Age-related changes in human cervical, thoracal and lumbar intervertebral disc exhibit a strong intra-individual correlation

Predictive factors for osteoporosis in adult spinal deformity patients

PURPOSE

This study aimed to identify predictive factors for femoral bone mineral density (BMD) in adult patients with spinal deformity and to establish cutoff values for detecting osteoporosis using preoperative computed tomography (CT) scans.

METHODS

A retrospective analysis was conducted on 90 patients with adult spinal deformity (ASD) who underwent preoperative bone density testing. Key parameters such as age, body mass index (BMI), and Hounsfield unit (HU) values from various vertebral levels were analyzed. Dual-energy X-ray absorptiometry (DXA) was used to measure BMD T-score, and HU values were measured at C2, C7, T8, T9, L1, L2, and L3.

RESULTS

Multivariate regression analyses identified BMI and HU at C2 as independent predictors of femoral T-score. The following predictive equation was developed: femoral T-score = - 5.178 + 0.053 × BMI + 0.006 × C2 HU (R2 = 0.50). The formula derived from these variables explained 50% of the variance in femoral T-score. Receiver operating characteristic analysis identified cutoff values for predicting osteoporosis as 281 for C2 HU and 22.9 for BMI. The areas under the curve were 0.751 and 0.638, respectively.

CONCLUSION

These findings suggest that HU values from preoperative CT scans can serve as reliable indicators of femoral T-score, offering an alternative to DXA in cases where DXA is unavailable or inaccurate due to factors like severe spinal degeneration. This approach could enhance the preoperative assessment of osteoporosis in ASD patients by facilitating more targeted use of DXA and improving overall clinical decision-making.

LEVEL OF EVIDENCE

IV.

Effects of Age and Muscle Activation on Three-Dimensional Spine Kinematics and Asymmetry in Elderly Adults

Background/Objectives: Limited spinal range of motion (ROM) is linked to low back disorders, emphasizing the need to maintain mobility in the elderly. This study measured maximum spinal ROM, asymmetrical patterns, and the effects of age and muscle activation on spinal mobility. Methods: Forty healthy participants aged 50 and older were recruited. An optical motion capture system recorded three-dimensional coordinates of reflective markers placed on spinal landmarks. Asymmetry was analyzed in sidebending and axial rotation. Electromyography (EMG) data were collected bilaterally from paraspinal muscles at L3 during flexion, extension, sidebending, and axial rotation. Results: Trunk ROM averaged 111° in flexion, 38° in extension, 46° in sidebending, and 87° in axial rotation. Kinematic asymmetry was observed in sidebending and axial rotation. ROM decreased with age in flexion motion (p ≤ 0.04). EMG activity was significantly correlated with ROM data for all combined motions (p = 0.0002). The strongest EMG signal was recorded during flexion, whereas the weakest signal was observed during extension. EMG activity also correlated with kinematic asymmetry (p ≤ 0.03). Conclusions: Age and muscle activation significantly influence spinal ROM in the elderly. Lumbar kinematic asymmetry can be partially attributed to paraspinal muscle activation, underscoring the importance of analyzing asymmetrical motions in conjunction with EMG activity.

Polygenic height prediction for the Han Chinese in Taiwan

Human height prediction based on genetic factors alone shows positive correlation, but predictors developed for one population perform less well when applied to population of different ancestries. In this study, we evaluated the utility of incorporating non-genetic factors in height predictors for the Han Chinese population in Taiwan. We analyzed data from 78,719 Taiwan Biobank (TWB) participants and 40,641 Taiwan Precision Medicine Initiative (TPMI) participants using genome-wide association study and multivariable linear regression least absolute shrinkage and selection operator (LASSO) methods to incorporate genetic and non-genetic factors for height prediction. Our findings establish that combining birth year (as a surrogate for nutritional status), age at measurement (to account for age-associated effects on height), and genetic profile data improves the accuracy of height prediction. This method enhances the correlation between predicted and actual height and significantly reduces the discrepancies between predicted and actual height in both males and females.

Protective effects of cannabinoid receptor 2 on annulus fibrosus degeneration by upregulating autophagy via AKT-mTOR-p70S6K signal pathway

As an important pathological process, annulus fibrosus (AF) degeneration contributes greatly to intervertebral disc degeneration (IVDD). Moreover, extracellular matrix (ECM) degradation and AF cell (AFC) autophagy are of utmost importance. The involvement of cannabinoid receptor type 2 (CB2) in the pathological mechanisms underlying different diseases has been demonstrated dueto its capacity toregulateautophagy. The objective of this study was to explore the impact of CB2-induced autophagy on AF degeneration and its underlying mechanism. First, the expression of CB2 in human degenerative AF tissues decreased with increasing degeneration degree, whereas its expression in rat AFCs increased in a concentration- and time-dependent manner following H2O2 intervention. Activation of CB2 increased collagen Ⅰ and Ⅱ expression while decreasing MMP3 and MMP13 expression. In addition, p62 expression decreased, whereas beclin-1 and LC3-Ⅱ/LC3-Ⅰ expression increased after JWH133 intervention. After CB2 activation, the addition of 3-MA impeded the synthesis of collagen Ⅰ and Ⅱ while preserving the elevated levels of MMP3 and MMP13. The activation of CB2 greatly suppressed the protein levels of the AKT/mTOR/p70S6K signaling pathway. In vivo, the JWH133 group exhibited elevated disk height index (DHI) and MRI signals, along with a comparatively intact structure of the intervertebral disc in contrast to the vehicle group. In general, CB2 activation could modulate apoptosis and autophagy in rat AFCs, thereby mitigating the advancement of IVDD. Moreover, the AKT/mTOR/p70S6K signaling pathway plays a role in the development of AF degeneration through the regulation of autophagy. The findings suggest that CB2 is a potentially effective therapeutic target for IVDD.

Biomechanical Motion Changes in Adjacent and Noncontiguous Segments Following Single-Level Anterior Cervical Discectomy and Fusion: A Computed Tomography-Based 3D Motion Capture Study

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is known to elicit adverse biomechanical effects on immediately adjacent segments; however, its impact on the kinematics of the remaining nonadjacent cervical levels has not been understood. This study aimed to explore the biomechanical impact of ACDF on kinematics beyond the immediate fusion site. We hypothesized that compensatory motion following single-level ACDF is not predictably distributed to adjacent segments due to compensation from noncontiguous levels.

METHODS

Six fresh-frozen cervical spines (C2-T1) underwent fluoroscopic screening and sagittal and coronal reformats from computed tomography scans and were utilized to grade segmental degeneration. Each specimen was tested to 30° of flexion and extension intact and following single-level ACDF at the C5-C6 level. The motions of each vertebral body were tracked using 3-dimensional (3D) motion capture into an inverse kinematics model, facilitating correlations between the 3D reconstruction from computed tomography images and the 3D motion capture data. This model was used to calculate each level's flexion/extension range of motion (ROM).

RESULTS

Single-level fusion at the C5-C6 level across all specimens resulted in a significant motion reduction of -6.8° (P = 0.002). No significant change in ROM occurred in the immediate adjacent segments C4-C5 (P = 0.07) or C6-C7 (P = 0.15). Hypermobility was observed in 2 specimens (33%) exclusively in adjacent segments. In contrast, the other 4 spines (66%) displayed hypermobility at noncontiguous segments. Hypermobility occurred in 42% (5/12) of the adjacent segments, 28% (5/18) of the noncontiguous segments, and 50% (3/6) of the cervicothoracic segments.

CONCLUSION

Single-level ACDF impacts ROM beyond adjacent segments, extending to noncontiguous levels. Compensatory motion, not limited to adjacent levels, may be influenced by degenerative changes in noncontiguous segments. Surprisingly, hypermobility may not occur in adjacent segments after ACDF.

CLINICAL RELEVANCE

Overall, the multifaceted biomechanical effects of ACDF underscore the need for a comprehensive understanding of cervical spine dynamics beyond immediate adjacency, and it needs to be taken into consideration when planning single-level ACDF.

LEVEL OF EVIDENCE: 4

The effects of lumbar stabilization exercises with and without jaw movements in non-specific low back pain (A randomized controlled trial)

Objective

This study aimed to investigate the added effect of jaw clenching on the efficacy of lumbar stabilization exercises to manage chronic non-specific low back pain.

Methods

This randomized controlled trial was conducted at the Sindh Institute of Physical Medicine and Rehabilitation (SIPM&R) Karachi from April 2021 to April 2023. Eighty patients with chronic non-specific low back pain participated in this study. Forty patients each were randomly allocated to the lumbar stability exercise (LSE) group' and the lumbar stability exercise with teeth clenching (LSETC) group. Patients in both groups performed respective exercises twice weekly for 12 weeks. The Numeric Pain Rating Scale (NPRS), Roland Morris Disability Questionnaire (RMDQ), and Pressure Biofeedback Unit (PBU) were used to assess pain, disability, and muscle endurance respectively. Data were collected at the baseline, after six weeks and 12 weeks of intervention. A p-value of <0.05 was considered statistically significant.

Results

Both groups showed statistically significant improvements in pain, disability, and muscle endurance. Upon further stratification, participants aged 20-30 years in the LSETC group showed significantly higher scores than the LSE group for NPRS, RMDQ, and PBU after 12 weeks. Overall, the LSETC group showed relatively higher improvement in mean scores for NPRS, RMDQ, and PBU than the LSE group.

Conclusion

Lumbar stabilization exercises with and without jaw movement are effective for the treatment of chronic non-specific low back pain. The addition of teeth clenching enhanced the effectiveness of lumbar stability exercises, especially in young adults. Trial Registration: Clinicaltrials.gov (NCT04801212), Prospectively registered on March 16, 2021.

Research on the role and mechanism of IL-17 in intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is one of the primary causes of low back pain (LBP), which seriously affects patients' quality of life. In recent years, interleukin (IL)-17 has been shown to be highly expressed in the intervertebral disc (IVD) tissues and serum of patients with IDD, and IL-17A has been shown to promote IDD through multiple pathways. We first searched databases such as PubMed, Cochrane, Embase, and Web of Science using the search terms "IL-17 or interleukin 17″ and "intervertebral discs". The search period ranged from the inception of the databases to December 2023. A total of 24 articles were selected after full-text screening. The main conclusion of the clinical studies was that IL-17A levels are significantly increased in the IVD tissues and serum of IDD patients. The results from the in vitro studies indicated that IL-17A can activate signaling pathways such as the NF-κB and MAPK pathways; promote inflammatory responses, extracellular matrix degradation, and angiogenesis; and inhibit autophagy in nucleus pulposus cells. The main finding of the in vivo experiments was that puncture of animal IVDs resulted in elevated levels of IL-17A within the IVD, thereby inducing IDD. Clinical studies, in vitro experiments, and in vivo experiments confirmed that IL-17A is closely related to IDD. Therefore, drugs that target IL-17A may be novel treatments for IDD, providing a new theoretical basis for IDD therapy.

Morphology and Composition of Lumbar Intervertebral Discs: Comparative Analyses of Manual Measurement and Computer-Assisted Algorithms

BACKGROUND

The morphology and internal composition, particularly the nucleus-to-cross sectional area (NP-to-CSA) ratio of the lumbar intervertebral discs (IVDs), is important information for finite element models (FEMs) of spinal loadings and biomechanical behaviors, and, yet, this has not been well investigated and reported.

METHODS

Anonymized MRI scans were retrieved from a previously established database, including a total of 400 lumbar IVDs from 123 subjects (58 F and 65 M). Measurements were conducted manually by a spine surgeon and using two computer-assisted segmentation algorithms, i.e., fuzzy C-means (FCM) and region growing (RG). The respective results were compared. The influence of gender and spinal level was also investigated.

RESULTS

Ratios derived from manual measurements and the two computer-assisted algorithms (FCM and RG) were 46%, 39%, and 38%, respectively. Ratios derived manually were significantly larger.

CONCLUSIONS

Computer-assisted methods provide reliable outcomes that are traditionally difficult for the manual measurement of internal composition. FEMs should consider the variability of NP-to-CSA ratios when studying the biomechanical behavior of the spine.

Examination of annulus fibrosus and nucleus pulposus in cervical and lumbar intervertebral disc herniation patients by scanning acoustic microscopy, scanning electron microscopy and energy dispersive spectroscopy

Intervertebral disc herniation (IVDH) is observed in humans as a result of the alteration of annulus fibrous (AF) and nucleus pulposus (NP) tissue compositions in intervertebral discs. In this study, we studied the feasibility of scanning acoustic microscopy (SAM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) in characterizing the herniated segments of AF and NP tissues from male and female patients. SAM determined the acoustic property variations in AF and NP tissues by calculating the acoustic impedance values of samples of 15 patients. SEM obtained higher resolution images and EDS made elemental analysis of the specimen. Consequently, we suggest that these techniques have the potential to be combined for the investigation and removal of the disrupted AF and NP tissues with micrometer resolution in clinics.

Potential molecular targets and drugs for basement membranes-related intervertebral disk degeneration through bioinformatics analysis and molecular docking

BACKGROUND

Through bioinformatics analysis to identify the hub genes of Intervertebral disc degeneration (IVDD) associated with basement membranes (BMs) and find out the potential molecular targets and drugs for BMs-related annulus fibrosus (AF) degeneration based on bioinformatic analysis and molecular approach.

METHODS

Intervertebral disc degeneration (IVDD) related targets were obtained from GeneCards, DisGenet and OMIM databases. BMs related genes were obtained from Basement membraneBASE database. The intersection targets were identified and subjected to protein-to-protein interaction (PPI) construction via STRING. Hub genes were identified and conducted Gene ontology (GO) and pathway enrichment analysis through MCODE and Clue GO in Cytospace respectively. DSigDB database was retrieved to predict therapeutic drugs and molecular docking was performed through PyMOL, AutoDock 1.5.6 to verify the binding energy between the drug and the different expressed hub genes. Finally, GSE70362 from GEO database was obtained to verify the different expression and correlation of each hub gene for AF degeneration.

RESULTS

We identified 41 intersection genes between 3 disease targets databases and Basement membraneBASE database. PPI network revealed 25 hub genes and they were mainly enriched in GO terms relating to glycosaminoglycan catabolic process, the TGF-β signaling pathway. 4 core targets were found to be significant via comparison of microarray samples and they showed strong correlation. The molecular docking results showed that the core targets have strong binding energy with predicting drugs including chitosamine and retinoic acid.

CONCLUSIONS

In this study, we identified hub genes, pathways, potential targets, and drugs for treatment in BMs-related AF degeneration and IVDD.

Contribution of immune cells to intervertebral disc degeneration and the potential of immunotherapy

Substantial evidence supports that chronic low back pain is associated with intervertebral disc degeneration (IDD), which is accompanied by decreased cell activity and matrix degradation. The role of immune cells, especially macrophages, in a variety of diseases has been extensively studied; therefore, their role in IDD has naturally attracted widespread scholarly interest. The IVD is considered to be an immunologically-privileged site given the presence of physical and biological barriers that include an avascular microenvironment, a high proteoglycan concentration, high physical pressure, the presence of apoptosis inducers such as Fas ligand, and the presence of notochordal cells. However, during IDD, immune cells with distinct characteristics appear in the IVD. Some of these immune cells release factors that promote the inflammatory response and angiogenesis in the disc and are, therefore, important drivers of IDD. Although some studies have elucidated the role of immune cells, no specific strategies related to systemic immunotherapy have been proposed. Herein, we summarize current knowledge of the presence and role of immune cells in IDD and consider that immunotherapy targeting immune cells may be a novel strategy for alleviating IDD symptoms.

Facet joint degeneration-An initial procedure of the cervical spine degeneration

Objective

This study aims to emphasize the initiating role of facet joint (FJ) degeneration in the process of cervical spine degeneration induced by tangential load, and we further validate it in a novel cervical spine degeneration animal model.

Methods

The characteristics of cervical degeneration in patients of different ages were summarized through case collection. In the rat models, Hematoxylin-Eosin, Safranin O staining, and micro-computed tomography were used to show the histopathological changes and bone fiber structure of FJ and the height of intervertebral disc (IVD) space. The ingrowth of nociceptive sensory nerve fibers was observed by immunofluorescence staining.

Results

FJ degeneration without IVDs degeneration was more common in people with cervical spondylosis in young patients. The obvious degeneration phenotypes of the FJs preceded the IVDs at the same cervical segment in our animal model. The SP+ and CGRP+ sensory nerve fibers were observed in the articular subchondral bone of degenerated FJs and porous endplates of degenerated IVDs.

Conclusion

The FJ degeneration may act as the major contributor to cervical spine degeneration in young people. The dysfunction of functional unit of spine, not a certain part of IVD tissue, results in the occurrence of cervical degeneration and neck pain.

Elucidating the Focal Immunomodulatory Clues Influencing Mesenchymal Stem Cells in the Milieu of Intervertebral Disc Degeneration

The intervertebral discs (IVDs) are a relatively mobile joint that interconnects vertebrae of the spine. Intervertebral disc degeneration (IVDD) is one of the leading causes of low back pain, which is most often related to patient morbidity as well as high medical costs. Patients with chronic IVDD often need surgery that may sometimes lead to biomechanical complications as well as augmented degeneration of the adjacent segments. Moreover, treatment modalities like rigid intervertebral fusion, dynamic instrumentation, as well as other surgical interventions are still controversial. Mesenchymal stem cells (MSCs) have exhibited to have immunomodulatory functions and the ability to differentiate into cartilage, making these cells possibly an epitome for IVD regeneration. Transplanted MSCs were able to repair IVDD back to the normal disc milieu via the activation of the generation of extracellular matrix (ECM) proteins such as aggrecan, proteoglycans and collagen types I and II. IVD milieu clues like, periostin, cluster of differentiation, tumor necrosis factor alpha, interleukins, chemokines, transforming growth factor beta, reactive oxygen species, toll-like receptors, tyrosine protein kinase receptor and disialoganglioside, exosomes are capable of influencing the MSCs during treatment of IVDD. ECM microenvironment clues above have potentials as biomarkers as well as accurate molecular targets for therapeutic intervention in IVDD.

Even mild intervertebral disc degeneration reduces the flexibility of the thoracic spine: an experimental study on 95 human specimens

BACKGROUND CONTEXT

Intervertebral disc degeneration represents one of multiple potential trigger factors for reduced passive spinal mobility and back pain. The effects of age-related degenerative intervertebral disc changes on spinal flexibility were however mainly investigated for the lumbar spine in the past, while intervertebral disc degeneration is also highly prevalent in the thoracic spine.

PURPOSE

To evaluate the effect of the degeneration grade on the range of motion and neutral zone of the thoracic spine.

STUDY DESIGN

Experimental study including combined radiological grading of intervertebral disc degeneration and biomechanical testing of 95 human thoracic functional spinal units (min. n=4 per level from T1-T2 to T11-T12) from 33 donors (15 female / 18 male, mean age 56 years, age range 37-80 years).

METHODS

Degeneration grades of the intervertebral discs were assessed using the validated x-ray grading scheme of Liebsch et al. (0=no, 1=mild, 2=moderate, 3=severe degeneration). Motion segments were loaded with pure moments in flexion/extension, lateral bending, and axial rotation to determine range of motion and neutral zone at 5 Nm.

RESULTS

All tested specimens exhibited degeneration grades between zero and two. Range of motion significantly decreased for grades one and two compared with grade zero in any motion direction (p<.05), showing the strongest decrease in extension comparing grade two with grade zero (-42%), while no significant differences were detected between grades one and two. Similar trends were found for the neutral zone with the strongest decrease in extension also comparing grade two with grade zero (-47%). Donor age did not significantly affect the range of motion, whereas the range of motion was significantly reduced in specimens from male donors due to the significantly higher degeneration grade in this study.

CONCLUSIONS

Even mild intervertebral disc degeneration reduces the range of motion and neutral zone of the thoracic spine in any motion plane, whereas progressing degeneration does not further affect its flexibility. This is in contrast to the lumbar spine, where a more gradual decrease of flexibility was found in prior studies, which might be explained by differences between thoracic and lumbar intervertebral disc morphologies.

CLINICAL SIGNIFICANCE

Thoracic intervertebral disc degeneration should be considered as one of multiple potential causal factors in patients showing reduced passive mobility and middle back pain.

The relationship between the flexor and extensor muscle areas and the presence and degree of intervertebral disc degeneration in the cervical region

BACKGROUND

This study aimed to investigate the relationship between the presence and degree of cervical intervertebral disc degeneration (IVDD) and the cervical region muscle areas.

METHODS

The magnetic resonance imaging (MRI) examination of the patients who were sent to our clinic for investigation of neck pain between 2019 and 2020 years were evaluated retrospectively. 143 Turkish women patients between 30 and 40 ages were examined in the study. The presence and degree of IVDD was evaluated for each patient. The areas of the cervical flexor and extensor paravertebral muscles were measured.

RESULTS

No cervical disc degeneration was present in 44 (30.76%) patients (grade 1). The cervical intervertebral disc degeneration was grade 2 in 28 (19.58%), grade-3 in 41 (28.67%), and grade 4 in 30 (20.97%) patients. In early stage degeneration (grade 2), an increase was observed in the area of all cervical paravertebral flexor and extensor muscles examined. As the degree of degeneration increased (grades 3 and 4), a decrease was observed in the areas of all muscles. Statistical significance was found for musculus (m) sternocleidomastoideus, m. levator scapulae, m. splenius capitis, m. semispinalis capitis, and m. multifidus muscles (P = .009, r = -0.261; P = .014, r = -0.248; P = .008, r = -0.267; P = .002, r = -0.307; P = .028, r = -0.222, respectively).

CONCLUSIONS

IVDD is common in middle-aged females with neck pain. An increase in muscles areas is observed in the early stages of cervical disc degeneration but progressive decrease develops in all cervical paraspinal muscles areas as the degree of disc degeneration increases.

Targeting Autophagy for Developing New Therapeutic Strategy in Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is a prevalent cause of low back pain. IVDD is characterized by abnormal expression of extracellular matrix components such as collagen and aggrecan. In addition, it results in dysfunctional growth, senescence, and death of intervertebral cells. The biological pathways involved in the development and progression of IVDD are not fully understood. Therefore, a better understanding of the molecular mechanisms underlying IVDD could aid in the development of strategies for prevention and treatment. Autophagy is a cellular process that removes damaged proteins and dysfunctional organelles, and its dysfunction is linked to a variety of diseases, including IVDD and osteoarthritis. In this review, we describe recent research findings on the role of autophagy in IVDD pathogenesis and highlight autophagy-targeting molecules which can be exploited to treat IVDD. Many studies exhibit that autophagy protects against and postpones disc degeneration. Further research is needed to determine whether autophagy is required for cell integrity in intervertebral discs and to establish autophagy as a viable therapeutic target for IVDD.

Influence of Age and Gender on Intervertebral Disk Degeneration and Height in the Thoracolumbar Spine

Introduction

Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk degenerative changes in the thoracolumbar spine or examined sex-specific differences. This study aimed to establish age-related changes and gender-specific differences of intervertebral disk height and disk degeneration of the thoracolumbar spine in a large cohort of relatively healthy subjects and also to evaluate the relationship between the degree of thoracolumbar disk height and disk degeneration.

Methods

Six hundred and twenty-seven relatively healthy subjects (307 males and 320 females; average age, 49.6±16.5 years) were enrolled. We included at least 50 males and 50 females in each decade of life between the 20s and the 70s. We measured intervertebral disk height from T10/T11 to L5/S1, vertebral body height from T10 to S1 on lateral neutral radiographs. Lumbar disk degeneration was defined according to the Pfirrmann classification in sagittal plane magnetic resonance imaging.

Results

Age-related decreases in intervertebral disk height were most prominent at L4/L5 in middle-aged and elderly individuals of both sexes. The grade of disk degeneration significantly increased with age in both genders at every level. Mild disk degeneration was observed even in the 20s. The disk degeneration occurred around the L4/L5 level. Although grade V disk degeneration was not identified for males in the 20s and the 30s, it appeared after the 40s and then increased further with age. The intervertebral disk height at the lower lumbar disks decreased with a progression in the disk degeneration grade in both genders.

Conclusions

This large-scale cross-sectional analysis of the thoracolumbar spine in relatively healthy subjects demonstrated that lumbar disk height narrowing progresses with age and is correlated with the progression of disk degeneration.

Relationship between cervical posterior subcutaneous fat tissue thickness and the presence and degree of cervical intervertebral disc degeneration

OBJECTIVE

This study aimed to investigate the relationship between cervical region subcutaneous fat tissue thickness and the presence and level of cervical intervertebral disc degeneration (IVDD).

METHODS

Magnetic resonance imaging examinations of patients referred to our clinic for the investigation of neck pain were evaluated retrospectively. A total of 300 women aged 30-40 years were included in the study. The presence and level of IVDD were evaluated for each patient. The cervical subcutaneous fat tissue thickness was also measured.

RESULTS

IVDD was determined as Grade 1 for 88 patients (29.3%), Grade 2 for 56 patients (18.6%), Grade 3 for 82 patients (27.3%), Grade 4 for 60 patients (20%), and Grade 5 for 14 patients (4.6%). Subcutaneous fat tissue thickness was higher in patients with cervical disc degeneration (mean: 6.28 ± 0.19 mm) than in those without cervical disc degeneration (mean: 5.33 ± 0.18 mm) (P = .001). There was a positive correlation between the degree of cervical disc degeneration and subcutaneous fat tissue thickness ( = 0.001, r = 0.245).

CONCLUSION

An increase in the cervical fat tissue thickness is a predisposing factor for the development of degeneration of the intervertebral disc. There is a close relationship between subcutaneous fat tissue thickness and the degree of degeneration.

Slanted slot was the most resistant to failure of ventral slot techniques tested in rabbit cervical vertebrae

The ventral slot technique is used to relieve neural compression secondary to intervertebral disc degeneration or disease. In the present study, the biomechanical properties of three different ventral surgical procedures in the rabbit C6–C7 vertebral motion unit (VMU) were assessed and compared with the intact C6–C7 VMU. The ventral slot procedure (slanted, full, or mini; n = 8/group) was performed on these cervical vertebrae. Normal spine torsion and flexion values were compared to those of spines subjected to slanted, full, and mini slot surgery. The slanted slot spines were the most stable, maintaining 70% of normal cervical spine strength, compared to 26% with the full slot and 30% with the mini slot. Regarding torsion, slanted slot spines showed 74% stability compared to the normal cervical spine, while the full slot and mini slot spines showed 58% and 62% stability, respectively. Flexion values were lower after all versions of the ventral slot procedure than in the normal spine, with the greatest flexion difference occurring after the full slot procedure (21% of the normal flexion value). The flexion values also differed significantly between the slanted and full spine groups, and all operated spines showing roughly 60% torsion rates compared with normal spines. The slanted slot maintains more stability in rabbit cervical spine than the other procedures. To our knowledge, this was the first study to examine biomechanical failure differences between the distinct versions of this ventral slot procedure.

The Proteolysis of ECM in Intervertebral Disc Degeneration

Intervertebral disc (IVD) degeneration (IDD) is a pathological process that commonly occurs throughout the human life span and is a major cause of lower back pain. Better elucidation of the molecular mechanisms involved in disc degeneration could provide a theoretical basis for the development of lumbar disc intervention strategies. In recent years, extracellular matrix (ECM) homeostasis has received much attention due to its relevance to the mechanical properties of IVDs. ECM proteolysis mediated by a variety of proteases is involved in the pathological process of disc degeneration. Here, we discuss in detail the relationship between the IVD as well as the ECM and the role of ECM proteolysis in the degenerative process of the IVD. Targeting ECM proteolysis-associated proteases may be an effective means of intervention in IDD.

Study on Transorgan Regulation of Intervertebral Disc and Extra-Skeletal Organs Through Exosomes Derived From Bone Marrow Mesenchymal Stem Cells

Exosomes are membranous lipid vesicles fused with intracellular multicellular bodies and then released into the extracellular environment. They contain various bioactive substances, including proteins, mRNA, miRNAs, lncRNAs, circRNAs, lipids, transcription factors, and cytokine receptors. Under certain conditions, bone marrow mesenchymal stem cells (BMSCs) can differentiate into osteoblasts, chondrocytes, adipocytes, and biological functions. This study provides a theoretical basis for the application of exosomes derived from bone marrow mesenchymal stem cells (BMSC-Exos) in osteology, exploring different sources of exosomes to improve bone microenvironment and resist bone metastasis. We also provided new ideas for the prevention and rehabilitation of human diseases by exosomes.

Effect of overload on changes in mechanical and structural properties of the annulus fibrosus of the intervertebral disc

The research focussed on analysing structural and mechanical properties in the intervertebral disc (IVD), caused by long-term cyclic loading. Spinal motion segments were divided into two groups: the control (C), and the group in which it was analysed the impact of posterior column in the load-bearing system of the spine-specimens with intact posterior column (IPC) and without posterior column (WPC). To evaluate the structural and mechanical changes, the specimens were tested with simulation of 100,000 compression-flexion load cycles after which it was performed macroscopic analysis. Mechanical properties of the annulus fibrosis (AF) from the anterior and posterior regions of the IVD were tested at the uniaxial tension test. The stiffness coefficient values were statistically 32% higher in the WPC group (110 N/mm) than in the IPC (79 N/mm). The dynamics of increase in this parameter does not correspond with the course of decrease in height loss. WPC segments revealed clear structural changes that mainly involve the posterior regions of the IVD (bulging and delamination with the effect of separation of collagen fibre bundles). Pathological changes also caused decreases in the value of stress in the AF. The greatest changes in the stress value about group C (7.43 ± 4.49 MPa) were observed in the front part of the fibrous ring, where this value was for IPC 4.49 ± 4.78 MPa and WPC 2.56 ± 1.01 MPa. The research indicates that the applied load model allows simulating damage that occurs in pathological IVD. And the posterior column's presence affects this change's dynamics, structural and mechanical properties of AF.

Proper animal experimental designs for preclinical research of biomaterials for intervertebral disc regeneration

Low back pain is a vital musculoskeletal disease that impairs life quality, leads to disability and imposes heavy economic burden on the society, while it is greatly attributed to intervertebral disc degeneration (IDD). However, the existing treatments, such as medicines, chiropractic adjustments and surgery, cannot achieve ideal disc regeneration. Therefore, advanced bioactive therapies are implemented, including stem cells delivery, bioreagents administration, and implantation of biomaterials etc. Among these researches, few reported unsatisfying regenerative outcomes. However, these advanced therapies have barely achieved successful clinical translation. The main reason for the inconsistency between satisfying preclinical results and poor clinical translation may largely rely on the animal models that cannot actually simulate the human disc degeneration. The inappropriate animal model also leads to difficulties in comparing the efficacies among biomaterials in different reaches. Therefore, animal models that better simulate the clinical charateristics of human IDD should be acknowledged. In addition, in vivo regenerative outcomes should be carefully evaluated to obtain robust results. Nevertheless, many researches neglect certain critical characteristics, such as adhesive properties for biomaterials blocking annulus fibrosus defects and hyperalgesia that is closely related to the clinical manifestations, e.g., low back pain. Herein, in this review, we summarized the animal models established for IDD, and highlighted the proper models and parameters that may result in acknowledged IDD models. Then, we discussed the existing biomaterials for disc regeneration and the characteristics that should be considered for regenerating different parts of discs. Finally, well-established assays and parameters for in vivo disc regeneration are explored.

Simultaneous quantification of cefuroxime and clindamycin in human lumbar anulus fibrosus, nucleus pulposus and serum via UPLC-MS/MS

BACKGROUND

This study aimed to develop a sensitive, accurate method for simultaneously quantifying cefuroxime and clindamycin in human serum, lumbar anulus fibrosus and nucleus pulposus.

METHODS

Cefuroxime and clindamycin were quantified using ultra high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple-reaction-monitoring mode on a triple-quadrupole AB Qtrap 5500 system in positive ion mode. Internal standards were D₃-cefuroxime and D_3,¹³C-clindamycin. Samples were pretreated by precipitating total protein.

RESULTS

The method showed high sensitivity and good linearity over broad calibration ranges from 100 to 100 000 ng/mL for cefuroxime and 10 to 10 000 ng/mL for clindamycin in serum, and from 10 to 10 000 ng/mL for cefuroxime and 1 to 1 000 ng/mL for clindamycin in lumbar nucleus pulposus. In all sample types, correlation coefficients were greater than 0.99, intra- and inter-day precision (relative standard deviation) was less than 15%, and accuracy (relative error) was within 14% for both analytes. This method was effective at quantifying penetration of cefuroxime and clindamycin in patients undergoing oblique lumbar interbody fusion surgery.

CONCLUSIONS

A very sensitive, specific method for simultaneous detection of cefuroxime and clindamycin has been developed for human lumbar anulus fibrosus, nucleus pulposus and serum samples.

Scoring Osteoarthritis Reliably in Large Joints and the Spine Using Whole-Body CT: OsteoArthritis Computed Tomography-Score (OACT-Score)

A standardized method to assess structural osteoarthritis (OA) burden thorough the body lacks from literature. Such a method can be valuable in developing personalized treatments for OA. We developed a reliable scoring system to evaluate OA in large joints and the spine-the OsteoArthritis Computed Tomography (OACT) score, using a convenience sample of 197 whole-body low-dose non-contrast CTs. An atlas, containing example images as reference points for training and scoring, are presented. Each joint was graded between 0-3. The total OA burden was calculated by summing scores of individual joints. Intra- and inter-observer reliability was tested 25 randomly selected scans (N = 600 joints). Intra-observer reliability and inter-observer reliability between three observers was assessed using intraclass correlation coefficient (ICC) and square-weighted kappa statistics. The square-weighted kappa for intra-observer reliability for OACT-score at joint-level ranged from 0.79 to 0.95; the ICC for the total OA grade was 0.97 (95%-CI, 0.94 to 0.99). Square-weighted kappa for interobserver reliability ranged from 0.48 to 0.95; the ICC for the total OA grade was 0.95 (95%-CI, 0.90 to 0.98). The OACT score, a new reproducible CT-based grading system reflecting OA burden in large joints and the spine, has a satisfactory reproducibility. The atlas can be used for research purposes, training, educational purposes and systemic grading of OA on CT-scans.

The Prevalence and Management of Stingers in College and Professional Collision Athletes

PURPOSE OF REVIEW

Particularly common in collision sports such as American football or rugby, stingers are a traumatic transient neuropraxia of a cervical nerve root(s) or brachial plexus that may last anywhere from minutes to hours. This review summarizes the knowledge on the diagnosis and management of stingers in college and professional collision athletes by providing an overview of their epidemiology and pathophysiology, followed by a discussion on current treatment guidelines and return-to-play recommendations.

RECENT FINDINGS

Despite modifications to tackling technique, increasing awareness, and various equipment options, American football continues to have a high rate of cervical spine injuries, the majority of which occur in preseason and regular season competition settings. The incidence of stingers has slowly increased among collision athletes, and nearly half of all players report sustaining at least one stinger in their career. Recent studies have shown certain anatomical changes in the cervical spine are related to acute and reoccurring stingers. Most players who experience stingers do not miss practices or games. Despite their prevalence, literature highlighting the impact of stingers on college and professional collision athletes is limited. Advances in imaging modalities and novel radiographic parameters have provided tools for screening athletes and can guide return-to-play decisions. Future research regarding appropriate screening practices for athletes with reoccurring stingers, use of protective equipment, and rehabilitation strategies are needed to identify predisposing factors, mitigate the risk of injury, and restore full functional strength and ability.

One strike loading organ culture model to investigate the post-traumatic disc degenerative condition

Background

Acute trauma on intervertebral discs (IVDs) is thought to be one of the risk factors for IVD degeneration. The pathophysiology of IVD degeneration induced by single high impact mechanical injury is not very well understood. The aim of this study was using a post-traumatic IVD model in a whole organ culture system to analyze the biological and biomechanical consequences of the single high-impact loading event on the cultured IVDs.

Methods

Isolated healthy bovine IVDs were loaded with a physiological loading protocol in the control group or with injurious loading (compression at 50% of IVD height) in the one strike loading (OSL) group. After another 1 day (short term) or 8 days (long term) of whole organ culture within a bioreactor, the samples were collected to analyze the cell viability, histological morphology and gene expression. The conditioned medium was collected daily to analyze the release of glycosaminoglycan (GAG) and nitric oxide (NO).

Results

The OSL IVD injury group showed signs of early degeneration including reduction of dynamic compressive stiffness, annulus fibrosus (AF) fissures and extracellular matrix degradation. Compared to the control group, the OSL model group showed more severe cell death (P ​< ​0.01) and higher GAG release in the culture medium (P ​< ​0.05). The MMP and ADAMTS families were up-regulated in both nucleus pulposus (NP) and AF tissues from the OSL model group (P ​< ​0.05). The OSL injury model induced a traumatic degenerative cascade in the whole organ cultured IVD.

Conclusions

The present study shows a single hyperphysiological mechanical compression applied to healthy bovine IVDs caused significant drop of cell viability, altered the mRNA expression in the IVD, and increased ECM degradation. The OSL IVD model could provide new insights into the mechanism of mechanical injury induced early IVD degeneration.

The translational potential of this article

This model has a high potential for investigation of the degeneration mechanism in post-traumatic IVD disease, identification of novel biomarkers and therapeutic targets, as well as screening of treatment therapies.

Expression of degenerative markers in intervertebral discs of young and elderly asymptomatic individuals

Intervertebral disc (IVD) degeneration is a remodeling process mediated by several growth factors and cytokines. This process has been extensively studied in vitro and with pathologic specimens obtained during surgery for scoliosis or back pain. However, the occurrence and temporal evolution of these molecules during normal aging, particularly in the cervical segment, is not known. Our objective was to study and compare the presence of putative mediators in the IVD of young (<35 years, G1) and elderly (>65 years, G2) presumably asymptomatic individuals. Thirty C4-5 and C5-6 discs and thirty L4-5 and L5-S1 discs per group were collected during the autopsy of individuals whose family members denied a history of neck or back pain. Discs were divided into anterior, central (lumbar only) and posterior sectors for analysis. Immunohistochemistry for TNF-α, IL-1β, VEGF, NGF-β, BDNF, TIMP-1, MMP-1, -2 and -3 was performed and reactivity compared between groups and sectors. All of these molecules were detected in every disc sector of both G1 and G2. Most statistical comparisons (25/45, 55.6%) revealed an increase in mediator expression in G2 in relation to G1. Regional differences in the expression of remodeling enzymes were rare; NGF-β and BDNF had slightly higher expression in the cervical segment of elderly individuals. A senescent profile with elevated VEGF, MMP-2 and MMP-3 was observed across most G2 disc regions and were generally elevated from G1. In conclusion, the mere presence of any of the studied molecules inside the IVD cannot be considered pathologic. Expression of remodeling enzymes and inflammatory mediators is relatively similar across different vertebral segments and disc regions leading to a common degenerated pattern, while neurotrophins have slightly higher expression in cervical discs. These findings support the concept that disc remodeling in different segments follows a similar pathway that can be potentially mediated to avoid structural failure.

Tissue Engineering the Annulus Fibrosus Using 3D Rings of Electrospun PCL:PLLA Angle-Ply Nanofiber Sheets

Treatments to alleviate chronic lower back pain, caused by intervertebral disc herniation as a consequence of degenerate annulus fibrosus (AF) tissue, fail to provide long-term relief and do not restore tissue structure or function. The future of AF tissue engineering relies on the production of its complex structure assisted by the many cells that are resident in the tissue. As such, this study aims to mimic the architecture and mechanical environment of outer AF tissue using electrospun fiber scaffolds made from a synthetic biopolymer blend of poly(ε-caprolactone) (PCL) and poly(L-lactic) acid (PLLA). Initially, an aligned bilayer PCL:PLLA scaffold was manually assembled at ±30° fibers direction to resemble the native AF lamellar layers; and bovine AF cells were used to investigate the effect of construct architecture on cell alignment and orientation. Bilayer scaffolds supported cell adhesion and influenced their orientation. Furthermore, significant improvements in tensile stiffness and strength were achieved, which were within the reported range for human AF tissue. Electrospun bilayer scaffolds are, however, essentially two-dimensional and fabrication of a complete three-dimensional (3D) circular construct to better replicate the AF's anatomical structure is yet to be achieved. For the first time, a custom-built Cell Sheet Rolling System (CSRS) was utilized to create a 3D circular lamellae construct that mimics the complex AF tissue and which overcomes this translational limitation. The CSRS equipment is a quick, automated process that allows the creation of multilayered, tube-like structures (with or without cells), which is ideal for mimicking human cervical AF tissue in term of tissue architecture and geometry. Tube-like structures (6 layers) were successfully created by rolling ±30° bilayer PCL:PLLA scaffolds seeded with bovine AF cells and subsequently cultured for 3 weeks. Cells remained viable, purposefully oriented with evidence of collagen type I deposition, which is the main structural component of AF tissue. This is the first study focused on applying CSRS technology for the fabrication of a more clinically-relevant, 3D tissue engineered scaffold for AF tissue regeneration.

Visualization of intervertebral disc degeneration in a cadaveric human lumbar spine using microcomputed tomography

Gross features of disc degeneration (DD) that are associated with back pain include tears in the anulus fibrosus, structural changes of the endplates, and a collapse of the anulus. The aim of this study is the detailed visualization and microstructural characterization of DD using microcomputed tomography (μCT) and a dedicated image post‐processing pipeline. In detail, we investigate a cadaveric spine that shows both types of DD between L1 and L2 and between L2 and L3, respectively. The lumbar spine was obtained from a male donor aged 74 years. The complete specimen was scanned using μCT with an isometric voxel size of 93 μm. Subsequently, regions of interest (ROI) were prepared featuring each complete intervertebral disc including the adjacent endplates. ROIs were then additionally scanned with a voxel size of 35 μm and by means of magnetic resonance imaging. The collapsed endplate of the superior L2 showed explicit signs of an endplate‐driven degeneration, including bony endplate failures. In contrast, the intervertebral disc between L2 and L3 showed indications of an annulus‐driven DD including severe disc height loss and concentric tears. Using μCT we were able to visualize and quantify bone and cartilage features in DD. We showed that in both cases a suite of structural changes accompanies cartilage degeneration, including microstructural bony adaptions to counteract changes in the biomechanical loading regimen.

Predicting In-Hospital Complications After Anterior Cervical Discectomy and Fusion: A Comparison of the Elixhauser and Charlson Comorbidity Indices

OBJECTIVE

The objective of this study was to determine the ability of the Elixhauser Comorbidity Index (ECI) and Charlson Comorbidity Index (CCI) to predict postoperative complications after anterior cervical discectomy and fusion (ACDF).

METHODS

This was a retrospective study of ACDF hospitalizations in the National Inpatient Sample from 2013 to 2014. The ECI and CCI were calculated, and patients who experienced postoperative complications were identified. The ability of these indexes to predict complications was compared using the c statistic (area under the receiver operating characteristic curve [AUC]). In addition, the CCI and ECI were compared with a base model that included age, sex, race, and primary payer.

RESULTS

A total of 261,780 patients were included. Patients who experienced a complication were more often male (P < 0.0001) and older (P < 0.0001). They also had a higher comorbidity burden as assessed by both the ECI (P < 0.0001) and the CCI (P < 0.0001). The ECI was superior in predicting airway complications (AUC, 0.81 vs. 0.75; P < 0.0001), hemorrhagic anemia (AUC, 0.67 vs. 0.63; P = 0.0015), pulmonary embolism (AUC, 0.91 vs. 0.77; P < 0.0001), wound dehiscence (AUC, 0.80 vs. 0.55; P = 0.0080), sepsis (AUC, 0.87 vs. 0.82; P = 0.0001), and septic shock (AUC, 0.94 vs. 0.83; P < 0.0001). The CCI was not found to be superior to the ECI for predicting any complications. Both were excellent for predicting mortality (ECI AUC, 0.87; CCI AUC, 0.90).

CONCLUSIONS

The ECI was superior to the CCI in predicting 6 of 15 complications in this study. Both are excellent tools for predicting mortality after ACDF.

Reciprocal Regulation of TRPS1 and miR-221 in Intervertebral Disc Cells

Intervertebral disc (IVD), a moderately moving joint located between the vertebrae, has a limited capacity for self-repair, and treating injured intervertebral discs remains a major challenge. The development of innovative therapies to reverse IVD degeneration relies primarily on the discovery of key molecules that, occupying critical points of regulatory mechanisms, can be proposed as potential intradiscal injectable biological agents. This study aimed to elucidate the underlying mechanism of the reciprocal regulation of two genes differently involved in IVD homeostasis, the miR-221 microRNA and the TRPS1 transcription factor. Human lumbar IVD tissue samples and IVD primary cells were used to specifically evaluate gene expression and perform functional analysis including the luciferase gene reporter assay, chromatin immunoprecipitation, cell transfection with hTRPS1 overexpression vector and antagomiR-221. A high-level expression of TRPS1 was significantly associated with a lower pathological stage, and TRPS1 overexpression strongly decreased miR-221 expression, while increasing the chondrogenic phenotype and markers of antioxidant defense and stemness. Additionally, TRPS1 was able to repress miR-221 expression by associating with its promoter and miR-221 negatively control TRPS1 expression by targeting the TRPS1-3'UTR gene. As a whole, these results suggest that, in IVD cells, a double-negative feedback loop between a potent chondrogenic differentiation suppressor (miR-221) and a regulator of axial skeleton development (TRPS1) exists. Our hypothesis is that the hostile degenerated IVD microenvironment may be counteracted by regenerative/reparative strategies aimed at maintaining or stimulating high levels of TRPS1 expression through inhibition of one of its negative regulators such as miR-221.

Intervertebral disc organ culture for the investigation of disc pathology and regeneration - benefits, limitations, and future directions of bioreactors

Low back pain is the leading cause of disability worldwide and in many patients the source of pain can be attributed to pathological changes within the intervertebral disc (IVD). As present treatment options fail to address the underlying biological problem, novel therapies are currently subject to intense research. The physiologic IVD microenvironment features a highly complex interaction of biochemical and mechanical factors influencing cell metabolism and extracellular matrix turnover and is therefore difficult to simulate for research purposes on IVD pathology. The first whole organ culture models were not able to sufficiently replicate human in vivo conditions as mechanical loading, the predominant way of IVD nutrient supply and waste exchange, remained disregarded. To mimic the unique IVD niche more realistically, whole organ culture bioreactors have been developed, allowing for dynamic loading of IVDs and nutrient exchange. Recent advancements on bioreactor systems have facilitated whole organ culture of various IVDs for extended periods. IVD organ culture bioreactors have the potential to bridge the gap between in vitro and in vivo systems and thus may give valuable insights on IVD pathology and/or potential novel treatment approaches if the respective model is adjusted according to a well-defined research question. In this review, we outline the potential of currently utilized IVD bioreactor systems and present suggestions for further developments to more reliably investigate IVD biology and novel treatment approaches.

The Evaluation of Glutathione Reductase and Malondialdehyde Levels in Patients With Lumbar Disc Degeneration Disease

BACKGROUND/AIM

Increased oxidative stress plays a crucial role in pathogenesis of various diseases. The present study aims to investigate glutathione reductase (GR) and malondialdehyde (MDA) enzymes as markers of oxidative stress mechanisms in lumbar disc degeneration disease (LDDD).

PATIENTS AND METHODS

The study group consisted of 39 patients diagnosed with LDD and 37 healthy individuals in the control group. The enzyme-linked immunosorbent assay (ELISA) method was used to determine serum GR and MDA levels in the two study groups.

RESULTS

Serum GR levels were significantly lower (p=0.008), while MDA levels were significantly higher in the patient group compared to the controls (p=0.025).

CONCLUSION

Oxidative stress mechanisms play a crucial role in disc degeneration and GR deficiency could be an eligible risk factor for LDDD.

Thoracolumbar Intervertebral Disc Area Morphometry in Elderly Chinese Men and Women: Radiographic Quantifications at Baseline and Changes at Year-4 Follow-up

STUDY DESIGN

A population-based radiographic study with longitudinal follow-up.

OBJECTIVE

To develop a quantitative index for lumbar disc space narrowing (DSN) evaluation in elderly subjects; to determine how DSN in the elderly is influenced by osteoporosis and sex.

SUMMARY OF BACKGROUND DATA

There is paucity of research on quantitative classification of lumbar DSN based on disc areal morphometry.

METHODS

With the database of Osteoporotic Fractures in Men (Hong Kong) and Osteoporotic Fractures in Women (Hong Kong) Studies and those who attended the year-4 follow-up (n = 1519 for men and n = 1546 for women), data of 491 women and 592 men were randomly selected. The anterior, middle, and posterior heights; anteroposterior diameter; and area of intervertebral discs (T4T5 to L4L5) were measured on lateral radiographs. Disc area index for lumbar spine (DAIL, disc area divided by the mean of the sum of square of the adjacent upper and lower vertebrae mid-height anterior-posterior diameter) was developed and compared with semiquantitative DSN expert grading.

RESULTS

DAIL correlated with semiquantitative grading, with sensitivity and specificity varying from 87.3% to 96.8% for grade 1 DSN (<30% reduction in disc height), and 92.9% to 100% for grade 3 DSN (>60% reduction in disc height). The thoracolumbar disc area loss among men and women during 4-years' follow-up period varied between 1.32% and 3.56%, and it was greater for women (mean: 2.44%) than for men (mean: 1.90%, P = 0.044). Majority of lumbar DSN progressions during 72 to 76 years old were progression from normal disc space to grade 1 DSN. Osteoporosis was associated with greater disc area decrease, both for thoracic and lumbar discs.

CONCLUSION

Lumbar DSN can be quantified using DAIL. In elderly Chinese, intervertebral disc narrowing over a 4-year period was greater in women than men, and associated with the presence of osteoporosis.

LEVEL OF EVIDENCE

3.

Halofuginone attenuates intervertebral discs degeneration by suppressing collagen I production and inactivating TGFβ and NF-кB pathway

Most low back pain is caused by intervertebral discs (IVD) degeneration, a disease that prevalence is increasing with age. Halofuginone, an analog of ferbrifugine isolated from plant Dichroa febrifuga, has drawn much attention in recent years for the wide range of bioactivities in malaria, cancer, fibrotic and autoimmune diseases. In this study, we evaluated the benefit effects of halofuginone in IVD degeneration treatment in a validated rabbit puncture model. Halofuginone treatment could attenuate disc degeneration by suppressing the decrease of discs height and nucleus pulposus signal strength. Besides, halofuginone treatment could suppress mRNA and protein expression of collagen I in nucleus pulposus. This might possibly due to the inactivation of transform growth factor-β (TGFβ) signal pathway by down-regulating p-Samd3 and up-regulating inhibitory Smad7. Then, we evaluated the effects of halofuginone treatment on nuclear factor of kappa B (NF-κB) signal pathway and its downstream pro-inflammatory cytokines. The level of p-p65 and p-IκBα was down-regulated in halofuginone treated group, indicating the inactivation of NF-κB signal pathway. The mRNA expression of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and interleukin 8 (IL-8) was decreased in nucleus pulposus too, indicating the down-regulation of pro-inflammatory cytokines. In conclusion, halofuginone treatment could attenuate IVD degeneration and this was possibly due to suppressing of collagen I production and inactivation of TGFβ and NF-κB signal pathway in nucleus pulposus of degenerated discs. These results suggest that halofuginone has the potential for IVD degeneration treatment, but more research is needed to validate this.

Cervical flexion and extension includes anti-directional cervical joint motion in healthy adults

BACKGROUND CONTEXT

Anti-directional cervical joint motion has previously been demonstrated. However, quantitative studies of anti-directional and pro-directional cervical flexion and extension motions have not been published.

PURPOSE

This study aimed for a quantitative assessment of directional and anti-directional cervical joint motion in healthy subjects.

STUDY DESIGN

An observational study was carried out.

PATIENTS SAMPLE

Eighteen healthy subjects comprised the study sample.

OUTCOME MEASURES

Anti-directional and pro-directional cervical flexion and extension motion from each cervical joint in degrees were the outcome measures.

METHODS

Fluoroscopy videos of cervical flexion and extension motions (from neutral to end-range) were acquired from 18 healthy subjects. The videos were divided into 10% epochs of C0/C7 range of motion (ROM). The pro-directional and anti-directional motions in each 10% epoch were extracted, and the ratios of anti-directional motions with respect to the pro-directional motions (0%=no anti-directional movement) were calculated for joints and 10% epochs.

RESULTS

The flexion and extension ROM for C0/C7 were 51.9°±9.3° and 57.2°±12.2°. The anti-directional motions of flexion and extension ROM constituted 42.8%±9.7% and 41.2%±8.2% of the respective pro-directional movements. For flexion, the first three joints (C0/C1, C1/C2, C2/C3) demonstrated larger ratios compared with the last three joints (C4/C5, C5/C6, C6/C7) (p<.03). For extension, C1/C2 and C2/C3 ratios were larger compared with C0/C1, C4/C5, and C5/C6 (p<.03). Comparisons between flexion and extension motions showed larger C0/C1 ratio but smaller C5/C6 and C6/C7 ratios in extension (p<.05).

CONCLUSIONS

This is the first report of quantified anti-directional cervical flexion and extension motion. The anti-directional motion is approximately 40% of the pro-directional motion. The results document that large proportions of anti-directional cervical flexion and extension motions were normal.

Age-related reduction in the expression of FOXO transcription factors and correlations with intervertebral disc degeneration

Aging is a main risk factor for intervertebral disc (IVD) degeneration, the main cause of low back pain. FOXO transcription factors are important regulators of tissue homeostasis and longevity. Here, we determined the expression pattern of FOXO in healthy and degenerated human IVD and the associations with IVD degeneration during mouse aging. FOXO expression was assessed by immunohistochemistry in normal and degenerated human IVD samples and in cervical and lumbar IVD from 6-, 12-, 24-, and 36-month-old C57BL/6J mice. Mouse spines were graded for key histological features of disc degeneration in all the time points and expression of two key FOXO downstream targets, sestrin 3 (SESN3) and superoxide dismutase (SOD2), was assessed by immunohistochemistry. Histological analysis revealed that FOXO proteins are expressed in all compartments of human and mouse IVD. Expression of FOXO1 and FOXO3, but not FOXO4, was significantly deceased in human degenerated discs. In mice, degenerative changes in the lumbar spine were seen at 24 and 36 months of age whereas cervical IVD showed increased histopathological scores at 36 months. FOXO expression was significantly reduced in lumbar IVD at 12-, 24-, and 36-month-old mice and in cervical IVD at 36-month-old mice when compared with the 6-month-old group. The reduction of FOXO expression in lumbar IVD was concomitant with a decrease in the expression of SESN3 and SOD2. These findings suggest that reduced FOXO expression occurs in lumbar IVD during aging and precedes the major histopathological changes associated with lumbar IVD degeneration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2682-2691, 2017.

Calcium Microcrystal Formation in Recurrent Herniation Patients After Autologous Disc Cell Transplantation

Autologous disc cell transplantation (ADCT) is a cell-based therapy aiming to initiate regeneration of intervertebral disc (IVD) tissue, but little is known about potential risks. This study aims to investigate the presence of structural phenomena accompanying the transformation process after ADCT treatment in IVD disease. Structural phenomena of ADCT-treated patients (Group 1, n = 10) with recurrent disc herniation were compared to conventionally-treated patients with recurrent herniation (Group 2, n = 10) and patients with a first-time herniation (Group 3, n = 10). For ethical reasons, a control group of ADCT patients who did not have a recurrent disc herniation was not possible. Tissue samples were obtained via micro-sequestrectomy after disc herniation and analyzed by micro-computed tomography, scanning electron microscopy, energy dispersive spectroscopy, and histology in terms of calcification zones, tissue structure, cell density, cell morphology, and elemental composition. The major differentiator between sample groups was calcium microcrystal formation in all ADCT samples, not found in any of the control group samples, which may indicate disc degradation. The incorporation of mineral particles provided clear contrast between the different materials and chemical analysis of a single particle indicated the presence of magnesium-containing calcium phosphate. As IVD calcification is a primary indicator of disc degeneration, further investigation of ADCT and detailed investigations assessing each patient's Pfirrmann degeneration grade following herniation is warranted. Structural phenomena unique to ADCT herniation prompt further investigation of the therapy's mechanisms and its effect on IVD tissue. However, the impossibility of a perfect control group limits the generalizable interpretation of the results.

The change of cervical spine alignment along with aging in asymptomatic population: a preliminary analysis

STUDY DESIGN

A cross-sectional study.

OBJECTIVE

To investigate the correlation of cervical spine alignment changes with aging in asymptomatic population.

BACKGROUND

Previous studies demonstrated the influence of lumbar and thoracic spine on cervical spine alignment, but few has reported the cervical spine alignment change along with aging in asymptomatic population.

METHODS

Asymptomatic population were divided into four groups according to different ages (Group A: ≤20 years; Group B: 21-40 years; Group C: 41-60 years; Group D: ≥61 years). Each group was composed of 30 subjects. The following parameters were measured: C0-1 Cobb angle, C1-2 Cobb angle, C2-7 Cobb angle, C1-7 sagittal vertical axis (C1-7 SVA), C2-7 SVA, central of gravity to C7 sagittal vertical axis (CG-C7 SVA), Thoracic Inlet Angle (TIA), Neck Tilt (NT), cervical tilt, cranial tilt, T1 slope (TS), TS-CL, and ANOVA statistical method was used to analyze the differences among four groups, and then, linear regression analysis was performed to analyze correlation of the cervical spine alignment with the aging.

RESULTS

C1-7 SVA, C2-7 SVA, CG-C7 SVA, TIA, NT, TS, and cranial tilt were found statistically different among four groups (P < 0.01). From Group A to Group D, the mean C1-7 SVA were 30.7, 26.0, 21.8, and 36.9 mm, the mean C2-7 SVA were 18.7, 14.7, 11.9, and 24.7 mm, and the mean CG-C7 SVA were 19.6, 16.6, 9.4, and 26.7 mm. The mean TIA were 62.4°, 65.0°, 71.8°, and 76.9°, the mean NT were 39.4°, 43.8°, 46.3°, and 48.2°, the mean TS were 23.0°, 21.1°, 25.5°, and 28.7°, and the mean cranial tilt were 5.7°, 4.8°, 3.0°, and 9.5°. Further linear regression indicated that TIA (r = 0.472; P < 0.0001), NT (r = 0.337; P = 0.0006), and TS (r = 0.299; P = 0.0025) were positively correlated with aging.

CONCLUSION

A gradual increase of TIA, NT, and TS, accompanied with an increased CL, is found along with aging in asymptomatic population, among which TIA, NT, and TS are significantly correlated with physiological nature of aging.

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.

Degenerative Changes in the Cervical Spine Are More Common in Middle-Aged Individuals with Thalidomide Embryopathy than in Healthy Controls

Background

Thalidomide was used as a sedative drug for pregnant women in the 1950–60:s and resulted in children born with thalidomide embryopathy (TE), including upper limb malformations. These may alter the motion pattern of the cervical spine by the use of head/shoulder and mouth grip.

Aims

To compare degenerative changes in the cervical spine in TE individuals with healthy controls (CTR).

Methods and Procedures

Twenty-seven middle-aged TE individuals and 27 age- and gender-matched CTR were examined by cervical spine MRI. The presence of malformations, disc herniation(s), osteophytes, nerve and medullary compression and the degree of disc degeneration (DD) were evaluated.

Outcomes and Results

Significantly higher degree of DD was seen in the TE group compared with the controls (p<0.001). Similar frequencies of disc herniation and disc space narrowing were observed in the two groups, but more foraminal narrowing was seen in the TE group (p = 0.002). DD was observed relatively frequently at all cervical levels in the TE group, however, mainly at the two lower levels in the CTR.

Conclusions and Implications

Middle-aged individuals with TE have a higher frequency of degenerative changes in the cervical spine than controls, possibly caused by an altered load on the cervical spine.

Glycosaminoglycan Chemical Exchange Saturation Transfer of Lumbar Intervertebral Discs in Healthy Volunteers

STUDY DESIGN

Evaluation of a new quantitative imaging technique in a prospective study design.

OBJECTIVE

To assess glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVDs) in healthy volunteers with chemical exchange saturation transfer (CEST).

SUMMARY OF BACKGROUND DATA

Biochemical alterations of lumbar discs are present before the appearance of morphological changes. GAG loss plays a central role in these degenerative processes.

METHODS

Lumbar intervertebral discs of healthy controls (26 women, 22 men; mean age 31 ± 8 years; range: 21-49 years) without lumbar back pain were examined at a 3 Tesla magnetic resonance imaging (MRI) scanner in this prospective study. None of the participants were overweight or had previous surgery of the lumbar spine. The MRI protocol included standard morphological, sagittal and transversal T2-weighted (T2w) images to assess Pfirrmann score and to detect disc disorders according to the Combined Task Force classification of five lumbar IVDs (L1 to S1). A prototype glycosaminoglycan chemical exchange saturation transfer (gagCEST) sequence was applied to measure GAG content of the nucleus pulposus (NP) and annulus fibrosus (AF) by identifying the magnetization transfer asymmetry ratio (MTRasym) in a region-of-interest analysis. Morphological and biochemical imaging analysis were statistically tested for quantitative differences between different grades of IVD degeneration and disc disorders.

RESULTS

gagCEST values of NP demonstrated a significant negative correlation with morphological Pfirrmann score (r = -0.562; P < 0.0001). The MTRasym values were higher in non-degenerative lumbar IVDs (Pfirrmann 1-2) compared with degenerative lumbar discs (Pfirrmann 3-5; 2.92% ± 1.42% vs. 0.78% ± 1.38%; P < 0.0001). The MTRasym values of NP were significantly higher in normal appearing discs compared with herniated IVDs (2.83% ± 1.52% vs. 1.55% ± 1.61%; P < 0.0001). We found a significant negative correlation between gagCEST values and the graduation of disc herniation (r = -0.372; P < 0.0001).

CONCLUSION

Biochemical imaging with gagCEST distinguished morphologically degenerative from non-degenerative lumbar IVDs (in NP and AF) of healthy volunteers at a clinical 3T-MRI system. The depletion of GAG content in degenerative lumbar discs correlated significantly with the morphological disc classification. We could demonstrate that disc disorders, such as protrusion and extrusion, were accompanied by lower GAG content.

LEVEL OF EVIDENCE

2.

Fibrin-genipin annulus fibrosus sealant as a delivery system for anti-TNFα drug

BACKGROUND CONTEXT

Intervertebral discs (IVDs) are attractive targets for local drug delivery because they are avascular structures with limited transport. Painful IVDs are in a chronic inflammatory state. Although anti-inflammatories show poor performance in clinical trials, their efficacy treating IVD cells suggests that sustained, local drug delivery directly to painful IVDs may be beneficial.

PURPOSE

The purpose of this study was to determine if genipin cross-linked fibrin (FibGen) with collagen Type I hollow spheres (CHS) can serve as a drug-delivery carrier for infliximab, the anti-tumor necrosis factor α (TNFα) drug. Infliximab was chosen as a model drug because of the known role of TNFα in increasing downstream production of several pro-inflammatory cytokines and pain mediators. Genipin cross-linked fibrin was used as drug carrier because it is adhesive, injectable, and slowly degrading hydrogel with the potential to seal annulus fibrosus (AF) defects. CHS allow simple and nondamaging drug loading and could act as a drug reservoir to improve sustained delivery.

STUDY DESIGN/SETTING

This is a study of biomaterials and human AF cell culture to determine drug release kinetics and efficacy.

METHODS

Infliximab was delivered at low and high concentrations using FibGen with and without CHS. Gels were analyzed for structure, drug release kinetics, and efficacy treating human AF cells after release.

RESULTS

Fibrin showed rapid infliximab drug release but degraded quickly. CHS alone showed a sustained release profile, but the small spheres may not remain in a degenerated IVD with fissures. Genipin cross-linked fibrin showed steady and low levels of infliximab release that was increased when loaded with higher drug concentrations. Infliximab was bound in CHS when delivered within FibGen and was only released after enzymatic degradation. The infliximab released over 20 days retained its bioactivity as confirmed by the sustained reduction of interleukin (IL)-1β, IL-6, IL-8, and TNFα concentrations produced by AF cells.

CONCLUSIONS

Direct mixing of infliximab into FibGen was the simplest drug-loading protocol capable of sustained release. Results show feasibility of using drug-loaded FibGen for delivery of infliximab and, in the context with the literature, show potential to seal AF defects and partially restore IVD biomechanics. Future investigations are required to determine if drug-loaded FibGen can effectively deliver drugs, seal AF defects, and promote IVD repair or prevent further IVD degeneration in vivo.

Lumbar annulus fibrosus biomechanical characterization in healthy children by ultrasound shear wave elastography

OBJECTIVES

Intervertebral disc (IVD) is key to spine biomechanics, and it is often involved in the cascade leading to spinal deformities such as idiopathic scoliosis, especially during the growth spurt. Recent progress in elastography techniques allows access to non-invasive measurement of cervical IVD in adults; the aim of this study was to determine the feasibility and reliability of shear wave elastography in healthy children lumbar IVD.

METHODS

Elastography measurements were performed in 31 healthy children (6-17 years old), in the annulus fibrosus and in the transverse plane of L5-S1 or L4-L5 IVD. Reliability was determined by three experienced operators repeating measurements.

RESULTS

Average shear wave speed in IVD was 2.9 ± 0.5 m/s; no significant correlations were observed with sex, age or body morphology. Intra-operator repeatability was 5.0 % while inter-operator reproducibility was 6.2 %. Intraclass correlation coefficient was higher than 0.9 for each operator.

CONCLUSIONS

Feasibility and reliability of IVD shear wave elastography were demonstrated. The measurement protocol is compatible with clinical routine and the results show the method's potential to give an insight into spine deformity progression and early detection.

KEY POINTS

• Intervertebral disc mechanical properties are key to spine biomechanics • Feasibility of shear wave elastography in children lumbar disc was assessed • Measurement was fast and reliable • Elastography could represent a novel biomarker for spine pathologies.

Mechanics and biology in intervertebral disc degeneration: a vicious circle

Intervertebral disc degeneration is a major cause of low back pain. Despite its long history and large socio-economical impact in western societies, the initiation and progress of disc degeneration is not well understood and a generic disease model is lacking. In literature, mechanics and biology have both been implicated as the predominant inductive cause; here we argue that they are interconnected and amplify each other. This view is supported by the growing awareness that cellular physiology is strongly affected by mechanical loading. We propose a vicious circle of mechanical overloading, catabolic cell response, and degeneration of the water-binding extracellular matrix. Rather than simplifying the disease, the model illustrates the complexity of disc degeneration, because all factors are interrelated. It may however solve some of the controversy in the field, because the vicious circle can be entered at any point, eventually leading to the same pathology. The proposed disease model explains the comparable efficacy of very different animal models of disc degeneration, but also helps to consider the consequences of therapeutic interventions, either at the cellular, material or mechanical level.