Measurement of vertebral endplate bone marrow lesion (Modic change) composition with water-fat MRI and relationship to patient-reported outcome measures

Three Stages on Magnetic Resonance Imaging of Lumbar Degenerative Spine

PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The advancement of MRI in differentiating Modic type I degenerative changes from early spinal infections

MRI is the most sensitive and specific imaging method for the detection of advanced spinal infections. However, the differential diagnosis of early spinal infection and Modic Type I degenerative changes based on conventional MRI is difficult clinically, as they both may mimic each other by showing hypointensity on T1 weighted images and hyperintensity on T2 weighted spine MRI images. This review summarizes recent advancements in MRI, which may be useful in discriminating degenerative Modic Type I endplate changes from early spinal infection, and evaluates the diagnostic accuracy and limitations of MRI. We aim to provide indications for early differential diagnosis to help initiate appropriate treatment in a timely manner so that associated complications can be avoided.

Intraosseous basivertebral nerve ablation: Pooled long-term outcomes from two prospective clinical trials

Background

Vertebrogenic pain is an established source of anterior column chronic low back pain (CLBP) resulting from damaged vertebral endplates with pain signals transmitted by the basivertebral nerve (BVN). Type 1 or Type 2 Modic changes on magnetic resonance imaging (MRI) are objective biomarkers for vertebrogenic pain. Radiofrequency ablation of the BVN (BVNA) has demonstrated both efficacy and effectiveness for the treatment of vertebrogenic pain in two randomized trials. Here, we report 3-year aggregate results from two prospective studies of BVNA-treated patients.

Methods

Pooled results at 3 years post-BVNA are reported for two studies with similar inclusion/exclusion criteria and outcomes measurements: 1) a prospective, open label, single-arm follow-up of the treatment arm of a randomized controlled trial (RCT) comparing BVNA to standard care (INTRACEPT Trial), and 2) a prospective, open label, single cohort long-term follow-up study of BVNA-treated patients. Paired datasets (baseline and 3-years) for mean changes in Oswestry disability index (ODI) and numeric pain scores (NPS) were analyzed using a two-sided t-test with a 0.05 level of significance.

Results

There were 95/113 (84%) BVNA patients who completed a 3-year visit across 22 study sites. At baseline, 71% of patients reported back pain for ≥5 years, 28% were taking opioids, 34% had spinal injections in the prior 12 months, and 14% had prior low back surgery. Pain and functional improvements were significant at 3 years with a mean reduction in NPS of 4.3 points from 6.7 ​at baseline (95% CI 3.8, 4.8; p<0.0001) and a mean reduction in ODI of 31.2 points from 46.1 ​at baseline (95% CI 28.4, 34.0; p<0.0001). Responder rates, using minimal clinically important differences of ≥15-points for ODI and ≥50% reduction in NPS from baseline to three years, were 85.3% and 72.6%, respectively (combined response 69.5%), with 26.3% of patients reporting 100% pain relief at 3 years. There was a 74% reduction in the use of opioids and 84% reduction in the use of therapeutic spinal interventions from baseline to 3 years. There were no serious device or device-procedure related adverse events reported through three years.

Conclusion

Intraosseous BVNA demonstrates statistically significant, clinically meaningful, and durable improvements in pain and function through 3 years in patients with primary vertebrogenic low back pain. BVNA-treated patients significantly reduced opioid use and interventions for low back pain.

K-line tilt as a novel potential risk factor for cervical Modic change: a retrospective study

BACKGROUND

Cervical sagittal parameters are important parameters that reflect the mechanical stress in the sagittal plane of the cervical spine and are an important basis for predicting the clinical status and prognosis of patients. Although it has been confirmed that there is a significant correlation between cervical Modic changes and some sagittal parameters. However, as a newly discovered sagittal parameter, there is no report on the relationship between the K-line tilt and the Modic changes of cervical spine.

METHODS

A retrospective analysis was performed for 240 patients who underwent cervical magnetic resonance imaging scan for neck and shoulder pain. Among them, 120 patients with Modic changes, namely the MC(+) group, were evenly divided into three subgroups of 40 patients in each group according to different subtypes, namely MCI subgroup, MCII subgroup and MCIII subgroup. One hundred twenty patients without Modic changes were included in MC(-) group. We measured and compared the sagittal parameters of cervical spine among different groups, including K-line tilt, C2-C7 sagittal axial vertical distance (C2-C7 SVA), T1 slope and C2-7 lordosis. Logistic regression was used to analyse the risk factors of cervical Modic changes.

RESULTS

The K-line tilt and C2-7 lordosis were significantly different between MC(+) group and MC(-) group (P < 0.05). The K-line tilt greater than 6.72° is a risk factor for Modic changes in cervical spine (P < 0.05). At the same time, the receiver operating characteristic curve showed that this change had moderate diagnostic value when the area under the curve was 0.77.

CONCLUSION

This study shows that the K-line tilt greater than 6.72° is a potential risk factor for Modic changes in cervical spine. When the K-line tilt is greater than 6.72°, we should be alert to the occurrence of Modic changes.

TRIAL REGISTRATION NUMBER

2022ER023-1.

Spatial distribution of fat infiltration within the paraspinal muscles: implications for chronic low back pain

PURPOSE

Fat infiltration (FI) of the paraspinal muscles (PSMs) measured using MRI is an aspect of muscle quality and is considered to be worse in chronic low back pain (cLBP) patients. However, there is not a clear association between paraspinal muscle FI and cLBP, leaving the clinical importance of paraspinal muscle composition unestablished. The spatial distribution of FI in the PSMs may inform mechanistic understanding of non-specific cLBP as it relates to degenerative intervertebral disc (IVD) pathology. We hypothesized that paraspinal muscle fat-mapping would reveal distinct FI distribution patterns in relation to cLBP symptoms and proximity to symptomatic IVD degeneration.

METHODS

From advanced-sequence water-fat MRI of 40 axial cLBP patients and 21 controls, we examined the spatial distribution of paraspinal muscle FI in relation to the center of rotation at the L4L5 disc. Using statistical parametric mapping, we compared FI patterns for multifidus (MF), erector spinae (ES), and psoas between patients and controls, and to the presence and severity of adjacent degenerative IVD pathology.

RESULTS

The spatial distribution of PSMs FI differs between PSMs and according to symptoms and the adjacent degenerative IVD pathology. Furthermore, the region of MF closest to the disc center of rotation appears most susceptible to FI in the presence of symptomatic IVD degeneration.

CONCLUSION

Our study identified spatial distribution patterns of FI in the PSMs as a potential diagnostic biomarker that may also provide granular mechanistic insights into spine biomechanics related to cLBP, as well as advancing the use of prior summary measures limited to overall muscle FI.

Pain Location and Exacerbating Activities Associated with Treatment Success Following Basivertebral Nerve Ablation: An Aggregated Cohort Study of Multicenter Prospective Clinical Trial Data

OBJECTIVE

Develop pain location "maps" and investigate the relationship between low back pain (LBP)-exacerbating activities and treatment response to basivertebral nerve radiofrequency ablation (BVN RFA) in patients with clinically suspected vertebral endplate pain (VEP).

DESIGN

Aggregated cohort study of 296 patients treated with BVN RFA at 33 centers in three prospective trials.

METHODS

Participant demographics, pain diagrams, and LBP-exacerbating activities were analyzed for predictors using stepwise logistic regression. Treatment success definitions were: (1) ≥50% LBP visual analog scale (VAS), (2) ≥15-point Oswestry Disability Index (ODI), and (3) ≥50% VAS or ≥15-point ODI improvements at 3 months post-BVN RFA.

RESULTS

Midline LBP correlated with BVN RFA treatment success in individuals with clinically-suspected VEP. Duration of pain ≥5 years (OR 2.366), lack of epidural steroid injection within 6 months before BVN RFA (OR 1.800), lack of baseline opioid use (OR 1.965), LBP exacerbation with activity (OR 2.099), and a lack of LBP with spinal extension (OR 1.845) were factors associated with increased odds of treatment success. Regressions areas under the curve (AUCs) were under 70%, indicative of low predictive value.

CONCLUSIONS

This study demonstrates that midline LBP correlates with BVN RFA treatment success in individuals with VEP. While none of the regression models demonstrated strong predictive value, the pain location and exacerbating factors identified in this analysis may aid clinicians in identifying patients where VEP should be more strongly suspected. The use of objective imaging biomarkers (Type 1 and/or 2 Modic changes) and a correlating presentation of anterior spinal element pain remain the most useful patient selection factors for BVN RFA.

The Relationship Between Patient Demographic and Clinical Characteristics and Successful Treatment Outcomes After Basivertebral Nerve Radiofrequency Ablation: A Pooled Cohort Study of Three Prospective Clinical Trials

OBJECTIVE

Multiple studies have demonstrated the safety and effectiveness of basivertebral nerve radiofrequency ablation (BVN RFA) for improving low back pain related to the vertebral endplate. However, the influence of patient demographic and clinical characteristics on treatment outcome is unknown.

DESIGN

Pooled cohort study of three clinical trials of patients with vertebral endplate pain identified by Type 1 and/or Type 2 Modic changes and a correlating presentation of anterior spinal element pain.

SETTING

Thirty-three global study centers.

SUBJECTS

Patients (n = 296) successfully treated with BVN RFA.

METHODS

Participant demographic and clinical characteristics were analyzed with stepwise logistic regression to identify predictors of treatment success. Three definitions of treatment success were defined: 1) ≥50% visual analog scale pain improvement, 2) ≥15-point Oswestry Disability Index (ODI) improvement, and 3) ≥50% visual analog scale or ≥15-point ODI improvement from baseline.

RESULTS

Low back pain of ≥5 years' duration and higher ODI scores at baseline increased the odds of treatment success, whereas baseline opioid use and higher Beck Depression Inventory scores reduced these odds. However, the three regression models demonstrated receiver-operating characteristics of 62-70% areas under the curve, and thus, limited predictive capacity.

CONCLUSIONS

This analysis identified no demographic or clinical characteristic that meaningfully increased or reduced the odds of treatment success from BVN RFA. On the basis of these findings and the high response rates from the three analyzed trials, we recommend the use of objective imaging biomarkers (Type 1 and/or 2 Modic changes) and a correlating presentation of anterior spinal element pain to determine optimal candidacy for BVN RFA.

Automatic detection and voxel-wise mapping of lumbar spine Modic changes with deep learning

Background

Modic changes (MCs) are the most prevalent classification system for describing magnetic resonance imaging (MRI) signal intensity changes in the vertebrae. However, there is a growing need for novel quantitative and standardized methods of characterizing these anomalies, particularly for lesions of transitional or mixed nature, due to the lack of conclusive evidence of their associations with low back pain. This retrospective imaging study aims to develop an interpretable deep learning-based detection tool for voxel-wise mapping of MCs.

Methods

Seventy-five lumbar spine MRI exams that presented with acute-to-chronic low back pain, radiculopathy, and other symptoms of the lumbar spine were enrolled. The pipeline consists of two deep convolutional neural networks to generate an interpretable voxel-wise Modic map. First, an autoencoder was trained to segment vertebral bodies from T1-weighted sagittal lumbar spine images. Next, two radiologists segmented and labeled MCs from a combined T1- and T2-weighted assessment to serve as ground truth for training a second autoencoder that performs segmentation of MCs. The voxels in the detected regions were then categorized to the appropriate Modic type using a rule-based signal intensity algorithm. Post hoc, three radiologists independently graded a second dataset with the aid of the model predictions in an artificial (AI)-assisted experiment.

Results

The model successfully identified the presence of changes in 85.7% of samples in the unseen test set with a sensitivity of 0.71 (±0.072), specificity of 0.95 (±0.022), and Cohen's kappa score of 0.63. In the AI-assisted experiment, the agreement between the junior radiologist and the senior neuroradiologist significantly improved from Cohen's kappa score of 0.52 to 0.58 (p < 0.05).

Conclusions

This deep learning-based approach demonstrates substantial agreement with radiologists and may serve as a tool to improve inter-rater reliability in the assessment of MCs.

Multi-scanner and multi-modal lumbar vertebral body and intervertebral disc segmentation database

Magnetic resonance imaging (MRI) is widely utilized for diagnosing and monitoring of spinal disorders. For a number of applications, particularly those related to quantitative MRI, an essential step towards achieving reliable and objective measurements is the segmentation of the examined structures. Performed manually, such process is time-consuming and prone to errors, posing a bottleneck to its clinical applicability. A more efficient analysis would be achieved by automating a segmentation process. However, routine spine MRI acquisitions pose several challenges for achieving robust and accurate segmentations, due to varying MRI acquisition characteristics occurring in data acquired from different sites. Moreover, heterogeneous annotated datasets, collected from multiple scanners with different pulse sequence protocols, are limited. Thus, we present a manually segmented lumbar spine MRI database containing a wide range of data obtained from multiple scanners and pulse sequences, with segmentations of lumbar vertebral bodies and intervertebral discs. The database is intended for the use in developing and testing of automated lumbar spine segmentation algorithms in multi-domain scenarios.

Measurement(s)	Vertebral Body • Intervertebral Disc
Technology Type(s)	Magnetic Resonance Imaging

Development of a standardized histopathology scoring system for human intervertebral disc degeneration: an Orthopaedic Research Society Spine Section Initiative

BACKGROUND

Histopathological analysis of intervertebral disc (IVD) tissues is a critical domain of back pain research. Identification, description, and classification of attributes that distinguish abnormal tissues form a basis for probing disease mechanisms and conceiving novel therapies. Unfortunately, lack of standardized methods and nomenclature can limit comparisons of results across studies and prevent organizing information into a clear representation of the hierarchical, spatial, and temporal patterns of IVD degeneration. Thus, the following Orthopaedic Research Society (ORS) Spine Section Initiative aimed to develop a standardized histopathology scoring scheme for human IVD degeneration.

METHODS

Guided by a working group of experts, this prospective process entailed a series of stages that consisted of reviewing and assessing past grading schemes, surveying IVD researchers globally on current practice and recommendations for a new grading system, utilizing expert opinion a taxonomy of histological grading was developed, and validation performed.

RESULTS

A standardized taxonomy was developed, which showed excellent intra-rater reliability for scoring nucleus pulposus (NP), annulus fibrosus (AF), and cartilaginous end plate (CEP) regions (interclass correlation [ICC] > .89). The ability to reliably detect subtle changes varied by IVD region, being poorest in the NP (ICC: .89-.95) where changes at the cellular level were important, vs the AF (ICC: .93-.98), CEP (ICC: .97-.98), and boney end plate (ICC: .96-.99) where matrix and structural changes varied more dramatically with degeneration.

CONCLUSIONS

The proposed grading system incorporates more comprehensive descriptions of degenerative features for all the IVD sub-tissues than prior criteria. While there was excellent reliability, our results reinforce the need for improved training, particularly for novice raters. Future evaluation of the proposed system in real-world settings (eg, at the microscope) will be needed to further refine criteria and more fully evaluate utility. This improved taxonomy could aid in the understanding of IVD degeneration phenotypes and their association with back pain.