as proinflammatory cytokines (TNF-α, IL-1β, and MCP-1) were expressed more in facet joints than the other tissues in patients with DLS; therefore, the etiology of inflammation might be more facet-centric. IL-19 and IL-20 induced proinflammatory cytokine expression in disc cells and might play a role in the pathogenesis of DLS.

Effect of Pulsed Radiofrequency Therapy on Chronic Refractory Atlanto-Occipital Joint Pain

OBJECTIVE

Despite several methods of conservative management, many patients with atlanto-occipital (AO) joint pain complain of persistent pain. In the current study, the authors investigated the clinical efficacy of intra-articular pulsed radiofrequency (PRF) therapy for the management of refractory chronic AO joint pain.

METHODS

Twenty patients with refractory AO joint pain were recruited, and each received intra-articular AO joint PRF stimulation. Pain reduction after PRF therapy was measured using a numerical rating scale (NRS) before and at 1 and 3 months after treatment. Successful pain relief was defined as ≥50% reduction in the NRS score compared with the pretreatment score. At 3 months after treatment, patient satisfaction levels were also examined. Patients reporting very good (score = 7) or good (score = 6) results were considered to be satisfied with the procedure.

RESULTS

The NRS scores changed significantly over time. At 1 and 3 months after PRF therapy, the NRS scores were significantly reduced compared with pretreatment scores. Sixteen of the 20 (80%) patients reported pain relief and were satisfied with treatment results 3 months after PRF. No adverse effects were reported.

CONCLUSIONS

Intra-articular PRF therapy is a beneficial treatment tool for managing refractory chronic AO joint pain.

Inflammatory Processes Associated with Canine Intervertebral Disc Herniation

Intervertebral disc herniation (IVDH) is an important pathology in humans and also in dogs. While the molecular disease mechanisms are well investigated in humans, little is known about the inflammatory mediators in naturally occurring canine IVDH. The objective of this study was to investigate whether the involved proinflammatory cytokines in human IVDH are also key cytokines in canine IVDH and thus to elucidate the suitability of the dog as a model for human trials. 59 samples from 25 dogs with surgically confirmed thoracolumbar IVDH were collected and classified in three subgroups: herniated (H), affected non-herniated (NH) disc, and adjacent non-affected (NA) disc. Discs from 11 healthy dogs acted as controls (C). Samples were analyzed for IL-1, IL-6, IL-8, and TNF-α expression (qPCR/ELISA) as well as cell infiltration and activation of the MAP kinase pathways (immunohistochemistry). Gene and protein expression of all key cytokines could be detected in IVDH affected dogs. Canine IVDH was significantly associated with a higher gene expression of IL-6 (H > C, NH > C) and TNF-α (H > C, NH > C, NA > C) and a significant down-regulation of IL-1β (H < C). Dogs with spontaneous pain had significantly higher IL-6 mRNA compared to those with pain arising only upon palpation. An inter-donor comparison (H and HN relative to NA) revealed a significant increase of IL-6 gene expression (H > NA, NH > NA). IL-8 (H > C, NA > C) and TNF-α (NH > C) protein levels were significantly increased in diseased dogs while inversely, IL-6 protein levels were significantly higher in patients with better clinical outcome. Aside from resident IVD cells, mostly monocytes and macrophages were found in extruded material, with concomitant activation of extracellular signal-regulated kinase p38 in the majority of samples. Dogs with spontaneous IVDH might provide a useful model for human disc diseases. Although the expression of key cytokines found in human IVDH was also demonstrated in canine tissue, the inflammatory mechanisms accompanying canine IVDH diverges partially from humans, which will require further investigations in the future. In dogs, IL-6 seems to play an important pathological role and may represent a new potential therapeutic target for canine patients.

Oligosaccharide nanomedicine of alginate sodium improves therapeutic results of posterior lumbar interbody fusion with cages for degenerative lumbar disease in osteoporosis patients by downregulating serum miR-155

Degenerative lumbar disease (DLD) is a significant issue for public health. Posterior lumbar intervertebral fusion with cages (PLIFC) has high-level fusion rate and realignment on DLD. However, there are some complications following the surgery. Alginate oligosaccharides (AOS) have antioxidant and anti-inflammatory activities and may be suitable for infection therapy. MiR-155 is a biomarker associated with inflammatory and oxidative stress. AOS may promote PLIFC therapy by regulating miR-155. Pluronic nanoparticles and oligosaccharide nanomedicine of alginate sodium (ONAS) were prepared with ampicillin at size <200 nm. Ninety-six DLD osteoporosis patients received PLIFC and were evenly assigned into ONAS group (OG, oral administration of 100 mg ONAS daily) and control group (PG, 100 mg pluronic nanoparticles). Serum miR-155 level was measured by real-time quantitative PCR. The levels of superoxide dismutase (SOD), glutathione (GSH), aspartate aminotransaminase (AST), alanine aminotransferase (ALT), interleukin-1β (IL-1β), and interleukin-1 receptor antagonist (IL-1ra) were measured. Weighted mean difference (WMD), relative risk (RR), complications, surgery infection rate, fusion rate, and Japanese Orthopaedic Association (JOA) scores were used to evaluate therapeutic efficacy. After 1-month therapy, infection rates and side effects were lower in OG than those in PG (RR =0.64, 95% confidence interval [CI] [0.48, 0.84], P=0.001). The fusion rates were higher in OG than in PG (WMD =21.96, 95% CI [−0.24, 37.62], P=0.021). The JOA scores were higher in OG than in PG (RR =0.52, 95% CI [0.33, 0.84], P=0.007), and no significant difference was found for the visual analog scale and Oswestry Disability Index. Serum levels of miR-155, ALT, AST, and IL-1β were lower while SOD, GSH, and IL-1ra were higher in OG than in PG. MiR-155 mimic increased the levels of ALT, AST, and IL-1β and reduced the levels of SOD, GSH, and IL-1ra. In contrast, miR-155 inhibitor had reverse results. Therefore, ONAS has better improvement in complications and therapeutic effects on DLD by regulating serum miR-155.

Scoping review to develop common data elements for lumbar spinal stenosis

BACKGROUND CONTEXT

Common data elements (CDE) represent an important tool for understanding and classifying health outcomes across settings. Although CDEs have been developed for a number of disorders, to date CDEs for lumbar spinal stenosis (LSS) have not been fully developed. To facilitate the identification of CDEs and measures to assess them, this technical study leverages the International Classification of Functioning, Disability and Health (ICF), peer-reviewed research, and a panel of experts to identify CDEs specific to LSS.

PURPOSE

The study aimed to define CDEs for disease characteristics and outcomes of LSS using the World Health Organization's ICF taxonomy, and to facilitate the selection of assessment instruments for research and clinical care.

DESIGN

This is a scoping review using a modified Delphi approach with a technical expert panel composed of clinicians and scientists representing the academia, policy and advocacy stakeholders, and professional associations with expertise in LSS.

METHODS

This is a scoping review to identify measures that assess LSS symptoms. Thirty-one subject matter experts (SMEs) prioritized ICF codes and evaluated instruments measuring specific domains. We used a modified Delphi technique to evaluate item-level content and achieve consensus.

RESULTS

SMEs prioritized 53 ICF codes; 3 received 100% endorsement, 27 received ≥90% endorsement, whereas the remaining 23 received ≥80% endorsement. Prioritized ICF codes represent diverse domains, including pain, activities and participation, and emotional well-being. The review yielded 58 instruments; we retained 24 for content analysis.

CONCLUSIONS

The retained instruments adequately represent the ICFs activities and participation, and body function domains. Body structure and environmental factors were assessed infrequently. Adoption of these CDEs may guide clinical decision making and facilitate comparative effectiveness trials for interventions focused on LSS.

Cytokine and chemokine profile changes in patients with lower segment lumbar degenerative spondylolisthesis

BACKGROUND

Lumbar degenerative spondylolisthesis (DS) develops as a result of inflammatory and remodeling processes in facet joints (FJs). Several inflammatory cytokines are involved in the osteoarthritic and remodeling changes that occur and in low-back and/or radicular pain, the most prevalent clinical symptom of disease. This study improves knowledge related to the roles that 27 cytokines, chemokines and growth factors play in the pathophysiology of lumbar DS.

MATERIAL AND METHODS

Cytokine levels were examined using capture sandwich immunoassay using the Bio-Plex^® 200 System and the Bio-PlexTM Human Cytokine Standard 27-Plex, Group I (Bio-Rad, Hercules, California, USA) separately in intervertebral discs (IVDs) and FJ bone tissue. The samples were obtained during primary spinal surgery from 9 patients suffering from lower segment lumbar DS. The pain intensity was assessed using a visual analog scale. The controls were tissue samples collected from both lower lumbar segment levels of 6 male subjects during a multiorgan procurement procedure.

RESULTS

The Bio-Plex^® assay revealed significant differences between the patients and controls in cytokines, chemokines and growth factor profiles: i, The elevated interleukin-6 (IL-6), IL-7, IL-13, tumor necrosis factor α (TNF-α), interferon γ and platelet-derived growth factor levels in lumbar DS samples of subchondral FJ bone. These indicated ongoing inflammation, bone formation and increased fibroblasts activity in the FJ bone. ii, The elevated levels of IL-6, IL-8, TNF-α, granulocyte-macrophage colony-stimulating factor and monocyte chemoattractant protein-1 in anulus fibrosus together with increased IL-6, IL-8, TNF-α and eotaxin and decreased IL-1-receptor antagonist in nucleus pulposus confirmed advanced IVD degeneration in the patient samples.

CONCLUSION

This study identified, for the first time, protective levels of cytokines, chemokines and growth factors in healthy subjects and supported their significant involvement in the pathogenesis of lumbar DS. The control samples and analytical methods used avoided any false changes in the cytokine levels due to secondary factors (e.g., death of donor and limited cytokine stability).

Correlation of lumbar lateral recess stenosis in magnetic resonance imaging and clinical symptoms

AIM

To assess the correlation of lateral recess stenosis (LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index (ODI).

METHODS

Nine hundred and twenty-seven patients with history of low back pain were included in this uncontrolled study. On magnetic resonance images (MRI) the lateral recesses (LR) at lumbar levels L4/5 and L5/S1 were evaluated and each nerve root was classified into a 4-point grading scale (Grade 0-3) as normal, not deviated, deviated or compressed. Patient symptoms and disability were assessed using ODI. The Spearman’s rank correlation coefficient was used for statistical analysis (P < 0.05).

RESULTS

Approximately half of the LR revealed stenosis (grade 1-3; 52% at level L4/5 and 42% at level L5/S1) with 2.2% and 1.9% respectively reveal a nerve root compression. The ODI score ranged from 0%-91.11% with an arithmetic mean of 34.06% ± 16.89%. We observed a very weak statistically significant positive correlation between ODI and LRS at lumbar levels L4/5 and L5/S1, each bilaterally (L4/5 left: rho < 0.105, P < 0.01; L4/5 right: rho < 0.111, P < 0.01; L5/S1 left: rho 0.128, P < 0.01; L5/S1 right: rho < 0.157, P < 0.001).

CONCLUSION

Although MRI is the standard imaging tool for diagnosing lumbar spinal stenosis, this study showed only a weak correlation of LRS on MRI and clinical findings. This can be attributed to a number of reasons outlined in this study, underlining that imaging findings alone are not sufficient to establish a reliable diagnosis for patients with LRS.

Expression of the JAK/STAT signaling pathway in the ligamentum flavum of patients with lumbar spinal canal stenosis

BACKGROUND

Ligamentum flavum (LF) hypertrophy is an important cause of lumbar spinal canal stenosis (LSS), one of the most common spinal disorders in the elderly. Although many cytokines are reported to be associated with LF hypertrophy, the intracellular signaling system is rarely discussed. The purpose of this study was to identify the JAK/STAT signaling pathway and to examine the role of the JAK/STAT systems in the hypertrophied LF.

METHODS

The LF of 10 LSS patients was analyzed and the expression of JAK1, STAT3, phosphorylated (p)-STAT3, and actin was examined by Western blot analysis. The expression of p-STAT3 was also examined by immunostaining and its positive cell ratio was compared between LSS and non-LSS samples. We measured the thickness of the LF on magnetic resonance images and studied the relationship between its thickness and the expression of p-STAT3.

RESULTS

JAK1, STAT3, and p-STAT3 were detected in almost all samples by Western blot analysis. Immunoreactivity against p-STAT3 was observed mainly in endothelial- and fibroblast-like cells. The expression of p-STAT3 was significantly higher in LSS than non-LSS samples; it was significantly stronger on the dorsal than the dural side of the LF and positively correlated with the thickness of the LF on the dorsal side.

CONCLUSIONS

The JAK/STAT signaling pathway is positively correlated with the thickness of the LF. Our findings suggest that JAK1 and STAT3 molecules are involved in and regulate LF hypertrophy.

A comprehensive review of pulsed radiofrequency in the treatment of pain associated with different spinal conditions

OBJECTIVE

The objective of this review was to evaluate the efficacy of pulsed radiofrequency (PRF) treatment of pain associated with different spinal conditions. The mechanisms of action and biological effects are shortly discussed to provide the scientific basis for this radiofrequency modality.

METHODS

We systematically searched for clinical studies on spinal clinical conditions using PRF. We searched the MEDLINE (PubMed) database. We classified the information in one table focusing on randomized controlled trials (RCTs) and other types of studies. Date of last electronic search was October 2016.

RESULTS

We found four RCTs that evaluated the efficacy of PRF on cervical radicular pain and five observational studies. Two trials and three observational studies were conducted in patients with facet pain. For disc-related pathology, we found one RCT with PRF applied intradiscally and three RCTs for dorsal root ganglia PRF modulation lumbosacral radicular pain. For sacroiliac joint pain, spondylolisthesis, malignancies and other minor spinal pathology, limited studies were conducted.

CONCLUSION

From the available evidence, the use of PRF to the dorsal root ganglion in cervical radicular pain is compelling. With regard to its lumbosacral counterpart, the use of PRF cannot be similarly advocated in view of the absence of standardization of PRF parameters, enrolment criteria and different methods in reporting results; but, the evidence is interesting. The use of PRF in lumbar facet pain was found to be less effective than conventional RF techniques. For the other different spinal conditions, we need further studies to assess the effectiveness of PRF. Advances in knowledge: The use of PRF in lumbar facet pain was found to be less effective than conventional RF techniques. For the other different spinal conditions, we need further studies to assess the effectiveness of PRF.

Lumbar Sympathetic Pulsed Radiofrequency Treatment for Primary Erythromelalgia: A Case Report

Erythromelalgia is often refractory and resistant to many forms of treatment. Numerous therapeutic options have been tried, but effective treatment remains elusive. The sympathetic nervous system has been involved in various painful conditions of neuropathic, vascular, and visceral origin. Sympathetic block is helpful in making a diagnosis and managing pain. We report a case of excellent pain relief after lumbar sympathetic pulsed radiofrequency treatment in a patient with primary erythromelalgia of the lower extremities. This case suggests the viability of pulsed radiofrequency treatment in patients with erythromelalgia.

Asymmetric Facet Joint Osteoarthritis and Its Relationships to Facet Orientation, Facet Tropism, and Ligamentum Flavum Thickening

STUDY DESIGN

The degrees of osteoarthritis of the left and right facet joints were evaluated by using computerized tomography among elderly patients with low back or leg pain.

OBJECTIVE

To reveal the phenomenon of asymmetry regarding facet joint osteoarthritis (FJOA) in old patients and establish its relationships to spinal level, facet orientation, facet tropism and ligamentum flavum (LF) thickening.

SUMMARY OF BACKGROUND DATA

There were few reports regarding left-right asymmetry among severity of FJOA and its relationships to spinal level, facet orientation, facet tropism, and LF thickening remained unclear.

METHODS

The grade of bilateral FJOA was evaluated using 4-grade scale on computerized tomography images at the L3-4, L4-5, and L5-S1 levels of patients with age ranging from 60 to 80 years. All subjects were divided into 2 groups: symmetric FJOA group (FJOA I-II on both sides or FJOA III-IV on both sides) and asymmetric FJOA group (FJOA I-II on one side and FJOA III-IV on the other side). The relationships of FJOA to spinal level, facet orientation, facet tropism, and LF hypertrophy were evaluated.

RESULTS

No association between asymmetric FJOA and spinal level was noted (P>0.05). In asymmetric FJOA group, significant difference in facet orientation between 2 sides was observed at the L4-5 (P=0.018) and L5-S1 levels (P=0.033). Compared with symmetric FJOA, asymmetric FJOA showed significant difference in prevalence of facet tropism at the L5-S1 level (P<0.001). The LF showed significantly thicker on the side of FJOA III-IV than the side of FJOA I-II at each level in asymmetric FJOA group (P<0.05). However, no difference was found in thickness between 2 sides in symmetric FJOA group (P>0.05).

CONCLUSIONS

Asymmetric FJOA is associated with facet orientation and tropism, but not with spinal level. There is a close relationship between severity of FJOA and LF thickness.

Toward a Mechanism-Based Approach to Pain Diagnosis

The past few decades have witnessed a huge leap forward in our understanding of the mechanistic underpinnings of pain, in normal states where it helps protect from injury, and also in pathological states where pain evolves from a symptom reflecting tissue injury to become the disease itself. However, despite these scientific advances, chronic pain remains extremely challenging to manage clinically. Although the number of potential treatment targets has grown substantially and a strong case has been made for a mechanism-based and individualized approach to pain therapy, arguably clinicians are not much more advanced now than 20 years ago, in their capacity to either diagnose or effectively treat their patients. The gulf between pain research and pain management is as wide as ever. We are still currently unable to apply an evidence-based approach to chronic pain management that reflects mechanistic understanding, and instead, clinical practice remains an empirical and often unsatisfactory journey for patients, whose individual response to treatment cannot be predicted. In this article we take a common and difficult to treat pain condition, chronic low back pain, and use its presentation in clinical practice as a framework to highlight what is known about pathophysiological pain mechanisms and how we could potentially detect these to drive rational treatment choice. We discuss how present methods of assessment and management still fall well short, however, of any mechanism-based or precision medicine approach. Nevertheless, substantial improvements in chronic pain management could be possible if a more strategic and coordinated approach were to evolve, one designed to identify the specific mechanisms driving the presenting pain phenotype. We present an analysis of such an approach, highlighting the major problems in identifying mechanisms in patients, and develop a framework for a pain diagnostic ladder that may prove useful in the future, consisting of successive identification of 3 steps: pain state, pain mechanism, and molecular target. Such an approach could serve as the foundation for a new era of individualized/precision pain medicine. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION)-American Pain Society (APS) Pain Taxonomy (AAPT) includes pain mechanisms as 1 of the 5 dimensions that need to be considered when making a diagnostic classification. The diagnostic ladder proposed in this article is consistent with and an extension of the AAPT.

PERSPECTIVE

We discuss how identifying the specific mechanisms that operate in the nervous system to produce chronic pain in individual patients could provide the basis for a targeted and rational precision medicine approach to controlling pain, using chronic low back pain as our example.

Medial Branch Blocks or Intra-Articular Injections as a Prognostic Tool Before Lumbar Facet Radiofrequency Denervation: A Multicenter, Case-Control Study

BACKGROUND

Medial branch blocks (MBBs) and intra-articular (IA) facet joint injections are both used to diagnose facet joint pain and are presumed to be equivalent. No study has sought to determine which has a better prognostic value before radiofrequency (RF) denervation.

METHODS

A case-control study was performed at 4 institutions in which RF denervation outcomes in patients who obtained 50% or more pain relief from either MBB (n = 212) or IA injections (n = 212) were compared. "Control" patients (MBB) were matched to "cases" by treating physician, last name, and date of treatments. During data mining, 87 patients were identified who underwent RF ablation after receiving both IA injections and MBB and were used for secondary analyses.

RESULTS

A total of 70.3% of MBB patients experienced 50% or more pain relief at the 3-month follow-up versus 60.8% in those who underwent IA injections (P = 0.041). In multivariable analysis, undergoing MBB was associated with RF treatment success (odds ratio [OR], 1.57; 95% confidence interval [95% CI], 1.0-2.39; P = 0.036), whereas opioid use (OR, 0.52; 95% CI, 0.34-0.79; P = 0.002) and previous back surgery (OR, 0.60; 95% CI, 0.38-0.95; P = 0.028) were associated with treatment failure. No significant differences were noted between MBB alone and combination treatment or single versus multiple blocks. In the secondary multivariable analysis including the combination IA + MBB group, MBB alone was again independently associated with an RF ablation treatment success (OR, 1.73; 95% CI, 1.12-2.67; P = 0.014).

CONCLUSIONS

When used as a prognostic tool before lumbar facet radiofrequency, MBB may be associated with a higher success rate than IA injections. Our results should be confirmed by large, prospective, randomized studies.

The Association Between Obesity and Low Back Pain and Disability Is Affected by Mood Disorders: A Population-Based, Cross-Sectional Study of Men

Low back pain (LBP) and obesity are major public health problems; however, the relationship between body composition and low back pain in men is unknown. This study aims to examine the association between body composition and LBP and disability in a population-based sample of men, as well as the factors that may affect this relationship. Nine hundred seventy-eight male participants from the Geelong Osteoporosis Study were invited to participate in a follow-up study in 2006. Participants completed questionnaires on sociodemographics and health status. Low back pain was determined using the validated Chronic Back Pain Grade Questionnaire and the presence of an emotional disorder was assessed using the Hospital Anxiety Depression Scale. Body composition was measured using dual energy x-ray absorptiometry. Of the 820 respondents (84% response rate), 124 (15%) had high-intensity low back pain and/or disability (back pain). Low back pain was associated with higher body mass index (28.7 ± 0.4 vs 27.3 ± 0.2 kg/m2, P = 0.02) and waist-hip ratio (0.97 ± 0.006 vs 0.96 ± 0.006, P = 0.04), with increased tendency toward having a higher fat mass index (8.0 vs 7.6 kg/m2, P = 0.08), but not fat-free mass index (P = 0.68). The associations between back pain and measures of obesity were stronger in those with an emotional disorder, particularly for waist-hip ratio (P = 0.05 for interaction) and fat mass index (P = 0.06 for interaction).In a population-based sample of men, high-intensity LBP and/or disability were associated with increased levels of obesity, particularly in those with an emotional disorder. This provides evidence to support a biopsychosocial interaction between emotional disorders and obesity with low back pain.

Association Between VDR FokI Polymorphism and Intervertebral Disk Degeneration

Intervertebral disk degeneration (IDD) is strongly associated with genetic predisposition and environmental susceptibility. Several studies been conducted to investigate the potential association between IDD and FokI polymorphism located in the gene encoding the vitamin D receptor (VDR), and inconsistent conclusions had been reached among different ethnic populations. In order to assess the association between the FokI polymorphism and the risk of IDD, we performed a comprehensive and systematic meta-analysis. Candidate articles were retrieved from PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and China Biology Medical (CBM) with strict inclusion criteria in January 2015. Among the 54 articles that were retrieved, only eight studies met the inclusion criteria. The pooled data analysis based on allele contrast, homozygote, heterozygote, dominant, and recessive models revealed no significant correlation between the FokI polymorphism and the risk of IDD. However, when stratified by ethnicity, significant associations were detected for Hispanics based on allele contrast (OR=1.395, 95% CI=1.059-1.836, P=0.018), homozygote (OR=1.849, 95% CI=1.001-3.416, P=0.049), heterozygote (OR=1.254, 95% CI=1.049-1.498, P=0.013), and dominant (OR=1.742, 95% CI=1.174-2.583, P=0.006) models, and for Asians using the dominant model (OR=1.293, 95% CI=1.025-1.632, P=0.030), whereas there is no significant association detected for Caucasians. In conclusion, FokI polymorphism is not generally associated with IDD, but there is increased risk for IDD in Hispanics and Asians carrying FokI allele T.

Characterization of degenerative human facet joints and facet joint capsular tissues

OBJECTIVE

Lumbar facet joint degeneration (FJD) may be an important cause of low back pain (LBP) and sciatica. The goal of this study was to characterize cellular alterations of inflammatory factor expression and neovascularization in human degenerative facet joint capsular (FJC) tissue. These alterations in FJC tissues in pain stimulation were also assessed.

DESIGN

FJs were obtained from consented patients undergoing spinal reconstruction surgery and cadaveric donors with no history of back pain. Histological analyses of the FJs were performed. Cytokine antibody array and quantitative real-time polymerase chain reaction (qPCR) were used to determine the production of inflammatory cytokines, and western blotting analyses (WB) were used to assay for cartilage-degrading enzymes and pain mediators. Ex vivo rat dorsal root ganglion (DRG) co-culture with human FJC tissues was also performed.

RESULTS

Increased neovascularization, inflammatory cell infiltration, and pain-related axonal-promoting factors were observed in degenerative FJCs surgically obtained from symptomatic subjects. Increased VEGF, (NGF/TrkA), and sensory neuronal distribution were also detected in degenerative FJC tissues from subjects with LBP. qPCR and WB results demonstrated highly upregulated inflammatory cytokines, pain mediators, and cartilage-degrading enzymes in degenerative FJCs. Results from ex vivo co-culture of the DRG and FJC tissue demonstrated that degenerative FJCs increased the expression of inflammatory pain molecules in the sensory neurons.

CONCLUSION

Degenerative FJCs possess greatly increased inflammatory and angiogenic features, suggesting that these factors play an important role in the progression of FJD and serve as a link between joint degeneration and neurological stimulation of afferent pain fibers.

Establishment of a rat model of adjuvant-induced osteoarthritis of the lumbar facet joint

To study the establishment of adjuvant-induced osteoarthritis of the lumbar facet joint in a rat model. Complete Freund's adjuvant (experimental group) and saline (control group) were randomly injected into the right and left side of rat, respectively. The rats were killed, and degeneration of lumbar facet joint was evaluated at macroscopic level and scored based on OARSI scores system. Moreover, Interleukin-1β and tumor necrosis factor-α levels in the synovium were measured. The macroscopic scores and OARSI scores of experimental group were higher than the control group (P < 0.05). The concentration of tumor necrosis factor-α was significantly increased only on 3- and 7-day post-surgery when compared with controls, and interleukin-1β was increased on days 3,7 and 14 post-surgery (P < 0.05). The rat model of adjuvant can induce degeneration of the lumbar facet joint. It can be useful for studies on mechanisms and treatment of lumbar facet joint osteoarthritis.

Developments in intervertebral disc disease research: pathophysiology, mechanobiology, and therapeutics

Low back pain is a leading cause of disability worldwide and the second most common cause of physician visits. There are many causes of back pain, and among them, disc herniation and intervertebral disc degeneration are the most common diagnoses and targets for intervention. Currently, clinical treatment outcomes are not strongly correlated with diagnoses, emphasizing the importance for characterizing more completely the mechanisms of degeneration and their relationships with symptoms. This review covers recent studies elucidating cellular and molecular changes associated with disc mechanobiology, as it relates to degeneration and regeneration. Specifically, we review findings on the biochemical changes in disc diseases, including cytokines, chemokines, and proteases; advancements in disc disease diagnostics using imaging modalities; updates on studies examining the response of the intervertebral disc to injury; and recent developments in repair strategies, including cell-based repair, biomaterials, and tissue engineering. Findings on the effects of the omega-6 fatty acid, linoleic acid, on nucleus pulposus tissue engineering are presented. Studies described in this review provide greater insights into the pathogenesis of disc degeneration and may define new paradigms for early or differential diagnostics of degeneration using new techniques such as systemic biomarkers. In addition, research on the mechanobiology of disease enriches the development of therapeutics for disc repair, with potential to diminish pain and disability associated with disc degeneration.

A new technique to treat facet joint pain with pulsed radiofrequency

INTRODUCTION

Facet joint pain affects 5% to 15% of the population with low back pain and the prevalence increases with age due to progression of arthritis. While conservative treatments are often unsuccessful, the scientific evidence on minimally invasive therapies such as intra-articular steroid infiltration and continuous and pulsed radiofrequency (PRF) of the medial branches is contradictory. Since PRF has recently been reported to successfully treat joint pain, a new application of this method is proposed for facetogenic lumbar pain via an intra-articular subcapsular approach. Here we reported two cases with successful treatment.

CASE PRESENTATION

A 71-year-old patient presented because of persisting pain in the left gluteal region radiating to the lateral thigh and calf when standing. Anti-inflammatory drugs produced only short-lasting insufficient relief. A 52-year-old employee was admitted in June 2012 because of axial lower lumbar pain with intermittent diffuse radiation to the right lower extremity that worsened during walking and lying down despite receiving analgesics and physiotherapy.

CONCLUSIONS

A new approach to treat lumbar facet joint pain with PRF is simple to perform and without serious complications. In view of the good long-lasting results obtained with the two reported cases, randomized control trials are necessary to validate this new approach.

Is there any relation between cervical cord plaques and discopathy in patients with multiple sclerosis?

INTRODUCTION

Multiple sclerosis (MS) is the most common chronic autoimmune demyelinating disease of the central nervous system. The purpose of this study is to determine the relationship between the site of the cervical discopathy and cervical spinal cord plaque in MS patients.

METHODS

This retrospective study included all patients with a definite diagnosis of MS who were treated at an outpatient clinic between September 2004 and September 2011. All patients underwent cervical magnetic resonance imaging (MRI) for primary investigation of the disease. Cervical MRI scans were evaluated for detection of any evidence of cervical discopathy and cervical MS plaques. Any correlation between the site of the MS lesions and discopathy was recorded.

RESULTS

From 536 patients who were involved in the study, 214 patients had both cervical discopathy and cervical cord plaques. In this group 148 (69.1% of patients) had cervical plaque at the same site of cervical discopathy. The number of patients with cervical cord plaque and discopathy at same site was significantly higher than those with plaque and discopathy at different sites (P<0.05).

CONCLUSION

The study data suggests a possible correlation between cervical discopathy and cervical MS plaque.

The Association of Each Disability Based on the Three Sub-Categories of the Roland-Morris Disability Questionnaire during Hospitalization with Itself at 1 Year Postoperatively in Patients with Degenerative Lumbar Spinal Stenosis

Study Design

A prospective study in a hospital.

Purpose

To investigate whether each disability based on the three sub-categories of the Roland-Morris disability questionnaire (RDQ) during hospitalization is associated with itself at 1 year postoperatively in patients with degenerative lumbar spinal stenosis (LSS).

Overview of Literature

Although the total score of the RDQ represents whole pain-related disabilities or health-related quality of life, it is a shortcoming that multi-dimensional changes in disabilities are difficult to understand when only using the RDQ.

Methods

Fifty-seven patients with LSS (men, 28; women, 29; 63.0±12.1 years) were included. Disabilities, pain intensity and depressive feelings were assessed at preoperation, discharge and 1 year postoperatively.

Results

The range of "mental and physical activities (MPA)," "functional movements on/around a bed (FM)" and "walking function (WF)" scores were 0 to 13 (median, 8), 0 to 6 (median, 6) and 0 to 4 (median, 3) at preoperation; 0 to 12 (median, 0), 0 to 6 (median, 0), and 0 to 4 (median, 0) at discharge; and 0 to 8 (median, 0), 0 to 5 (median, 0), and 0 to 4 (median, 0) at 1 year postoperatively, respectively. The following significant multiple regression equations were obtained: MPA at 1 year postoperatively=0.56 (MPA at discharge)-0.10 (depression at discharge)+0.90 (adjusted r²=0.41), FM at 1 year postoperatively=0.35 (MPA at discharge)-0.06 (depression at discharge)+0.40 (adjusted r²=0.45) and WF at 1 year postoperatively=0.59 (WF at discharge)-0.08 (depression at discharge)+0.63 (adjusted r²=0.29).

Conclusions

In our LSS population, each disability based on MPA and WF at discharge is associated with itself in the future. Therefore, disabilities excluding functional movements are longitudinally independent.

Thickening of spine ligamentum flavum and facet tropism

OBJECTIVE: This study investigated the thickening of the ligamentum flavum (LF) and its correlation with facet tropism and its severity at different levels of the spine. METHOD: This retrospective study was performed with patients with chronic back pain consecutively admitted to a specialized spinal surgery service between January 2012 and January 2013. All patients underwent magnetic resonance imaging (MRI) to measure the thickness of the LF and facet tropism severity (severe, moderate or absent) according to the spine levels (L3 -L4, L4-L5, L5-S1). The association between the thickness of LF and facet tropism was analyzed. RESULTS: During the study period, 98 consecutive patients were enrolled with a mean age of 53.6 years, most women (59.2%). There was no significant difference between the thicknesses of the ligament and the presence of tropism in different spinal levels (p > 0.05). The thickness of LF was significantly associated with the severity of tropism only in L5-S1 level (p < 0.03). CONCLUSIONS: Our results show that there is a positive relationship between severe facet tropism and increased thickness of the LF in the L5-S1 level.

MMP-1 overexpression induced by IL-1β: possible mechanism for inflammation in degenerative lumbar facet joint

BACKGROUND

More and more attention has been focused on the inflammation or degeneration caused by biochemical factors in radiculopathy during lumbar facet joint degeneration. This study was designed to examine the expression and relationship of MMP-1/TIMP-1 and interleukin-1β (IL-1β), and to analyze the possible mechanism in degenerative lumbar facet joint disease.

METHODS

Lumbar facet joint cartilage and synovial tissues in 36 cases of posterior lumbar surgery were harvested to investigate IL-1β and MMP-1/TIMP-1 by immunohistochemistry and Western blot analysis. Double labeling immunofluorescence and real-time PCR, respectively, were used to assess the relationship between IL-1β and MMP-1.

RESULTS

IL-1β and MMP-1 were low in the lumbar disc herniation (LDH) group, and increased markedly in the lumbar spinal canal stenosis (LSCS) group (P < 0.05). However, there is no significant difference of TIMP-1 between LDH group and LSCS group (P > 0.05). Double staining results indicated that IL-1β overlapped with MMP-1 in the LSCS group. Moreover, real-time PCR results showed that MMP-1 mRNA in chondrocytes in vitro was affected in a dose- and time-dependent manner in response to IL-1β stimulation.

CONCLUSIONS

Overexpression of MMP-1, induced by IL-1β, plays an important role in the inflammatory process of lumbar facet joint degeneration.

Establishing an optimal "cutoff" threshold for diagnostic lumbar facet blocks: a prospective correlational study

OBJECTIVES

Diagnostic medial branch blocks (MBB) are considered the reference standard for diagnosing facetogenic pain and selecting patients for radiofrequency (RF) denervation. Great controversy exists regarding the ideal cutoff for designating a block as positive. The purpose of this study is to determine the optimal pain relief threshold for selecting patients for RF denervation after diagnostic MBB.

METHODS

In this multicenter, prospective correlational study, 61 consecutive patients undergoing lumbar facet RF denervation after experiencing significant pain relief after MBB were enrolled. A positive outcome was defined as a ≥50% reduction in back pain at rest or with activity coupled with a positive satisfaction score lasting longer than 3 months. The relationship between pain relief after the blocks and denervation outcomes was evaluated by pairwise correlation matrix, receiver's operating characteristic curve, and stratifying outcomes based on 10- and 17-percentage point intervals for MBB.

RESULTS

There were no significant differences in RF outcomes based on any MBB pain relief cutoff over 50%. A trend was noted whereby those patients who obtained <50% pain relief reported poorer outcomes. No optimal threshold for designating a diagnostic block as positive, above 50% pain relief, could be calculated.

CONCLUSION

Employing more stringent selection criteria for lumbar facet RF is likely to result in withholding a beneficial procedure from a substantial number of patients, without improving success rates.

Belief reinforcement: one reason why costs for low back pain have not decreased

Recent figures show that there has been no change in the upward trend of direct and indirect costs for the largely benign symptom of low back pain in Western societies. This is despite greater understanding and the recommendation of a much more conservative and independent approach to its management. Moreover, in recent years, several large-scale education programs that aim to bring knowledge of the public (including general practitioners) more in line with evidence-based best practice were carried out in different countries. The hope was that the information imparted would change beliefs, ie, dysfunctional patient behavior and biomedical practice on the part of clinicians. However, these programs had no influence on behavior or costs in three out of the four countries in which they were implemented. It is argued that one reason for the overall lack of success is that it is extremely difficult to alter the potentially disabling belief among the lay public that low back pain has a structural mechanical cause. An important reason for this is that this belief continues to be regularly reinforced by the conditions of care of a range of "hands-on" providers, for whom idiosyncratic variations of that view are fundamental to their professional existence.

Elevated IL-1β and IL-6 levels in lumbar herniated discs in patients with sciatic pain

PURPOSE

Previous experimental models have shown that proinflammatory cytokines modulate peripheral and central nociception. However, the direct correlation between inflammation and pain in patients remains unclear. Our aim is to correlate the levels of inflammation in the spine with pre- and postoperative pain scores after discectomy.

METHODS

Paravertebral muscle, annulus fibrosus (AF) and nucleus pulposus (NP) biopsies were intraoperatively collected from ten lumbar disc hernia (LDH) patients suffering from chronic sciatic pain and, as painless controls, five scoliosis patients. IL-1β and IL-6 expressions in these biopsies were assessed by qPCR and western blot. The amount of pain, indicated on a 0-10 point visual analogue scale (VAS), was assessed 1 day before surgery and 6 weeks and 1 year after surgery. For analysis purposes, LDH patients were grouped into painful (VAS ≥ 3.5) and non-painful (VAS < 3.5). LDH painful patient group showed a onefold increased mRNA expression of IL-1β in the NP, and IL-6 in the AF and NP (p < 0.05 vs. controls).

RESULTS

By western blot analysis, both cytokines were clearly visible in all LDH biopsies, but not in controls. However, cytokine expression of the painful patient group did not differ from those of the non-painful patient group. In addition, there was no correlation between VAS scores and either marker.

CONCLUSIONS

These findings support the idea that LDH is accompanied by a local inflammatory process. Yet, the lack of correlation between IL-1β or IL-6 expression and the severity pain suggests that these cytokines may not play a leading role in maintaining a pain generating network.

No effect of 6-month intake of glucosamine sulfate on Modic changes or high intensity zones in the lumbar spine: sub-group analysis of a randomized controlled trial

Background

The underlying pathology and natural course of Modic changes (MC) in the vertebral body marrow and high intensity zones (HIZs) in the annulus fibrosus is not completely clarified. These findings on magnetic resonance imaging (MRI) have initiated different treatments with little or unclear effect. In a randomized trial (n = 250), glucosamine sulfate (GS) had no effect on low back pain related disability. GS could still have an effect on MC and HIZ. In this sub-study, 45 patients from the trial who had MC and/or HIZ at pre-treatment underwent follow-up MRI. The aim was to examine the course of MC and HIZ and to compare this course between groups treated with 6-month intake of oral GS versus placebo.

Results

Of 141 pre-treatment MC in 42 (of 45) patients, 29 (20.6%) MC in 18 patients had altered type and 14 MC in 9 patients had altered size (decreased for 1 MC) 6-18 months later: odds ratio (OR) for type vs. size alterations 4.0; 95% confidence interval (CI) 1.2-17.7. No MC resolved. HIZ vanished from 3 of 23 discs in 3 of 21 patients with pre-treatment HIZ. Ten new MC (all type I or I/II) occurred in 8 patients and 2 new HIZs in 2 patients. The GS group (n = 19) and placebo group (n = 26) did not differ in proportions of MC with decreased (OR 1.6; 95% CI 0.4-6.1) or increased type I dominance at follow-up (OR placebo:GS 2.4; 95% CI 0.6-9.7), or with increased size (OR 1.0; 95% CI 0.2-4.7). HIZ vanished from 1 of 8 discs in 1 of 8 patients in the GS group vs. 2 of 15 discs in 2 of 13 patients in the placebo group (OR 0.8; 95% CI 0.02-12.2).

Conclusions

In this sub-group analysis of a placebo-controlled trial, the effect of GS on MC and HIZs was no different from the effect of the placebo intervention. MC and HIZs remained mostly unchanged during the 6-18 months study period. Some short term changes did occur and MC more often altered type than size.

Trial registration

NCT00404079 at http://www.clinicaltrial.gov.

Mechanisms of chronic pain from whiplash injury

This article is to provide insights into the mechanisms underlying chronic pain from whiplash injury. Studies show that injury produces plasticity changes of different neuronal structures that are responsible for amplification of nociception and exaggerated pain responses. There is consistent evidence for hypersensitivity of the central nervous system to sensory stimulation in chronic pain after whiplash injury. Tissue damage, detected or not by the available diagnostic methods, is probably the main determinant of central hypersensitivity. Different mechanisms underlie and co-exist in the chronic whiplash condition. Spinal cord hyperexcitability in patients with chronic pain after whiplash injury can cause exaggerated pain following low intensity nociceptive or innocuous peripheral stimulation. Spinal hypersensitivity may explain pain in the absence of detectable tissue damage. Whiplash is a heterogeneous condition with some individuals showing features suggestive of neuropathic pain. A predominantly neuropathic pain component is related to a higher pain/disability level.

Innervation of cervical ventral facet joint capsule: Histological evidence

AIM: To assess the presence of nerves in ventral facet joint capsules as facet capsules are generally implicated in neck pain.

METHODS: Twenty-four ventral cervical facet joint capsules were harvested from 3 unembalmed cadavers. Paraffin sections from these capsules were processed to identify neurofilament and substance P immunoreactive fibers. Nerve fiber presence was also verified by a silver impregnation method.

RESULTS: Neurofilament reactive fibers were observed in sections from 9 capsules. They were observed in areas with collagen fibers and areas with irregular connective tissue. Substance P reactive nerve fibers were found in sections from 7 capsules in similar areas. Silver impregnation also revealed the presence of nerve fibers. The nerve fibers were also found as bundles in the lateral margins of the capsule. A Pacinian corpuscle-like ending was also observed in one specimen.

CONCLUSION: Nerve fibers revealed by neurofilament immunoreactivity and silver staining support innervation of the ventral aspect of the facet joint capsule. The presence of substance P reactive fibers supports the potential role of these elements in mediating pain. The presence of a Pacinian-like ending implicates a potential role in joint movement.