Genetic factors are associated with modic changes in endplates of lumbar vertebral bodies

Clinical and Radiological Outcomes of Cervical Disc Arthroplasty in Patients with Modic Change

OBJECTIVE

Modic change (MC) is defined as abnormalities observed in the intervertebral disc subchondral and adjacent vertebral endplate subchondral bone changes. Most studies on MC were reported in the lumbar spine and associated with lower back pain. However, MC has been rarely reported in the cervical spine, let alone in those who underwent cervical disc replacement (CDR). This study aimed to focus on MC in the cervical spine and reveal clinical and radiological parameters, especially heterotopic ossification (HO), for patients who underwent CDR. Furthermore, we illustrated the association between MC and HO.

METHODS

We retrospectively reviewed patients who underwent CDA from January 2008 to December 2019. The Japanese Orthopaedic Association (JOA), Neck Disability Index (NDI), and Visual Analog Scale (VAS) scores were used to evaluate the clinical outcomes. Radiological evaluations were used to conclude the cervical alignment (CL) and range of motion (ROM) of C2-7, functional spinal unit angle (FSUA), shell angle (SA), FSU height, and HO. Univariate and multivariate logistic regressions were performed to identify the risk factors for HO. The Kaplan-Meier (K-M) method was used to analyze potential risk factors, and multivariate Cox regression was used to identify independent risk factors.

RESULTS

A total of 139 patients were evaluated, with a mean follow-up time of 46.53 ± 26.60 months. Forty-nine patients were assigned to the MC group and 90 to the non-MC group. The incidence of MC was 35.3%, with type 2 being the most common. Clinical outcomes (JOA, NDI, VAS) showed no significant difference between the two groups. The differences in C2-7 ROM between the two groups were not significant, while the differences in SA ROM and FSUA ROM were significantly higher in the non-MC than in the MC group (p < 0.05). Besides, FSU height in MC group was significantly lower than that in non-MC group. Parameters concerning CL, including C2-7, FSUA, SA, were not significantly different between the two groups. The incidence of HO and high-grade HO, respectively, in the MC group was 83.7% and 30.6%, while that in the non-MC group was 53.3% and 2.2%, and such differences were significant (p < 0.05). Multivariate logistic regression analyses and Cox regression showed that MC and involved level were significantly associated with HO occurrence (p < 0.05). No implant migration and secondary surgery were observed.

CONCLUSION

MC mainly affected the incidence of HO. Preoperative MC was significantly associated with HO formation after CDR and should be identified as a potential risk factor for HO. Rigorous criteria for MC should be taken into consideration when selecting appropriate candidates for CDR.

Investigating the impact of cartilaginous endplate herniation on recovery from percutaneous endoscopic lumbar discectomy

OBJECTIVE

This study aimed to evaluate the influence of herniation of cartilaginous endplates on postoperative pain and functional recovery in patients undergoing percutaneous endoscopic lumbar discectomy (PELD) for lumbar disc herniation (LDH).

METHODS

A retrospective analysis was conducted on 126 patients with LDH treated with PELD at the Third Hospital of Hebei Medical University from January 2021 to January 2022. Whether cartilaginous endplates had herniated was identified by analyzing these specific findings from MRI scans: posterior marginal nodes, posterior osteophytes, mid endplate irregularities, heterogeneous low signal intensity of extruded material, and Modic changes in posterior corners and mid endplates. Patients were assessed for postoperative pain using the Visual Analogue Scale (VAS) and functional recovery using the Oswestry Disability Index (ODI) and Modified MacNab criteria. Statistical analyses compared outcomes based on the presence of herniation of cartilaginous endplates.

RESULTS

Patients with herniation of cartilaginous endplates experienced higher pain scores early postoperatively but showed significant improvement in pain and functional status over the long term. The back pain VAS scores showed significant differences between the groups with and without herniation of cartilaginous endplates on postoperative day 1 and 1 month (P < 0.05). Leg pain VAS scores showed significant differences on postoperative day 1 (P < 0.05). Modic changes were significantly associated with variations in postoperative recovery, highlighting their importance in predicting patient outcomes. In patients with herniation of cartilaginous endplates, there were statistically significant differences in the back pain VAS scores at 1 month postoperatively and the ODI functional scores on postoperative day 1 between the groups with and without Modic changes (P < 0.05). There were no significant differences in the surgical outcomes between patients with and without these conditions regarding the Modified MacNab criteria (P > 0.05).

CONCLUSION

Herniation of cartilaginous endplates significantly affect early postoperative pain and functional recovery in LDH patients undergoing PELD. These findings emphasize the need for clinical consideration of these imaging features in the preoperative planning and postoperative management to enhance patient outcomes and satisfaction.

The Clinical Significance of the Modic Changes Grading Score

STUDY DESIGN

Cross-sectional retrospective observational study.

OBJECTIVE

To evaluate the reliability and clinical utility of the Modic changes (MC) grading score.

METHOD

Patients from the Danish national spine registry, DaneSpine, scheduled for lumbar discectomy were identified. MRI of patients with MC were graded based on vertical height involvement: Grade A (<25%), Grade B (25%-50%), and Grade C (>50%). All MRIs were reviewed by 2 physicians to evaluate the reliability of the MC grade.

RESULTS

Of 213 patients included, 142 patients had MC, 71 with MC-1 and 71 with MC-2; 34% were Grade A, 45% were Grade B, and 21% were Grade C. MC grade demonstrated substantial intra-rater (κ = .68) and inter-rater (κ = .61) reliability. A significantly higher proportion (n = 40, 57%) of patients with MC-1 had a severe MC grade compared to patients with MC-2 (n = 30, 43%, P < .001). Severe MC grade was associated with the presence of severe lumbar disc degeneration (DD) (Pfirrmann grade = V, P = .024), worse preoperative ODI (52.49 vs 44.17, P = .021) and EQ-5D scores (.26 vs .46, P = .053). MC alone including type was not associated with a significant difference in patient-reported outcomes (P > .05).

CONCLUSION

The MC grade score was demonstrated to have substantial intra- and inter-observer reliability. Severe MC grade was associated with both severe DD and MC type, being more prevalent in patients with MC-1. The MC grade was also significantly associated with worse disability and reduced health-related quality of life. Results from the study suggest that MC grade is more clinically important than MC type.

Discovery of circulating blood biomarkers in patients with and without Modic changes of the lumbar spine: a preliminary analysis

PURPOSE

The following study aimed to determine the existence of blood biomarkers in symptomatic patients with or without lumbar Modic changes (MC).

METHODS

A cross-sectional sub-analyses of a prospective cohort was performed. Fasting blood samples were collected from patients with and without lumbar MC who had undergone spinal fusion or microdiscectomy. An 80-plex panel and CCL5/RANTES were used to assess preoperative plasma cytokine concentrations. Patient demographics and imaging phenotypes were also assessed.

RESULTS

Thirty-one subjects were analysed (n = 18 no MC; n = 13 MC). No significant differences were found in age, sex, body mass index, smoking and alcohol history, and surgical procedure (i.e. fusion, decompression) between the two groups (p > 0.05). Several statistically significant blood biomarkers in MC patients were identified, including elevated levels of C-C Motif Chemokine Ligand 5 (CCL5, p = 0.0006), while Macrophage Migration Inhibitory Factor (MIF) was significantly lower (p = 0.009). Additionally, C-X-C Motif Chemokine Ligand 5 (CXCL5, p = 0.052), Pentraxin 3 (PTX3, p = 0.06) and Galectin-3 (Gal-3, p = 0.07) showed potential relevance. Moreover, MC patients exhibited significantly higher levels of disc degeneration (p = 0.0001) and displacement severity (p = 0.020). Based on multivariate analyses and controlling for disc degeneration/displacement, CCL5 (OR 1.02; 95% CI 1.002-1.033; p = 0.028) and MIF (OR 0.60; 95% CI 0.382-0.951; p = 0.030) were independently associated with MC patients.

CONCLUSION

This "proof-of-concept" study is the first to identify specific and significantly circulating blood biomarkers associated with symptomatic patients with lumbar MC, independent of disc alterations of degeneration and/or bulges/herniations. Specifically, differences in CCL5 and MIF protein levels were significantly noted in MC patients compared to those without MC.

A novel missense COL9A3 variant in a pedigree with multiple lumbar disc herniation

Trp3 allele in COL9A3 gene has been widely studied in populations with intervertebral disc disease. We identified a novel pathogenic variant in COL9A3 gene in a pedigree with multiple lumbar disc herniation (LDH). The proband was a 14-year-old boy who developed LDH at the L4/5 and L5/S1 spinal segments. His father, paternal aunt and grandfather were diagnosed with LDH at an age of 35, 30 and 23, respectively. By applying whole exome sequencing, a heterozygous missense variant (c.1150C > T, p.Arg384Trp) in COL9A3 was identified. According to the ACMG guidelines, this variant is predicted to be pathogenic. In addition, prediction tools found COL9A3 protein of this variant a reduced stability, some changed charge properties, and an altered spatial conformation. Findings expanded the mutational spectrum of LDH and contributed to the understanding of COL9A3 in the pathogenesis of LDH.

Modic change is associated with increased BMI but not autoimmune diseases in TwinsUK

PURPOSE

Low back pain (LBP) is one of the largest causes of morbidity worldwide. The aetiology of LBP is complex, and many factors contribute to the onset. Bone marrow lesions within the vertebra adjacent to an intervertebral degenerate disc named Modic change (MC) have been suggested as a diagnostic subgroup of LBP. Autoimmune response has been proposed to be one of the causes that promote the development of MC. The aim of the current investigation is to assess prevalence and severity of MC and LBP in participants with an autoimmune disease diagnosis in a well-documented cohort of adult twin volunteers.

METHODS

Multivariate generalized mixed linear models (GLMM) were implemented in order to calculate the association between having an autoimmune disorder and MC prevalence, width and severe and disabling LBP. The model was corrected for family structure as well as for covariates such as age, BMI and smoking.

RESULTS

No association was found between diagnosis of autoimmune disorder and MC. Interestingly, BMI was independently associated with MC width but not to MC prevalence. These results help to shed light on the relationship between MC and autoimmunity as well as the role of BMI in the development of the lesions.

CONCLUSION

This study is the first to examine autoimmune disorders and MC prevalence in a large, population-based female cohort. The study was well powered to detect a small effect. No association was found between having a diagnosis of one or more autoimmune conditions and MC prevalence, width or LBP.

Genetic Variations in IL-1β, TNF-α, and TGF-β Associated with the Severity of Chronic Cervical Spondylitis in Patients

Chronic cervical spondylitis (CCS), a degenerative disorder of the spine, is known for causing disability among old and young people. Single-nucleotide polymorphisms (SNPs) in various cytokine genes have demonstrated an impactful association with several inflammatory disorders. In the present study, we have investigated the SNPs and allelic distribution of the three most prevalent cytokines genes, IL-1β (-511C/T), TNF-α (-308G/A), and TGF-β (-509C/T), along with serum levels of these cytokines in 252 subjects. SNPs were analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and digested fragments were separated and visualized using agarose gel electrophoresis and Native Polyacrylamide gel electrophoresis (PAGE). The serum cytokine levels were analyzed with a flow cytometer using a customized multiplex bead-based assay. It was observed that these SNPs did not reflect the susceptibility to CCS but were associated with susceptibility to CCS. We found a significant association between the C/C and G/G genotypes and the C and G alleles of IL-1β and TNF-α, respectively, suggesting a lower risk of CCS. The frequency distribution of risk alleles (-511T) and (-308A) were simultaneously higher in CCS compared to the control, reflecting the susceptibility to CCS. TGF-β showed a significant association with disease susceptibility, along with a significant correlation between age and the chronicity of CCS. The serum cytokine levels were significantly different in CCS and controls.

Gene locus polymorphisms and expression levels of interleukin-1 in lumbar disc disease: A MOOSE-compliant meta-analysis and immunohistochemical study

OBJECTIVE

To investigate the association between interleukin (IL)-1α (rs1800587), IL-1β (rs1143634) and IL-1 receptor antagonist (RN) variable number tandem repeat polymorphisms, expression levels and lumbar disc disease (LDD).

METHODS

All relevant articles were searched from 4 databases including PubMed, Embase, Web of Science and China National Knowledge Infrastructure. Odds ratios (OR) with 95% confidence intervals (CI) were calculated to evaluate the association between IL-1 gene locus polymorphisms (rs1800587 in IL-1α, rs1143634 in IL-1β, variable number tandem repeat in interleukin-1 receptor antagonist) and LDD susceptibility. Statistical analysis was conducted by Review Manager (Revman) 5.31 software (Nordic Cochrane Centre, Cochrane Collaboration, Copenhagen, Denmark). Furthermore, qRT-PCR and immunohistochemistry were performed to evaluate IL-1α, IL-1β and interleukin-1 receptor antagonist expressions in the normal and degenerated disc.

RESULTS

A total of 15 case-control studies (1455 cases and 2362 controls) were included in our meta-analysis. The pooled results suggested that IL-1α rs1800587 polymorphism was associated with an increased risk of LDD in overall population (T vs. C, OR = 1.21, 95% CI = 1.04-1.40, P = .01). The subgroup analysis found a significant association between IL-1β rs1143634 polymorphism and LDD in Asian population (T vs. C, OR = 0.61, 95% CI = 0.39-0.96, P = .03). Results of qRT-PCR and immunohistochemistry demonstrated that expressions of IL-1α and IL-1β were significantly increased in the degenerated disc. (all P < .05).

CONCLUSION

IL-1α rs1800587 and IL-1β rs1143634 polymorphisms were significantly associated with LDD in overall population and in Asian population, respectively. The increased expression levels of IL-1α and IL-1β may be the important risk factors for LDD.

Immuno-Modulatory Effects of Intervertebral Disc Cells

Low back pain is a highly prevalent, chronic, and costly medical condition predominantly triggered by intervertebral disc degeneration (IDD). IDD is often caused by structural and biochemical changes in intervertebral discs (IVD) that prompt a pathologic shift from an anabolic to catabolic state, affecting extracellular matrix (ECM) production, enzyme generation, cytokine and chemokine production, neurotrophic and angiogenic factor production. The IVD is an immune-privileged organ. However, during degeneration immune cells and inflammatory factors can infiltrate through defects in the cartilage endplate and annulus fibrosus fissures, further accelerating the catabolic environment. Remarkably, though, catabolic ECM disruption also occurs in the absence of immune cell infiltration, largely due to native disc cell production of catabolic enzymes and cytokines. An unbalanced metabolism could be induced by many different factors, including a harsh microenvironment, biomechanical cues, genetics, and infection. The complex, multifactorial nature of IDD brings the challenge of identifying key factors which initiate the degenerative cascade, eventually leading to back pain. These factors are often investigated through methods including animal models, 3D cell culture, bioreactors, and computational models. However, the crosstalk between the IVD, immune system, and shifted metabolism is frequently misconstrued, often with the assumption that the presence of cytokines and chemokines is synonymous to inflammation or an immune response, which is not true for the intact disc. Therefore, this review will tackle immunomodulatory and IVD cell roles in IDD, clarifying the differences between cellular involvements and implications for therapeutic development and assessing models used to explore inflammatory or catabolic IVD environments.

ISSLS PRIZE in Clinical Science 2022: Epidemiology, risk factors and clinical impact of juvenile Modic changes in paediatric patients with low back pain

PURPOSE

It's a long-held belief that Modic changes (MC) occur only in adults, with advanced age, and are highly associated with pain and adverse outcomes. The following study addressed the epidemiology, risk factors and clinical relevance of MC in young paediatric patients.

METHODS

Two hundred and seven consecutive patients with no history of deformities, neoplasms, trauma, or infections were included in this ambispective study. MRIs were utilized to assess MCs and types, and other degenerative disc/endplate abnormalities. Subject demographics, duration of symptoms, clinic visits, conservative management (physical therapy, NSAIDs, opioids, injections) and surgery were noted.

RESULTS

The mean age was 16.5 years old (46.9% males), 14% had MCs and they occurred throughout the spine. Subject baseline demographics were similar between MCs and non-MCs patients (p > 0.05). Modic type 2 (50%) was the most common type (type 1:27.1%; type 3:18.8%; mixed:4.7%). Multivariate analyses noted that endplate damage (OR: 11.36), disc degeneration (OR: 5.81), disc space narrowing (OR: 5.77), Schmorl's nodes (OR: 4.30) and spondylolisthesis (OR: 3.55) to be significantly associated with MCs (p < 0.05). No significant differences in conservative management were noted between Modic and non-MCs patients (p > 0.05). Among surgery patients (n = 44), 21% also had MCs (p = 0.134). Symptom-duration was significantly greater in MC patients (p = 0.049).

CONCLUSION

Contrary to traditional dogma, robust evidence now exists noting that MCs and their types can develop in children. Our findings give credence to the "Juvenile" variant of MCs, whereby its implications throughout the lifespan need to be assessed. Juvenile MCs have prolonged symptoms and related to specific structural spine phenotypes.

Modic Change: An Emerging Complication in the Aging Population

STUDY DESIGN

This was a literature review.

OBJECTIVE

The objective of this study was to review the pathogenesis, prevalence, clinical associations, diagnostic modalities, and treatment options for patients with lower back pain (LBP) associated with Modic change (MC).

SUMMARY OF BACKGROUND DATA

Vertebral body endplates are located between the intervertebral disk and adjacent vertebral body. Despite their crucial roles in nutrition and biomechanical stability, vertebral endplates are extremely susceptible to mechanical failure. Studies examining the events leading to disk degeneration have shown that failure often begins at the endplates. Endplate degeneration with subchondral bone marrow changes were originally noticed on magnetic resonance imaging. These magnetic resonance imaging signal changes were classified as MC.

METHODS

A literature review was conducted on the history, etiology, risk factors, diagnostic modalities, and treatment of LBP with MC.

RESULTS

Type 1 MC refers to the presence of increased vascularization and bone marrow edema within the vertebral body. Type 2 MC involves fatty marrow replacement within the vertebral body. Type 3 MC reflects subchondral bone sclerosis. Despite the original classification, research has supported the notion that MCs possess a transitional nature. Furthermore, type 1 MCs have been strongly associated with inflammation and severe LBP, while types 2 and 3 tend to be more stable and demonstrate less refractory pain. With a strong association to LBP, understanding the etiology of MC is crucial to optimal treatment planning. Various etiologic theories have been proposed including autoimmunity, mechanics, infection, and genetic factors.

CONCLUSIONS

With the aging nature of the population, MC has emerged as an extremely prevalent issue. Research into the pathogenesis of MC is important for planning preventative and therapeutic strategies. Such strategies may include rehabilitation, surgical fixation, stabilization, steroid or cement injection, or antibiotics. Improved diagnostic methods in clinical practice are thus critical to properly identify patients suffering from MC, plan early intervention, and hasten return to functioning.

Modic changes and its association with other MRI phenotypes in east Anatolian low back pain patients

OBJECTIVE

Modic changes (MCs) are known to be associated with low back pain (LBP). Literature contains conflicting reports about the prevalence of MCs and other spinal phenotypes among different populations with LBP patients. We aimed to evaluate the prevalence of MCs in the lumbar spine and associated features in Eastern Anatolian chronic LBP patients.

METHODS

The study sample comprised of 786 consecutive patients [(490 female, 296 male), (mean age 39.7; range 20-78)] with a history of low back pain for at least 3 months. Data about MCs involvement, Schmorl's nodes (SN), disc degeneration (DD), disc displacement, disc height and osteophytes were obtained via MRI. Patients' demographic characteristics, Oswestry disability index (ODI) and visual analog scale (VAS) scores were assessed using a questionnaire.

RESULTS

MCs were present in 67.2% (528/786) of the patients. Of all evaluated lumbar-level changes, 86 (6.2%) were Type I, 991 (76.8%) were Type II, 11 (0.8%) were Type III, 47 (6.5%) were Type II/III, 89 (8.5%) were Type I/II, and 29 (1.2%) were Type I/II/III MCs. MCs were significantly associated with severe DD (p < 0.001), disc displacement (p < 0.001), SN (p < 0.001), and osteophytes (p < 0.001). In the multivariate regression analysis, BMI (for both ODI and VAS) and age (only for ODI) were the only independent predictors of clinical severity.

CONCLUSIONS

The present study is the largest cross-sectional study of adult members of the Eastern Anatolian population with chronic LBP. Modic changes were detected in 67.2% of patients with chronic LBP and the prevalence of other phenotypic features differed significantly between MCs and non-MCs disc levels. Nevertheless, the results of the current study do not support a causal relationship of MCs or any MRI changes with clinical symptom severity.

Diagnostic Role of Magnetic Resonance Imaging in Low Back Pain Caused by Vertebral Endplate Degeneration

Low back pain (LBP) is a common health issue worldwide with a huge economic burden on healthcare systems. In the United States alone, the cost is estimated to be $100 billion each year. Intervertebral disc degeneration is considered one of the primary causes of LBP. Moreover, the critical role of the vertebral endplates in disc degeneration and LBP is becoming apparent. Endplate abnormalities are closely correlated with disc degeneration and pain in the lumbar spine. Imaging modalities such as plain film radiography, computed tomography, and fluoroscopy are helpful but not very effective in detecting the causes behind LBP. Magnetic resonance imaging (MRI) can be used to acquire high-quality three-dimensional images of the lumbar spine without using ionizing radiation. Therefore, it is increasingly being used to diagnose spinal disorders. However, according to the American College of Radiology, current referral and justification guidelines for MRI are not sufficiently clear to guide clinical practice. This review aimed to evaluate the role of MRI in diagnosing LBP by considering the correlative contributions of vertebral endplates. The findings of the review indicate that MRI allows for fine evaluations of endplate morphology, endplate defects, diffusion and perfusion properties of the endplate, and Modic changes. Changes in these characteristics of the endplate were found to be closely correlated with disc degeneration and LBP. The collective evidence from the literature suggests that MRI may be the imaging modality of choice for patients suffering from LBP. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 3.

Lifestyle and lifetime occupational exposures may not play a role in the pathogenesis of Modic changes on the lumbar spine MR images

BACKGROUND CONTEXT

Modic changes (MCs) have long been suspected as a pathologic cause of back pain. Although much attention has been focused on clinical perspectives, the etiology of MCs remains unclear. Although some studies have reported that sex, body mass index (BMI), cigarette smoking, and physical loading may associate with MCs, the observed associations are inconsistent among studies.

PURPOSE

To investigate associations between MCs and lifestyle and lifetime occupational exposures using a general population sample.

STUDY DESIGN

Cross-sectional study.

PATIENT SAMPLE

The study was an extension of the Hangzhou Lumbar Spine Study, a population-based study of mainland Chinese focusing on lumbar degenerative changes. A total of 644 randomly selected subjects from a typical community in Hangzhou, Eastern China participated.

OUTCOME MEASURES

The presence and type of MCs in the lumbosacral spine were evaluated on sagittal magnetic resonance images. Demographics, lifestyle factors, and occupational exposures were measured using a structured interview.

METHODS

Univariate and multivariate logistic regressions were used to examine the associations of MCs with various environmental exposures.

RESULTS

Among the 644 subjects (52.6±13.9 years; range 20-88 years) included in this study, 44.7% had MCs. In univariate regression analyses, the presence of MCs was associated with greater age, higher BMI, greater cigarette smoking, regular exercise, and absence of daily vehicle vibration. Modic changes were not univariately associated with sex or alcohol consumption. In addition, all occupational loading measurements were associated with the occurrence of MCs in univariate analyses, except work time spent in vehicles and work-related back injuries. However, in multivariate regression analyses, no statistically significant associations between the occurrence of MCs and lifestyle or lifetime occupational exposures were observed after adjusting for age, sex, and BMI.

CONCLUSIONS

Age is an important determinant of MCs, with BMI and sex also playing a role. Lifestyle and occupational factors appear to have minor effects, if any, on the pathogenesis of MCs in the lumbar spine.

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

Background

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

Methods

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

Results

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

Conclusions

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

Redefining lumbar spinal stenosis as a developmental syndrome: does age matter?

OBJECTIVE

Age is commonly thought to be a risk factor in defining lumbar spinal stenosis (LSS) degenerative or developmental subtypes. This article is a follow-up to a previous article ("Redefining Lumbar Spinal Stenosis as a Developmental Syndrome: An MRI-Based Multivariate Analysis of Findings in 709 Patients Throughout the 16- to 82-Year Age Spectrum") that describes the radiological differences between developmental and degenerative types of LSS. MRI-based analysis of "degeneration" variables and spinal canal morphometric characteristics of LSS segments have been thought to correlate with age at presentation.

METHODS

The authors performed a re-analysis of data from their previously reported prospective MRI-based study, stratifying data from the 709 cases into 3 age categories of equal size (instead of the original < 60 vs ≥ 60 years). Relative spinal canal dimensions, as well as radiological degenerative variables from L1 to S1, were analyzed across age groups in a multivariate mode. The total degenerative scale score (TDSS) for each lumbar segment from L1 to S1 was calculated for each patient. The relationships between age and qualitative stenosis grades, TDSS, disc degeneration, and facet degeneration were analyzed using Pearson's product-moment correlation and multiple regression.

RESULTS

Multivariate analysis of TDSS and spinal canal dimensions revealed highly significant differences across the 3 age groups at L2-3 and L3-4 and a weaker, but still significant, association with changes at L5-S1. Age helped to explain only 9.6% and 12.2% of the variance in TDSS at L1-2 and L2-3, respectively, with a moderate positive correlation, and 7.8%, 1.2%, and 1.9% of the variance in TDSS at L3-4, L4-5, and L5-S1, respectively, with weak positive correlation. Age explained 24%, 26%, and 18.4% of the variance in lumbar intervertebral disc (LID) degeneration at L1-2, L2-3, and L3-4, respectively, while it explained only 6.2% and 7.2% of the variance of LID degeneration at L4-5 and L5-S1, respectively. Age explained only 2.5%, 4.0%, 1.2%, 0.8%, and 0.8% of the variance in facet degeneration at L1-2, L2-3, L3-4, L4-5, and L5-S1, respectively.

CONCLUSIONS

Age at presentation correlated weakly with degeneration variables and spinal canal morphometries in LSS segments. Age correlated with upper lumbar segment (L1-4) degeneration more than with lower segment (L4-S1) degeneration. The actual chronological age of the patients did not significantly correlate with the extent of degenerative pathology of the lumbar stenosis segments. These study results lend support for a developmental contribution to LSS.

Genome-wide meta-analysis identifies genetic locus on chromosome 9 associated with Modic changes

BACKGROUND

Low back pain (LBP) is a common disabling condition. Lumbar disc degeneration (LDD) may be a contributing factor for LBP. Modic change (MC), a distinct phenotype of LDD, is presented as a pathological bone marrow signal change adjacent to vertebral endplate on MRI. It is strongly associated with LBP and has heritability around 30%. Our objective was to identify genetic loci associated with MC using a genome-wide meta-analysis.

METHODS

Presence of MC was evaluated in lumbar MRI in the Northern Finland Birth Cohort 1966 (n=1182) and TwinsUK (n=647). Genome-wide association analyses were carried out using linear regression model. Inverse-variance weighting approach was used in the meta-analysis.

RESULTS

A locus associated with MC (p<5e-8) was found on chromosome 9 with the lead SNP rs1934268 in an intron of the PTPRD gene. It is located in the binding region of BCL11A, SPI1 and PBX3 transcription factors. The SNP was nominally associated with LBP in TwinsUK (p=0.001) but not associated in the UK Biobank (p=0.914). Suggestive signals (p<1e-5) were identified near XKR4, SCIN, MGMT, DLG2, ZNF184 and OPRK1.

CONCLUSION

PTPRD is a novel candidate gene for MC that may act via the development of cartilage or nervous system; further work is needed to define the mechanisms underlying the pathways leading to development of MC. This is the first genome-wide meta-analysis of MC, and the results pave the way for further studies on the genetic factors underlying the various features of spine degeneration and LBP.

Redefining lumbar spinal stenosis as a developmental syndrome: an MRI-based multivariate analysis of findings in 709 patients throughout the 16- to 82-year age spectrum

OBJECTIVEUsing an imaging-based prospective comparative study of 709 eligible patients that was designed to assess lumbar spinal stenosis (LSS) in the ages between 16 and 82 years, the authors aimed to determine whether they could formulate radiological structural differences between the developmental and degenerative types of LSS.METHODSMRI structural changes were prospectively reviewed from 2 age cohorts of patients: those who presented clinically before the age of 60 years and those who presented at 60 years or older. Categorical degeneration variables at L1-S1 segments were compared. A multivariate comparative analysis of global radiographic degenerative variables and spinal dimensions was conducted in both cohorts. The age at presentation was correlated as a covariable.RESULTSA multivariate analysis demonstrated no significant between-groups differences in spinal canal dimensions and stenosis grades in any segments after age was adjusted for. There were no significant variances between the 2 cohorts in global degenerative variables, except at the L4-5 and L5-S1 segments, but with only small effect sizes. Age-related degeneration was found in the upper lumbar segments (L1-4) more than the lower lumbar segments (L4-S1). These findings challenge the notion that stenosis at L4-5 and L5-S1 is mainly associated with degenerative LSS.CONCLUSIONSIntegration of all the morphometric and qualitative characteristics of the 2 LSS cohorts provides evidence for a developmental background for LSS. Based on these findings the authors propose the concept of LSS as a developmental syndrome with superimposed degenerative changes. Further studies can be conducted to clarify the clinical definition of LSS and appropriate management approaches.

Fat Mass and Obesity-Associated (FTO) Gene Polymorphisms Are Associated with Risk of Intervertebral Disc Degeneration in Chinese Han Population: A Case Control Study

BACKGROUND The present study aimed to evaluate whether the fat mass and obesity-associated (FTO) gene polymorphisms are associated with risk of intervertebral disc degeneration (IDD) in a largest Chinese Han population. MATERIAL AND METHODS There were 502 IDD patients and 497 healthy controls enrolled in this study. Nineteen single nucleotide polymorphisms (SNPs) in the FTO gene were tested using the Sequenom MassARRAY platform. The Hardy-Weinberg equilibrium test, followed by allelic, genotypic, haplotypic association, and SNP interaction analyses were used for SNP evaluation. The Genotype-Tissue Expression (GTEx) database was used to evaluate expression quantitative trait loci (eQTL) value of polymorphism. Spearman rank correlation and logistic regression analyses were used for assessing the internal relation between genotypic changes and the risk of IDD. RESULTS Seventeen SNPs survived the Hardy-Weinberg equilibrium test. Allelic analysis showed that allele T of SNP rs1121980 was a risk allele. Haplotypic and SNP interaction analyses suggested that 2 haplotypes and 5 SNP combinations were associated with the predisposition of IDD respectively. GTEx database revealed that the SNP rs1121980 might interfere with the expression of the FTO gene in the muscle-skeletal system. Through clinical statistics analysis, the different genotypes of rs1121980 can present different disease severity of IDD. CONCLUSIONS Our study suggests that rs1121980 can become a biomarker for the screening and prognosis of IDD. The 2 haplotype blocks and 5 SNP-SNP combinations that we discovered might be indicative of the onset of IDD. Therefore, our study might serve as evidence for future IDD molecular diagnosis.

The influence of spinal-pelvic parameters on the prevalence of endplate Modic changes in degenerative thoracolumbar/lumbar kyphosis patients

Background

The typical degeneration of the vertebral endplate shown in MRI imaging is Modic change. The aim of this study was to observe the distribution of the Modic changes of vertebral endplate in degenerative thoracolumbar/lumbar kyphosis (DTK/LK) patients and analyse the correlation between spinal-pelvic parameters and Modic changes.

Methods

The imaging data of 58 patients diagnosed with DTK/LK (coronal Cobb angle<10°with sagittal imbalance) in our hospital from March 2016 to May 2017 were reviewed retrospectively. Observe the prevalence, type and distribution characteristics of Modic changes occurred at the vertebral endplate from T10 to S1;analyse the correlation between Modic changes and disc degeneration, the sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT) and pelvic incidence (PI).

Results

Of the 928 intervertebral endplates from 58 patients, Modic changes occurred at 90 endplates (9.7%) of 30 patients (51.7%). 5 endplates (0.5%) of 3 patients (5.2%) were classified as type I, 68 endplates (7.3%) of 25 patients (43.1%) as type II, 17 endplates (1.8%) of 9 patients (15.5%) as type III. The location of the degenerative endplates: 2 (2.2%) superior and inferior endplates of L1, 3 (3.3%) inferior endplates of T11and T12, 4 (4.4%) superior endplates of L2, 6 (6.7%) inferior endplates of L2 and L4, 8 (8.9%) superior endplates of S1, 9 (10%) superior endplates of L3, 11 (12.2%) inferior endplates of L3 and L5 and superior endplates of L4, 12 (13.3%) superior endplates of L5. Modic changes were significantly correlated with intervertebral disc degeneration (r = 0.414, p<0.01); the amount of Modic changes were significantly correlated with LL (r = -0.562, p = 0.012), SS (r = -0.46, p = 0.048), PT (r = 0.516, p = 0.024).

Conclusions

Most of the Modic changes of vertebral endplates in DTK/LK patients are type II which are prevalently located at L3/4, L4/5 and L5/S1. The Modic changes of vertebral endplates were found to be significantly correlated with disc degeneration, LL, SS, and PT.

Genetic background of degenerative disc disease in the lumbar spine

This is a review paper on the topic of genetic background of degenerative disc diseases in the lumbar spine. Lumbar disc diseases (LDDs), such as lumbar disc degeneration and lumbar disc herniation, are the main cause of low back pain. There are a lot of studies that tried to identify the causes of LDDs. The causes have been categorized into environmental factors and genetic factors. Recent studies revealed that LDDs are mainly caused by genetic factors. Numerous studies have been carried out using the genetic approach for LDDs. The history of these studies is divided into three periods: (1) era of epidemiological research using familial background and twins, (2) era of genomic research using DNA polymorphisms to identify susceptible genes for LDDs, and (3) era of functional research to determine how the genes cause LDDs. This review article was undertaken to present the history of genetic approach to LDDs and to discuss the current issues and future perspectives.

A Whole Exome Study Identifies Novel Candidate Genes for Vertebral Bone Marrow Signal Changes (Modic Changes)

STUDY DESIGN

A family-based study.

OBJECTIVE

The aim of this study was to identify rare genetic factors predisposing to Modic changes (MCs).

SUMMARY OF BACKGROUND DATA

Lumbar disc degeneration (LDD) is one of the contributing factors behind low back pain (LBP). Lumbar MC visualized as bone marrow signal intensity changes on magnetic resonance imaging (MRI) represent a specific phenotype of LDD, which has a stronger association with LBP than LDD without MC.

METHODS

The study set consisted of two Finnish families: Family I included seven affected and four unaffected individuals and Family II eight affected and seven unaffected individuals. MCs were evaluated in 26 individuals using MRI. Whole exome sequencing was used to identify alleles cosegregating with MC. Annotate variation was used to carry out functional annotation of alleles and their frequencies were evaluated using 1000Genomes, Sequencing Initiative Suomi (SISu), and the Exome Aggregation Consortium (ExAC) databases.

RESULTS

We identified predisposing genetic alleles for MC in two Finnish families. In each family, only single allele cosegregated with MC. In Family I, the observed allele was an insertion and deletion in the HSPG2 gene, resulting in a premature termination codon. In Family II, a single nucleotide polymorphism (rs61753465) in the MAML1 gene was identified in all affected family members.

CONCLUSION

We have identified two novel candidate genes, MAML1 and HSPG2, associating with MC. These genes are important in cartilage structure and joint cartilage maintenance. Our findings are novel among lumbar spine degenerative phenotypes.

LEVEL OF EVIDENCE

N/A.

Prevalence, Patterns, and Genetic Association Analysis of Modic Vertebral Endplate Changes

STUDY DESIGN

A prospective genetic association study.

PURPOSE

The etiology of Modic changes (MCs) is unclear. Recently, the role of genetic factors in the etiology of MCs has been evaluated. However, studies with a larger patient subset are lacking, and candidate genes involved in other disc degeneration phenotypes have not been evaluated. We studied the prevalence of MCs and genetic association of 41 candidate genes in a large Indian cohort.

OVERVIEW OF LITERATURE

MCs are vertebral endplate signal changes predominantly observed in the lumbar spine. A significant association between MCs and lumbar disc degeneration and nonspecific low back pain has been described, with the etiopathogenesis implicating various mechanical, infective, and biochemical factors.

METHODS

We studied 809 patients using 1.5-T magnetic resonance imaging to determine the prevalence, patterns, distribution, and type of lumbar MCs. Genetic association analysis of 71 single nucleotide polymorphisms (SNPs) of 41 candidate genes was performed based on the presence or absence of MCs. SNPs were genotyped using the Sequenome platform, and an association test was performed using PLINK software.

RESULTS

The mean age of the study population (n=809) was 36.7±10.8 years. Based on the presence of MCs, the cohort was divided into 702 controls and 107 cases (prevalence, 13%). MCs were more commonly present in the lower (149/251, 59.4%) than in the upper (102/251, 40.6%) endplates. L4-5 endplates were the most commonly affected levels (30.7%). Type 2 MCs were the most commonly observed pattern (n=206, 82%). The rs2228570 SNP of VDR (p=0.02) and rs17099008 SNP of MMP20 (p=0.03) were significantly associated with MCs.

CONCLUSIONS

Genetic polymorphisms of SNPs of VDR and MMP20 were significantly associated with MCs. Understanding the etiopathogenetic mechanisms of MCs is important for planning preventive and therapeutic strategies.

Association between vitamin D receptor gene polymorphisms and intervertebral disc degeneration: A meta-analysis

BACKGROUND

Studies that have investigated the association between vitamin D receptor (VDR) gene polymorphisms and intervertebral disc degeneration (IDD) have yielded inconsistent results.

METHODS

To investigate the association between VDR gene polymorphisms and IDD, a systematic literature search for relevant published studies was performed on PubMed, Embase, Web of Science, Cochrane library, Wan-Fang, and CNKI databases. A random effects model was used for heterogeneous data; while a fixed effect model was used for homogenous data. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to evaluate the strength of the association.

RESULTS

We observed no association between VDR FokI, TaqI-ApaI polymorphisms and IDD. However, on subgroup analysis by ethnicity, VDR FokI mutation was associated with a significantly lower risk for IDD [dominant model: OR = 0.78, 95% CI = 0.65-0.93; heterozygote model: OR = 0.76, 95% CI = 0.63-0.92; allele model: OR = 0.86, 95% CI = 0.75-0.98] among Caucasians.

CONCLUSION

These results suggest that the VDR FokI polymorphism may be associated with IDD among Caucasians. However, the association between VDR TaqI-ApaI polymorphisms and IDD in Asians is still not clear. Further well-designed studies are needed to arrive at a definitive conclusion.

Intervertebral disc and vertebral endplate subchondral changes associated with Modic 1 changes of the lumbar spine: a cross-sectional study

BACKGROUND

Modic 1 changes are usually associated with degenerative disc disease (DDD). We aimed to compare Modic 1 changes with advanced degenerative disc disease (>50%-intervertebral space narrowing [IVSN]) to Modic 1 changes with less advanced lumbar degenerative disc disease (≤50%-IVSN).

METHODS

We conducted a cross-sectional study. The computerized MRI database from a French tertiary care hospital was searched. Patients were included if they were ≥ 18 years old and had a lumbar MRI between January 1, 2006 and January 31, 2008, that showed a Modic 1 signal at a single level. The strength of the magnet was 1.5 T. MRI were reviewed by 2 assessors. Age and gender were recorded. MRI changes involving the intervertebral disc and the vertebral endplate subchondral bone were assessed for Modic 1 signal, intervertebral space narrowing, asymmetrical degenerative disc disease, spondylolisthesis, anterior and posterior intervertebral disc herniation, and anterior and lateral osteophytes. These outcomes were compared between >50%-IVSN Modic 1 and ≤50%-IVSN Modic 1 groups. For bivariate analysis, comparisons involved nonparametric Kruskal-Wallis test for quantitative variables and nonparametric Fisher's exact test for qualitative variables. Multivariate analysis was conducted to determine factors independently associated with <50%-IVSN Modic 1 changes by backward stepwise regression. Informed consent and formal approval from Institutional Review Board is not required for this type of study. This statement was confirmed by our Institutional Review Board.

RESULTS

MRI for 101 individuals were eligible. Patients' mean (SD) age was 56.6(13.4) years, and 41/101(40.6%) were men. Modic 1 were most frequently observed at L4/L5 and L5/S1 (37[36.6%] cases each). As compared with >50%-IVSN Modic 1 patients, ≤50%-IVSN Modic 1 patients were younger (mean[SD] age 51.5[14.1] vs 58.8[12.6] years, p = 0.019), Modic 1 were more frequent at L5/S1 level (19[61.3%] vs 18[25.7%], p = 0.001), and anterior and lateral osteophytes were less frequent (13[41.9%] vs 55[78.6%], p < 0.001, and 11[35.5%] vs 48[68.6%], p = 0.002, respectively).

CONCLUSIONS

≤50%-IVSN Modic 1 are rather found in young men at L5/S1 level and are associated with less frequent osteophytes than >50%-IVSN Modic, while >50%-IVSN Modic 1 are rather found in older women at L4/L5 level.

Single Nucleotide Variants of Candidate Genes in Aggrecan Metabolic Pathway Are Associated with Lumbar Disc Degeneration and Modic Changes

Introduction

Lumbar disc degeneration (LDD) is genetically determined and severity of LDD is associated with Modic changes. Aggrecan is a major proteoglycan in the intervertebral disc and end plate. Progressive reduction of aggrecan is a main feature of LDD and Modic changes.

Objectives

The study investigated the associations of single nucleotide variants (SNVs) of candidate genes in the aggrecan metabolic pathway with the severity of LDD and Modic changes. In-silico functional analysis of significant SNVs was also assessed.

Methods

A descriptive cross sectional study was carried out on 106 patients with chronic mechanical low back pain. T1, T2 sagittal lumbar MRI scans were used to assess the severity of LDD and Modic changes. 62 SNVs in ten candidate genes (ACAN, IL1A, IL1B, IL6, MMP3, ADAMTS4, ADAMTS5, TIMP1, TIMP2 and TIMP3) were genotyped on Sequenom MassARRAY iPLEX platform. Multiple linear regression analysis was carried out using PLINK 1.9 in accordance with additive genetic model. In-silico functional analysis was carried out using Provean, SIFT, PolyPhen and Mutation Taster.

Results

Mean age was 52.42±9.42 years. 74 (69.8%) were females. The rs2856836, rs1304037, rs17561 and rs1800587 variants of the IL1A gene were associated with the severity of LDD and Modic changes. The rs41270041 variant of the ADAMTS4 gene and the rs226794 variant of the ADAMTS5 gene were associated with severity of LDD while the rs34884997 variant of the ADAMTS4 gene, the rs55933916 variant of the ADAMTS5 gene and the rs9862 variant of the TIMP3 gene were associated with severity of Modic changes. The rs17561 variant of the IL1A gene was predicted as pathogenic by the PolyPhen prediction tool.

Conclusions

SNVs of candidate genes in ACAN metabolic pathway are associated with severity of LDD and Modic changes in patients with chronic mechanical low back pain. Predictions of in-silico functional analysis of significant SNVs are inconsistent.

Interleukin 1 Polymorphisms Contribute to Intervertebral Disc Degeneration Risk: A Meta-Analysis

OBJECTIVE

We performed a meta-analysis to assess association between interleukin 1 (IL-1) polymorphisms and the risk of Intervertebral Disc Degeneration (IDD).

BACKGROUND

A series of studies have investigated the association between common single nucleotide polymorphisms in IL-1 and IDD risk; however, the overall results are inconclusive.

METHODS

Two independent investigators conducted a systematic search for relevant available studies. Allele frequencies were extracted from each study. The association between the IL-1α (+889C/T) or IL-1β (+3954C/T) polymorphism and IDD risk was measured by odds ratios (OR) with 95% confidence intervals (95% CI).

RESULTS

Five and six studies, respectively, were ultimately included in the meta-analysis for the IL-1α (+889C/T) and IL-1β (+3954C/T) polymorphism. The combined results showed that the IL-1α (+889C/T) polymorphism was significantly associated with increased susceptibility to IDD, particularly in Caucasians (TT versus CC: OR = 2.95, 95% CI: 1.45, 6.04; Pheterogeneity = 0.82; TT versus

CC/CT

OR = 2.29, 95% CI: 1.18, 4.47; Pheterogeneity = 0.20). In contrast, the IL-1β (+3954C/T) polymorphism showed a trend towards increased risk in Caucasians but no association in Asians.

CONCLUSION

This meta-analysis suggested that the IL-1α (+889C/T) polymorphism is significantly associated with risk of IDD, especially in Caucasian populations.

BsmI, ApaI and TaqI Polymorphisms in the Vitamin D Receptor Gene (VDR) and Association with Lumbar Spine Pathologies: An Italian Case-Control Study

Three adjacent single nucleotide polymorphisms of the vitamin D receptor gene (VDR) BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) are commonly studied in several pathologies. We aimed to evaluate the distribution of VDR BsmI, ApaI, and TaqI allele, genotype, and haplotype frequencies in an Italian cohort of 266 patients with lumbar spine disorders assessed by Magnetic Resonance Imaging and 252 asymptomatic controls. The exposure to putative risk factors was evaluated by a questionnaire. Polymorphisms were detected by PCR-RFLP and TaqMan^® SNP Genotyping Assay. The results were statistically adjusted for the identified conventional risk factors. The three SNPs were in linkage disequilibrium. For all cases BbAaTT was a 3-fold risk factor OR = 3.38), whereas bbAATT (OR = 0.22), and bbaaTT (OR = 0.47) genotypes were found to be protective. Specifically, for patients affected by disc herniation only (n = 88) and all lumbar pathologies excluding stenosis and/or spondylolistesis (n = 215) B allele, Bb, Aa, and BbAaTT genotypes were risky, whereas b allele, bb, aa, and bbaaTT genotypes were protective. In patients affected by osteochondrosis with or without disc hernation (n = 50), T allele, Aa, and bbAaTT genotypes were risky, whereas t allele, AA, tt genotypes were protective. In patients affected by stenosis and/or spondylolistesis (n = 51) no significant associations were found. This is the first study showing an association of the three genetic VDR variants BsmI, ApaI, and TaqI and lumbar spine pathologies. Our study contributes to delineate genetic risk factors for specific subgroups of patients with lumbar spine pathologies highlighting the importance of haplotype analysis, and of detailed clinical evaluation of the patients for identification of genetic biomarkers.

Effect of a hypercholesterolemia as a starting factor on spinal degeneration in rabbits and role of Vitamin E (α-tocopherol)

Background:

To identify the role of the hypercholesterolemia as a starting factor in discovertebral degeneration that ultimately causes lower back pain, and investigate the role of Vitamin E in this process.

Methods:

The rabbits (n = 32) were divided into two broad experimental groups: A control group, and a hypercholesterolemia group, namely cholesterol, and cholesterol plus Vitamin E groups and they were fed sequentially for 4 or 8 weeks. Serum cholesterol and Vitamin E (α-tocopherol) levels were determined; vascular tissue was prepared for histopathological analyses and vertebra was decalcified for the study.

Results:

Cholesterol diet group resulted approximately 44-fold of increase plasma cholesterol levels over the 4-week control values. Additional supplementation with Vitamin E group induced a plasma cholesterol level increase of only 37-fold as compared to the control group. In the cholesterol groups, light microscope examination revealed atherosclerotic plaque in major arteries. However, in the cholesterol plus Vitamin E treatment groups, no lipid accumulation or foam cell formation was visible in the abdominal aorta and vertebral segmental artery. In histopathological examination, we found degenerative changes in the discovertebral unit in cholesterol treated groups.

Conclusion:

Hypercholesterolemia causes fat accumulation in the disc endplate and vertebral body that causes blood supply disturbances which might be a starting factor of discovertebral degeneration. This event was not reversed by the elimination of cholesterol from the diet. Vitamin E supplementation was not effective in reducing fat accumulation in vertebral bone marrow. As a result, we conclude that degeneration of the discovertebral unit is not related to atherosclerotic changes in the major blood vessels.

Intervertebral disc development and disease-related genetic polymorphisms

The intervertebral disc (IVD) comprises a gelatinous inner core (nucleus pulposus; NP) and concentric rings (annulus fibrosus; AF). The NP, an important structure for shock absorption in the vertebrate spinal motion segment, can be traced back to the notochord in ontogenetic lineage. In vertebrates, the notochord undergoes mucinoid changes, and had been considered vestigial until recently. However, observed correlations between IVD degeneration and back pain in humans have renewed interest in the IVD in biomedical fields. Beyond its mechanical contribution to development, the notochord is also an essential signaling center, which coordinates formation of the neural tube and somites. The pertinent signaling molecules, particularly TGF-β and bone morphogenetic proteins (BMPs), continue to play roles in the adult tissues and have been utilized for tissue regeneration. Genetic factors are major determinants of who will develop IVD degeneration and related back pain, and seem to correlate better with disc degeneration and back pain than do external forces on the spine. In summary, the spinal column is a landmark development in evolution. Genes directing the development of the IVD may also contribute to its maintenance, degeneration, and regeneration. Likewise, structural genes as well as genes responsible for maintenance of the structure are related to IVD degeneration. Finally, genes responsible for inflammation may play a dual role in exacerbating degeneration or facilitating repair responses depending on the context.

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

BACKGROUND CONTEXT

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

PURPOSE

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

STUDY DESIGN/SETTING

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

PATIENT SAMPLE

This study consisted of 2,449 Southern Chinese volunteers.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Are the presence of MODIC changes on MRI scans related to "improvement" in low back pain patients treated with lumbar facet joint injections?

BACKGROUND

Modic changes (MC) have been linked with low back pain (LBP) and worse outcomes from some treatments. No studies have investigated the impact that MCs may have on patient outcomes from lumbar facet injections. Therefore, the purpose of this study is to investigate whether the presence of Modic changes is related to 'improvement' in patients undergoing imaging-guided lumbar facet injection therapy.

METHODS

Outcomes from 226 patients with MRI scans within 3 months of their imaging-guided lumbar facet injections were investigated to determine whether MCs are related to 'improvement' post injection. At 1 day, 1 week and 1 month post injection the Patients Global Impression of Change scale answers were collected by postal questionnaire. This was the primary outcome measure. The numerical rating scale for pain data was collected prior to treatment and at the same post injection time points. The MRI scans were independently evaluated by two examiners for the presence/absence of Modic changes and the type of Modic change if present. Kappa statistics were used for reliability of diagnosis analysis. Chi-squared test and logistic regression analysis tested MCs with 'improvement'.

RESULTS

Intra- and inter-examiner reliability for the diagnosis of MCs was Kappa = 0.77 and 0.74. Intra- and inter-examiner reliability for categorizing MCs was K = 0.77 and K = 0.78. At 1 month post injection 45.2 % of patients without MCs reported clinically relevant 'improvement' compared to 34.2 % of patients with MC I and 32.1 % of patients with MC II. However, this did not reach statistical significance. Logistic regression found that Modic changes were not predictive of 'improvement'.

CONCLUSIONS

There was a tendency for patients without MCs to have better outcomes but this did not reach statistical significance. The reliability of diagnosing MCs was substantial.

From Modic 1 vertebral-endplate subchondral bone signal changes detected by MRI to the concept of 'active discopathy'

Late-1980s MRI-detected vertebral-endplate subchondral bone signal changes associated with degenerative disc disease as well as recent studies suggest that in some patients, non-specific chronic low back pain (NS cLBP) can be defined by specific clinical, radiological and biological features, for a concept of active discopathy. This concept allows for associating a particular NS cLBP phenotype to a specific anatomical lesion, namely those with Modic 1 signal changes seen on MRI. Local inflammation is thought to play a pivotal role in these changes. Other etiopathogenic processes may include local infection and mechanical or biochemical stress combined with predisposing genetic factors; treatment strategies remain debated. Modic 1 changes detected by MRI can be considered a first biomarker in NS cLBP. Such changes are of high clinical relevance because they are associated with a specific clinical phenotype and can be targeted by specific treatments.

Osteoclast activators are elevated in intervertebral disks with Modic changes among patients operated for herniated nucleus pulposus

PURPOSE

Modic changes (MC) are associated with low back pain (LBP). Inflammation is considered as a key factor that triggers symptoms in especially type I MC, but so far of the potential inflammatory candidates only TNFα has been linked to MC. The objective of the study was to analyze a set of inflammatory mediators in human surgical disk samples and quantify their association with MC in the adjacent vertebral bodies.

METHODS

The study sample consisted of 51 intervertebral disk tissue specimens; 20 'No MC' disks, 19 'Type I MC' disks, and 12 'Type II MC' disks. mRNA expression of 46 cytokines was quantified from isolated RNA. Tissue samples were stained using hematoxylin and eosin, toluidine blue, Herovici, CD68 and CD163.

RESULTS

No significant differences were found in the amount of macrophages or presence of chondrocyte conglomerates between the MC groups. Of the multiple genes tested, statistically significant associations were observed for M-CSF1 (p = 0.028), RANKL (p = 0.035), RUNX1 (p = 0.032), and RUNX2 (p = 0.047) that were increased in 'Type II MC,' while OSCAR (p = 0.042) was increased in 'Type I MC' group compared to 'No MC.'

CONCLUSIONS

Since these cytokines are related to differentiation and proliferation of osteoclasts, our data suggest that the stimulation of vertebral osteoclasts by factors secreted by disk tissue is involved in the pathophysiology of MC.

Gender differences in the VDR-FokI polymorphism and conventional non-genetic risk factors in association with lumbar spine pathologies in an Italian case-control study

Recently, the FokI polymorphism (rs2228570) in the vitamin D receptor gene (VDR) and conventional risk factors were associated with spine disorders in the Italian population, but without gender analysis. Two-hundred and sixty-seven patients (149 males, 118 females) with lumbar spine disorders were assessed by magnetic resonance imaging (MRI) and 254 (127 males, 127 females) asymptomatic controls were enrolled. The exposure to putative risk factors was evaluated and FokI polymorphism was detected by PCR-restriction fragment length polymorphism (PCR-RFLP). An association between lumbar spine pathologies and higher than average age; overweight; family history; lower leisure physical activity; smoking habit; higher number of hours/day exposure to vibration and more sedentary or intense physical job demand was observed in male patients. In contrast, in females, only higher age, overweight, family history and lower leisure physical activity were risk factors. FF genotype was a 2-fold risk factor to develop discopathies and/or osteochondrosis concomitant with disc herniation for both gender patients, while heterozygous Ff was protective for females only. In males only ff genotype was protective for discopathies and/or osteochondrosis and F allele was a 2-fold risk factor for hernia; discopathies; discopathies and/or osteochondrosis. Sex-related differences in voluntary behaviors, exposure to environmental risks and genetic background could be crucial for a gender-differentiated management of patients with spine disorders.

Genetic susceptibility of lumbar degenerative disc disease in young Indian adults

PURPOSE

Although the exact mechanisms that lead to degenerative disc disease (DDD) are not well understood, a significant genetic influence has been found. Focusing on DDD that occurs in young adults can be valuable in determining the exact role of genetic predisposition to DDD.

METHODS

Patients (<40 years) with lumbar disc degeneration were evaluated with MRI imaging (1.5 Tesla) and genetic association analysis for 58 single nucleotide polymorphism (SNP) of 35 candidate genes was performed. Disc degeneration of individual discs of lumbar spine from L1 to S1 was graded by Pfirrmann's grading. The subjects were stratified into two groups based on Total Disc Degenerative Score (TDDS). Based on TDDS, the severity of DDD was classified as mild (Group A: TDDS <10) and severe (Group B: TDDS >10).

RESULTS

695 Indian subjects including 308 with mild TDDS and 387 with severe TDDS were studied. The mean age of the patients was 29.6 ± 6.9 years in group A and 31.7 ± 6.1 in group B (p < 0.05). Five of the 35 candidate genes viz., rs1337185 of COL11A (p = 0.02), rs5275 (p = 0.03) and rs5277 (p = 0.05) of COX2, rs7575934 of IL1F5 (p = 0.04), rs3213718 of CALM1 (p = 0.04) and rs162509 of ADAMTS5 (p = 0.04) were found to be significantly associated with severe TDDS.

CONCLUSION

The study identifies specific SNP associations of five genes in young adults with severe lumbar disc degeneration. These five genes (COL11A1, ADAMTS5, CALM1, IL1F5 and COX2) have different functions in the matrix metabolism, intracellular signalling and inflammatory cascade. This shows that disc degeneration is a complex disease with an intricate interplay of multiple genetic polymorphisms.

Genetic polymorphisms of interleukin-1 alpha and the vitamin d receptor in mexican mestizo patients with intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is the most common diagnosis in patients with back pain, a leading cause of musculoskeletal disability worldwide. Several conditions, such as occupational activities, gender, age, and obesity, have been associated with IDD. However, the development of this disease has strong genetic determinants. In this study, we explore the possible association between rs1800587 (c.-949C>T) of interleukin-1 alpha (IL1A) and rs2228570 (c.2T>V) and rs731236 (c.1056T>C) of vitamin D receptor (VDR) gene polymorphisms and the development of IDD in northwestern Mexican Mestizo population. Gene polymorphisms were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism, in two groups matched by age and gender: patients with symptomatic lumbar IDD (n = 100) and subjects with normal lumbar-spine MRI-scans (n = 100). Distribution of the mutated alleles in patients and controls was 27.0% versus 28.0% (P = 0.455) for T of rs1800587 (IL1A); 53.0% versus 58.0% (P = 0.183) for V of rs2228570 (VDR); and 18.0% versus 21.0% (P = 0.262) for C of rs731236 (VDR). Our results showed no association between the studied polymorphisms and IDD in this population. This is the first report on the contribution of gene polymorphisms on IDD in a Mexican population.

Role of IL1A rs1800587, IL1B rs1143627 and IL1RN rs2234677 genotype regarding development of chronic lumbar radicular pain; a prospective one-year study

Previous studies indicate that lumbar radicular pain following disc herniation may be associated with release of several pro-inflammatory mediators, including interleukin-1 (IL1). In the present study, we examined how genetic variability in IL1A (rs1800587 C>T), IL1B (rs1143627 T>C) and IL1RN (rs2234677 G>A) influenced the clinical outcome the first year after disc herniation. Patients (n = 258) with lumbar radicular pain due to disc herniation were recruited from two hospitals in Norway. Pain and disability were measured by visual analogue scale (VAS) and Oswestry Disability Index (ODI) over a 12 month period. The result showed that patients with the IL1A T allele, in combination with the IL1RN A allele had more pain and a slower recovery than other patients (VAS p = 0.049, ODI p = 0.059 rmANOVA; VAS p = 0.003, ODI p = 0.050 one-way ANOVA at 12 months). However, regarding the IL1B/IL1RN genotype, no clear effect on recovery was observed (VAS p = 0.175, ODI p = 0.055 rmANOVA; VAS p = 0.105, ODI p = 0.214 one-way ANOVA at 12 months). The data suggest that the IL1A T/IL1RN A genotype, but not the IL1B T/IL1RN A genotype, may increase the risk of a chronic outcome in patients following disc herniation.

Effects of Transplantation of hTIMP-1-Expressing Bone Marrow Mesenchymal Stem Cells on the Extracellular Matrix of Degenerative Intervertebral Discs in an In Vivo Rabbit Model

STUDY DESIGN

Prospective, randomized, and controlled animal study.

OBJECTIVE

To observe extracellular matrix (ECM) changes in degenerative intervertebral disc (IVD) after transplantation of bone marrow mesenchymal stem cells (BMSCs) virally transfected with a construct expressing "human tissue inhibitor of metalloproteinase 1" (hTIMP-1), and to discuss the feasibility of using this approach to treat IVD degeneration.

SUMMARY OF BACKGROUND DATA

Intervertebral disc (IVD) degeneration is characterized by decreased cell numbers, bioactivity of the nucleus pulposus, and remodeled ECM. Exogenous genes can be targeted into cells to produce inhibition of ECM degradation and increase ECM content in IVDs, and thereby potentially stop or reverse degenerative processes and modify disc structure.

METHODS

BMSCs were isolated from a pure New Zealand white rabbit and identified by flow cytometry. Transgenic BMSCs were acquired by transfection with a recombinant adenovirus vector carrying the hTIMP-1 gene. Animal models of IVD degeneration were established by annulus puncture and then given intra-nucleus pulposus injections according to their random assignment into 3 groups: (1) a transgenic BMSC transplantation (TgBT) group that received BMSCs transfected with an hTIMP-1-expressing adenovirus vector; (2) a BMSC transplantation (BT) group that received unaltered BMSCs; and (3) a control group that received cell-free phosphate-buffered saline. Degree of degeneration was evaluated 12 weeks after modeling. ECM content was quantified using immunohistochemistry and spectrophotography. Expression of hTIMP-1 was observed via quantitative polymerase chain reaction, western blot, and immunohistochemistry.

RESULTS

Significantly fewer degenerative changes and increased ECM content were observed in the TBT and BT groups than the control group animals (P < 0.05). The TBT group had greater ECM content than did the BT group (P < 0.05), as well as higher levels of hTIMP-1 mRNA and protein.

CONCLUSION

Transplantation of BMSCs transfected with hTIMP-1 can increase ECM content by inhibiting ECM degradation and promoting ECM synthesis.

LEVEL OF EVIDENCE

N/A.

FokI polymorphism in the vitamin D receptor gene (VDR) and its association with lumbar spine pathologies in the Italian population: a case-control study

Alterations in vitamin D homeostasis, mainly involving its nuclear receptor (VDR), could have a role in the pathophysiology of the spine. The association between VDR polymorphisms and spine disorders has been analyzed in different ethnic groups, focusing on the functional FokI polymorphism. However, so far, inconsistent findings were reported. The aims of this study were to evaluate, in the Italian white population, the VDR FokI polymorphism frequencies distribution in subjects with clearly defined lumbar spinal pathologies compared to asymptomatic controls and to analyze the interplay of genetic and conventional risk factors. Using a case-control design, 267 patients with spinal disorders and 220 asymptomatic controls were enrolled, evaluating their exposition to putative risk factors. Patients’ clinical assessment was performed by Magnetic Resonance Imaging. FokI polymorphism (rs2228570) was detected by PCR-RFLP. Genotypes were designated by a lowercase letter (f allele, T nucleotide) for the presence of the restriction site and by a capital letter (F allele, C nucleotide) for its absence. Family history, higher age and BMI, exposure to vibration, physical job demand, smoking habit and lower practice of leisure physical activity were associated with spinal disorders. The FF genotype and F allele represented approximately 2-fold risk factors to develop discopathies and/or osteochondrosis concomitant with disc herniation, while f allele was protective. In conclusion, the link we observed between VDR FokI variants and specific lumbar spine pathologies suggests that spinal tissue degeneration is influenced by the genetic background. Future studies should evaluate the signaling pathways involving alterations in VDR and influencing the development and/or progression of spine disorders.

Relationship between vitamin D receptor gene (VDR) polymorphisms, vitamin D status, osteoarthritis and intervertebral disc degeneration

The vitamin D endocrine system is involved in bony and cartilaginous metabolisms and alterations in the homeostasis of this system could be associated to pathological conditions of cartilaginous tissue. In this context, the presence of polymorphisms in the vitamin D receptor gene (VDR), in association with the susceptibility to common osteochondral diseases, was largely investigated. The aim of this review was to summarize data present in literature, analyzing the association of the VDR polymorphisms, vitamin D status and knee cartilage and intervertebral disc pathologies, trying to suggest links between the different specific pathologies analyzed. Concerning the association between VDR polymorphisms and cartilaginous tissue diseases, we found controversial reports. However, the great majority of papers reported an association with lumbar disc degeneration, whereas about half of the studies found an association with osteoarthritis. A further association between VDR polymorphisms (in linkage disequilibrium) and the presence of specific characteristics of these diseases, in particular the formation of osteophytes, was evidenced. Finally, the influence of vitamin D status on these pathologies was evaluated, trying to evidence the relation between the presence of particular genetic variants in the VDR and vitamin D levels or to show whether a particular vitamin D status could predispose to the development or progression of such diseases, however, no significant associations were found. In the future, given the role of vitamin D system in the cartilaginous tissue metabolism, it could be interesting to perform functional and tissue specific studies to analyze the interplay between the different VDR variants and its ligand.

Treatment outcome of chronic low back pain and radiographic lumbar disc degeneration are associated with inflammatory and matrix degrading gene variants: a prospective genetic association study

BACKGROUND

Inflammatory and matrix degrading gene variants have been reported to be associated with disc degeneration. Some of these variants also modulate peripheral pain. This study examines the association of these genetic variants with radiographic lumbar disc degeneration and changes in pain and disability at long-term after surgical and cognitive behavioural management.

METHODS

93 unrelated patients with chronic low back pain (CLBP) for duration of >1 year and lumbar disc degeneration were treated with lumbar fusion or cognitive intervention and exercises. Standardised questionnaires included the Oswestry Disability Index (ODI) and Visual Analog Score (VAS) for CLBP, were filled in by patients both at baseline and at 9 years follow-up. Degenerative changes at baseline Magnetic Resonance Imaging and Computed Tomography scans, were graded as moderate and severe (N=79). Yield and quality of blood and saliva DNA was assessed by nano drop spectrophotometry. Eight SNPs in 5 inflammatory and matrix degrading genes were successfully genotyped. Single marker and haplotype association with severity of degeneration, number of discs involved, changes in ODI and VAS CLBP, was done using Haploview, linear regression and R-package Haplostats.

RESULTS

Association analysis of individual SNPs revealed association of IL18RAP polymorphism rs1420100 with severe degeneration (p = 0.05) and more than one degenerated disc (p = 0.02). From the same gene two SNPs, rs917997 and rs1420106, were found to be in strong linkage disequilibrium (LD) and were associated with post treatment improvement in disability (p = 0.02). Haplotype association analysis of 5 SNPs spanning across IL18RAP, IL18R1 and IL1A genes revealed significant associations with improvement in disability (p=0.02) and reduction in pain (p=0.04). An association was found between MMP3 polymorphism rs72520913 and improvement in pain (p = 0.03) and with severe degeneration (p = 0.006).

CONCLUSIONS

The findings of the current study suggest a role of variation at inflammatory and matrix degrading genes with severity of lumbar disc degeneration, pain and disability.

Vertebral subchondral bone

Vertebral subchondral bone, also known as bony or osseous endplate, is an important anatomical part of the spine, including cartilage endplate and intervertebral disk. Vertebral subchondral bone plays a critical role in spinal function and maintenance of intervertebral disk health. Recent data suggest that some vertebral subchondral bone changes, detected by MRI and described as Modic changes, may be specifically associated with degenerative disk disease and chronic low back pain, and that these changes may be related to local inflammation. Thus, Modic changes may be a useful imaging biomarker to identify particular sub-groups of patients with chronic low back pain for whom a link between pathoanatomy, namely vertebral subchondral bone alterations, and pain can be established. Such identification may give rise to develop more specific therapies targeting, for example, inflammatory changes involving vertebral subchondral bone in Modic change-associated non-specific chronic low back pain.

Genetic association studies in lumbar disc degeneration: a systematic review

Objective

Low back pain is associated with lumbar disc degeneration, which is mainly due to genetic predisposition. The objective of this study was to perform a systematic review to evaluate genetic association studies in lumbar disc degeneration as defined on magnetic resonance imaging (MRI) in humans.

Methods

A systematic literature search was conducted in MEDLINE, MEDLINE In-Process, SCOPUS, ISI Web of Science, The Genetic Association Database and The Human Genome Epidemiology Network for information published between 1990–2011 addressing genes and lumbar disc degeneration. Two investigators independently identified studies to determine inclusion, after which they performed data extraction and analysis. The level of cumulative genetic association evidence was analyzed according to The HuGENet Working Group guidelines.

Results

Fifty-two studies were included for review. Forty-eight studies reported at least one positive association between a genetic marker and lumbar disc degeneration. The phenotype definition of lumbar disc degeneration was highly variable between the studies and replications were inconsistent. Most of the associations presented with a weak level of evidence. The level of evidence was moderate for ASPN (D-repeat), COL11A1 (rs1676486), GDF5 (rs143383), SKT (rs16924573), THBS2 (rs9406328) and MMP9 (rs17576).

Conclusions

Based on this first extensive systematic review on the topic, the credibility of reported genetic associations is mostly weak. Clear definition of lumbar disc degeneration phenotypes and large population-based cohorts are needed. An international consortium is needed to standardize genetic association studies in relation to disc degeneration.

Genetic susceptibility of intervertebral disc degeneration among young Finnish adults

BACKGROUND

Disc degeneration (DD) is a common condition that progresses with aging. Although the events leading to DD are not well understood, a significant genetic influence has been found. This study was undertaken to assess the association between relevant candidate gene polymorphisms and moderate DD in a well-defined and characterized cohort of young adults. Focusing on young age can be valuable in determining genetic predisposition to DD.

METHODS

We investigated the associations of existing candidate genes for DD among 538 young adults with a mean age of 19 belonging to the 1986 Northern Finland Birth Cohort. Nineteen single nucleotide polymorphisms (SNP) in 16 genes were genotyped. We evaluated lumbar DD using the modified Pfirrmann classification and a 1.5-T magnetic resonance scanner for imaging.

RESULTS

Of the 538 individuals studied, 46% had no degeneration, while 54% had DD and 51% of these had moderate DD. The risk of DD was significantly higher in subjects with an allele G of IL6 SNPs rs1800795 (OR 1.45, 95% CI 1.07-1.96) and rs1800797 (OR 1.37, 95% CI 1.02-1.85) in the additive inheritance model. The role of IL6 was further supported by the haplotype analysis, which resulted in an association between the GGG haplotype (SNPs rs1800797, rs1800796 and rs1800795) and DD with an OR of 1.51 (95% CI 1.11-2.04). In addition, we observed an association between DD and two other polymorphisms, SKT rs16924573 (OR 0.27 95% CI 0.07-0.96) and CILP rs2073711 in women (OR 2.04, 95% CI 1.07-3.89).

CONCLUSION

Our results indicate that IL6, SKT and CILP are involved in the etiology of DD among young adults.

Management of degenerative disk disease and chronic low back pain

Degenerative disk disease is a strong etiologic risk factor of chronic low back pain (LBP). A multidisciplinary approach to treatment is often warranted. Patient education, medication, and cognitive behavioral therapies are essential in the treatment of chronic LBP sufferers. Surgical intervention with a rehabilitation regime is sometimes advocated. Prognostic factors related to the outcome of different treatments include maladaptive pain coping and genetics. The identification of pain genes may assist in determining individuals susceptible to pain and in patient selection for appropriate therapy. Biologic therapies show promise, but clinical trials are needed before advocating their use in humans.

Association of FAS and FAS ligand polymorphisms with the susceptibility and severity of lumbar disc degeneration in Chinese Han population

CONTEXT

Apoptosis is involved in the mechanism of lumbar disc degeneration (LDD).

OBJECTIVE

We aim to determine whether the polymorphisms of FAS and FASL are associated with the presence and severity of LDD.

METHODS

A total of 348 patients with LDD and 215 healthy controls were genotyped.

RESULTS

Patients with LDD showed higher frequency of-1377GA and AA, as well as-844CT and TT genotypes than normal controls. These genotypes were found to be associated with the risk of higher grades of LDD.

CONCLUSION

The polymorphisms of FAS and FASL may be associated with the presence and severity of LDD.

Degenerative marrow (modic) changes on cervical spine magnetic resonance imaging scans: prevalence, inter- and intra-examiner reliability and link to disc herniation

STUDY DESIGN

A prevalence and reliability study of Modic changes (MCs) in the cervical spine.

OBJECTIVE

To assess the prevalence and reliability of diagnosing and classifying MCs and their relationship to disc herniations (DHs) in the cervical spine.

SUMMARY OF BACKGROUND DATA

Degenerative marrow (Modic) changes in the spine can be seen on MRI with some evidence linking them to pain. Many studies have been published on MCs in the lumbar spine, but only one small prevalence study focusing on MCs in the cervical spine has been reported.

METHODS

The cervical magnetic resonance imaging (MRI) scans of 500 patients over the age of 50 were retrospectively evaluated for the prevalence, type, and location of MCs and DHs. Two hundred of these same scans were independently analyzed by a second observer to evaluate interobserver reliability of diagnosis with 100 re-evaluated by the same observer 1 month later to assess intraobserver reliability. The SPSS program and Kappa statistics were used to assess prevalence and reliability. The risk ratio comparison of DH and MC was calculated.

RESULTS

Four hundred and twenty-six patients (85.2%) met the inclusion criteria. MCs were observed in 40.4% of patients (14.4% of all motion segments). A 4.3% were type 1 and 10.1% were type 2. DH were seen in 78.2% of patients (13.3% of motion segments). Both MC and DH were most frequently observed at C5/6 and C6/7. Disc extrusions were positively associated with MC (RR=2.4). The reliability showed an upper moderate interobserver (k=0.54) and an almost perfect intraobserver agreement (k=0.82).

CONCLUSION

A high prevalence of MCs was observed with type 2 predominating. The C5/6 and C6/7 levels are most effected. Patients with MC are more likely to have a DH at the same level. MC type 2 predominates. The classification is reliable.

Modic changes and associated features in Southern European chronic low back pain patients

BACKGROUND CONTEXT

Conflicting reports exist regarding the prevalence of Modic changes among low back pain (LBP) patients and factors associated with their existence.

PURPOSE

To assess the prevalence of Modic changes and other findings on lumbar magnetic resonance imaging (MRI) among Spanish adult chronic LBP patients and the patient characteristics and radiological findings associated with Modic changes.

STUDY DESIGN

A cross-sectional imaging study among chronic LBP patients.

PATIENT SAMPLE

Four hundred eighty-seven patients (263 women and 224 men) undergoing lumbar spine MRI examination for chronic LBP.

OUTCOME MEASURES

Gender, age, body mass index (BMI), lifetime smoking exposure, degree of physical activity, and image features (disc degeneration, type and extension of Modic changes, disc contour, annular tears, spinal stenosis, and spondylolisthesis).

METHODS

Ten radiologists from six hospitals across six cities in Spain consecutively recruited adult patients in whom lumbar MRI had been prescribed for LBP lasting ≥3 months. Patients' characteristics and imaging findings were assessed through previously validated instruments. A multivariate logistic regression model was developed to assess the features associated with Modic changes.

RESULTS

Modic changes were found in 81% of the patients. The most common was Type II (51.3%), affecting only the end plate. Variables associated with Type I changes were disc contour abnormalities, spondylolisthesis, and disc degeneration. The same variables were associated with a higher risk of Type II or any type of Modic changes, as well as being male, and having a higher BMI.

CONCLUSIONS

Modic changes are found in 81% (95% confidence interval, 77-85) of adult Spanish patients in whom an MRI is prescribed for chronic LBP. Modic changes are more likely to be found in males with a high BMI, who also show disc contour abnormalities, spondylolisthesis, or disc degeneration.

[Long-lasting low back pain and MRI changes in the intervertebral discs]

BACKGROUND

Although low back pain is usually temporary, some patients do not recover and need treatment. Therefore, it is important to uncover causal and contributing factors. Here we give an overview of recent research on MRI findings and genetic factors that may be important for development of long-lasting low back pain.

MATERIAL AND METHODS

A non-systematic search in PubMed and EMBASE was performed. The relevant research articles identified, as well as the authors' knowledge of the field formed the basis for this review.

RESULTS

It is generally accepted that low back pain often stems from intervertebral discs, facet joints and lumbar multifundi muscles. However, it is also known that many patients with pronounced disc degeneration have so-called Modic changes, i.e. MRI changes in bone marrow close to the vertebral endplates. Several recent studies have shown an association between such changes and pain. It has also been demonstrated that patients with Modic changes and low back pain often have concomitant inflammation and growth of nociceptive nerve fibers into the endplates. To which extent this occurs, may be partly based on genetics.

INTERPRETATIONS

Genetic factors may contribute to low back pain. New knowledge about genetic factors and Modic changes can create a basis for better diagnostics and more specific treatment of patients with long-lasting low back pain.