Pathophysiology of lumbar disc degeneration: a review of the literature

Enzymatic chemonucleolysis for lumbar disc herniation-an assessment of historical and contemporary efficacy and safety: a systematic review and meta-analysis

Lumbar disc herniation (LDH) is often managed surgically. Enzymatic chemonucleolysis emerged as a non-surgical alternative. This systematic review and meta-analysis aims to assess the efficacy and safety of chemonucleolytic enzymes for LDH. The primary objective is to evaluate efficacy through "treatment success" (i.e., pain reduction) and severe adverse events (SAEs) rates. Additionally, differences in efficacy and safety trends among chemonucleolytic enzymes are explored. Following our PROSPERO registered protocol (CRD42023451546) and PRISMA guidelines, a systematic search of PubMed and Web of Science databases was conducted up to July 18, 2023. Inclusion criteria involved human LDH treatment with enzymatic chemonucleolysis reagents, assessing pain alleviation, imaging changes, and reporting on SAEs, with focus on allergic reactions. Quality assessment employed the Cochrane Source of Bias and MINORS tools. Meta-analysis utilized odds ratios (OR) with 95% confidence intervals (CI). Among 62 included studies (12,368 patients), chemonucleolysis demonstrated an 79% treatment success rate and significantly outperformed placebo controls (OR 3.35, 95% CI 2.41-4.65) and scored similar to surgical interventions (OR 0.65, 95% CI 0.20-2.10). SAEs occurred in 1.4% of cases, with slightly higher rates in chymopapain cohorts. No significant differences in "proceeding to surgery" rates were observed between chemonucleolysis and control cohorts. Limitations include dated and heterogeneous studies, emphasizing the need for higher-quality trials. Further optimization through careful patient selection and advances in therapy implementation may further enhance outcomes. The observed benefits call for wider clinical exploration and adoption. No funding was received for this review.

Three Stages on Magnetic Resonance Imaging of Lumbar Degenerative Spine

PURPOSES

To propose a new lumbar degenerative staging system using the current radiological classification system.

METHODS

A cross-sectional analysis of retrospective databases between January 2018 and December 2022 was performed. Total of 410 patients for Modic changes, paravertebral muscle fat infiltration, disc degeneration, articular process degeneration, vertebral endplate degeneration and other structures, and disc displacement, Spondylolisthesis, and stenosis, and grouped patients according to stage were assessed. Visual analog scale, Japanese Orthopaedic Association, and Oswestry Disability Index scores were used to assess low back pain strength, neurological function, and quality of life, respectively.

RESULTS

The lumbar degeneration staging system consists of 8 variables, which can be divided into 3 steps: early, middle and late, and the correlation between each variable is strong (P < 0.05). The later the staging, the worse the Japanese Orthopaedic Association, visual analog scale, and Oswestry Disability Index scores.

CONCLUSIONS

Patients with later stages have worse clinical scores. This staging system recommends a uniform classification to assess lumbar degeneration.

Non-Surgical Approaches to the Management of Lumbar Disc Herniation Associated with Radiculopathy: A Narrative Review

Lumbar disc herniation associated with radiculopathy (LDHR) is among the most frequent causes of spine-related disorders. This condition is triggered by irritation of the nerve root caused by a herniated disc. Many non-surgical and surgical approaches are available for managing this prevalent disorder. Non-surgical treatment approaches are considered the preferred initial management methods as they are proven to be efficient in reducing both pain and disability in the absence of any red flags. The methodology employed in this review involves an extensive exploration of recent clinical research, focusing on various non-surgical approaches for LDHR. By exploring the effectiveness and patient-related outcomes of various conservative approaches, including physical therapy modalities and alternative therapies, therapists gain valuable insights that can inform clinical decision-making, ultimately contributing to enhanced patient care and improved outcomes in the treatment of LDHR. The objective of this article is to introduce advanced and new treatment techniques, supplementing existing knowledge on various conservative treatments. It provides a comprehensive overview of the current therapeutic landscape, thereby suggesting pathways for future research to fill the gaps in knowledge. Specific to our detailed review, we identified the following interventions to yield moderate evidence (Level B) of effectiveness for the conservative treatment of LDHR: patient education and self-management, McKenzie method, mobilization and manipulation, exercise therapy, traction (short-term outcomes), neural mobilization, and epidural injections. Two interventions were identified to have weak evidence of effectiveness (Level C): traction for long-term outcomes and dry needling. Three interventions were identified to have conflicting or no evidence (Level D) of effectiveness: electro-diagnostic-based management, laser and ultrasound, and electrotherapy.

Abnormal brain activity in lumbar disc herniation patients with chronic pain is associated with their clinical symptoms

Introduction

Lumbar disc herniation, a chronic degenerative disease, is one of the major contributors to chronic low back pain and disability. Although many studies have been conducted in the past on brain function in chronic low back pain, most of these studies did not classify chronic low back pain (cLBP) patients according to their etiology. The lack of etiologic classification may lead to inconsistencies between findings, and the correlation between differences in brain activation and clinical symptoms in patients with cLBP was less studied in the past.

Methods

In this study, 36 lumbar disc herniation patients with chronic low back pain (LDHCP) and 36 healthy controls (HCs) were included to study brain activity abnormalities in LDHCP. Visual analogue scale (VAS), oswestry disability index (ODI), self-rating anxiety scale (SAS), self-rating depression scale (SDS) were used to assess clinical symptoms.

Results

The results showed that LDHCP patients exhibited abnormally increased and diminished activation of brain regions compared to HCs. Correlation analysis showed that the amplitude of low frequency fluctuations (ALFF) in the left middle frontal gyrus is negatively correlated with SAS and VAS, while the right superior temporal gyrus is positively correlated with SAS and VAS, the dorsolateral left superior frontal gyrus and the right middle frontal gyrus are negatively correlated with VAS and SAS, respectively.

Conclusion

LDHCP patients have brain regions with abnormally increased and abnormally decreased activation compared to healthy controls. Furthermore, some of the abnormally activated brain regions were correlated with clinical pain or emotional symptoms.

Predictors of reoperation in hispanic-americans with recurrent lumbosacral disc herniation following primary hemilaminectomy and discectomy surgery

Background

Multiple risk factors for recurrent lumbosacral disc herniation (rLDH) have been evaluated. However, it has been difficult to establish a consensus due to conflicting results. Therefore, the aim of our study was to evaluate the predictors of reoperation in Hispanic-Americans with rLDH following primary hemilaminectomy and discectomy surgery.

Methods

A retrospective case-control study of 451 Hispanic-Americans with lumbosacral disc herniation (LDH) was conducted. The sample was divided into two groups: reoperated (cases) and non-reoperated (controls). Preoperative, operative, and postoperative variables of initial surgery were compared between the two groups.

Results

The reoperation rate was 11.5%, with a mean interval between primary surgery and reoperation of 3.32 years ± 2.07. Analysis of preoperative variables identified a higher rate of reoperation in patients who were unemployed (cases: 48.1%, controls: 17.1%, p=0.001). A significant difference was also seen regarding the presence of gastrointestinal disease (cases: 11.5%, controls: 4.3%, p=0.038). However, there were no differences in the sociodemographic factors, preoperative physical exam, preoperative management, radiological parameters, or operative data. Those patients with persistent postoperative lower extremity pain, radiculopathy, low back pain, and buttock pain demonstrated a higher correlation with rLDH. Multivariable logistic regression analysis identified a significant difference only in work status (employed; OR and 95% CI [0.60 (0.55, 0.67)], p=0.002) and presence of postoperative low back pain (OR and 95% CI [2.17 (1.13, 4.29)], p=0.014).

Conclusions

Patients who required reoperation due to rLDH were more frequently unemployed and/or suffered postoperative low back pain after primary hemilaminectomy and discectomy surgery.

Regenerative medicine for the treatment of chronic low back pain: a narrative review

Low back pain (LBP) is a common and important clinical problem. In addition to pain, patients are also affected by personal, social, and economic burdens. Intervertebral disc (IVD) degeneration is a common cause of LBP, further increasing the patient's morbidity and medical costs. The limitations of current treatment strategies for long-term pain relief mean that increasing attention has been paid to regenerative medicine. We carried out a narrative review to explore the roles of four types of regenerative medicine for treating LBP: marrow-derived stem cells, growth factors, platelet-rich plasma, and prolotherapy. Marrow-derived stem cells are regarded as an ideal cell source for IVD regeneration. Growth factors may stimulate the synthesis of extracellular matrix and attenuate or reverse the degenerative process in IVD, while platelet-rich plasma, which contains multiple growth factors, is thought to be a promising alternative therapy for IVD degeneration. Prolotherapy can initiate the body's inflammatory healing response to repair injured joints and connective tissues. This review summarizes the mechanisms, in vitro and in vivo studies, and clinical applications of these four types of regenerative medicine in patients with LBP.

Crossing the Bridge From Degeneration to Deformity: When Does Sagittal Correction Impact Outcomes in Adult Spinal Deformity Surgery?

BACKGROUND

Patients with less severe adult spinal deformity (ASD) undergo surgical correction and often achieve good clinical outcomes. However, it is not well understood how much clinical improvement is due to sagittal correction rather than treatment of the spondylotic process.

PURPOSE

Determine baseline thresholds in radiographic parameters that, when exceeded, may result in substantive clinical improvement from surgical correction.

STUDY DESIGN

Retrospective.

MATERIALS AND METHODS

ASD patients with BL and two-year data were included. Parameters assessed: sagittal vertical axis, pelvic incidence-lumbar lordosis mismatch, pelvic tilt, T1 pelvic angle, L1 pelvic angle, L4-S1 lordosis, C2-C7 sagittal vertical axis, C2-T3, C2 slope. Outcomes: Good Outcome (GO) at two years: [meeting either: (1) Substantial Clinical Benefit for Oswestry Disability Index (change >18.8), or (2) Oswestry Disability Index <15 and Scoliosis Research Society Total>4.5]. Binary logistic regression assessed each parameter to determine if correction was more likely needed to achieve GO. Conditional inference tree run machine learning analysis generated baseline thresholds for each parameter, above which, correction was necessary to achieve GO.

RESULTS

We included 431 ASD patients. There were 223 (50%) that achieved a GO by two years. Binary logistic regression analysis demonstrated, with increasing baseline severity in deformity, sagittal correction was more often seen in those achieving GO for each parameter(all P <0.001). Of patients with baseline T1 pelvic angle above the threshold, 95% required correction to meet GO (95% vs. 54%, P <0.001). A baseline pelvic incidence-lumbar lordosis >10° (74% of patients meeting GO) needed correction to achieve GO (odds ratio: 2.6, 95% confidence interval: 1.4-4.8). A baseline C2 slope >15° also necessitated correction to obtain clinical success (odds ratio: 7.7, 95% confidence interval: 3.7-15.7).

CONCLUSIONS

Our study highlighted point may be present at which sagittal correction has an outsized influence on clinical improvement, reflecting the line where deformity becomes a significant contributor to disability. These new thresholds give us insight into which patients may be more suitable for sagittal correction, as opposed to intervention for the spondylotic process only, leading to a more efficient utility of surgical intervention for ASD.

Prevalence of Long-Term Low Back Pain After Symptomatic Lumbar Disc Herniation

OBJECTIVE

Lumbar disc herniation (LDH) is a global issue associated with potentially debilitating long-term consequences, including chronic low back pain (LBP). Short-term outcomes (<2 years) of patients with LDH have been extensively studied and demonstrate improvements in back and leg pain for both operative and conservative management. However, these improvements may not be sustained long-term (>2 years); patients with LDH may develop recurrent disc herniations, progressive degenerative disc disease, and LBP regardless of management strategy. Therefore, our objective is to determine the prevalence of chronic LBP after LDH, understand the relationship between LDH and chronic LBP, and investigate the relationship between radiological findings and postoperative pain outcomes.

METHODS

We performed a literature review on the PubMed database via a combination medical subject heading and keyword-based approach for long-term LBP outcomes in patients with LDH.

RESULTS

Fifteen studies (2019 patients) evaluated surgical and/or nonoperative outcomes of patients with LDH . Regardless of surgical or nonoperative management, 46.2% of patients with LDH experienced some degree of LBP long-term (range 2-27 years) as compared to a point prevalence of LBP in the general population of only 11.9%.

CONCLUSIONS

Patients with LDH are more likely to experience long-term LBP compared to the general population (46.2% vs. 11.9%). Additionally, understanding the relationship between radiological findings and pain outcomes remains a major challenge as the presence of radiological changes and the degree of LBP do not always correlate. Therefore, higher quality studies are needed to better understand the relationship between radiological findings and pain outcomes.

[Intraosseous blockades and local injection of HYALREPAIR-02 Chondroreparant combination in low back pain treatment]

OBJECTIVE

Studying the effectiveness of the combined use of intraosseous blockades (IOB) and intramuscular local injection therapy using bottled forms of HYALREPAIR-02 Chondroreparant 02/10 in patients with lumbar dorsopathy and recurrent back pain syndrome.

MATERIAL AND METHODS

30 patients (16 men and 14 women) with chronic recurrent lumbar dorsopathy with pain and myofascial syndromes were examined. Group 1 included 17 patients, whose treatment included the use of IOB and intramuscular local injection therapy using bottled forms of HYALREPAIR-02 Chondroreparant 02/10. Group 2 included 13 patients who received only IOB. To assess the pain syndrome, a visual analogue pain scale (VAS), a Russian version of the McGill Pain Questionnaire (MPBI), and a body diagram questionnaire were used.

RESULTS

After the course of treatment, in both groups there was a decrease in the severity of pain according to VAS, RMBO, and a decrease in the area of pain distribution according to the Body Scheme questionnaire (p<0.05). The values on the RMBO questionnaire in both groups also decreased by more than 2 times compared to the initial value. A statistically more significant regression of pain syndrome and a decrease in disability were noted in group 1 (p<0.05). 2 months after the end of the course of treatment, the pain syndrome did not recur in any patient. Within 3 to 6 months, back pain recurred in 4 (23.5%) patients of the 1st group and in 6 (46.2%) patients of the 2nd group. A total of 90 IOB procedures were performed; no complications or side effects were noted.

CONCLUSION

The combination of IOB and intramuscular local injection therapy using the vial form of HYALREPAIR-02 Chondroreparant in the treatment of patients with degenerative diseases of the spine and back pain is an effective and safe method of therapy. Such treatment strategy allowed to relieve back pain more effectively and improved long-term clinical outcome.

Biomedical applications of silk and its role for intervertebral disc repair

Intervertebral disc (IVD) degeneration (IDD) is the main contributor to chronic low back pain. To date, the present therapies mainly focus on treating the symptoms caused by IDD rather than addressing the problem itself. For this reason, researchers have searched for a suitable biomaterial to repair and/or regenerate the IVD. A promising candidate to fill this gap is silk, which has already been used as a biomaterial for many years. Therefore, this review aims first to elaborate on the different origins from which silk is harvested, the individual composition, and the characteristics of each silk type. Another goal is to enlighten why silk is so suitable as a biomaterial, discuss its functionalization, and how it could be used for tissue engineering purposes. The second part of this review aims to provide an overview of preclinical studies using silk-based biomaterials to repair the inner region of the IVD, the nucleus pulposus (NP), and the IVD's outer area, the annulus fibrosus (AF). Since the NP and the AF differ fundamentally in their structure, different therapeutic approaches are required. Consequently, silk-containing hydrogels have been used mainly to repair the NP, and silk-based scaffolds have been used for the AF. Although most preclinical studies have shown promising results in IVD-related repair and regeneration, their clinical transition is yet to come.

Multicenter Retrospective Analysis of Intradiscal Condoliase Injection Therapy for Lumbar Disc Herniation

Background and Objectives: Intradiscal injection of Condoliase (chondroitin sulfate ABC endolyase), a glycosaminoglycan-degrading enzyme, is employed as a minimally invasive treatment for lumbar disc herniation (LDH) and represents a promising option between conservative treatment and surgical intervention. Since its 2018 approval in Japan, multiple single-site trails have highlighted its effectiveness, however, the effect of LDH types, and influences of patient age, sex, etc., on treatment success remains unclear. Moreover, data on teenagers and elderly patients has not been reported. In this retrospective multi-center study, we sought to classify prognostic factors for successful condoliase treatment for LDH and assess its effect on patients < 20 and ≥70 years old. Materials and Methods: We reviewed the records of 137 LDH patients treated through condoliase at four Japanese institutions and assessed its effectiveness among different age categories on alleviation of visual analog scale (VAS) of leg pain, low back pain and numbness, as well as ODI and JOA scores. Moreover, we divided them into either a “group-A” category if a ≥50% improvement in baseline leg pain VAS was observed or “group-N” if VAS leg pain improved <50%. Next, we assessed the differences in clinical and demographic distribution between group-A and group-N. Results: Fifty-five patients were classified as group-A (77.5%) and 16 patients were allocated to group-N (22.5%). A significant difference in Pfirrmann classification was found between both cohorts, with grade IV suggested to be most receptive. A posterior disc angle > 5° was also found to approach statical significance. In all age groups, average VAS scores showed improvement. However, 75% of adolescent patients showed deterioration in Pfirrmann classification following treatment. Conclusions: Intradiscal condoliase injection is an effective treatment for LDH, even in patients with large vertebral translation and posterior disc angles, regardless of age. However, since condoliase imposes a risk of progressing disc degeneration, its indication for younger patients remains controversial.

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

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

BEL AĞRISI ŞİKAYETİ OLAN HASTALARDA PSOAS KAS DEJENERASYONUNUN DİSK VE FASET EKLEM DEJENERASYONU İLE İLİŞKİSİNİN LOMBER MRG İLE ORTAYA KONMASI:

Purpose: The purpose of the present study was to determine the relationship between PSOAS muscle lipoatrophy and facet and disc degeneration in patients with low back pain with lumbar Magnetic Resonance Imaging (MRI). Materials and Methods: A total of 304 patients who had low back pain were included in this retrospective cross-sectional study. The lumbar MRIs of all patients were evaluated for signs of PSOAS muscle atrophy. Fat content for each muscle was graded semi-quantitatively (Grade 0-4). The disc and facet joint degenerations of each patient were also graded. PSOAS muscle thickness was measured in the mediolateral axial plane parallel to the vertebra. Results: It was found that the mean right PSOAS muscle thickness score of the patients was 35.9±7.2 mm on average, and the mean left PSOAS muscle thickness score was 35.8±7.1 mm. It was also found that 41.8% of the right PSOAS muscle degeneration was Grade 1, 41.1% was Grade 2, 33.6% of the left PSOAS muscle degeneration was Grade 1, 45.1% was Grade 2, 64.1% of the right facet degeneration was Grade 1, 23.4% was Grade 2, and 53.9% of the left facet degeneration was Grade 1, and 30.3% was Grade 2. Conclusion: When lumbar spine MRI examinations are evaluated, PSOAS muscles must also be evaluated in terms of atrophy. Indicating PSOAS muscle lipoatrophy in patients with low back pain may be useful for better rehabilitation planning.

Pediatric lumbar disc herniation: a report of two cases and review of the literature

BACKGROUND

Lumbar disc herniation (LDH) is not a common condition in children. Most reports on pediatric LDH concern the outcomes of surgeries performed in children in whom nonsurgical treatment failed while the outcome of nonsurgical treatment of LDH in children was rarely reported.

CASES PRESENTATION

Case 1: a 10-year-old girl presented with back pain and sciatica in her left leg for over 3 months. The physical examination revealed exacerbation of back pain by waist extension or flexion, and a positive Lasegue's sign was revealed in her left leg. Magnetic resonance imaging (MRI) revealed lumbar disc herniation at the L5/S1 level. She was diagnosed with LDH. After receiving nonsurgical treatment of traditional Chinese medicine (TCM) for 30 days, the girl had mild low back pain and sciatica and the symptoms had resolved completely at the 3-month follow-up. There was no recurrence within the following 2 years. MRI performed 30 months later revealed that the herniated disc did not shrink significantly. However, she was totally asymptomatic at the follow-up performed 30 months later. Case 2: a 13-year-old boy presented with sciatica in his left leg for over 3 months. The physical examination revealed that Lasegue's sign was positive in the left leg, the level of muscle strength in the left ankle plantar flexors was grade 4. MRI revealed a lumbar disc herniation at the L5/S1 level. He was diagnosed with LDH. The boy underwent 2 weeks of TCM treatment, and exhibited a favorable outcome: only mild pain was noticed in his left buttocks after walking for more than 15 min. He was asymptomatic at the 3-month follow-up and there was no recurrence within the next 3 years. MRI scan performed at 40 months later showed no significant resorption of the herniated disc. However, he was totally asymptomatic at the follow-up performed 40 months later.

CONCLUSIONS

For the nonsurgical treatment of pediatric LDH, resorption of herniated discs is not necessary for favorable long-term outcomes, and children with symptomatic LDH may become asymptomatic without resorption.

Posterior epidural intervertebral disc migration and sequestration: A systematic review

Posterior epidural intervertebral disc migration and sequestration (PEIMS) is a rare and debilitating complication of degenerative disc disease. Radiological differential diagnosis is often challenging, complicating the accurate planning of appropriate treatment strategies. We systematically reviewed the literature on PEIMS, focusing on clinical-radiological features and available treatments. PubMed, Scopus, Web of Science, and Cochrane were searched to include studies reporting clinical data of patients with PEIMS. Clinical characteristics, treatment strategies, and functional outcomes were analyzed. We included 82 studies comprising 157 patients. Median age was 54 years (range, 19-91). PEIMSs occurred spontaneously (49.7%) or acutely in patients with underlying progressive degenerative disc disease (50.3%). The most common symptoms were lower-back pain (77.1%) and radiculopathy (66.2%), mainly involving the L5 nerve root (43.8%). PEIMSs were mostly detected at MRI (93%) and/or CT (7%), frequently located in the lumbar spine (81.5%). Median maximum PEIMS diameter was 2.4 cm (range, 1.2-5.0). Surgical debulking was completed in 150 patients (95.5%), sometimes coupled with decompressive laminectomy (65%) or hemilaminectomy (19.1%). Median follow-up time was 3 months (range, 0.5-36.0). Post-treatment symptomatic improvement was reported in 153 patients (97.5%), with total recovery in 118 (75.2%). All 7 patients (4.5%) who received conservative non-surgical management had total clinical recovery at ≤ 3 months follow-ups. PEIMS is a challenging entity that may severely quality-of-life in patients with degenerative disc disease. Surgical removal represents the gold standard to improve patient's functional status. Spine fusion and conservative strategies proved to be effective in some cases.

Development of a finite element lumbar spine model to predict intervertebral disc herniation risk factors

The objective of the current study was to develop a lumbar motion segment FE model that predicts disc herniation risk. The posterolateral nucleus extrusion force and disc pressure increased as the amount of flexion and magnitude of compression was increased in all loading scenarios. The nucleus extrusion force and posterior stress in the annulus both increased when exposed to a combination of compression and flexion. Results of the current study confirmed the authors hypothesis that the model would accurately predict herniation risk when exposed to a biomechanical environment known to cause herniations.

Transcriptional profiling of intervertebral disc in a post-traumatic early degeneration organ culture model

INTRODUCTION

The goal of this study is to characterize transcriptome changes and gene regulation networks in an organ culture system that mimics early post-traumatic intervertebral disc (IVD) degeneration.

METHODS

To mimic a traumatic insult, bovine caudal IVDs underwent one strike loading. The control group was cultured under physiological loading. At 24 hours after one strike or physiological loading, RNA was extracted from nucleus pulposus (NP) and annulus fibrosus (AF) tissue. High throughput next generation RNA sequencing was performed to identify differentially expressed genes (DEGs) between the one strike loading group and the control group. Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes analyses were performed to analyze DEGs and pathways. Protein-protein interaction (PPI) network was analyzed with cytoscape software. DEGs were verified using qRT-PCR. Degenerated human IVD tissue was collected for immunofluorescence staining to verify the expression of DEGs in human disc tissue.

RESULTS

One strike loading resulted in significant gene expression changes compared with physiological loading. In total 253 DEGs were found in NP tissue and 208 DEGs in AF tissue. Many of the highly dysregulated genes have known functions in disc degeneration and extracellular matrix (ECM) homeostasis. ACTB, ACTG, PFN1, MYL12B in NP tissue and FGF1, SPP1 in AF tissue were verified by qRT-PCR and immunofluorescence imaging. The identified DEGs were involved in focal adhesion, ECM-receptor interaction, PI3K-AKT, and cytokine-cytokine receptor interaction pathways. Three clusters of PPI networks were identified. GO enrichment revealed that these DEGs were mainly involved in inflammatory response, the ECM and growth factor signaling and protein folding biological process.

CONCLUSION

Our study revealed different DEGs, pathways, biological process and PPI networks involved in post-traumatic IVD degeneration. These findings will advance the understanding of the pathogenesis of IVD degeneration, and help to identify novel biomarkers for the disease diagnosis.

Cost effectiveness of outpatient lumbar discectomy

Background

Microdiscectomy is the most commonly performed spine surgery and the first transitioning for outpatient settings. However, this transition was never studied, in what comes to cost-utility assessment. Accordingly, this economic study aims to access the cost-effectiveness of outpatient lumbar microdiscectomy when compared with the inpatient procedure.

Methods

This is a cost utility study, adopting the hospital perspective. Direct medical costs were retrieved from the assessment of 20 patients undergoing outpatient lumbar microdiscectomy and 20 undergoing inpatient lumbar microdiscectomy Quality-adjusted life-years were calculated from Oswestry Disability Index values (ODI). ODI was prospectively assessed in outpatients in pre and 3- and 6-month post-operative evaluations. Inpatient ODI data were estimated from a meta-analysis. A probabilistic sensitivity analysis was performed and incremental cost-effectiveness ratio (ICER) calculated.

Results

Outpatient procedure was cost-saving in all models tested. At 3-month assessment ICER ranged from €135,753 to €345,755/QALY, higher than the predefined threshold of €60,000/QALY gained. At 6-month costs were lower and utilities were higher in outpatient, overpowering the inpatient procedure. Probabilistic sensitivity analysis showed that in 65% to 73% of simulations outpatient was the better option. The savings with outpatient were about 55% of inpatient values, with similar utility scores. No 30-day readmissions were recorded in either group.

Conclusion

This is the first economic study on cost-effectiveness of outpatient lumbar microdiscectomy, showing a significant reduction in costs, with a similar clinical outcome, proving it cost-effective.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00272-w.

Platelet-Rich Plasma Versus Corticosteroid Injection for Lumbar Spondylosis and Sacroiliac Arthropathy: A Systematic Review of Comparative Studies

This systematic review compares clinical outcomes between platelet-rich plasma (PRP) and corticosteroid injections for the treatment of lumbar spondylosis and sacroiliac arthropathy. A systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO) and performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the Pubmed, SCOPUS, and Ovid MEDLINE databases. All level I-III evidence comparative studies published in the English language investigating the clinical outcomes between PRP and corticosteroid injections for the treatment of lumbar spondylosis and sacroiliac arthropathy were included. Five studies (242 patients, 114 PRP, 128 corticosteroid) were analyzed. One randomized study was level I evidence, two randomized studies were level II, and two non-randomized studies were level III. Final follow-up ranged from six weeks to six months. Four studies found that both PRP and corticosteroid treatment led to a statistically significant reduction in the visual analog scale (VAS). One found that only the PRP group led to a statistically significant reduction in VAS. Three studies found more significant improvements in one or more clinical outcome scores among PRP patients as compared with corticosteroid patients at the three- to six-month follow-up. Two studies found no difference in outcome score improvements between the two groups at six- to 12-week follow-up. There were no reports of major complications. There were no significant differences in minor complication rates between the two groups. In conclusion, both PRP and corticosteroid injections are safe and effective options for the treatment of lumbar spondylosis and sacroiliac arthropathy. There is some evidence that PRP injection is a more effective option at long-term follow-up compared with corticosteroid injection. Further randomized controlled trials with longer-term follow-up are necessary to compare its long-term efficacy.

Comparison of the histopathological differences between the spinal material and posterior longitudinal ligament in patients with lumbar disc herniation: A focus on the etiopathogenesis

BACKGROUND

Lumbar disc herniation (LDH) occurs owing to the inability of the posterior longitudinal ligament (PLL) to preserve the disc material within the intervertebral space. There is apparently no study that has investigated the histopathological changes occurring in both PLL and disc material in patients with LDH.

OBJECTIVE

Investigate and compare the histopathological changes occurring in PLL and disc material of the patients who underwent a surgical operation for LDH.

DESIGN

Descriptive, cross-sectional.

SETTING

Pathology and neurosurgery departments of a tertiary health care institution PATIENTS AND METHODS: The study included patients who underwent surgical operation for LDH from January 2018 to May 2019 and whose PLL and disc material were removed together, and had disc degeneration findings that were radiologically and histologically concordant.

MAIN OUTCOME MEASURES

PLL degeneration scores according to the histopathological findings, changes in disc materials according to the MRI findings, disc degeneration scores according to the histo-pathological findings.

SAMPLE SIZE

50.

RESULTS

MRI and histological examinations showed fully degenerated black discs (Grade 2) in 12 patients, partially degenerated discs (Grade 1) in 29 patients and fresh/acute discs (Grade 0) in 9 patients. The PLL showed grade 0 degeneration in 2 patients, grade 1 degeneration in 23 patients, and grade 2 degeneration in 25 patients. PLL degeneration grades were higher than the disc degeneration grades (P=.002).

CONCLUSION

Longitudinal ligament degeneration can play a significant role in the pathogenesis of LDH. To the best of our knowledge, this study represents the first to focus on the histopathological changes occurring in both the PLL and disc material in patients with LDH.

LIMITATIONS

Small sample, retrospective CONFLICT OF INTEREST: None.

Microarray analysis reveals an inflammatory transcriptomic signature in peripheral blood for sciatica

BACKGROUND

Although the pathology of sciatica has been studied extensively, the transcriptional changes in the peripheral blood caused by sciatica have not been characterized. This study aimed to characterize the peripheral blood transcriptomic signature for sciatica.

METHODS

We used a microarray to identify differentially expressed genes in the peripheral blood of patients with sciatica compared with that of healthy controls, performed a functional analysis to reveal the peripheral blood transcriptomic signature for sciatica, and conducted a network analysis to identify key genes that contribute to the observed transcriptional changes. The expression levels of these key genes were assessed by qRT-PCR.

RESULTS

We found that 153 genes were differentially expressed in the peripheral blood of patients with sciatica compared with that of healthy controls, and 131 and 22 of these were upregulated and downregulated, respectively. A functional analysis revealed that these differentially expressed genes (DEGs) were strongly enriched for the inflammatory response or immunity. The network analysis revealed that a group of genes, most of which are related to the inflammatory response, played a key role in the dysregulation of these DEGs. These key genes are Toll-like receptor 4, matrix metallopeptidase 9, myeloperoxidase, cathelicidin antimicrobial peptide, resistin and Toll-like receptor 5, and a qRT-PCR analysis validated the higher transcript levels of these key genes in the peripheral blood of patients with sciatica than in that of healthy controls.

CONCLUSION

We revealed inflammatory characteristics that serve as a peripheral blood transcriptomic signature for sciatica and identified genes that are essential for mRNA dysregulation in the peripheral blood of patients with sciatica.

Does oblique lumbar interbody fusion promote adjacent degeneration in degenerative disc disease: A finite element analysis

BACKGROUND

The number of oblique lumbar interbody fusion (OLIF) procedures has continued to rise over recent years. Adjacent segment degeneration (ASD) is a common complication following vertebral body fusion. Although the precise mechanism remains uncertain, ASD has gradually become more common in OLIF. Therefore, the present study analyzed the association between disc degeneration and OLIF to explore whether adjacent degeneration was promoted by OLIF in degenerative disc disease.

METHODS

A three-dimensional nonlinear finite element (FE) model of the L3-S1 lumbar spine was developed and validated. Three lumbar spine degeneration models with different degrees of degeneration (mild, moderate and severe) and a model of OLIF surgery were constructed at the L4-L5 level. When subjected to a follower compressive load (500 N), hybrid moment loading was applied to all models of the lumbar spine and the range of motion (ROM), intradiscal pressure (IDP), facet joint force (FJF), average mises stress in the annulus (AMSA), average tresca stress in the annulus (ATSA) and average endplate stress (AES) were measured.

RESULTS

Compared with the healthy lumbar spine model, the ROM, IDP, FJF, AMSA, ATSA and AES of the segments adjacent to the degenerated segment increased in each posture as the degree of disc degeneration increased. In different directions of motion, the ROM, IDP, FJF, AMSA, ATSA and AES in the OLIF model in the L3-L4 and L5-S1 segments were higher than those of the healthy model and each degenerated model. Compared with the healthy model, the largest relative increase in biomechanical parameters above (ROM, IDP, FJF, AMSA, ATSA or AES) was observed in the L3-L4 segment in the OLIF model, of 77.13%, 32.63%, 237.19%, 45.36%, 110.92% and 80.28%, respectively. In the L5-S1 segment the corresponding values were 68.88%, 36.12%, 147.24%, 46.00%, 45.88% and 51.29%, respectively.

CONCLUSIONS

Both degenerated discs and OLIF surgery modified the pattern of motion and load distribution of adjacent segments (L3-L4 and L5-S1 segments). The increases in the biomechanical parameters of segments adjacent to the surgical segment in the OLIF model were more apparent than those of the degenerated models. In summary, OLIF risked accelerating the degeneration of segments adjacent to those of a surgical segment.

Grape seed extract inhibits nucleus pulposus cell apoptosis and attenuates annular puncture induced intervertebral disc degeneration in rabbit model

Low back pain is a musculoskeletal disorders implicated to disc degeneration. Grape seed extracts (GSEs) is a natural flavonoids rich compound with antioxidants and anti-inflammatory properties. This study is aimed at investigating the inhibitory and anabolic response of GSE on annular punctured induced disc degeneration in rabbit model. Twenty-Eight New Zealand white rabbits (weighing about 2.0-3.5 kg) were used with institutional animal care committee's approval. The animals were divided into four groups (n=7 per group). Group A (non-punctured group) received distilled water orally for 4 weeks. Group B (punctured group) received distilled water for 4 weeks. Group C (punctured treated group) received distilled water for 4 weeks and thereafter received 500 mg/kg of GSE for another 4 weeks. Group D received 500 mg/kg of GSE immediately after puncture for 4 weeks. At the end of the experiment, the animals were sacrificed with intramuscular injection of ketamine followed by intravenous injection of sodium pentobarbital. The percentage disc height index of the punctured group showed significant decrease compared to the control and treated groups. Histological and immunohistochemical studies showed distortion in the disc morphology, decrease in chondrocyte like cells, disorganization of collagen and elastic fibers, increase Bax expression levels in the punctured group compared to control and treated groups which was attenuated after GSE administration. GSE has preventive and restorative effects on punctured induced disc preventing the degradation of collagen fibrils within the disc tissues.

Disc degeneration induces a mechano-sensitization of disc afferent nerve fibers that associates with low back pain

OBJECTIVE

We aimed to investigate mechano-sensitivity at the afferent nerve fibers projecting to degenerated intervertebral disc (IVD) and nociceptive behaviour in a rat model of low back pain (LBP).

DESIGN

Animal model with LBP was established by lumbar 4/5 IVD puncture and nucleus pulposus aspiration. In vivo single nerve recordings (n = 121) were introduced to measure discharge frequency at the afferent nerve fiber innervating the IVD during mechanical stimulations (von Frey filament or intradiscal pressure). Nerve growth factor (NGF) expression levels in the IVD (n = 20) were assessed by Western blot. LBP-related behaviour (n = 22) was assessed by measuring changes in rearing, mechanical paw-withdrawal threshold, and dynamic weight bearing in a freely walking rat. Inhibitory effect of morphine on the neuronal excitability (n = 19) and painful behaviour (n = 28) was also assessed.

RESULTS

Compared to those with sham or naïve IVD, animal group with degenerated IVD displayed the sensitized neuronal responses and painful behaviour, with hyperexcitability of the afferent nerve fibers in any range of mechanical stimulations (von Frey filament stimulation; 1, 2, and 26 g; intradiscal pressure, 1,500-3,000 mm Hg), strong upregulation of NGF (200-250 % increase), and LBP-like behaviour such as failure of rearing, front limbs-dependent walking pattern, and hypersensitivity in hind-paws. However, the neuronal hyperexcitability and pain behaviour were attenuated after local (30 μM) or systemic (3 mg kg^-1) morphine administration.

CONCLUSIONS

Our study suggests that enhanced mechano-sensitivity at the afferent nerve fiber innervating degenerated IVD is deeply correlated with LBP development, which supports the hypothesis that hyperexcited responses at the nerve fibers represent a decisive source of LBP.

Identification of Key Genes Potentially Related to Intervertebral Disk Degeneration by Microarray Analysis

Aims: This study was designed to investigate differentially expressed genes (DEGs) in the annulus fibrosus (AF), nucleus pulposus (NP), and whole blood (WB) of intervertebral disk degeneration (IDD) patients. Materials and Methods: We retrieved microarray data set GSE70362, which contains the gene expression profiles of 24 AF and 24 NP samples from the Gene Expression Omnibus and identified DEGs in degenerative AF (AF-DEGs) and NP (NP-DEGs) samples compared with nondegenerative samples. We also examined gene expression profiles in WB from patients with IDD and healthy volunteers to identify DEGs in WB (WB-DEGs). We performed functional analyses on the DEGs common to AF-DEGs, NP-DEGs, and WB-DEGs. Expression of the common DEGs was partially validated by quantitative real-time-polymerase chain reaction (QRT-PCR). Results: In total, 846 AF-DEGs, 902 NP-DEGs, and 862 WB-DEGs were identified, and 22 DEGs were common among the three groups. Functional analyses showed that the common DEGs were enriched in 33 biological processes, 16 cellular components, 4 molecular functions, and 9 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways; 13 of the common DEGs were included in the protein-protein interaction (PPI) network and superoxide dismutase 2 (SOD2) was identified as a hub gene in the PPI network. The QRT-PCR results for the expression of the genes protein disulfide isomerase family A member 4, FKBP prolyl isomerase 11, ectonucleotide pyrophosphatase/phosphodiesterase 4, SOD2, and actin binding LIM protein 1, were consistent with the gene chip hybridization results. Conclusions: This study identified key genes for future investigations of the underlying molecular mechanisms of IDD. These genes may provide future targets for the clinical treatment and diagnosis of IDD.

Cell Therapy for Treatment of Intervertebral Disc Degeneration: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To review, critically appraise, and synthesize evidence on use of cell therapy for intervertebral disc repair.

METHODS

A systematic search of PubMed/MEDLINE was conducted for literature published through October 31, 2018 and EMBASE and ClinicalTrials.gov databases through April 13, 2018 comparing allogenic or autologous cell therapy for intervertebral disc (IVD) repair in the lumbar or cervical spine. In the absence of comparative studies, case series of ≥10 patients were considered.

RESULTS

From 1039 potentially relevant citations, 8 studies across 10 publications on IVD cell therapies in the lumbar spine met the inclusion criteria. All studies were small and primarily case series. For allogenic cell sources, no difference in function or pain between mesenchymal cell treatment and sham were reported in 1 small randomized controlled trial; 1 small case series reported improved function and pain relative to baseline but it was unclear if the change was clinically significant. Similarly for autologous cell sources, limited data across case series suggest pain and function may be improved relative to baseline; whether the changes were clinically significant was not clear. Safety data was sparse and poorly reported. The need for subsequent surgery was reported in 3 case-series studies ranging from 6% to 80%.

CONCLUSIONS

The overall strength of evidence for efficacy and safety of cell therapy for lumbar IVD repair was very low primarily due to substantial risk of bias, small sample sizes and lack of a comparator intervention. Methodologically sound studies comparing cell therapies to other treatments are needed.

Bioinformatics analysis reveals different gene expression patterns in the annulus fibrosis and nucleus pulpous during intervertebral disc degeneration

Degeneration of the intervertebral disc (IVD), which consists of the annulus fibrosus (AF) and nucleus pulposus (NP), is a multifactorial physiological process associated with lower back pain. Despite decades of research, the knowledge of the underlying molecular mechanisms of IVD degeneration (IDD) has remained limited. The present study aimed to reveal the differential gene expression patterns in AF and NP during the process of IDD and to identify key biomarkers contributing to these differences. The microarray dataset GSE70362 containing 24 AF and 24 NP samples was retrieved from the Gene Expression Omnibus database. Of these, 8 healthy samples were discarded. GeneSpring11.5 software was employed to identify differentially expressed genes (DEGs). Metascape online tools were used to perform enrichment analyses. Finally, the DEGs were mapped with the Search Tool for the Retrieval of Interacting Genes, and a protein-protein interaction (PPI) network was constructed in Cytoscape software. A total of 87 DEGs were identified. Gene ontology enrichment revealed that these DEGs were mainly involved in the inflammatory response, the extracellular matrix and RNA polymerase II transcription factor activity. Pathway enrichment revealed that the DEGs were mainly involved in the transforming growth factor (TGF-β) and estrogen signaling pathways. Matrix metalloproteinase (MMP)1 and interleukin (IL)6 were included in the genes enriched in rheumatoid arthritis, whereas bone morphogenetic protein (BMP)2 and thrombospondin 1 (THBS1) were among the genes enriched in the TGF-β signaling pathway. In the PPI network, IL6 was identified as the central gene. In conclusion, as MMP1 has been demonstrated degrade collagen III at higher rates compared with other types of collagen (which is at a higher quantity in AF than NP), collagen types may be in different distribution patterns, which may contribute to the upregulation of MMP1 in AF. Differences in the expression of BMP2, ESR1 and THBS1 may explain for the pathological differences between AF and NP. IL6 may have a key role in different degeneration processes in AF and NP.

Plain radiograghs of lumbar spine in patients with low back pain

Low back pain (LBP) is a common presenting complaint in our hospital in Enugu Nigeria. Three hundred thirty-three radiographs of patients with LBP were studied. A lot of them had bony outgrowths (osteophytes) on the spine. Plain radiograph of the spine is useful in studying these patients' condition.

INTRODUCTION

Low back pain (LBP) is one of the common symptoms which bring patients to hospital and ultimately to radiology department for medical assistance. Plain radiographs of lumbar spine are usually the initial imaging tools requested by clinicians. The objective of this study is to evaluate commonest finding in patients with LBP to guide physicians for improved management.

METHODS

This work was a retrospective study. Plain films of these patients with LBP at the University of Nigeria Teaching Hospital, Enugu, were assessed by two radiologists. Findings documented and analyzed using IBM'S SPSS 22. Association was determined using chi-square with level of significance, p < 0.05.

RESULTS

Total number of radiographs reviewed was 333. One hundred and eighty-three (55.0%) patients were females. Age ranged from 14 to 101 years. Mean age of 53.4 ± 15.9 years. Disc space was normal in majority (55.3%, 184/333) of patients; narrowing was observed in most others (43.2%, 144/333), about half of the narrowing occurring along with vacuum phenomenon. Osteophytes were commonest finding in a total of 284/333 (85.3%) existing alone or in combination with other findings. Proportion of patients with osteophytes was highest in sixth to eighth decade of life (98.8% of 61-80 age group), followed by 41-60 age group (92.9%). This association between age group and the presence of osteophytes was statistically significant (p < 0.000). Anterior vertebral body was affected in 85.0% (284/333) of patients.

CONCLUSIONS

Osteophytes are common radiologic features in LBP. Anterior vertebral body is most affected. It is commoner in the older age group. Plain radiograph is an invaluable imaging tool in the management of LBP in this part of the world.

Cartilage Endplate Thickness Variation Measured by Ultrashort Echo-Time MRI Is Associated With Adjacent Disc Degeneration

STUDY DESIGN

A magnetic resonance imaging study of human cadaver spines.

OBJECTIVE

To investigate associations between cartilage endplate (CEP) thickness and disc degeneration.

SUMMARY OF BACKGROUND DATA

Damage to the CEP is associated with spinal injury and back pain. However, CEP morphology and its association with disc degeneration have not been well characterized.

METHODS

Ten lumbar motion segments with varying degrees of disc degeneration were harvested from six cadaveric spines and scanned with magnetic resonance imaging in the sagittal plane using a T2-weighted two-dimensional (2D) sequence, a three-dimensional (3D) ultrashort echo-time (UTE) imaging sequence, and a 3D T1ρ mapping sequence. CEP thicknesses were calculated from 3D UTE image data using a custom, automated algorithm, and these values were validated against histology measurements. Pfirrmann grades and T1ρ values in the disc were assessed and correlated with CEP thickness.

RESULTS

The mean CEP thickness calculated from UTE images was 0.74 ± 0.04 mm. Statistical comparisons between histology and UTE-derived measurements of CEP thickness showed significant agreement, with the mean difference not significantly different from zero (P = 0.32). Within-disc variation of T1ρ (standard deviation) was significantly lower for Pfirrmann grade 4 than Pfirrmann grade 3 (P < 0.05). Within-disc variation of T1ρ and adjacent CEP thickness heterogeneity (coefficient of variation) had a significant negative correlation (r = -0.65, P = 0.04). The standard deviation of T1ρand the mean CEP thickness showed a moderate positive correlation (r = 0.40, P = 0.26).

CONCLUSION

This study demonstrates that quantitative measurements of CEP thickness measured from UTE magnetic resonance imaging are associated with disc degeneration. Our results suggest that variability in CEP thickness and T1ρ, rather than their mean values, may serve as valuable diagnostic markers for disc degeneration.

LEVEL OF EVIDENCE

N/A.

Platelet-rich plasma injections: an emerging therapy for chronic discogenic low back pain

Autologous platelet-rich plasma (PRP) injections have been investigated in recent years as an emerging therapy for various musculoskeletal conditions, including lumbar degenerative disc disease. Although PRP has received increasing attention from medical science experts, comprehensive clinical reports of its efficacy are limited to those treating knee osteoarthritis and epicondylitis. Use of PRP is gaining popularity in the area of degenerative disc disease, but there is a clear need for reliable clinical evidence of its applications and effectiveness. In this article, we review the current literature on PRP therapy and its potential use in the treatment of chronic discogenic low back pain, with a focus on evidence from clinical trials.

Safety and tolerability of intradiscal implantation of combined autologous adipose-derived mesenchymal stem cells and hyaluronic acid in patients with chronic discogenic low back pain: 1-year follow-up of a phase I study

Background

Adipose tissue-derived mesenchymal stem cells (AT-MSCs) offer potential as a therapeutic option for chronic discogenic low back pain (LBP) because of their immunomodulatory functions and capacity for cartilage differentiation. The goal of this study was to assess the safety and tolerability of a single intradiscal implantation of combined AT-MSCs and hyaluronic acid (HA) derivative in patients with chronic discogenic LBP.

Methods

We performed a single-arm phase I clinical trial with a 12-month follow-up and enrolled 10 eligible chronic LBP patients. Chronic LBP had lasted for more than 3 months with a minimum intensity of 4/10 on a visual analogue scale (VAS) and disability level ≥ 30% on the Oswestry Disability Index (ODI). The 10 patients underwent a single intradiscal injection of combined HA derivative and AT-MSCs at a dose of 2 × 10⁷ cells/disc (n = 5) or 4 × 10⁷ cells/disc (n = 5). Safety and treatment outcomes were evaluated by assessing VAS, ODI, Short Form-36 (SF-36), and imaging (lumbar spine X-ray imaging and MRI) at regular intervals over 1 year.

Results

No patients were lost at any point during the 1-year clinical study. We observed no procedure or stem cell-related adverse events or serious adverse events during the 1-year follow-up period. VAS, ODI, and SF-36 scores significantly improved in both groups receiving both low (cases 2, 4, and 5) and high (cases 7, 8, and 9) cell doses, and did not differ significantly between the two groups. Among six patients who achieved significant improvement in VAS, ODI, and SF-36, three patients (cases 4, 8, and 9) were determined to have increased water content based on an increased apparent diffusion coefficient on diffusion MRI.

Conclusions

Combined implantation of AT-MSCs and HA derivative in chronic discogenic LBP is safe and tolerable. However, the efficacy of combined AT-MSCs and HA should be investigated in a randomized controlled trial in a larger population.

Trial registration

ClinicalTrials.gov NCT02338271. Registered 7 January 2015.

Gender differences in the relationship between socioeconomic status and height loss among the elderly in South Korea: Korean National Health and Nutrition Examination Survey 2008-2010

This study aimed to examine average height loss and the relationship between height loss and socioeconomic status (SES) among the elderly in South Korea.Data were obtained from the Korean National Health and Nutrition Examination Survey 2008-2010. A total of 5265 subjects (2818 men and 2447 women) were included. Height loss was calculated as the difference between the subject's self-reported maximum adult height and their measured current height. The height loss values were divided into quartiles (Q1-Q4) for men and women. SES was determined using a self-reported questionnaire for education level, family income, and occupation.Height loss was associated with SES in all age groups, and mean height loss increased with age. In the relationship between education level and maximum height loss (Q4), men with ≤6, 7-9, or 10-12 years of education had higher odds ratios for the prevalence of height loss (Q4) than men with the highest education level (≥13 years). With regard to the relationship between the income level and height loss (Q4), the subjects with the lowest income had an increased prevalence of maximum height loss (Q4) than the subjects with the highest income (odds ratios = 2.03 in men and 1.94 in women). Maximum height loss (Q4) was more prevalent in men and women with a low SES and less prevalent in men with a high SES than in men with a middle SES.Height loss (Q4) was associated with education level in men and with income level (especially low income) in men and women. Height loss was also associated with a low SES in men and women.

Interleukin 6 (IL-6) and IL-10 Promoter Region Polymorphisms Are Associated with Risk of Lumbar Disc Herniation in a Northern Chinese Han Population

AIM

This study assessed the association of single-nucleotide polymorphisms (SNPs) in the proinflammatory cytokines interleukin 6 (IL-6) and IL-10 with the risk of lumbar disc herniation in a Chinese Han population.

METHODS

We collected blood samples from 267 patients with lumbar disc herniation (case group) and 300 normals (control group) and performed analyses of the IL-6 572C/G and 174G/C SNPs as well as the IL-10 592A/C and 1082G/A SNPs using TaqMan technology.

RESULTS

The frequencies of the IL-6-572 GG, GC, and CC genotypes were 5.99%, 42.3%, and 51.6%, respectively, in the case group, and 1.6%, 24%, and 64.3%, respectively, in the control group. Thus, the relative risk of the IL-6-572 G genotype (GG plus GC) was 1.69-fold higher for developing lumbar disc herniation compared to the CC genotype (95% confidence interval: 1.16-2.39, p < 0.01). The risks associated with the IL-6-572 CG and GG genotypes were 1.55- and 4.48-fold higher, respectively, versus the CC genotype for developing lumbar disc herniation (p < 0.01). The IL-10-1082 AG genotype was significantly higher in the case group (26.22%) versus the control group (11.67%); whereas the AA genotype was lower in the case group (73.78%) versus the control group (88.33%; p < 0.05). The IL-10-1082 G allele frequency was significantly higher in the case group (13.11%) versus the control group (5.83%; p < 0.05).

CONCLUSION

This study demonstrates that genetic variants in the promoter regions of the IL-6 and IL-10 genes are associated with lumbar disc herniation risk in this Northern Chinese Han population.

The relationship between cervical and lumbar spine lesions in rheumatoid arthritis with a focus on endplate erosion

STUDY DESIGN

A cross-sectional imaging study.

OBJECTIVE

To investigate the relationship between cervical and lumbar spine lesions in patients with rheumatoid arthritis (RA), and to analyze associated factors in those with concurrent cervical and lumbar endplate erosion (EE).

SUMMARY OF BACKGROUND DATA

Both the lumbar and cervical spines are often involved in RA, but little is known about the relationship between cervical and lumbar lesions. EE is often found in the spine of RA patients, but its prevalence and associated factors have not been well studied.

METHODS

We enrolled 201 RA patients in this study. Cervical lesions (horizontal and vertical atlantoaxial dislocation, subaxial subluxation) and lumbar lesions (vertebral fracture, scoliosis, spondylolisthesis) were evaluated on plain radiographs. EE was evaluated on sagittal T1-weighted magnetic resonance images, and graded into 4 categories. The prevalence of each lesion was calculated, and correlations between general cervical and lumbar lesions and between cervical and lumbar EE were analyzed. To assess the clinical condition of RA, we evaluated disease duration, Steinbrocker stage, modified Stanford Health Assessment Questionnaire results, and Disease Activity Score for 28 joints with the erythrocyte sedimentation rate. Factors associated with concurrent lumbar and cervical EE were analyzed using multiple logistic regression analysis.

RESULTS

Cervical lesions were found in 42.3% of patients and lumbar lesions in 56.2%. There was no significant correlation between the presence of cervical and the presence of lumbar lesions, but patients with cervical subaxial subluxation were significantly more likely to have lumbar spondylolisthesis. Cervical EE (≥1 points) was found in 61.2% of patients and lumbar EE in 39.3%. Total cervical EE score was significantly correlated with lumbar EE score. Moderate/high disease activity, Steinbrocker stage IV, and severe cervical or lumbar disk degeneration were associated with concurrent cervical and lumbar EE.

CONCLUSIONS

Some cervical lesions are significantly associated with lumbar spinal lesions. Concurrent cervical and lumbar EE are related to RA disease activity and peripheral joint deterioration, suggesting that RA activity may play an important role in total spinal involvement.

[Degenerative and age-related alterations of the spine]

Degenerative alterations of the spine occur in an individual-specific manner with increasing age. This is not only dependent on external factors, such as hard physical labor over many years but can also be genetically influenced as demonstrated in recent studies. The spinal cord is well-protected within the spinal canal but can be impaired by degenerative alterations of the intervertebral discs and functional spinal segments. Depositions or narrowing of nerve structures can cause lasting pain or focal neurological deficits, such as paralysis or sensitivity disorders. These complaints can slowly develop over years, e.g. by a gradually increasing bony narrowing of the spinal canal (spinal canal stenosis) or can occur suddenly, e.g. an acute herniated disc. However, low back pain is much more common and occurs in approximately 80 % of people sometime during their lifetime. It is necessary to recognize the normal age-related anatomical alterations in magnetic resonance imaging (MRI), particularly for intervertebral discs in order to interpret these correctly. Knowledge of the spectrum of the various age-related degenerative processes which can occur in intervertebral discs and vertebral bodies is necessary to be able to differentiate them from pathological alterations. This is important because therapy decisions are often made as a direct result of MRI.

Dysregulated COL3A1 and RPL8, RPS16, and RPS23 in Disc Degeneration Revealed by Bioinformatics Methods

STUDY DESIGN

Bioinformatics analysis of published microarray data.

OBJECTIVE

This study aimed to reveal the possible genes and pathways related to the pathogenesis of disc degeneration (DD) by analyzing the microarray data.

SUMMARY OF BACKGROUND DATA

DD is one of the main causes of low back pain, which has become an enormous economic burden for society.

METHODS

Gene expression data of annulus cells and nucleus pulposus cells from patients with DD and controls subjects were downloaded from Gene Expression Omnibus. T test and enrichment analysis were used to identify differentially expressed genes (DEGs) and DEGs-associated functions and pathways in DD, respectively. Protein-protein interaction network and module were constructed to analyze the key nodes associated with this disease.

RESULTS

A total of 326 DEGs and 35 DEGs were obtained from the annulus cells and nucleus pulposus cells, respectively. The DEGs of DD in annulus cells were mainly involved in translation, cell adhesion, cell death regulation, and skeletal system development whereas the DEGs in nucleus pulposus cells were mainly related to the biological processes of vascular system development, skeletal system development, and enzyme-linked receptor protein signaling pathway. COL3A1 was the common DEG in both annulus cells and nucleus pulposus cells. The genes encode ribosomal proteins (RPL8, RPS16, and RPS23) in module were enriched in biological processes of translation, translation elongation, and RNA processing.

CONCLUSION

The results revealed the involvement of COL3A1 in skeletal system process and RPL8, RPS16, and RPS23 in the protein synthesis processes in the progression of DD, suggesting their potential use in the diagnosis and therapy of DD.

LEVEL OF EVIDENCE

N/A.

Plasma metabonomic profiling of lumbar disc herniation and its traditional Chinese medicine subtypes in patients by using gas chromatography coupled with mass spectrometry

Lumbar disc herniation (LDH) is a commonly occurring disease, threatening human health and life quality. Lack of a gold standard of diagnosis has hindered the efficiency and efficacy of clinical therapy against LDH. Traditional Chinese medicine (TCM) has provided an experience-based but subjective diagnosis system for LDH, demanding objective evidence and explanation. In this study, we adopted a metabonomics approach using gas chromatography-mass spectrometry (GC-MS) to profile metabolic characteristics of LDH and its TCM subtypes. Plasma samples of 41 LDH patients and 25 healthy controls were collected. LDH patients were classified into two main subtypes, the reality syndrome and deficiency syndrome, according to TCM theory. By using multivariate statistical analysis and metabolism network analysis, we found diverse perturbations of metabolites in amino acid metabolism and carbohydrate metabolism, in which the amino acids (glutamic acid, aspartic acid, glycine, etc.) were up-regulated and a key carbohydrate metabolite (glucose 1-phosphate) was down-regulated. Few differences were found between the two TCM subtypes. Our findings reveal the metabolic disorders of LDH for the first time and demonstrate the feasibility of the metabonomics approach for LDH research but not for its TCM subtypes.

Association of the Polymorphism of TRAIL with the Risk and Severity of Lumbar Disc Degeneration in Chinese Han Population

BACKGROUND

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis of various normal and tumor cells. Apoptosis plays an important role in the development of lumbar disc degeneration (LDD).

AIMS

The aim of this study was to determine whether the 1595C/T polymorphism of the TRAIL gene is associated with the increased risk and severity of LDD in the Chinese Han population.

METHODS

This study consisted of 312 patients with LDD and 196 healthy controls. The grade of disc degeneration was determined according to Schneiderman's classification for magnetic resonance imaging (MRI).

RESULTS

The genotype frequency of the 1595C/T polymorphism was in agreement with the Hardy-Weinberg equilibrium (p=0.278). Patients with LDD had significantly lower frequencies of CT and TT genotypes compared with normal controls (p<0.001). In addition, a lower frequency of the T allele was found in patients with LDD than normal controls (p<0.001). Unconditional logistic regression analysis revealed that CT and TT genotypes were both significantly associated with a reduced risk of LDD compared with the CC genotype (p<0.001; odds ratio [OR] 0.327; 95% confidence interval [95% CI] 0.217-0.493 and p<0.001; OR 0.393; 95% CI 0.234-0.661, respectively). Furthermore, the T allele was significantly associated with a decreased risk of LDD compared with the C allele (p<0.001; OR 0.483; 95% CI 0.369-0.633). In addition, the CT and TT genotypes, as well as the T allele, were associated with lower degenerative grades of LDD compared with the CC genotype and the C allele, respectively (p=0.008 and p=0.001, respectively).

CONCLUSION

The 1595C/T polymorphism of TRAIL may be adversely associated with the risk and severity of LDD in the Chinese Han population.

Shape-memory porous alginate scaffolds for regeneration of the annulus fibrosus: effect of TGF-β3 supplementation and oxygen culture conditions

Disc herniation as a result of degenerative or traumatic injury is believed to be the primary instigator of low back pain. At present there is a lack of viable treatment options to repair damaged annulus fibrosus (AF) tissue. Developing alternative strategies to fill and repair ruptured AF tissue is a key challenge. In this work we developed a porous alginate scaffold with shape-memory properties which can be delivered using minimally invasive approaches and recover its original geometry once hydrated. Covalently cross-linked alginate hydrogels were created using carbodiimide chemistry, followed by a freeze-drying step to impart porosity and create porous scaffolds. Results showed that porous alginate scaffolds exhibited shape-memory recovery and mechanical behaviour that could be modulated depending on the cross-linker concentrations. The scaffold can be repeatedly compressed and expanded, which provides the potential to deliver the biomaterial directly to the damaged area of the AF tissue. In vitro experiments demonstrated that scaffolds were cytocompatible and supported cell seeding, penetration and proliferation under intervertebral-disc-like microenvironmental conditions (low glucose media and low oxygen concentration). Extracellular matrix (ECM) was secreted by AF cells with TGF-β3 stimulation and after 21days had filled the porous scaffold network. This biological matrix was rich in sulfated glycosaminoglycan and collagen type I, which are the main compounds of native AF tissue. Successful ECM deposition was also confirmed by the increase in the peak stress of the scaffold. However, the immaturity of the matrix network after only 21days of in vitro culture was not sufficient to attain native AF tissue mechanical properties. The ability to deliver porous scaffolds using minimal invasive approaches that can potentially promote the regeneration of AF defects provides an exciting new avenue for disc repair.

Phenotype variations affect genetic association studies of degenerative disc disease: conclusions of analysis of genetic association of 58 single nucleotide polymorphisms with highly specific phenotypes for disc degeneration in 332 subjects

BACKGROUND CONTEXT

Although the influence of genetics on the process of disc degeneration is well recognized, in recently published studies, there is a wide variation in the race and selection criteria for such study populations. More importantly, the radiographic features of disc degeneration that are selected to represent the disc degeneration phenotype are variable in these studies. The study presented here evaluates the association between single nucleotide polymorphisms (SNPs) of candidate genes and three distinct radiographic features that can be defined as the degenerative disc disease (DDD) phenotype.

PURPOSE

The study objectives were to examine the allelic diversity of 58 SNPs related to 35 candidate genes related to lumbar DDD, to evaluate the association in a hitherto unevaluated ethnic Indian population that represents more than one-sixth of the world population, and to analyze how genetic associations can vary in the same study subjects with the choice of phenotype.

STUDY DESIGN

A cross-sectional, case-control study of an ethnic Indian population was carried out.

METHODS

Fifty-eight SNPs in 35 potential candidate genes were evaluated in 342 subjects and the associations were analyzed against three highly specific markers for DDD, namely disc degeneration by Pfirrmann grading, end-plate damage evaluated by total end-plate damage score, and annular tears evaluated by disc herniations and hyperintense zones. Genotyping of cases and controls was performed on a genome-wide SNP array to identify potential associated disease loci. The results from the genome-wide SNP array were then used to facilitate SNP selection and genotype validation was conducted using Sequenom-based genotyping.

RESULTS

Eleven of the 58 SNPs provided evidence of association with one of the phenotypes. For annular tears, rs1042631 SNP of AGC1 and rs467691 SNP of ADAMTS5 were highly significantly associated (p<.01) and SNPs in NGFB, IL1B, IL18RAP, and MMP10 were also significantly associated (p<.05). The rs4076018 SNP of NGFB was highly significant (p<.01) and rs2292657 SNP of GLI1 was significantly (p<.05) correlated to disc degeneration. For end-plate damage, the rs2252070 SNP of MMP 13 showed a significant association (p<.05). Previously associated genes such as COL 9, SKT, CHST 3, CILP, IGFR, SOXp, BMP, MMP 2-12, ADH2, IL1RN, and COX2 were not significantly associated and new associations (NGFB and GLI1) were identified. The validity of all the associations was found to be phenotype dependent.

CONCLUSIONS

For the first time, genetic associations with DDD have been performed in an Indian population. Apart from identifying new associations, the highlight of the study was that in the same study population with DDD, SNP associations completely changed when different radiographic features were used to define the DDD phenotype. Our study results therefore indicate that standardization of the phenotypes chosen to study the genetics of disc degeneration is essential and should be strongly considered before planning genetic association studies.

Evaluation of intervertebral disc cartilaginous endplate structure using magnetic resonance imaging

PURPOSE

The cartilaginous endplate (CEP) is a thin layer of hyaline cartilage positioned between the vertebral endplate and nucleus pulposus (NP) that functions both as a mechanical barrier and as a gateway for nutrient transport into the disc. Despite its critical role in disc nutrition and degeneration, the morphology of the CEP has not been well characterized. The objective of this study was to visualize and report observations of the CEP three-dimensional morphology, and quantify CEP thickness using an MRI FLASH (fast low-angle shot) pulse sequence.

METHODS

MR imaging of ex vivo human cadaveric lumbar spine segments (N = 17) was performed in a 7T MRI scanner with sequence parameters that were selected by utilizing high-resolution T1 mapping, and an analytical MRI signal model to optimize image contrast between CEP and NP. The CEP thickness at five locations along the mid-sagittal AP direction (center, 5 mm, 10 mm off-center towards anterior and posterior) was measured, and analyzed using two-way ANOVA and a post hoc Bonferonni test. For further investigation, six in vivo volunteers were imaged with a similar sequence in a 3T MRI scanner. In addition, decalcified and undecalcified histology was performed, which confirmed that the FLASH sequence successfully detected the CEP.

RESULTS

CEP thickness determined by MRI in the mid-sagittal plane across all lumbar disc levels and locations was 0.77 ± 0.24 mm ex vivo. The CEP thickness was not different across disc levels, but was thinner toward the center of the disc.

CONCLUSIONS

This study demonstrates the potential of MRI FLASH imaging for structural quantification of the CEP geometry, which may be developed as a technique to evaluate changes in the CEP with disc degeneration in future applications.

Osthole, a herbal compound, alleviates nucleus pulposus-evoked nociceptive responses through the suppression of overexpression of acid-sensing ion channel 3 (ASIC3) in rat dorsal root ganglion

BACKGROUND

Osthole (Ost), a natural coumarin derivative, has been shown to inhibit many pro-inflammatory mediators and block voltage-gated Na+ channels. During inflammation, acidosis is an important pain inducer which activates nociceptors by gating depolarizing cationic channels, such as acid-sensing ion channel 3 (ASIC3). The aim of this study was to examine the effects of Ost on nucleus pulposus-evoked nociceptive responses and ASIC3 over-expression in the rat dorsal root ganglion, and to investigate the possible mechanism.

MATERIAL/METHODS

Radicular pain was generated with application of nucleus pulposus (NP) to nerve root. Mechanical allodynia was evaluated using von Frey filaments with logarithmically incremental rigidity to calculate the 50% probability thresholds for mechanical paw withdrawal. ASIC3 protein expression in dorsal root ganglions (DRGs) was assessed with Western blot and immunohistochemistry. Membrane potential (MP) shift of DRG neurons induced by ASIC3-sensitive acid (pH6.5) was determined by DiBAC(4) (3) fluorescence intensity (F.I.).

RESULTS

The NP-evoked mechanical hyperalgesia model showed allodynia for 3 weeks, and ASIC3 expression was up-regulated in DRG neurons, reaching peak on Day 7. Epidural administration of Ost induced a remarkable and prolonged antinociceptive effect, accompanied by an inhibition of over-expressed ASIC3 protein and of abnormal shift of MP. Amiloride (Ami), an antagonist of ASIC3, strengthened the antinociceptive effect of Ost.

CONCLUSIONS

Up-regulation of ASIC3 expression may be associated with NP-evoked mechanical hyperalgesia. A single epidural injection of Ost decreased ASIC3 expression in DGR neurons and the pain in the NP-evoked mechanical hyperalgesia model. Osthole may be of great benefit for preventing chronic pain status often seen in lumbar disc herniation (LDH).

Height loss in older women: risk of hip fracture and mortality independent of vertebral fractures

We examined if height loss in older women predicts risk of hip fractures, other nonspine fractures, and mortality, and whether this risk is independent of both vertebral fractures (VFx) and bone mineral density (BMD) by dual-energy X-ray absorptiometry. Among 3124 women age 65 and older in the Study of Osteoporotic Fractures, we assessed the association with measured height change between year 0 (1986-1988) and year 15 (2002-2004) and subsequent risk of radiologically confirmed hip fractures, other nonspine fractures, and mortality assessed via death certificates. Follow-up occurred every 4 months for fractures and vital status (>95% contacts complete). Cox proportional hazards models assessed risk of hip fracture, nonspine fracture, and mortality over a mean of 5 years after height change was assessed (ie, after final height measurement). After adjustment for VFx, BMD, and other potential covariates, height loss >5 cm was associated with a marked increased risk of hip fracture [hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.06, 2.12], nonspine fracture (HR 1.48; 95% CI 1.20, 1.83), and mortality (1.45; 95% CI 1.21, 1.73). Although primary analyses were a subset of 3124 survivors healthy enough to return for a year 15 height measurement, a sensitivity analysis in the entire cohort (n = 9677) using initial height in earlier adulthood [self-reported height at age 25 (-40 years) to measured height age >65 years (Year 0)] demonstrated consistent results. Height loss >5 cm (2″) in older women was associated with a nearly 50% increased risk of hip fracture, nonspine fracture, and mortality-independent of incident VFx and BMD.

Intervertebral disk tissue engineering using biphasic silk composite scaffolds

Scaffolds composed of synthetic, natural, and hybrid materials have been investigated as options to restore intervertebral disk (IVD) tissue function. These systems fall short of the lamellar features of the native annulus fibrosus (AF) tissue or focus only on the nucleus pulposus (NP) tissue. However, successful regeneration of the entire IVD requires a combination approach to restore functions of both the AF and NP. To address this need, a biphasic biomaterial structure was generated by using silk protein for the AF and fibrin/hyaluronic acid (HA) gels for the NP. Two cell types, porcine AF cells and chondrocytes, were utilized. For the AF tissue, two types of scaffold morphologies, lamellar and porous, were studied with the porous system serving as a control. Toroidal scaffolds formed out of the lamellar, and porous silk materials were used to generate structures with an outer diameter of 8 mm, inner diameter of 3.5 mm, and a height of 3 mm (the interlamellar distance in the lamellar scaffold was 150-250 μm, and the average pore sizes in the porous scaffolds were 100-250 μm). The scaffolds were seeded with porcine AF cells to form AF tissue, whereas porcine chondrocytes were encapsulated in fibrin/HA hydrogels for the NP tissue and embedded in the center of the toroidal disk. Histology, biochemical assays, and gene expression indicated that the lamellar scaffolds supported AF-like tissue over 2 weeks. Porcine chondrocytes formed the NP phenotype within the hydrogel after 4 weeks of culture with the AF tissue that had been previously cultured for 2 weeks, for a total of 6 weeks of cultivation. This biphasic scaffold simulating in combination of both AF and NP tissues was effective in the formation of the total IVD in vitro.