The location of Modic changes in the lumbar spine: a meta-analysis

Inhibition of TrkB-BDNF positive feedback loop attenuates intervertebral disc degeneration and low back pain in a composite mouse model

Intervertebral disc degeneration (IVDD) is a significant contributor to low back pain (LBP); however, the specific mechanisms involved remain unclear. Herein, a novel LBP mouse model was developed by integrating a bipedal standing model with a lumbar spine instability model (BS + LSI). This model effectively reproduced the behavioral characteristics of LBP and the pathological features of IVDD. Notably, a higher degree of degeneration and innervation in the endplates were observed in the BS + LSI mice. Transcriptome analysis revealed a significant upregulation of Ntrk2, the gene encoding TrkB, in the intervertebral discs of BS + LSI mice. Immunohistochemical staining further confirmed elevated expression of TrkB and its ligand BDNF in the endplates of these mice. Moreover, cyclic tensile strain (CTS) (20 %, 0.1 Hz, 24 h) upregulated TrkB expression and activated NF-κB signaling pathway to promote inflammatory responses in endplate chondrocytes. siBDNF transfection or treatment with the TrkB inhibitor ANA-12 effectively inhibited these pathological changes. Mechanistically, TrkB promoted BDNF expression by enhancing CREB phosphorylation, thereby establishing a TrkB-CREB-BDNF positive feedback loop. In vivo injection of ANA-12 significantly alleviated endplate inflammation and LBP-related behaviors in BS + LSI mice. Thus, an effective and replicable mouse model of LBP was established to identify TrkB as both the receptor for and an upstream regulator of BDNF, making it a crucial target for interventions to alleviate CEP inflammation and LBP.

Evaluation of the efficacy, in terms of pain and disability, of a functional restoration programme in patients with chronic low back pain according to the presence of Modic 1 discopathy

OBJECTIVES

Modic type 1 disc disease (MD1) appears to be related to severe Chronic Low Back Pain (CLBP). Functional Restoration Programmes (FRP) recommended in CLBP may not be suitable for patients with MD1. The main objective was to evaluate the effectiveness of a FRP, on the perceived incapacity and the pain intensity, in patients with non-specific CLBP according to the presence of MD1.

METHODS

We performed a single-centre retrospective cohort study in which 271 patients were included. After one month in the FRP, this programme was considered "successful" if the pain visual analog scale had decreased by at least 20/100 millimetres and if the score of the French version of the Roland-Morris disability questionnaire had decreased by at least 4/24 points.

RESULTS

The 271 patients had an average age of 43.2 (8.0) years and 58.3% were women. Out of our entire population, 128 (47.2%) patients were considered successful, and 51 (18.8%) patients had MD1. In patients without MD1, there was 49.1% success while this rate was 39.2% in those with MD1, but this difference was not statistically significant.

CONCLUSIONS

We found no significant difference in the combination of pain and perceived disability after one month of a FRP in patients with CLBP without MD1 compared to those with CLBP with MD1. It therefore seems legitimate to offer FRP-type rehabilitation in patients with non-specific CLBP with MD1.

Relationship Between Vertebral Bone Marrow Edema and Early Progression of Intervertebral Disc Wedge or Narrowing After Lumbar Decompression Surgery

STUDY DESIGN

A retrospective study.

OBJECTIVES

The aim of this study was to review clinical and imaging features in patients with lumbar spinal canal stenosis (LSS) with and without postoperative early progression of intervertebral disc degeneration (IDD) and to identify predictive factors.

SUMMARY OF BACKGROUND DATA

Progression of IDD after lumbar decompression surgery can induce low back pain and leg pain, and may require revision surgery. However, risk factors for postoperative radiological changes indicating IDD linked to development of symptoms have not been described.

METHODS

We included 564 patients with LSS without degenerative lumbar scoliosis who underwent lumbar decompression surgery without fusion. Clinical features and imaging findings were compared in cases with (group P) and without (group N) progression of IDD (intervertebral disc wedge or narrowing) at 1 year after surgery.

RESULTS

Of the 564 patients, 49 (8.7%) were in group P. On preoperative MRI, all patients in group P had findings of vertebral bone marrow edema (diffuse high intensity on T2-weighted images and low-intensity on T1-weighted images), compared to only 5.4% in group N. The rate of revision surgery was significantly higher in group P in 5 years' follow-up (12.2% vs. 1.4%, P < 0.01). In group P, 44.9% of patients developed postoperative symptoms associated with postoperative radiological changes, and the frequency was higher in narrowing-type than in wedge-type cases. Vertebral bone marrow edema area and IDD grade were not predictors for postoperative early IDD progression.

CONCLUSION

Careful consideration is required to determine whether lumbar decompression surgery should be performed if vertebral bone marrow edema is detected on MRI, since this is a predictor for a negative clinical outcome. If surgery is symptomati-cally urgent, careful clinical and radiological follow-up is required.Level of Evidence: 4.

Spinal disorders mimicking infection

Spinal infections are very commonly encountered by radiologists in their routine clinical practice. In case of typical MRI features, the diagnosis is relatively easy to interpret, all the more so if the clinical and laboratory findings are in agreement with the radiological findings. In many cases, the radiologist is able to make the right diagnosis, thereby avoiding a disco-vertebral biopsy, which is technically challenging and associated with a risk of negative results. However, several diseases mimic similar patterns, such as degenerative changes (Modic) and crystal-induced discopathy. Differentiation between these diagnoses relies on imaging changes in endplate contours as well as in disc signal. This review sought to illustrate the imaging pattern of spinal diseases mimicking an infection and to define characteristic MRI and CT patterns allowing to distinguish between these different disco-vertebral disorders. The contribution of advanced techniques, such as DWI and dual-energy CT (DECT) is also discussed.

Is the Distribution Pattern of Modic Changes in Vertebral End-plates Associated With the Severity of Intervertebral Disc Degeneration?: A Cross-sectional Analysis of 527 Caucasians

BACKGROUND

Low back pain (LBP) is one of the most common disorders, with many possible causes including intervertebral disc degeneration (IVDD) and Modic changes. In this study we aimed to analyze whether the distribution pattern of Modic changes in the vertebral end-plates was associated with the severity of IVDD.

METHODS

We conducted a cross-sectional analysis of a retrospective database. Patients with constant LBP were evaluated in terms of IVDD and Modic changes on lumbar spine magnetic resonance imaging. Statistical analyses were specifically performed for the lower lumbar levels.

RESULTS

We evaluated 527 patients. Modic changes were detected in 25% of the patients. Severe IVDD was detected in 90% and 88% of patients with Modic changes through the whole end-plates at L4-L5 and L5-S1 levels, respectively. Patients with Modic changes at L5-S1 level had significantly lower lumbar lordosis. Presence of severe IVDD at L4-L5 and L5-S1 levels was associated with 2.7- and 2.9-times higher risk of more widely distributed Modic changes in those vertebral end-plates, respectively.

CONCLUSIONS

Severe IVDD was significantly more common in patients with Modic changes through the whole end-plate and in those with Modic type I changes.

Vertebral Bone Marrow and Endplate Assessment on MR Imaging for the Differentiation of Modic Type 1 Endplate Changes and Infectious Spondylodiscitis

On magnetic resonance (MR) imaging, Modic type 1 (MT1) endplate changes and infectious spondylodiscitis share similar findings. Therefore, this study investigated vertebral bone marrow and endplate changes to enable their differentiation. The lumbar spine MR examinations of 91 adult patients were retrospectively included: 39 with MT1; 19 with early spondylodiscitis without abscess; and 33 with advanced spondylodiscitis with abscess. The assessment included percentage of bone marrow edema on sagittal short tau inversion recovery images, and the signal ratio of edema to unaffected bone and endplate contour (normal; irregular, yet intact; blurred; destructive) on sagittal unenhanced T1-weighted images. Differences were tested for statistical significance by Chi-square test and mixed model analysis of variance. The MR diagnostic accuracy in differentiating MT1 and spondylodiscitis was assessed by cross-tabulation and receiver-operating characteristic analysis. The endplate contours, edema extents, and T1-signal ratios of MT1 (extent, 31.96%; ratio, 0.83) were significantly different (p < 0.001) from early spondylodiscitis (56.42%; 0.60), and advanced spondylodiscitis (91.84%; 0.61). The highest diagnostic accuracy (sensitivity, 94.87%; specificity, 94.23%; accuracy, 94.51%) in identifying MT1 was provided by an irregular, yet intact endplate contour. This may be a useful MR feature for the differentiation between MT1 and spondylodiscitis, particularly in its early stage.

Risk Factors for Negative Global Treatment Outcomes in Lumbar Spinal Stenosis Surgery: A Mixed Effects Model Analysis of Data from an International Spine Registry

OBJECTIVE

To determine risk factors for negative global treatment outcomes as self-assessed by patients undergoing surgical treatment for lumbar spinal stenosis (LSS).

METHODS

Patients from the Spine Tango registry undergoing first-time surgery for LSS were analyzed. The primary outcome was global treatment outcomes measured at the last available follow-up ≥3 months postoperatively using a single question rating how much the operation had helped the patient's back problem (negative = no change/operation made things worse). A 2-level logistic mixed effects model with the treating department as the random effect was used to assess factors associated with a negative outcome.

RESULTS

A total of 4504 patients from 39 departments in 10 countries were included. Overall, 14.4% of patients reported a negative global treatment outcome after an average follow-up of 1.3 years. In patients with dominant leg pain, negative outcome was associated with higher baseline back pain; in those with dominant back pain, it was associated with higher baseline back pain, ASA (American Society of Anesthesiologists) ≥3, lower age, not having rigid stabilization, not having disc herniation, and the vertebral level of the most severely affected segment (L5/S1 vs. L3/4). Four departments had significantly higher odds of a negative outcome, whereas 1 department had significantly lower odds. Three out of the 4 negative effects were related to 2 departments from 1 country.

CONCLUSIONS

LSS surgery fails to help at least 1 in 10 patients. High baseline back pain is the most important factor associated with a negative treatment outcome. Department-level and potentially country-level factors of unknown origin explained a nonnegligible variation in the treatment results.

Patients with Modic type 2 change have a severe radiographic representation in the process of lumbar degeneration: a retrospective imaging study

Background

There are few studies to investigate changes in imaging parameters of Modic changes (MCs). The imaging studies examining the distinctions in the lumbar sagittal parameters between MCs and lumbar disc degeneration (LDD) are still lacking. The purpose of this study was to identify the differences in the lumbar sagittal parameters among patients for LDD with/without Modic type 2 change (MII).

Methods

A total of 208 patients with lumbar degenerative disease from January 2017 to August 2018 volunteered for this study. Sixty-two patients with MII were used as the MC group. The other 146 patients served as the disc degeneration (DD) group. The DD scores and sagittal parameters were measured on magnetic resonance imaging (MRI) and X-ray by using Surgimap software.

Results

The prevalence of MII for patients with degenerative lumbar diseases in this study was 29.81%, primarily located at L5/S1. There were significant differences in lumbar lordosis (LL) and sacral slope (SS) between these two groups (P < 0.05). Similarly, the significant decrease in intervertebral height index (IHI) was found at L3-S1 in the MC group, compared with the DD group (P < 0.05). However, a significant difference in intervertebral angle (IVA) was observed only at L5/S1 (P < 0.05). The MC group had the smaller endplate concave angle (ECA) than the DD group from L3 caudal endplate to S1 cranial endplate (P < 0.05).

Conclusions

MII has a severe radiographic representation in the process of lumbar degeneration than patients without MII, and the overconcentration of load caused by the smaller LL, SS, and IVA may be a reasonable explanation to answer why MCs are more common at the L5/S1.

New insights into the natural course and clinical relevance of Modic changes over 2 years following lumbar limited discectomy: analysis of prospective collected data

PURPOSE

Few retrospective studies have addressed Modic changes (MC) following lumbar spine surgery, though it is usually assumed that MC increase in grade and incidence. To test this conventional wisdom, we investigated the natural course of MC following primary lumbar limited discectomy with two-year follow-up. In addition, a possible clinical relevance to those changes was assessed.

METHODS

The data of the control group (278 subjects) of a prospective randomized, controlled trial (RCT) were evaluated retrospectively.

RESULTS

We did not observe a simple increase in MC with regard to grade. There is variable activity observed in Type 2 (at 12 months) and in Type 1 (at 24 months). Conversion from one grade to another may occur and may be upward or downward. The incidence of MC increased slightly over time, as after surgery a decreasing percentage of the study group remained without MC over two years (1 year: 34% (85/250); 2 years: 30% (72/237)). Radiological parameters (rotation, translation, and spondylolisthesis) had no significant correlation to MC or MC subtypes. Lastly, we found that neither the different MC types nor their changes were correlated with clinical parameters (VAS back, VAS leg, ODI score) preoperatively or during follow-up.

CONCLUSION

The pattern of Modic changes following lumbar limited discectomy is complex, not simply increasing. There is variable activity in MC Types 1 and 2 at the different time points of follow-up, and conversion from a higher grader to a lower one or vice versa is possible. These slides can be retrieved under Electronic Supplementary Material.

Active discopathy: a clinical reality

In the late 1980s, the description by Modic and colleagues of elementary discovertebral changes detected on MRI (Modic classification) suggested for the first time a possible correlation between anatomical and clinical features in a subgroup of patients with non-specific chronic low back pain. Degenerative disc disease is frequent and usually asymptomatic, but Modic 1 changes in the vertebral endplates adjacent to a degenerated disc are associated with inflammatory-like chronic low back pain and low-grade local and systemic inflammation, which led to the concept of ‘active discopathy’. Active discopathy shares some similarities with acute flares of peripheral osteoarthritis. Likewise, what triggers disc activation and how it self-limits remain unknown. A better understanding of mechanisms underlying disc activation and its self-limitation is of clinical relevance because it may enable the design of more targeted pharmacological and non-pharmacological interventions for the subgroup of patients with chronic low back pain and active discopathy. Here, we narratively review current disc-centred biomechanical and biochemical hypotheses of disc activation and discuss evidence of interactions with adverse personal and environmental factors.

Prevalence of Modic changes in the lumbar vertebrae and their associations with workload, smoking and weight in northern China

The distribution of Modic changes (MCs) in the lumbar endplates and the evaluation of the relationships between MCs and risk factors are vital for research into MCs. The T1-weighted and T2-weighted sagittal MRI scans of 210 patients who exhibited lumbar intervertebral disc degeneration were retrospectively reviewed. The patients' weights, genders, smoking statuses, physical activity levels and specific types of MC were recorded. The associations between MCs and risk factors, such as physical work, smoking and body mass index, were also analysed. MCs were observed in 47 patients (22.4%), including 16 males and 31 females. Among all patients, the L5/S1 lumbar level was most likely to suffer MCs. The MCs were predominantly type II. MCs occurred more often in obese patients than in normal and overweight patients (P < 0.05). Patients whose jobs required heavy labour were more likely to develop MCs (P < 0.05). Heavy work and obesity were related to type III MCs more strongly than the other types (P > 0.05). Smoking seemed not to be correlated with the incidence of MCs (P > 0.05). Gender, obesity and heavy work were strongly associated with MCs. Biomechanical factors may play a critical role in the development of MCs.