Neck and back pain and intervertebral disc degeneration: Role of occupational factors

Hydration State Throughout Porcine Lumbar Intervertebral Discs: Comparing Fresh and Frozen-Thawed Specimens

Water content in intervertebral discs (IVDs) is essential for physiological and mechanical function. Freezing post-mortem tissue prior to biomechanical testing is a common practice to prevent tissue degradation, but this process has been theorized to alter hydration within IVDs. The hydration state throughout porcine lumbar IVDs, a common lumbar surrogate, is unknown as are the effects of freezing on porcine IVD hydration. Nineteen porcine lumbar spines were stored in one of the three conditions: frozen (- 20 °C) wrapped in saline-soaked gauze, frozen (- 20 °C) without saline, or fresh. Water content was measured in four disc regions within each of 89 discs: nucleus pulposus (NP), inner (AF-A), intermediate (AF-B), and outer (AF-C) annulus fibrosus. A three-factor, repeated measure analysis of variance was conducted for storage condition, spinal level, and repeated measure disc region. No significant differences were observed in spinal level or storage condition as a main effect. Mean hydration was significantly different in each disc region with mass percentage of water found to be 88.8 ± 1.7% in NP, 79.6 ± 3.8% in AF-A, 71.9 ± 3.7% in AF-B, and 62.3 ± 3.3% in AF-C. No significant differences were shown in NP and AF-C regions between storage conditions. Two significant differences in storage condition were observed in AF-A and AF-B regions, but there is likely no biological difference in these populations. Water content throughout porcine lumbar IVD was determined and results suggest one freeze-thaw cycle at - 20 °C does not alter the overall hydration within the porcine lumbar IVD.

Potential Use of Extracellular Vesicles in the Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is a major cause of low back pain, and several studies have evaluated the efficacy of extracellular vesicles (EVs) in the treatment of IVDD. The databases PubMed, Embase, and Cochrane Library were systematically searched from inception to the end of 2022 to identify studies investigating the therapeutic potential of cell-derived EVs for IVDD treatment. The following outcome measures were utilized: magnetic resonance imaging (MRI) Pfirrmann grading system, disc height index (DHI), histological grading, and apoptosis rate. A comprehensive meta-analysis was conducted, including a total of 13 articles comprising 19 studies involving 218 experimental animals. Comparative analysis between normal cell-derived EVs and placebo revealed significant reductions in MRI grade, increased DHI values, decreased nucleus pulposus cell apoptosis rates, and improved tissue grades. These findings collectively demonstrate the effective inhibition of IVDD through the application of EVs derived from cells. In conclusion, this study provides an updated synthesis of evidence supporting the efficacy of EVs as a promising therapeutic approach for IVDD treatment.

Application and development of hydrogel biomaterials for the treatment of intervertebral disc degeneration: a literature review

Low back pain caused by disc herniation and spinal stenosis imposes an enormous medical burden on society due to its high prevalence and refractory nature. This is mainly due to the long-term inflammation and degradation of the extracellular matrix in the process of intervertebral disc degeneration (IVDD), which manifests as loss of water in the nucleus pulposus (NP) and the formation of fibrous disc fissures. Biomaterial repair strategies involving hydrogels play an important role in the treatment of intervertebral disc degeneration. Excellent biocompatibility, tunable mechanical properties, easy modification, injectability, and the ability to encapsulate drugs, cells, genes, etc. make hydrogels good candidates as scaffolds and cell/drug carriers for treating NP degeneration and other aspects of IVDD. This review first briefly describes the anatomy, pathology, and current treatments of IVDD, and then introduces different types of hydrogels and addresses "smart hydrogels". Finally, we discuss the feasibility and prospects of using hydrogels to treat IVDD.

Identification of CXCL16 as a diagnostic biomarker for obesity and intervertebral disc degeneration based on machine learning

Intervertebral disc degeneration (IDD) is the primary cause of neck and back pain. Obesity has been established as a significant risk factor for IDD. The objective of this study was to explore the molecular mechanisms affecting obesity and IDD by identifying the overlapping crosstalk genes associated with both conditions. The identification of specific diagnostic biomarkers for obesity and IDD would have crucial clinical implications. We obtained gene expression profiles of GSE70362 and GSE152991 from the Gene Expression Omnibus, followed by their analysis using two machine learning algorithms, least absolute shrinkage and selection operator and support vector machine-recursive feature elimination, which enabled the identification of C-X-C motif chemokine ligand 16 (CXCL16) as a shared diagnostic biomarker for obesity and IDD. Additionally, gene set variant analysis was used to explore the potential mechanism of CXCL16 in these diseases, and CXCL16 was found to affect IDD through its effect on fatty acid metabolism. Furthermore, correlation analysis between CXCL16 and immune cells demonstrated that CXCL16 negatively regulated T helper 17 cells to promote IDD. Finally, independent external datasets (GSE124272 and GSE59034) were used to verify the diagnostic efficacy of CXCL16. In conclusion, a common diagnostic biomarker for obesity and IDD, CXCL16, was identified using a machine learning algorithm. This study provides a new perspective for exploring the possible mechanisms by which obesity impacts the development of IDD.

Leptin Induces MMP-1 Expression Through the RhoA/ERK1/2/NF-κB Axis in Human Intervertebral Disc Cartilage Endplate-Derived Stem Cells

Purpose

Intervertebral disc (IVD) degeneration, associated with aging, may cause low back pain and disability, with obesity as a significant risk factor. In a prior study, we found a positive correlation between IVD degeneration and levels of matrix metalloproteinase-1 (MMP-1) and leptin. Yet, the interaction between MMP-1 and leptin in IVD degeneration is unclear. Our research seeks to explore leptin's influence on MMP-1 expression and the underlying mechanisms in human intervertebral disc cartilage endplate-derived stem cells, specifically SV40 cells.

Methods

The mRNA and protein expression in leptin-stimulated SV40 cells were assessed using RT-real-time PCR and Western blotting or ELISA, respectively. We examined leptin-mediated RhoA activation through a GTP-bound RhoA pull-down assay. Furthermore, the phosphorylation levels of mitogen-activated protein kinases and AKT in leptin-stimulated SV40 cells were analyzed using Western blotting. The activation of NF-κB by leptin was investigated by assessing phosphorylation of IKKα/β, IκBα, and NF-κB p65, along with the nuclear translocation of NF-κB p65. To understand the underlying mechanism behind leptin-mediated MMP-1 expression, we employed specific inhibitors.

Results

Leptin triggered the mRNA and protein expression of MMP-1 in SV40 cells. In-depth mechanistic investigations uncovered that leptin heightened RhoA activity, promoted ERK1/2 phosphorylation, and increased NF-κB activity. However, leptin did not induce phosphorylation of JNK1/2, p38, or AKT. When we inhibited RhoA, ERK1/2, and NF-κB, it resulted in a decrease in MMP-1 expression. Conversely, inhibition of reactive oxygen species and NADPH oxidase did not yield the same outcome. Additionally, inhibiting RhoA or ERK1/2 led to a reduction in leptin-induced NF-κB activation. Moreover, inhibiting RhoA also decreased leptin-mediated ERK1/2 phosphorylation.

Conclusion

These results indicated that leptin induced MMP-1 expression in SV40 cells through the RhoA/ERK1/2/NF-κB axis. This study provided the pathogenic role of leptin and suggested the potential therapeutic target for IVD degeneration.

Artificial intelligence in predicting early-onset adjacent segment degeneration following anterior cervical discectomy and fusion

PURPOSE

Anterior cervical discectomy and fusion (ACDF) is a common surgical treatment for degenerative disease in the cervical spine. However, resultant biomechanical alterations may predispose to early-onset adjacent segment degeneration (EO-ASD), which may become symptomatic and require reoperation. This study aimed to develop and validate a machine learning (ML) model to predict EO-ASD following ACDF.

METHODS

Retrospective review of prospectively collected data of patients undergoing ACDF at a quaternary referral medical center was performed. Patients > 18 years of age with > 6 months of follow-up and complete pre- and postoperative X-ray and MRI imaging were included. An ML-based algorithm was developed to predict EO-ASD based on preoperative demographic, clinical, and radiographic parameters, and model performance was evaluated according to discrimination and overall performance.

RESULTS

In total, 366 ACDF patients were included (50.8% male, mean age 51.4 ± 11.1 years). Over 18.7 ± 20.9 months of follow-up, 97 (26.5%) patients developed EO-ASD. The model demonstrated good discrimination and overall performance according to precision (EO-ASD: 0.70, non-ASD: 0.88), recall (EO-ASD: 0.73, non-ASD: 0.87), accuracy (0.82), F1-score (0.79), Brier score (0.203), and AUC (0.794), with C4/C5 posterior disc bulge, C4/C5 anterior disc bulge, C6 posterior superior osteophyte, presence of osteophytes, and C6/C7 anterior disc bulge identified as the most important predictive features.

CONCLUSIONS

Through an ML approach, the model identified risk factors and predicted development of EO-ASD following ACDF with good discrimination and overall performance. By addressing the shortcomings of traditional statistics, ML techniques can support discovery, clinical decision-making, and precision-based spine care.

Association between Occupation and Cervical Disc Degeneration in 1211 Asymptomatic Subjects

Magnetic resonance imaging (MRI) system has frequently observed degenerative changes in the cervical discs of healthy subjects. Although there are concerns regarding the link between an individual's occupation and intervertebral disc degeneration (IDD) in the cervical spine, whether the occupation affects IDD is still not clear. This study aimed to evaluate the occupation and IDD interplay using cervical spine MRI among a cohort of healthy individuals, and to evaluate any association between the type of labor and IDD. Using MRI, we prospectively measured at every level, the anteroposterior (AP) intervertebral disc diameter and disc height, in a cohort of 1211 healthy volunteers (606 (50%) male; mean age, 49.5 years). Using a minimum of 100 male and female each from the third to eighth decades of age (20-79 years), IDD was evaluated based on the modified Pfirrmann classification system to derive a disc degeneration score (DDS). We also measured the AP diameters of disc protrusion and of the dural sac as well as the spinal cord. The overall DDS and number of disc protrusions increased with age. Among 11 occupations, there were no significant differences in AP diameter of the dural sac as well as the spinal cord. For the four labor types (heavy object handling, same position maintenance, cervical extension position, and cervical flexion position), there were no significant differences in overall DDS and number of disc protrusions, with or without work. Also, among the four labor types, there were no significant differences in the AP diameter of the dural sac as well as the spinal cord. In this cross-sectional survey of cervical spine MRI data among healthy adult volunteers, occupation and type of labor might have no effect on IDD in the cervical spine.

A protocol for recruiting and analyzing the disease-oriented Russian disc degeneration study (RuDDS) biobank for functional omics studies of lumbar disc degeneration

Lumbar intervertebral disc degeneration (DD) disease is one of the main risk factors for low back pain and a leading cause of population absenteeism and disability worldwide. Despite a variety of biological studies, lumbar DD is not yet fully understood, partially because there are only few studies that use systematic and integrative approaches. This urges the need for studies that integrate different omics (including genomics and transcriptomics) measured on samples within a single cohort. This protocol describes a disease-oriented Russian disc degeneration study (RuDDS) biobank recruitment and analyses aimed to facilitate further omics studies of lumbar DD integrating genomic, transcriptomic and glycomic data. A total of 1,100 participants aged over 18 with available lumbar MRI scans, medical histories and biological material (whole blood, plasma and intervertebral disc tissue samples from surgically treated patients) will be enrolled during the three-year period from two Russian clinical centers. Whole blood, plasma and disc tissue specimens will be used for genotyping with genome-wide SNP-arrays, glycome profiling and RNA sequencing, respectively. Omics data will be further used for a genome-wide association study of lumbar DD with in silico functional annotation, analysis of plasma glycome and lumbar DD disease interactions and transcriptomic data analysis including an investigation of differential expression patterns associated with lumbar DD disease. Statistical tests applied in each of the analyses will meet the standard criteria specific to the attributed study field. In a long term, the results of the study will expand fundamental knowledge about lumbar DD development and contribute to the elaboration of novel personalized approaches for disease prediction and therapy. Additionally to the lumbar disc degeneration study, a RuDDS cohort could be used for other genetic studies, as it will have unique omics data.

Trial registration numberNCT04600544.

Effects of Changes in Osmolarity on the Biological Activity of Human Normal Nucleus Pulposus Mesenchymal Stem Cells

The expansion and maintenance of the NPMSC (nucleus pulposus mesenchymal stem cell) phenotype are considered as potential therapeutic tools for clinical applications in intervertebral disc tissue engineering and regenerative medicine. However, the harsh microenvironment within the intervertebral disc is the main limitation of its regeneration. The osmolarity of the intervertebral disc is higher than that of other tissues, which has an important influence on the biological characteristics of NPMSCs. In this study, we observed the effect of different osmolarities on the biological characteristics of human normal NPMSCs cultured in vitro and explored the role of osmolarity in intervertebral disc degeneration. Our data demonstrated that the change in osmotic pressure has an important effect on the biological activity of NPMSCs, and this effect may occur through the P16^INK4A/Rb pathway. This study provides a theoretical basis for the future treatment of intervertebral disc degeneration.

MicroRNA-137 inhibits the inflammatory response and extracellular matrix degradation in lipopolysaccharide-stimulated human nucleus pulposus cells by targeting activin a receptor type I

This study aimed to investigate the role played by microRNA (miR)-137 in intervertebral disc degeneration via targeting activin A receptor type I (ACVR1) and the underlying mechanism. Human nucleus pulposus cells were exposed to 10 ng/mL lipopolysaccharide (LPS) to establish an in vitro intervertebral disc degeneration model. ACVR1, extracellular matrix degradation-associated genes (aggrecan and collagen type II) and miR-137 levels were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blotting assays. The MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay and flow cytometry were used to evaluate nucleus pulposus cell viability and apoptosis. Additionally, the association between miR-137 and ACVR1 was predicted and verified using bioinformatic software and dual-luciferase reporter assays. Furthermore, the secretion of inflammatory factors was analyzed via enzyme linked immunosorbent assay (ELISA). Our results confirmed that ACVR1 was upregulated in lipopolysaccharide-treated nucleus pulposus cells. Lipopolysaccharide suppressed cell viability, promoted apoptosis, enhanced the secretion of inflammatory factors, and reduced aggrecan and collagen type II expression. However, these results were reversed upon ACVR1 silencing. Our data revealed that ACVR1 directly targets miR-137 and is negatively regulated by miR-137 in nucleus pulposus cells. Additionally, the miR-137 mimic promoted cell growth, reduced cell apoptosis, reduced the secretion of inflammatory cytokines, and accelerated extracellular matrix accumulation in lipopolysaccharide-exposed nucleus pulposus cells. However, ACVR1 plasmid abolished the functions of the miR-137 mimic in lipopolysaccharide-exposed nucleus pulposus cells. Together, these findings indicate that miR-137 suppresses the inflammatory response and extracellular matrix degradation in lipopolysaccharide-treated nucleus pulposus cells by targeting ACVR1.

Cervical Disc Degeneration and Vertebral Endplate Defects After the Fused Operation

STUDY DESIGN

Longitudinal study of cervical MR in patients with degenerative disc disease (DDD).

OBJECTIVE

To evaluate the evolution of the degenerative changes in the C2-D1 cervical segments and to assess the association magnetic resonance imaging (MRI) parameters with clinical symptoms after surgical treatment in patients with DDD.

SUMMARY OF BACKGROUND DATA

The evolution of degenerative changes in the cervical spine is poorly understood. Endplate defects can be of great importance in progressive disc degeneration (DD). Clarification of this predictor may be important in determining the treatment tactics in patients with DDD.

METHODS

The study included patients who had 2-years' follow-up after cervical fusion for spondylotic radiculo- with/without myelopathy. Demographic data (age, sex, surgical data) were assessed; clinical data (visual analogue scale [VAS] neck, VAS arm, Neck Disability Index [NDI]) and cervical MRI (DD grades by Pfirrmann, Modic changes (MC), total endplate scores (TEPS) were compared to preoperative data.

RESULTS

The median follow-up term was 26.5 (18.9-33.1) months. All patients reported a decrease neck pain and arm pain at follow-up (P < 0.001). There was observed the change in MC types (P < 0.001) and an increase of TEPS (P < 0.05). 71.7% discs remained unchanged during the follow-up, but a significant number of discs went from Grade 2 to Grade 3 and from Grade 3 to Grade 4 by Pfirrmann (P < 0.001). Clinical scores (VAS neck, VAS arm, NDI) had no correlation with MRI changes (P > 0.05). DD was associated with TEPS (odds ratio [OR] 2.05-5.47, P < 0.05) and patients' age (OR 1.11-2.33, P < 0.05) at all cervical levels; with MC types, but only at C4-C5 and C6-C7 levels (OR = 2.91 and 2.79, respectively, P < 0.05). Receiver-operating characteristic analysis showed a TEPS threshold value of 7, above which the probability of DD significantly higher.

CONCLUSION

During 2 years' follow-up the significant increase of DD grades by Pfirrmann was observed at C4-C6 levels (P < 0.001). A significant association DD with TEPS and age at all cervical levels was determined.Level of Evidence: 3.

Dentists have a high occupational risk of neck disorders with impact on somatosensory function and neck mobility

OBJECTIVES

Musculoskeletal disorders (MSDs) in the neck and shoulder region may be associated with significant impairment of quality of life and well-being. The study was to determine the prevalence of painful MSDs in Chinese dentists and evaluate somatosensory function and neck mobility compared with non-dental professional controls.

METHODS

One hundred dentists (age: 36.5 ± 9.8 years) and 102 controls (age: 36.2 ± 10.0 years) were recruited between September 2019 and December 2020. The Medical Outcome Study 36-item short-form health survey questionnaire and information of MSDs history were recorded. The cervical range of motion (CROM) with and without pain, and the pressure pain thresholds (PPTs) of the facial and neck muscles were tested. Chi-square test, Mann-Whitney U test and multiple linear regression analysis were used to analyze the data. The factors in the multiple linear regression analysis were occupation, working age, and gender.

RESULTS

The prevalence rate of neck pain was significantly higher in dentists (73.0%) compared with the controls (52.0%) (P = .002). The regression models of cervical range of posterior extension, lateral flexion and rotation were statistically significant (P ≤ .001). The regression models of PPTs of the tested facial and neck muscles were statistically significant (P < .001).

CONCLUSION

Dentists are at higher risk of neck pain. The bigger cervical range of left rotation of dentists could be related to the working posture. The lower PPTs in dentists may reflect a hypersensitivity in the facial and neck muscles. Preventive measures are needed to reduce occupational hazards in dentists.

Three-Dimensional Finite Element Analysis of L4-5 Degenerative Lumbar Disc Traction under Different Pushing Heights

Objective

To study and analyze the changes of intervertebral foramen height and area of the degenerative L4-5 intervertebral disc under different pushing heights by the finite element method.

Methods

CT and MRI images of T12-S1 segments were obtained from a healthy volunteer who met the inclusion criteria. A DR machine was used to capture images of the lumbar lateral section before and after simultaneous pushing of the L4 and L5 spinous processes by manipulation called Daogaijinbei, and the measurement showed that the displacement changes of L4 and L5 were both approximately 10 cm, so the pushing height was set at 0-10 cm. A three-dimensional finite element model of the entire normal lumbar spine was established using Mimics 16.0, Geomagic Studio 2014, Hypermesh 13.0, MSC.Patran 2012, and so on. The disc height and nucleus area of the lumbar disc of the normal entire lumbar disc model were adjusted to establish models of the L4-5 disc with mild, moderate, and severe degeneration. Changes of disc height and area of the L4-5 degenerative intervertebral disc under different pushing heights were calculated.

Results

The size of the L4-5 intervertebral foramen was analyzed from the height and area of the intervertebral foramen, and the results showed the following: (1) as for the normal lumbar disc and a lumbar of the L4-5 disc with mild and moderate degeneration, the height of the L4-5 intervertebral foramen and its area both increased during pushing between 0 and 8 cm. After the pushing height reached 8 cm, the height and area of the L4-5 intervertebral foramen gradually became stable; (2) as for the L4-5 disc with severe degeneration, during the process of pushing, the height and area of the L4-5 intervertebral foramen increased slightly, but this change was not obvious.

Conclusions

After the spinal manipulation, the sizes of the L4-5 intervertebral foramen of the L4-5 disc with mild and moderate degeneration were significantly larger than those before pushing; in contrast, the size of L4-5 intervertebral foramen of the L4-5 disc with severe lumbar degeneration was not significantly changed.

Prevalence and risk of spinal pain among physiotherapists in Poland

Background

The purpose of this study was to determine the prevalence, symptoms of, and risk factors for spinal pain in physiotherapists, as well as to analyse the correlation between these factors and the nature of the work, anthropometric features of the respondents, and the level of their physical activity.

Methods

The study was conducted among 240 physiotherapists (71 male and 169 female) with a mean age of 38.7 years. They were divided into three groups: physical therapy (37), kinesitherapy (158) and massage (45). Physiotherapists were evaluated with a specially designed questionnaire, the postural discomfort chart, the Neck Disability Index (NDI) questionnaire, and the Oswestry Disability Index (ODI) questionnaire.

Results

The analysis showed a 91.7% incidence of spinal pain in physiotherapists (91.1% for kinesitherapy, 97.3% for physical therapy, and 88.9% for massage). The study revealed that 50.2% of physiotherapists indicated one to five pain episodes in their careers. Most respondents reported pain in the lumbosacral spine (82%) and the cervical spine (67%). Most respondents (58.5%) scored the pain as moderate (VAS scale). Carrying (62.6%) and torso bending (37.4%) were indicated as the causes of pain.

Conclusions

Physiotherapists demonstrate a high prevalence of spinal pain. Physical activity reduces the frequency of pain episodes.

[The optimization of differential diagnosis and treatment of cervical radiculopathy (SHERPA study)]

OBJECTIVE

To improve the algorithm of differential diagnosis and complex treatment of patients with CR.

MATERIAL AND METHODS

Forty-two patients with CR were divided into 2 groups. Patients of the first group (n=21) received basic treatment (NSAID, myorelaxants, local injections with glucocorticoids (on demand), B vitamins and non-pharmacological methods) and the anticholinesterase drug ipidacrine. The second group (n=21) had only basic treatment. The total duration of the study was 45 days. The effectiveness of treatment was evaluated with VAS, NDI, GROC and total duration of disability period.

RESULTS

A battery of tests for the diagnosis of CR that included Spurling test, motor strength deficiency, ULTT, pain pattern, shoulder adduction test (diagnostic complex SPASIBO), has been developed. A positive result of all 5 tests guarantees the 94.7% accuracy of CR diagnosis. The application of ipidacrine has allowed a significant (p<0.05) reduction of pain, enhancement of daily living activities and subjective improvement of well-being of patients after 1 month of treatment and mostly after 45 days. Besides, there was a considerable (p<0.05) reduction of the disability period in the first group of patients compared to the control one.

CONCLUSION

The diagnostic complex SPASIBO should be used in diagnosis of CR. It is highly recommended to include ipidacrine in the complex treatment of CR.

Stem Cell Senescence: the Obstacle of the Treatment of Degenerative Disk Disease

Intervertebral disc (IVD) has a pivotal role in the maintenance of flexible motion. IVD degeneration is one of the primary causes of low back pain and disability, which seriously influences patients' health, and increases the family and social economic burden. Recently, stem cell therapy has been proven to be more effective on IVD degeneration disease. However, stem cell senescence is the limiting factor in the IVD degeneration treatment. Senescent stem cells have a negative effect on the self-repair on IVD degeneration. In this review, we delineate that the factors such as telomerase shortening, DNA damage, oxidative stress, microenvironment and exosomes will induce stem cell aging. Recent studies tried to delay the aging of stem cells by regulating the expression of aging-related genes and proteins, changing the activity of telomerase, improving the survival microenvironment of stem cells and drug treatment. Understanding the mechanism of stem cell aging and exploring new approaches to delay or reverse stem cell aging asks for research on the repair of the degenerated disc.

The association between occupational loading and spine degeneration on imaging - a systematic review and meta-analysis

Background

There are inconsistencies in findings regarding the relationship of occupational loading with spinal degeneration or structural damage. Thus, a systematic review was conducted to determine the current state of knowledge on the association of occupational loading and spine degeneration on imaging.

Methods

We performed electronic searches on MEDLINE, CINAHL and EMBASE. We included cross-sectional, case control and cohort studies evaluating occupational loading as the exposure and lumbar spine structural findings on imaging as the outcomes. When possible, results were pooled.

Results

Seventeen studies were included in the review. Ten studies evaluated the association of occupational loading with disc degeneration (signal intensity), four of which were pooled into a meta-analysis. Of the 10 studies, only two did not identify a relationship between occupation loading and disc degeneration. A meta-analysis including four of the studies demonstrated an association between higher loading and degeneration for all spinal levels, with odds ratios between 1.6 and 3.3. Seven studies evaluated disc height narrowing and seven evaluate disc bulge, with six and five identifying an association of loading and with imaging findings respectively. Three studies evaluated modic changes and one identified and association with occupational load.

Conclusions

There was moderate evidence suggesting a modest association between occupational loading and disc degeneration (signal intensity), and low-quality evidence of an association between occupational loading and disc narrowing and bulging.

Feasibility of T2 Mapping and Magnetic Transfer Ratio for Diagnosis of Intervertebral Disc Degeneration at the Cervicothoracic Junction: A Pilot Study

Background

Intervertebral disc degeneration (IDD) at the cervicothoracic junction of spine is clinically relevant, however, little attention had been paid. T2 mapping and magnetic transfer ratio (MTR) are useful magnetic resonance imaging (MRI) techniques to quantitatively evaluate IDD, revealing the biochemical changes within the intervertebral disc. To compare T2 mapping with MTR imaging regarding their accuracy to quantitatively diagnose intervertebral disc degeneration at the cervicothoracic junction, influences of anatomical level, gender, age, and Pfirrmann grade of T2 relaxation time values and MTR values were evaluated.

Methods

Sixty-seven patients with neck and upper back pain were included and examined with both T2 mapping and MTR imaging. The Pfirrmann grade, T2 relaxation time values, and MTR value of each disc between C7 and T3 were measured. Differences were investigated among different segmental levels, genders, age ranges, and Pfirrmann grades. The diagnostic accuracy of both MRI techniques was compared using the receiver operating characteristic (ROC) curves.

Results

No significant difference was detected comparing T2 relaxation time values or MTR values among different anatomical levels, genders, and segmental levels. And we generally found that T2 relaxation time values decreased, while MTR value increased with increasing age. Importantly, we demonstrated the significant correlation between either T2 relaxation time values or MTR value and Pfirrmann grade.

Conclusion

We proved the better accuracy of T2 mapping over MTR imaging to quantitatively evaluate the intervertebral disc degeneration of the cervicothoracic junction.

Nucleus pulposus cell apoptosis is attenuated by CDMP-2 through regulating oxidative damage under the hyperosmotic environment

Disc nucleus pulposus (NP) cell experiences periodic osmolarity alterations during daily activities, which has been proved to affect cell biology in vitro The present study was aimed to investigate the effects of cartilage-derived morphogenetic protein-2 (CDMP-2) on NP cell apoptosis under the hyperosmolarity culture and the potential mechanism. Isolated rat NP cells were cultured in the in situ-osmolarity medium or hyperosmolarity medium for 3 days. CDMP-2 was added into the hyperosmolarity medium to investigate its effects on NP cell apoptosis. Cell apoptosis rate, caspase-3 activity, gene expression of Bcl-2, Bax, and caspase-3, and protein expression of Bcl-2, Bax, and cleaved caspase-3 were analyzed to evaluate NP cell apoptosis. Additionally, the intracellular reactive oxygen species (ROS) and the total superoxide dismutase (SOD) activity were analyzed to investigate the potential role of oxidative damage in this process. In the hyperosmolarity culture, NP cells showed a significantly increased cell apoptosis rate and caspase-3 activity, an up-regulated expression of Bax and caspase-3/cleaved-caspase-3 and a down-regulated expression of Bcl-2. However, CDMP-2 partly inhibited these effects of hyperosmolarity culture on NP cells. Additionally, the hyperosmolarity culture significantly increased ROS content and decreased the total SOD activity compared with the in situ-osmolarity culture, whereas exogenous CDMP-2 partly decreased the ROS content and increased the total SOD activity in the hyperosmolarity culture. In conclusion, CDMP-2 is effective in attenuating hyperosmolarity environment-induced NP cell apoptosis, and this process may be mediated through inhibiting oxidative stress damage. The present study indicates that CDMP-2 may be helpful to retard hyperosmolarity niche-mediated disc degeneration.

Evaluation of Common Variants in Matrix Metalloproteinase-9 Gene with Lumbar Disc Herniation in Han Chinese Population

OBJECTIVE

Lumbar disc herniation (LDH) is a common and frequent orthopedic disease with strong genetic determinants. The disruption of the intervertebral disc extracellular matrix has been found to play a key role in the development of LDH, suggesting that abnormal matrix metalloproteinases (MMPs) may promote the degradation of the disc matrix. MMP-9, an important member of the MMP family, is a good candidate for the LDH susceptibility gene. The present study aimed to investigate the association of common variants in the MMP-9 gene with the risk, severity, and clinical characteristic variables of LDH.

MATERIALS AND METHODS

Fourteen tag single nucleotide polymorphisms (SNPs) entirely covering the region of the MMP-9 gene were analyzed in a sample of 845 patients and 1751 healthy controls.

RESULTS

The SNP rs17576 was found to be significantly associated with susceptibility to LDH (OR = 0.77, p = 0.0002), which was also confirmed by haplotype-based analyses (rs79845319-rs17576-rs45437897, global p < 0.001). Our results indicated that the A allele of rs17576 reduced the risk of LDH by ∼23% on average. Furthermore, the G allele of rs17576 was found to correlate with more severe grades of disc degeneration.

CONCLUSION

Our results provide additional evidence supporting an important role of the MMP-9 gene in the pathogenesis of LDH.

Curative effect of posterior lumbar interbody fusion in the treatment of single-segment lumbar degenerative disease and changes in adjacent segment quantitative score

Curative effect of posterior lumbar interbody fusion (PLIF) in the treatment of single-segment lumbar degenerative disease and changes in adjacent segment quantitative score was investigated. A total of 86 patients with single-segment lumbar degenerative disease were randomly selected and divided into control group (n=43) and observation group (n=43). The control group was treated with posterolateral lumbar fusion, while the observation group was treated with PLIF. The observation group had a significantly longer operation time and shorter hospitalization time compared with the control group (P<0.05). The excellent-good rate of treatment in the observation group (90.69%) was obviously higher than that in the control group (62.79%) (P<0.05). The levels of creatine phosphokinase in the two groups were significantly increased at 1, 3 and 5 days after operation (P<0.05), and reached the peak at 1 day after operation and returned to normal basically at 7 days after operation. Oswestry disability index in the observation group at 1, 6 and 12 months after operation were significantly lower than those in the control group (P<0.05). There was no significant difference in the MRI-T2 relaxation time of multifidus muscle at 3 months after operation between the two groups (P>0.05). The grade I and II interbody fusion rates in the observation group at 12 months after operation were significantly higher than those in the control group (P<0.05). The mean spinal canal areas and adjacent segment quantitative scores in the two groups after operation were significantly improved compared with those before operation, and they were improved more obviously in the observation group than those in the control group (P<0.05). PLIF has a more definite short-term curative effect and a higher interbody fusion rate in the treatment of single-segment lumbar degenerative disease, which is more conducive to promoting the postoperative rehabilitation of patients and slowing down the occurrence of adjacent segment degeneration.

Apparent Diffusion Coefficient of Diffusion-Weighted Imaging in Evaluation of Cervical Intervertebral Disc Degeneration: An Observational Study with 3.0 T Magnetic Resonance Imaging

Aims

To investigate the correlation between the apparent diffusion coefficient (ADC) value and cervical intervertebral disc degeneration in adult symptomatic patients.

Methods

A total of 52 symptomatic and 40 healthy volunteers were included. DWI and routine MRI examinations were performed to their cervical spines. The cervical discs (from C2-C3 to C6-C7) were graded according to the Pfirrmann grading system, and ADC values of the nucleus pulposus (NP) were measured. Differences of the ADC values between different genders and anatomic levels were analyzed; the correlation between the ADC value and the Pfirrmann grade was investigated. The cut-off ADC values of each Pfirrmann grade were calculated.

Results

The mean ADC value of the NP decreased with increasing Pfirrmann grade (I–V) upon both patients and asymptotic volunteers. The ADC value decreased descendingly from C2-C3 to C5-C6 (P < 0.05) and then increased at C6-C7 (P < 0.05). Additionally, the comparison of the ADC values between different genders achieved statistical significance at each anatomical level (P < 0.05), except at C6-C7 (P > 0.05). Significant negative correlations between the ADC value and either age or Pfirrmann grade were observed.

Conclusions

Our preliminary findings suggest that the ADC value obtained by DWI can provide a reliable indicator to evaluate the cervical disc degeneration.

Whole Spine Disc Degeneration Survey according to the Ages and Sex Using Pfirrmann Disc Degeneration Grades

Objective

Pfirrmann disc grade is a useful scoring tool for evaluating disc degeneration, but normal values according to aging process has not been elucidated. This study was conducted to identify the prevalence and pattern of whole spine disc degeneration according to ages and gender differences.

Methods

Total 653 patients (336 male and 317 female patients, 48.1±58.7 years old) who took whole spine magnetic resonance images were enrolled in this study. There were 19 cases in their 2nd decades and 74 cases in 3rd decades, 141 cases in 4th decades, 129 cases in 5th decades, 139 cases in 6th decades, and 93 cases in 7th decades, 58 cases in over 8th decades. Pfirrmann disc grades were measured according to sex and ages by 2 neurosurgeons that were blind to this study.

Results

All spinal disc degeneration grades were correlated with ageing. The Pfirrmann disc grades of degeneration in all spine levels showed the statistically significant difference according to the ages (p<0.001). The common Pfirrmann disc grades according to the ages were grade 3 among 2nd to 5th decades, and grade 4 was more common than 6th decades. The lower cervical level (C2–3 to C4–5) and lumbar level (L1–2 to L5–S1) were happened relatively early severe disc degeneration compared to other levels. The intersexual differences were increased after 6th decades.

Conclusion

Disc degeneration is natural course after one’s 2nd decades. And its incidence and grade were increased with age, and more affected by sexual difference after 6th decades.

Progranulin derived engineered protein Atsttrin suppresses TNF-α-mediated inflammation in intervertebral disc degenerative disease

Atsttrin, an engineered molecule composed of three fragments of progranulin(PGRN), exerts comparable anti-inflammation ability. Intervertebral disc degeneration (IDD) is involved in inflammation in which TNF-α plays a key role. This study aims to examine the effect and the mechanism of Atsttrin in the pathogenesis of intervertebral disc degeneration. For this purpose, we took advantage of murine and human intervertebral disc (IVD) and examined the expression of TNF-α in IVD tissues using immunohistochemistry and TNF-α level in peripheral sera by ELISA assay. Moreover, murine IVD was taken to undergo the Safranin O and HE staining. Furthermore, primary human nucleus pulposus cells were used for immunohistochemistry staining, fluorescent staining, Western Blot, ELISA assay and RT-PCR assay. Herein we found TNF-α expression was elevated in intervertebral disc and peripheral sera in patients with IDD. Interestingly, Atsttrin effectively inhibited TNF-α-mediated catabolism in murine disc by ex vivo study. TNF-α-induced inflammatory cytokines were strongly reduced in presence of Atsttrin in primary human disc. Mechanism study indicated Atsttrin protected against intervertebral disc degeneration by inhibiting TNF-α-induced inflammation. These findings show that Atsttrin is a potential molecular target for disc degenerative diseases.

Infrarenal aortic diameter, aortoiliac bifurcation level and lumbar disc degenerative changes: a cross-sectional MR study

PURPOSE

To examine a possible correlation of infrarenal aortic diameter and aortoiliac bifurcation level with lumbar disc degenerative changes.

METHODS

This was a cross-sectional, single-center retrospective study on lumbar magnetic resonance images of patients with low back pain (n = 496). Lumbar disc degenerative changes were reported on the basis of the Pfirrmann grading system and accordingly, patients were grouped as with grade I-II findings (n = 192), with grade III findings (n = 64) and with grade IV-V findings (n = 240). The groups were matched for sex, body mass index and the history of diabetes mellitus, hypertension, hyperlipidemia and smoking. Infrarenal aortic diameter and aortoiliac bifurcation level were compared between the three groups.

RESULTS

Pairwise comparisons between the three groups of patients with Pfirrmann grades of I-II, III and IV-V revealed significant differences (p < 0.05) in terms of the median infrarenal aortic diameter (17 mm [interquartile range 4], 18 mm [4] and 19 mm [4], respectively) and the median aortoiliac bifurcation level (3 [2], 4 [2] and 5 [3], respectively; the higher the value, the more the caudal displacement). These associations were independent of conventional risk factors of atherosclerosis (including age) and from each other.

CONCLUSIONS

This study showed a significant, direct correlation of the infrarenal aortic diameter and the level of aortoiliac bifurcation with lumbar intervertebral degenerative changes according to the Pfirrmann grading system. The associations were independent of well-known risk factors of atherosclerosis and from each other.

Association of COL11A1 4603C/T polymorphism with cervical disc degeneration in collegiate wrestlers

BACKGROUND

The authors previously identified that COL11A1 gene polymorphism is not a susceptibility factor for lumbar disc degeneration (LDD) in athletes. However, the relationship between COL11A1 gene polymorphism and cervical disc degeneration (CDD) remains unclear. We hypothesized that significant associations between COL11A1 4603C/T gene polymorphism and CDD, but not LDD, in collegiate wrestlers exist. This study aims to examine the relationship between CDD, LDD, and COL11A1 4603C/T gene polymorphism in collegiate wrestlers.

METHODS

The subjects enrolled in this study were 92 (Study-1) and 123 (Study-2) Japanese collegiate male wrestlers. Study-1 and Study-2 were conducted in 2010-2012 and 2012-2015, respectively.

RESULTS

CDD and LDD prevalence among the wrestlers was 51.1% (47/92) and 43.9% (54/123), respectively. We found that COL11A1 4603C/T was significantly associated with CDD, but not with LDD. Using logistic regression analysis with concomitant confounding factors, we further confirmed that COL11A1 4603C/T was a significant risk factor for CDD (co-dominant genetic model [CC vs. CT+TT]: adjusted odds ratio [OR] 2.28; 95% CI: 1.13-4.59; dominant genetic model [CC+CT vs. TT]: adjusted OR 11.71; 95% CI: 1.36-101.06).

CONCLUSIONS

Results suggest that COL11A1 4603C/T gene polymorphism is associated with an increased risk of CDD, but not LDD, in Japanese collegiate wrestlers.

Ageing affects chondroitin sulfates and their synthetic enzymes in the intervertebral disc

The depletion of chondroitin sulfates (CSs) within the intervertebral disc (IVD) during degenerative disc disease (DDD) results in a decrease in tissue hydration, a loss of fluid movement, cell apoptosis, a loss of nerve growth inhibition and ultimately, the loss of disc function. To date, little is known with regards to the structure and content of chondroitin sulfates (CSs) during IVD ageing. The behavior of glycosaminoglycans (GAGs), specifically CSs, as well as xylosyltransferase I (XT-I) and glucuronyltransferase I (GT-I), two key enzymes involved in CS synthesis as a primer of glycosaminoglycan (GAG) chain elongation and GAG synthesis in the nucleus pulposus (NP), respectively, were evaluated in a bovine ageing IVD model. Here, we showed significant changes in the composition of GAGs during the disc ageing process (6-month-old, 2-year-old and 8-year-old IVDs representing the immature to mature skeleton). The CS quantity and composition of annulus fibrosus (AF) and NP were determined. The expression of both XT-I and GT-I was detected using immunohistochemistry. A significant decrease in GAGs was observed during the ageing process. CSs are affected at both the structural and quantitative levels with important changes in sulfation observed upon maturity, which correlated with a decrease in the expression of both XT-I and GT-I. A progressive switch of the sulfation profile was noted in both NP and AF tissues from 6 months to 8 years. These changes give an appreciation of the potential impact of CSs on the disc biology and the development of therapeutic approaches for disc regeneration and repair.

Value of delayed gadolinium-enhanced magnetic resonance imaging of cartilage for the pre-operative assessment of cervical intervertebral discs

The study was performed to preoperatively assess the cartilage integrity of cervical intervertebral discs (IVDs) using Delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC). Therefore, 53 cervical intervertebral discs of nine preoperative patients with neck and shoulder/arm pain scheduled for discectomy (five females, four males; mean age: 47.1 ± 8.4 years; range: 36-58 years) were included for biochemical analysis in this retrospective study. The patients underwent 3T magnetic resonance imaging (MRI) including biochemical imaging with dGEMRIC and morphological, sagittal T2 weighted (T2w) imaging. Cervical IVDs were rated using an MRI based grading system for cervical IVDs on T2w images. Region-of-interest measurements were performed in the nucleus pulposus (NP) and annulus fibrosus (AF) and a dGEMRIC index was calculated. Our results demonstrated that IVDs scheduled for discectomy showed significantly lower dGEMRIC index compared to IVDs that did not require surgical intervention in NP and AF (NP: 898.4 ± 191.9 ms vs. 1,150.3 ± 320.7 ms, p = 0.008; AF: 738.7 ± 183.8 ms vs. 984.6 ± 178.9 ms, p = 0.008). For Miyazaki score 3, the dGEMRIC indices were significantly lower in IVDs scheduled for surgery compared to non-operated discs for NP (p = 0.043) and AF (p = 0.018). In conclusion we could demonstrate that biochemical imaging with dGEMRIC is feasible in cervical IVDs. Significantly lower dGEMRIC index suggested GAG depletion in degenerated cervical IVD, scheduled for discectomy. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1824-1830, 2017.

Meta-analysis of the effects of genetic polymorphisms on intervertebral disc degeneration

INTRODUCTION

Chronic low back pain is a significant public health issue. Both its direct and indirect cost represents tens of billions of US dollars. Although chronic low back pain can be the result of many factors, the predominant cause is disc degeneration. Recent studies have shown genetic involvement in up to 74% of cases. This study aimed to evaluate genetic risk factors of disc degeneration by performing a systematic analysis of association studies. The objective is to provide a guide for practice by assessing the clinical relevance of current information.

METHODS AND MATERIALS

We performed a meta-analysis of 3122 items collected from 6 databases. 74 articles were selected according to our inclusion criteria. 18 (24%) could be grouped into 16 meta-analyses of 16 mutations in 12 genes. The statistics of the meta-analysis were conducted through Revman 5.1 software.

RESULTS

The items included are 10,250 cases and 14,136 controls. The GOLD range from 3.42 to 0.38. Two alleles were significantly associated with disc degeneration: IL-6 rs1800797 and MMP-9 rs17576 and one proved to be protective: IL-6 rs1800795. 13 meta-analyses did not yield significant results and methodological heterogeneity.

DISCUSSION

The results highlight the lack of methodological rigor in most of the studies. The absence of international clinical and radiological classification of early disc degeneration, limits the homogeneity of studies. Understanding which populations are predisposed to this significant public health problem may change our approach to diagnostic and therapeutic methods. This work opens up enormous opportunities to provide a genetic solution and consider new diagnostic and therapeutic means to this public health problem.

T2 relaxation time for intervertebral disc degeneration in patients with upper back pain: initial results on the clinical use of 3.0 Tesla MRI

Background

Magnetic resonance imaging (MRI) is a useful non-invasive tool for evaluating abnormalities of intervertebral discs. However, there are few studies which applied functional MRI techniques to investigate degenerative changes in cervical and cervicothoracic junction (CTJ) spine among adults. The aim of this study was to compare T2 relaxation time measurement evaluation with morphological grading for assessing cervical and CTJ intervertebral discs (IVD) in the patients suffering neck, shoulder, and upper back pain.

Methods

Sixty-three patients (378 IVDs) and 60 asymptomatic volunteers (360 IVDs) of the cervical and CTJ discs were assessed using a 3.0 T magnetic resonance imaging (MRI) protocol, including an sagittal T2 relaxation time protocol. The relaxation time values of the nucleus pulposus (NP) were recorded and all discs were visually graded according to Pfirrman’s grading system. The correlation between T2 relaxation time values and qualitative clinical grading of degeneration, patient age, sex and anatomic level were analyzed

Results

There is a clear trend of decreasing mean T2 values of the NP associate with increasing Pfirrmann grades (C2-T1) for both patients and asymptotic volunteers. Significant T2 differences were seen among grades I-V (P < 0.05). However, grade V was not observed in the CTJ. Linear correlation analysis revealed a strong negative association between T2 values of the NP and Pfirrmann grade (r = −0.588, r = −0.808) of C2-7 and C7T1. Age were also significantly correlated NP T2 values (r = −0.525, r = −0.723) for patients and volunteers. Moreover, the receiver operating characteristic analysis for average measures in a range from 0.70-0.79 (C2-7) to 0.84-0.89 (C7T1) for patients.

Conclusions

T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of IVD degeneration and age-associated disc changes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12880-017-0182-z) contains supplementary material, which is available to authorized users.

Clinical and biomechanical researches of polyetheretherketone (PEEK) rods for semi-rigid lumbar fusion: a systematic review

Lumbar spinal fusion using rigid rods is a common surgical technique. However, adjacent segment disease and other adverse effects can occur. Dynamic stabilization devices preserve physiologic motion and reduce painful stress but have a high rate of construct failure and reoperation. Polyetheretherketone (PEEK) rods for semi-rigid fusions have a similar stiffness and adequate stabilization power compared with titanium rods, but with improved load sharing and reduced mechanical failure. The purpose of this paper is to review and evaluate the clinical and biomechanical performance of PEEK rods. A systematic review of clinical and biomechanical studies was conducted. A literature search using the PubMed, EMBASE, and Cochrane Library databases identified studies that met the eligibility criteria. Eight clinical studies and 15 biomechanical studies were included in this systematic review. The visual analog scale and the Oswestry disability index improved significantly in most studies, with satisfactory fusion rates. The occurrence of adjacent segment disease was low. In biomechanical studies, PEEK rods demonstrated a superior load-sharing distribution, a larger adjacent segment range of motion, and reduced stress at the rod-screw/screw-bone interfaces compared with titanium rods. The PEEK rod construct was simple to assemble and had a reliable in vivo performance compared with dynamic devices. The quality of clinical studies was low with confounding results, although results from mechanical studies were encouraging. There is no evidence strong enough to confirm better outcomes with PEEK rods than titanium rods. More studies with better protocols, a larger sample size, and a longer follow-up time are needed.

The Association Between Low Back Pain and Composition of IgG Glycome

Low back pain (LBP) is a common debilitating condition which aetiology and pathogenesis are poorly understood. We carried out a first so far analysis of associations between LBP and plasma IgG N-glycome in a sample of 4511 twins from TwinsUK database assessed for LBP, lumbar disc degeneration (LDD) as its possible cause, and IgG-glycan levels. Using weighted correlation network analysis, we established a correlation between LBP and glycan modules featured by glycans that either promote or block antibody-dependent cell-mediated cytotoxicity (ADCC). The levels of four glycan traits representing two of those modules were statistically significantly different in monozygotic twins discordant for LBP. Also, the trend to higher prevalence of systemic inflammatory disorders was shown for twins with low level of fucosylated glycans and high level of non-fucosylated glycans. Core fucosylation of IgG is a “safety switch” reducing ADCC, thus our results suggest the involvement of ADCC and associated inflammation in pathogenesis of LBP. No correlation between LDD scores and glycans was found assuming that the inflammation may not be a part of LDD. These data provide a new insight into understanding the complex pathophysiology of LBP and suggest glycan levels as a possible biomarker for inflammation-related subtypes of LBP.

Biochemical imaging of cervical intervertebral discs with glycosaminoglycan chemical exchange saturation transfer magnetic resonance imaging: feasibility and initial results

OBJECTIVE

To evaluate glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging at 3T in the assessment of the GAG content of cervical IVDs in healthy volunteers.

MATERIALS AND METHODS

Forty-two cervical intervertebral discs of seven healthy volunteers (four females, three males; mean age: 21.4 ± 1.4 years; range: 19-24 years) were examined at a 3T MRI scanner in this prospective study. The MRI protocol comprised standard morphological, sagittal T2 weighted (T2w) images to assess the magnetic resonance imaging (MRI) based grading system for cervical intervertebral disc degeneration (IVD) and biochemical imaging with gagCEST to calculate a region-of-interest analysis of nucleus pulposus (NP) and annulus fibrosus (AF).

RESULTS

GagCEST of cervical IVDs was technically successful at 3T with significant higher gagCEST values in NP compared to AF (1.17% ± 1.03% vs. 0.79% ± 1.75%; p = 0.005). We found topological differences of gagCEST values of the cervical spine with significant higher gagCEST effects in lower IVDs (r = 1; p = 0). We could demonstrate a significant, negative correlation between gagCEST values and cervical disc degeneration of NP (r = -0.360; p = 0.019). Non-degenerated IVDs had significantly higher gagCEST effects compared to degenerated IVDs in NP (1.76% ± 0.92% vs. 0.52% ± 1.17%; p < 0.001).

CONCLUSION

Biochemical imaging of cervical IVDs is feasible at 3T. GagCEST analysis demonstrated a topological GAG distribution of the cervical spine. The depletion of GAG in the NP with increasing level of morphological degeneration can be assessed using gagCEST imaging.

Modic changes of the lumbar spine: prevalence, risk factors, and association with disc degeneration and low back pain in a large-scale population-based cohort

BACKGROUND CONTEXT

Modic changes (MC) are bone marrow lesions on magnetic resonance imaging (MRI), suggestive of being associated with low back pain (LBP). Data on determinants of MC and their association with disc degeneration and other spinal phenotypes, as well as that of LBP, rely mostly on small-scale patient populations and remain controversial.

PURPOSE

This study addressed the potential determinants of MC and their association with disc degeneration and LBP among Southern Chinese.

STUDY DESIGN/SETTING

A cross-sectional, population-based study was carried out.

PATIENT SAMPLE

This study consisted of 2,449 Southern Chinese volunteers.

METHODS

Sagittal T2-weighted MRIs of the lumbar spine were assessed for the presence of MC and other spinal phenotypes (eg, disc degeneration, disc displacement, Schmorl nodes) in all individuals. Subjects' demographics, occupation, lifestyle, and clinical profiles were assessed.

RESULTS

The overall prevalence of MC was 5.8% (n=141), which increased with advancing age. Modic changes predominantly occurred at the lowest two lumbar levels (83%). In the multivariate analyses, only the presence of disc displacement and a higher disc degeneration score were associated with MC at the upper lumbar levels (L1/L2-L3/L4) (p<.01). The presence of MC at the lowest two lumbar levels (L4/L5-L5/S1) were associated with age, the presence of Schmorl nodes, disc degeneration or displacement, and historical lumbar injury (p<.01). Subjects who were both smokers and overweight or obese had increased likelihood of MC in the lower spine (OR: 2.18; 95% CI: 1.10-4.30). The presence of MC at the lower lumbar levels were associated with historical LBP (OR: 1.93; 95% CI: 1.05-3.54) and with severity and duration of symptoms (p<.05).

CONCLUSIONS

Based on one of the largest MRI studies to assess lumbar MC, we noted that MC were associated with both disc degeneration and the presence and severity of LBP. Determinants and association of MC with disc degeneration and clinical symptoms in the upper versus the lower lumbar spine were different. Our study further stresses the significance of MC as important imaging phenotypes associated with LBP.

Cartilage Derived Morphogenetic Protein-2 Induces Cell Migration and Its Chondrogenic Potential in C28/I2 Cells

BACKGROUND

Intervertebral disc degeneration is a major cause of low back pain. Previous researches have demonstrated local administration of signalling molecules as potential biological therapies for disc regeneration. Our laboratory has published encouraging results for effectiveness of injection of the cartilage derived morphogenetic protein-2 (CDMP-2) into ovine discs following annular injury. To elucidate the mechanisms underpinning these in vivo effects, this project aimed to investigate the potential of CDMP-2 on cellular migration, proliferation and extracellular matrix production in a human chondrocytic cell line.

METHODS

To evaluate cell motility, cells were seeded into Boyden chambers and CDMP-2 as a chemo-attractant or a stimulant was placed into either the bottom or top chambers respectively. Cells that had completed migration through the porous membrane were visualized by immunocytochemical staining and analysed using Image J. The effect of CDMP-2 on cell proliferation, proteoglycan and collagen production, as well as chondrogenic gene expression in human chondrocytic cell line C28/I2 was also examined.

RESULTS

The results revealed that cells migrated significantly under the influence of CDMP-2 (200 ng/ml) stimulation compared to control (3-fold increase, p = 0.033) and demonstrated a significant chemotactic movement towards a solution of 200ng/ml CDMP-2 (>2-fold increase, p = 0.027). A 35% increase in C28/I2 proliferation was observed after CDMP-2 stimulation (p < 0.0001) compared to control, and in the presence of 100ng/ml CDMP-2, proteoglycan synthesis had an 8-fold increase (p = 0.048). Similarly, gene expression analysis demonstrated increased expression of aggrecan, collagen types II, X and XXVII, BMPR-1A and BMPR-2 when cells were treated with CDMP-2.

CONCLUSION

The study shows that C28/I2 cells can migrate under the influence of CDMP-2 as a chemoattractant or migration stimulator, suggestive of an effect on chondrocytic cells in the intervertebral disc. Further, CDMP-2 can stimulate C28/I2 cells to proliferate and synthesize key extracellular matrix proteins.

Low back pain, intervertebral disc and occupational diseases

Nonspecific low back pain and sciatica are prevalent diseases among working adults and have become a worrying occupational health issue because they sometimes affect continuation or resumption of employment. Epidemiological studies that based questionnaires on workers' healthcare consumption have shown a higher prevalence of these disorders in certain industrial sectors. Thus, low back disorders are usually more prevalent among workers exposed to cumulative lumbar load such as manual handling, awkward postures of the trunk and whole-body vibrations. In addition, morphological and biomechanical studies have compared disc space narrowing and the intensity of lumbar workload. Although debated, the relationship between disc degeneration and biomechanical work exposures seems to be usually accepted by most authors. In response to a considerable need of prevention and compensation for workers, low back pain and/or disc disease can be recognized as an occupational diseases in several countries but the criteria of recognition remains heterogeneous from one country to another.

Matrix metalloproteinase-3, vitamin D receptor gene polymorphisms, and occupational risk factors in lumbar disc degeneration

BACKGROUND

Lumbar disc degeneration (LDD) is a process that begins early in life, contributing to the development of low back pain. LDD is a consequence of a variety of factors, and its etiology remains poorly understood. Objectives to investigate occupational and genetic risk factors inducing lumbar disc degeneration, and to evaluate the possible association of genetic polymorphisms of matrix metalloproteinase 3 (MMP-3) and vitamin D receptor (VDR) with the severity of LDD in an Egyptian population.

SUBJECTS AND METHODS

A case control study involving 84 LDD and 60 controls was carried out. Five types of work related factors were investigated by questionnaire, complete neurological examination for all subjects and MRI for the cases. Polymerase chain reaction and restriction fragment length polymorphism methods were applied to detect polymorphisms in MMP-3 Promoter (-1,171 6A/5A) (rs 731236) and VDR-Apa (rs 35068180).

RESULTS

We found that family history, back injury, smoking, high level of sitting, bending/twisting, physical workload, lifting, whole body vibration, mutant allele 5A of MMP-3 and mutant allele T of VDR were significantly associated with LDD (OR = 2.9, 3.1, 2.1, 11.1, 15.9, 11.7, 8.2, 12.6, 2.5 and 3.1 respectively, p < 0.05). Cases that carry allele 5A and/or allele T were associated with LDD severity.

CONCLUSION

LDD is closely associated in occurrence and severity with occupational, environmental risk factors and susceptibility genes namely MMP-3, and VDR (ApaI). This study throws light on the importance of screening for early detection of susceptible individuals and disease prevention.

Differential expression of extracellular-signal-regulated kinase 5 (ERK5) in normal and degenerated human nucleus pulposus tissues and cells

Extracellular-signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and regulates a wide variety of cellular processes such as proliferation, differentiation, necrosis, apoptosis and degeneration. However, the expression of ERK5 and its role in degenerated human nucleus pulposus (NP) is hitherto unknown. In this study, we observed the differential expression of ERK5 in normal and degenerated human nucleus pulposus tissues by using immunohistochemical staining and Western blot. Treatment of NP cells with Pro-inflammatory cytokine, TNF-α decreased ERK5 gene expression as well as NP marker gene expression; including the type II collagen and aggrecan. Suppression of ERK5 gene expression in NP cells by ERK5 siRNA resulted in decreased gene expression of type II collagen and aggrecan. Furthermore, inhibition of ERK5 activation by BIX02188 (5μM) decreased the gene expression of type II collagen and aggrecan in NP cells. Our results document the expression of ERK5 in degenerated nucleus pulposus tissues, and suggest a potential involvement of ERK5 in human degenerated nucleus pulposus.

Prevertebral vascular and esophageal consideration during percutaneous cervical disc procedures

STUDY DESIGN

A retrospective review series.

OBJECTIVE

To identify vascular anatomy and esophageal deviations that may interfere with a percutaneous anterior approach in cervical spine surgery.

SUMMARY OF BACKGROUND DATA

The percutaneous anterior approach has been used for minimally invasive interventions of cervical disc diseases. Although the percutaneous anterior approach is frequently performed, reports of obstructing anatomical structures and procedural risks are limited.

METHODS

Cervical magnetic resonance images obtained from December 2012 to April 2013 from a total of 511 patients at Guro Teun Teun Hospital were evaluated in this study. Each axial T2-weighted MR image from the disc levels of C3-C4 to C6-C7 (total, 3066 images) was reviewed to check for the presence of small vessels along the trajectories of percutaneous cervical procedures on the left and right sides. Esophageal deviation was also measured at level C6-C7.

RESULTS

Small vessels in the anterior neck were present, respectively, in 50.5% (trajectory on the left side) and in 49.1% (trajectory on the right side) at disc level C3-C4, in 30.3% and 28.8% at C4-C5, in 24.1% and 7.6% at C5-C6, and in 55.2% and 43.1% at C6-C7. There were no differences in the number of small vessels between the left and right sides at the upper cervical level (C3-C4-C5), but small vessels were less frequently observed on the right side at lower cervical levels (C5-C6-C7). Differences in esophageal deviation were also observed, with less deviation to the right side (0.63 ± 0.35 cm) than the left (1.18 ± 0.52 cm). As well, an esophageal diverticulum was observed in 1 case on the left side.

CONCLUSION

Although surgical approaches are mostly concerned with the location of pathology to be removed, a right-sided percutaneous approach seems preferable because poses less of a risk of encountering small vessels and causing esophageal injury.

LEVEL OF EVIDENCE

4.

Quantitative T2 magnetic resonance imaging compared to morphological grading of the early cervical intervertebral disc degeneration: an evaluation approach in asymptomatic young adults

Objective

The objective of this study was to evaluate the efficacy of quantitative T2 magnetic resonance imaging (MRI) for quantifying early cervical intervertebral disc (IVD) degeneration in asymptomatic young adults by correlating the T2 value with Pfirrmann grade, sex, and anatomic level.

Methods

Seventy asymptomatic young subjects (34 men and 36 women; mean age, 22.80±2.11 yr; range, 18–25 years) underwent 3.0-T MRI to obtain morphological data (one T1-fast spin echo (FSE) and three-plane T2-FSE, used to assign a Pfirrmann grade (I–V)) and for T2 mapping (multi-echo spin echo). T2 values in the nucleus pulposus (NP, n = 350) and anulus fibrosus (AF, n = 700) were obtained. Differences in T2 values between sexes and anatomic level were evaluated, and linear correlation analysis of T2 values versus degenerative grade was conducted.

Findings

Cervical IVDs of healthy young adults were commonly determined to be at Pfirrmann grades I and II. T2 values of NPs were significantly higher than those of AF at all anatomic levels (P<0.000). The NP, anterior AF and posterior AF values did not differ significantly between genders at the same anatomic level (P>0.05). T2 values decreased linearly with degenerative grade. Linear correlation analysis revealed a strong negative association between the Pfirrmann grade and the T2 values of the NP (P = 0.000) but not the T2 values of the AF (P = 0.854). However, non-degenerated discs (Pfirrmann grades I and II) showed a wide range of T2 relaxation time. T2 values according to disc degeneration level classification were as follows: grade I (>62.03 ms), grade II (54.60–62.03 ms), grade III (<54.60 ms).

Conclusions

T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of cervical IVD degeneration and to create a reliable quantitative in healthy young adults.

Spinal deformity in aged zebrafish is accompanied by degenerative changes to their vertebrae that resemble osteoarthritis

Age-related degenerative changes within the vertebral column are a significant cause of morbidity with considerable socio-economic impact worldwide. An improved understanding of these changes through the development of experimental models may lead to improvements in existing clinical treatment options. The zebrafish is a well-established model for the study of skeletogenesis with significant potential in gerontological research. With advancing age, zebrafish frequently develop gross deformities of their vertebral column, previously ascribed to reduced trunk muscle tone. In this study, we assess degenerative changes specifically within the bone and cartilage of the vertebral column of zebrafish at 1, 2 and 3-years of age. We show increased frequency and severity of spinal deformities/curvatures with age. Underlying the most severe phenotypes are partial or complete vertebral dislocations and focal thickening of the vertebral bone at the joint margins. MicroCT examination demonstrates small defects, fractures and morphological evidence suggestive of bone erosion and remodeling (i.e. osteophytes) within the vertebrae during aging, but no significant change in bone density. Light and electron microscopic examination reveal striking age-related changes in cell morphology, suggestive of chondroptosis, and tissue remodelling of the vertebral cartilage, particularly within the pericellular micro-environment. Glycosaminoglycan analysis of the vertebral column by HPLC demonstrates a consistent, age-related increase in the yield of total chondroitin sulfate disaccharide, but no change in sulfation pattern, supported by immunohistochemical analysis. Immunohistochemistry strongly identifies all three chondroitin/dermatan sulphate isoforms (C-0-S, C-4-S/DS and C-6-S) within the vertebral cartilage, particularly within the pericellular micro-environment. In contrast, keratan sulfate immunolocalises specifically with the notochordal tissue of the intervertebral disc, and its labelling diminishes with age. In summary, these observations raise the prospect that zebrafish, in addition to modelling skeletal development, may have utility in modelling age-related degenerative changes that affect the skeleton during senescence.

Polymorphism in the hypoxia-inducible factor 1alpha gene may confer susceptibility to LDD in Chinese cohort

Objective

This study aimed to investigate whether or not hypoxia-inducible factor-1α (HIF-1α) gene variants are associated with the susceptibility and clinical characteristics of lumbar disc degeneration (LDD).

Methods

We examined 320 patients with LDD and 447 gender- and age-matched control subjects. We also determined the HIF-1α gene variants, including C1772T (P582S) and G1790A (A588T) polymorphisms.

Results

Significant differences were observed in allelic and genotypic distributions of 1790 A > G polymorphisms between LDD cases and control subjects. Logistic regression revealed that 1790 AA genotypes indicated a protective effect against the development of LDD. The HIF-1α 1790 A > G polymorphisms also affected the severity of LDD as evaluated based on the modified Japanese Orthopedic Association (mJOA) scores. The 1790 AA genotype carriers exhibited significantly lower mJOA scores than AG and GG carriers. C1772T did not show any association with the risk and severity of LDD.

Conclusion

Our study suggested that HIF-1α 1790 A > G polymorphisms may be used as a molecular marker to determine the susceptibility and severity of LDD.

Genetic polymorphisms associated with intervertebral disc degeneration

BACKGROUND CONTEXT

Disc degeneration (DD) is a multifaceted chronic process that alters the structure and function of the intervertebral discs and can lead to painful conditions. The pathophysiology of degeneration is not well understood, but previous studies suggest that certain genetic polymorphisms may be important contributing factors leading to an increased risk of DD.

PURPOSE

To review the genetic factors in DD with a focus on polymorphisms and their putative role in the pathophysiology of degeneration. Elucidating the genetic components that are associated with degeneration could provide insights into the mechanism of the process. Furthermore, defining these relationships and eventually using them in a clinical setting may allow an identification and early intervention for those who are at a high risk for painful DD.

STUDY DESIGN

Literature review.

METHODS

This literature review focused on the studies concerning genetic polymorphisms and their associations with DD.

RESULTS

Genetic polymorphisms in 20 genes have been analyzed in association with DD, including vitamin D receptor, growth differentiation factor 5 (GDF5), aggrecan, collagen Types I, IX, and XI, fibronectin, hyaluronan and proteoglycan link protein 1 (HAPLN1), thrombospondin, cartilage intermediate layer protein (CILP), asporin, MMP1, 2, and 3, parkinson protein 2, E3 ubiquitin protein ligase (PARK2), proteosome subunit β type 9 (PSMB9), tissue inhibitor of metalloproteinase (TIMP), cyclooxygenase-2 (COX2), and IL1α, IL1β, and IL6. Each genetic polymorphism codes for a protein that has a functional role in the pathogenesis of DD.

CONCLUSIONS

There are known associations between several genetic polymorphisms and DD. Of the 20 genes analyzed, polymorphisms in vitamin D receptor, aggrecan, Type IX collagen, asporin, MMP3, IL1, and IL6 show the most promise as functional variants. Genetic studies are crucial for understanding the mechanism of the degeneration. This genetic information could eventually be used as a predictive model for determining a patient's risk for symptomatic DD.

Challenges and strategies in the repair of ruptured annulus fibrosus

Lumbar discectomy is the surgical procedure most frequently performed for patients suffering from low back pain and sciatica. Disc herniation as a consequence of degenerative or traumatic processes is commonly encountered as the underlying cause for the painful condition. While discectomy provides favourable outcome in a majority of cases, there are conditions where unmet requirements exist in terms of treatment, such as large disc protrusions with minimal disc degeneration; in these cases, the high rate of recurrent disc herniation after discectomy is a prevalent problem. An effective biological annular repair could improve the surgical outcome in patients with contained disc herniations but otherwise minor degenerative changes. An attractive approach is a tissue-engineered implant that will enable/stimulate the repair of the ruptured annulus. The strategy is to develop three-dimensional scaffolds and activate them by seeding cells or by incorporating molecular signals that enable new matrix synthesis at the defect site, while the biomaterial provides immediate closure of the defect and maintains the mechanical properties of the disc. This review is structured into (1) introduction, (2) clinical problems, current treatment options and needs, (3) biomechanical demands, (4) cellular and extracellular components, (5) biomaterials for delivery, scaffolding and support, (6) pre-clinical models for evaluation of newly developed cell- and material-based therapies, and (7) conclusions. This article highlights that an interdisciplinary approach is necessary for successful development of new clinical methods for annulus fibrosus repair. This will benefit from a close collaboration between research groups with expertise in all areas addressed in this review.

Novel genetic variants associated with lumbar disc degeneration in northern Europeans: a meta-analysis of 4600 subjects

OBJECTIVE

Lumbar disc degeneration (LDD) is an important cause of low back pain, which is a common and costly problem. LDD is characterised by disc space narrowing and osteophyte growth at the circumference of the disc. To date, the agnostic search of the genome by genome-wide association (GWA) to identify common variants associated with LDD has not been fruitful. This study is the first GWA meta-analysis of LDD.

METHODS

We have developed a continuous trait based on disc space narrowing and osteophytes growth which is measurable on all forms of imaging (plain radiograph, CT scan and MRI) and performed a meta-analysis of five cohorts of Northern European extraction each having GWA data imputed to HapMap V.2.

RESULTS

This study of 4600 individuals identified four single nucleotide polymorphisms with p<5×10(-8), the threshold set for genome-wide significance. We identified a variant in the PARK2 gene (p=2.8×10(-8)) associated with LDD. Differential methylation at one CpG island of the PARK2 promoter was observed in a small subset of subjects (β=8.74×10(-4), p=0.006).

CONCLUSIONS

LDD accounts for a considerable proportion of low back pain and the pathogenesis of LDD is poorly understood. This work provides evidence of association of the PARK2 gene and suggests that methylation of the PARK2 promoter may influence degeneration of the intervertebral disc. This gene has not previously been considered a candidate in LDD and further functional work is needed on this hitherto unsuspected pathway.