Lumbar disc high-intensity zone. Correlation of magnetic resonance imaging and discography

Complementary Repair Therapy as a Trending Topic in Discogenic Pain: A Bibliometric Study Over the Past 40 Years

Background and Aims

Bibliometric analysis has been frequently employed for visualizing trends within a particular scientific domain. The pain associated with discogenic origins has a significant impact on one's quality of life, but there is currently a lack of bibliometric analysis in the literature. Hence, this study aimed to examine related research in the field and identify the latest topics that are currently trending by conducting a bibliometric analysis.

Methods

The Bibliometrix which developed in the statistical R-packages was used for the data analysis. All related eligible publications were identified, and studies published from 1982 to 2023 were extracted from the Web of Science database.

Results

Disc repair, bone marrow cells, platelet-rich plasma, and the activation of inflammatory responses were identified as the trending topics after analyzing 977 journal articles. The most productive and influential journal was SPINE (Phila Pa 1976), which accounted for the largest publications and highest H index. The most productive and locally cited authors were Takahashi K., Ohtori S., and Aoki Y. from Chiba University. The top three productive and globally cited institutions were Chiba University, followed by University of California San Francisco and Korea University. The USA, China, and Japan were demonstrated as the most productive and globally cited countries.

Conclusion

This study performed the first bibliometric analysis on discogenic pain and provided valuable insights into the latest trending topics in the field. Analysis reveals that recent research has primarily focused on complementary and regenerative approaches for repairing painful discs, as well as the role of inflammatory responses in disc pathology.

Does the high-intensity zone of lumbar intervertebral disc at magnetic resonance imaging have diagnostic value for discogenic low back pain? A meta-analysis

OBJECTIVE

The correlation between high-intensity zone (HIZ) of lumbar disc magnetic resonance imaging (MRI) and discogenic low back pain (DLBP) is currently controversial, this study aimed to systematically evaluate the correlation between HIZ of lumbar disc MRI and positive discography, as well as its diagnostic value for DLBP.

METHOD

Databases were searched to include research literature on high intensity zone (HIZ) related to discography and DLBP diagnosis. HIZ is a separate small, confined area of high signal located at the posterior border of the annulus fibrosus on MRI T2-weighted images of the lumbar spine, which is separated from the nucleus pulposus but has a higher signal than the nucleus pulposus. Studies on the correlation of HIZ with discography and DLBP diagnosis were searched in the Pubmed, EMBASE, Cochrane Central, Science Direct, China Knowledge Network, Wanfang Database, and China Biomedical Literature Databases, Scopus from January 1992 to June 2024. The outcomes were diagnostic values of HIZ for DLBP. The risk assessment was performed by Deeks' funnel methods in the Stata 17.0 software after 2 investigators independently screened the literature, extracted information and evaluated the risk of bias of the included studies.

RESULTS

A total of 25 studies including 5889 patients were included. meta-analysis showed that the sensitivity of HIZ for the diagnosis of DLBP was (0.49, 95% CI [0.37,0.61]) and specificity was (0.89, 95% CI [0.85,0.93]); the positive likelihood ratio was (4.52, 95% CI [3.28,6.25]) and the negative likelihood ratio was (0.58, 95% CI [0.46,0.71]). The diagnostic ratio was (7.87, 95% CI [5.05,12.26]).

CONCLUSION

The available evidence suggests that HIZ has acceptable sensitivity and high specificity in the diagnosis of DLBP. Due to the limitation of the number and quality of included studies, the above conclusions need to be validated by more high-quality studies.

Intradiscal Steroid Injections for Degenerative Disc Disease With Modic Changes: A Retrospective Study of Therapeutic and Diagnostic Features

PURPOSE

Anterior column pain refers to axial low back pain (LBP) originating from the intervertebral disc or vertebral endplates (discogenic or vertebrogenic pain). We sought to assess the safety and effectiveness of intradiscal steroid injection (IDSI) in diagnosing and treating patients with LBP arising from the anterior column.

PATIENTS AND METHODS

This is a retrospective chart review of 66 patients who underwent 77 injections in an outpatient, private practice setting for the treatment of chronic lower back with history and physical exam findings indicating an origin within the anterior column and magnetic resonance imaging (MRI) findings of Modic changes associated with disc degeneration of grade 4 or above on the modified Pfirrmann scale. Patients reported pain as measured by the numerical rating scale (NRS) before the injection, at the time of their follow-up, and their maximum pain relief. The primary outcome was the change in NRS before and after the injections. The secondary outcome determined if the changes in the subjects' NRS met the minimal clinically important change (MCIC) criteria for LBP. We conducted a statistical analysis using a paired sample t-test.

RESULTS

There was a statistically significant difference between the pre-injection and follow-up NRS scores (p < 0.001) and a significant difference between pre-injection and maximum relief NRS scores (p < 0.001). Most subjects (55/77, 71.4%) met the MCIC to relieve their chronic LBP at the time of the follow-up evaluation.

CONCLUSION

For patients with chronic LBP and degenerative endplate changes, IDSIs provided these patients with significant short-term pain relief from pain arising from the anterior column.

Imaging of Discogenic and Vertebrogenic Pain

Chronic low back pain is a major source of pain and disability globally involving multifactorial causes. Historically, intervertebral disc degeneration and disruption have been associated as primary back pain triggers of the anterior column, termed "discogenic pain." Recently, the vertebral endplates have been identified as another possible pain trigger of the anterior column. This "endplate-driven" model, defined "vertebrogenic pain," is often interconnected with disc degeneration. Diagnosis of vertebrogenic and discogenic pain relies on imaging techniques that isolate pain generators and exclude comorbid conditions. Traditional methods, like radiographs and discography, are augmented by more sensitive methods, including SPECT, CT, and MRI. Morphologic MRI is pivotal in revealing indicators of vertebrogenic (eg, Modic endplate changes) and discogenic pain (eg, disc degeneration and annular fissures). More advanced methods, like ultra-short-echo time imaging, and quantitative MRI further amplify MRI's accuracy in the detection of painful endplate and disc pathology. This review explores the pathophysiology of vertebrogenic and discogenic pain as well as the impact of different imaging modalities in the diagnosis of low back pain. We hope this information can help identify patients who may benefit from personalized clinical treatment and image-guided therapies.

Pain behavior and phenotype in a modified anterior lumbar disc puncture mouse model

Background

An experimental study was performed to improve the anterior approach model of intervertebral disc degeneration (IVDD).

Objective

The aims of this study were to investigate the anterior approach model of IVDD for the cause of death, phenotypes, and underlying mechanisms of low back pain in mice.

Method

In this study, we conducted an anterior puncture procedure on a cohort of 300 C57BL/6J mice that were 8 weeks old. Our investigation focused on exploring the causes of death in the study population (n = 300) and assessing the time-course changes in various parameters, including radiographical, histological, immunofluorescence, and immunohistochemistry analyses (n = 10). Additionally, we conducted behavioral assessments on a subset of the animals (n = 30).

Results

Transverse vertebral artery rupture is a major factor in surgical death. Radiographical analyses showed that the hydration of the nucleus pulposus began to decrease at 2 weeks after puncture and obviously disappeared over 4 weeks. 3D-CT showed that disc height was significantly decreased at 4 weeks. Osteophyte at the anterior vertebral rims was observed at 2 weeks after the puncture. As the time course increased, histological analyses showed progressive disruption of the destruction of the extracellular matrix and increased secretion of inflammatory cytokines and apoptosis. Behavioral signs of low back pain were increased between the puncture and sham groups at 4 weeks.

Conclusion

The improvement of anterior intervertebral disc approach model in mice will be useful to investigate underlying mechanisms and potential therapeutic strategies for behavior and phenotypes. Furthermore, the application of vibrational pre-treatment can be used to increase the sensitivity of axial back pain in the model, thereby providing researchers with a reliable method for measuring this critical phenotype.

Coexistence of Vertebral and Intervertebral Disc Changes in Low Back Pain Patients-In Depth Characterization with Same Day MRI and CT Discography

The aim of this study was to investigate to what extent annular fissures, vertebral and endplate changes, and Modic changes (MCs), coexist in low back pain (LBP) patients by using multiple imaging modalities. Sixty-two LBP patients (mean age 45 years, range 24-63, 53% men) were examined with same-day CT-discography and MRI. Intervertebral discs punctured for discography (n = 204) were evaluated on MRI [Pfirrmann grade, High-Intensity Zone (HIZ)] and on CT-discograms [Modified Dallas Discogram Score (DDS)]. DDS≥ 1, i.e., disc fissures involving the outer annulus were further digitomized into delimitable fissuring (<50% of annulus affected) or non-delimitable annular fissuring. Using both MRI and CT, adjacent vertebrae and endplates were assessed for MC, vertebral sclerosis, and a modified endplate defect score (EPS). In 194 discs the contrast agent was adequately injected during discography, of which 160 (83%) displayed outer annular fissures, with 91 (47%) of the latter being delimitable fissures. Most discs with delimitable fissures were moderately degenerated; 68% Pfirrmann grade ≤3, 71% EPS ≤ 2, and 12% displayed MC. The majority (76%) of MCs were associated with advanced adjacent disc degeneration; 84% Pfirrmann grade ≥4, 76% with non-delimitable annular fissuring, 59% EPS≥ 4, and 34% EPS of 3. A total 95 HIZ (47%) were found, of which 54 had delimitable fissuring, while the remainder displayed non-delimitable fissuring. Vertebral sclerosis was commonly observed (26%), both with MCs (73%) and without MCs (27%), and not specifically linked to MC type 3. A total of 97% of segments with vertebral sclerosis displayed outer annular fissures. These findings were significant (0.046 > p > 0.0001), except between HIZ and adjacent sclerosis (p = 0.303). To conclude, the present study confirmed a close interplay between the disc and adjacent vertebra and endplates. The fact that a majority of discs with delimitable annular fissures did not coexist with pronounced endplate changes and/or MCs, however, supports the theory that disc fissuring is an early event in the degenerative cascade. This was further supported by the fact that MCs were strongly linked to extensive disc fissuring and to advanced endplate damage. Further, vertebral sclerosis was common also in vertebra without MCs and strongly associated to annular fissuring, indicating that sclerosis is a previously underestimated feature of a general degenerative process.

The correlation between the lumbar disc MRI high-intensity zone and discogenic low back pain: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the correlation between the MRI high-intensity zone (HIZ) and the pathogenesis of discogenic low back pain.

METHODS

Literature from PubMed, EMBASE, Cochrane Library, Science Direct, China Knowledge Network, Wanfang Database, and China Biomedical Literature Database was searched until August 2023. Cohort studies including patients with low back pain who underwent lumbar spine MRI and discography, as well as the results evaluating the correlation between HIZ and discography for morphological changes in the disc and pain replication phenomena, were included in the analysis. The literature that met the inclusion criteria was screened, and the methodological quality of the included studies was evaluated. Meta-analysis of the extracted data was performed by using RevMan 5.1.1.

RESULTS

In total, 28 reports were included in this meta-analysis. There was a statistically significant correlation between a positive HIZ and abnormal disc morphology in discography (OR 28.15, 95% CI [7.38, 107.46], p < 0.00001). Patients with HIZ-positive discs had a significantly higher incidence of consistent pain (71.0%, 969/1365) than those with HIZ-negative imaging (29.0%, 1314/4524) (OR 7.71, 95% CI [5.29, 11.23], p < 0.00001).Segments that were HIZ-positive and had abnormal disc morphology had a higher incidence of consistent pain (86.1%, 230/267) than HIZ-negative subjects (32.2%, 75/233) (OR 14.09, 95% CI [2.12, 93.48], p = 0.006).

CONCLUSION

A positive MRI T2-weighted image of the lumbar disc with HIZ indicates disc degeneration. In addition, HIZ may be a specific indicator for the physical diagnosis of discogenic low back pain. A more advanced degree of disc degeneration on the basis of HIZ positivity corresponded to a greater probability of discography-induced consistent pain, whereas the degree of disc degeneration on the basis of HIZ negativity was less correlated with contrast-induced consistent pain.

Low back pain of disc, sacroiliac joint, or facet joint origin: a diagnostic accuracy systematic review

Background

The accuracy of diagnostic tests available in primary care to identify the disc, sacroiliac joint, and facet joint as the source of low back pain is uncertain.

Methods

Systematic review of diagnostic tests available in primary care. MEDLINE, CINAHL, and EMBASE were searched between March 2006 and 25th January 2023. Pairs of reviewers independently screened all studies, extracted data, and assessed risk of bias using QUADAS-2. Pooling was performed for homogenous studies. Positive likelihood ratios (+LR) ≥2 and negative likelihood ratios (-LR) ≤0.5 were considered informative. This review is registered with PROSPERO (CRD42020169828).

Findings

We included 62 studies: 35 investigated the disc, 14 the facet joint, 11 the sacroiliac joint, and 2 investigated all three structures in patients with persistent low back pain. For risk of bias, the domain 'reference standard' scored worst, however approximately half the studies were of low risk of bias for every other domain. For the disc, pooling demonstrated MRI findings of disc degeneration and annular fissure resulted in informative +LRs: 2.53 (95% CI: 1.57-4.07) and 2.88 (95% CI: 2.02-4.10) and -LRs: 0.15 (95% CI: 0.09-0.24) and 0.24 (95% CI: 0.10-0.55) respectively. Pooled results for Modic type 1, Modic type 2, and HIZ on MRI, and centralisation phenomenon yielded informative +LRs: 10.00 (95% CI: 4.20-23.82), 8.03 (95% CI: 3.23-19.97), 3.10 (95% CI: 2.27-4.25), and 3.06 (95% CI: 1.44-6.50) respectively, but uninformative -LRs: 0.84 (95% CI: 0.74-0.96), 0.88 (95% CI: 0.80-0.96), 0.61 (95% CI: 0.48-0.77), and 0.66 (95% CI: 0.52-0.84) respectively. For the facet joint, pooling demonstrated facet joint uptake on SPECT resulted in informative +LRs: 2.80 (95% CI: 1.82-4.31) and -LRs: 0.44 (95% CI: 0.25-0.77). For the sacroiliac joint, a combination of pain provocation tests and absence of midline low back pain resulted in informative +LRs of 2.41 (95% CI: 1.89-3.07) and 2.44 (95% CI: 1.50-3.98) and -LRs of 0.35 (95% CI: 0.12-1.01) and 0.31 (95% CI: 0.21-0.47) respectively. Radionuclide imaging yielded an informative +LR 7.33 (95% CI: 1.42-37.80) but an uninformative -LR 0.74 (95% CI: 0.41-1.34).

Interpretation

There are informative diagnostic tests for the disc, sacroiliac joint, and facet joint (only one test). The evidence suggests a diagnosis may be possible for some patients with low back pain, potentially guiding targeted and specific treatment approaches.

Funding

There was no funding for this study.

5-Year progression prediction of endplate defects: Utilizing the EDPP-Flow convolutional neural network based on unbalanced data

Background

Lumbar disc degeneration (LDD) is considered as one of the main causes of low back pain. For clinical diagnosis of LDD, magnetic resonance imaging (MRI) is commonly used. Schmorl's node, high intensity zone (HIZ), Modic changes, and other MRI biomarkers of intervertebral disc (IVD) degeneration are also associated with low back pain. However, the progression and natural history of these features are unclear and there is limited predictive capacity with MRI.

Purpose

We aim to establish and validate a deep learning pipeline, EDPP-Flow, for the 5-year progression prediction of Schmorl's node, HIZ, and Modic changes, based on clinical MRIs.

Materials and methods

An MRI dataset developed on 1152 volunteers was used in this study. For each volunteer, two MRI scans, at baseline and 5-year follow-up, were collected and pathology labels were annotated as present or absent (with/without pathology) by two specialists with over 10 years of clinical experience. Our pipeline contained the published MRI-SegFlow and state-of-the-art convolutional neural network for progression prediction of endplate defects. The label distribution of the dataset is unbalanced, where the number of present samples was much smaller than absent samples. The resampling and data augmentation strategies were adopted to increase the number of present samples in the training process and balance the influence of different samples on the model, which can improve the prediction accuracy.

Results

Our pipeline achieved high weighted accuracy, sensitivity, and specificity for progression prediction of Schmorl's node (89.46 ± 3.71%, 89.19 ± 2.70%, 89.72 ± 2.42%), HIZ (91.75 ± 2.48%, 93.07 ± 3.96%, 90.43 ± 2.51%), and Modic changes (87.51 ± 2.23%, 87.93 ± 1.72%, 87.10 ± 1.99%), on the unbalanced dataset (present sample's percentages of the 3 pathologies above were 4.3%, 11.7%, and 6.7%).

Conclusion

We developed and validated a deep learning pipeline, for the progression prediction of endplate defects, which showed high prediction accuracy on unbalanced data. The method has significant potential for clinical implementation.

Precision pain management in interventional radiology

Pain is a common manifestation of several benign and malignant conditions. Inadequate response to conservative therapies is often succeeded by incremental use of analgesics and opioids; however, such an approach is often ineffective, not well tolerated by patients, and carries the risk of addiction leading to the opioid crisis. Implementing minimally invasive percutaneous procedures, performed by interventional radiologists has proven to be successful in providing safe, effective, and patient-specific therapies across a wide range of painful conditions. In the present narrative review, we will review the repertoire of minimally invasive imaging guided interventions, which have been successfully used to treat common painful benign and malignant conditions. We briefly describe each technique, common indications, and expected results.

Lumbar endoscopic spine surgery for persistent genital arousal disorder/genitopelvic dysesthesia resulting from lumbosacral annular tear-induced sacral radiculopathy

BACKGROUND

Persistent genital arousal disorder/genitopelvic dysesthesia (PGAD/GPD) is characterized by distressing, abnormal genitopelvic sensations, especially unwanted arousal. In a subgroup of patients with PGAD/GPD, cauda equina Tarlov cyst-induced sacral radiculopathy has been reported to trigger the disorder. In our evaluation of lumbosacral magnetic resonance images in patients with PGAD/GPD and suspected sacral radiculopathy, some had no Tarlov cysts but showed lumbosacral disc annular tear pathology.

AIM

The aims were 2-fold: (1) to utilize a novel multidisciplinary step-care management algorithm designed to identify a subgroup of patients with PGAD/GPD and lumbosacral annular tear-induced sacral radiculopathy who could benefit from lumbar endoscopic spine surgery (LESS) and (2) to evaluate long-term safety and efficacy of LESS.

METHODS

Clinical data were collected on patients with PGAD/GPD who underwent LESS between 2016 and 2020 with at least 1-year follow-up. LESS was indicated because all had lumbosacral annular tear-induced sacral radiculopathy confirmed by our multidisciplinary management algorithm that included the following: step A, a detailed psychosocial and medical history; step B, noninvasive assessments for sacral radiculopathy; step C, targeted diagnostic transforaminal epidural spinal injections resulting in a temporary, clinically significant reduction of PGAD/GPD symptoms; and step D, surgical intervention with LESS and postoperative follow-up.

OUTCOMES

Treatment outcome was based on the validated Patient Global Impression of Improvement, measured at postoperative intervals.

RESULTS

Our cohort included 15 cisgendered women and 5 cisgendered men (mean ± SD age, 40.3 ± 16.8 years) with PGAD/GPD who fulfilled the criteria of lumbosacral annular tear-induced sacral radiculopathy based on our multidisciplinary management algorithm. Patients were followed for an average of 20 months (range, 12-37) post-LESS. Lumbosacral annular tear pathology was identified at multiple levels, the most common being L4-L5 and L5-S1. Twenty-two LESS procedures were performed in 20 patients. Overall, 80% (16/20) reported improvement on the Patient Global Impression of Improvement; 65% (13/20) reported improvement as much better or very much better. All patients were discharged the same day. There were no surgical complications.

CLINICAL IMPLICATIONS

Among the many recognized triggers for PGAD/GPD, this subgroup exhibited lumbosacral annular tear-induced sacral radiculopathy and experienced long-term alleviation of symptoms by LESS.

STRENGTHS AND LIMITATIONS

Strengths include long-term post-surgical follow-up and demonstration that LESS effectively treats patients with PGAD/GPD who have lumbosacral annular tear-induced sacral radiculopathy, as established by a multidisciplinary step-care management algorithm. Limitations include the small study cohort and the unavailability of a clinical measure specific for PGAD/GPD.

CONCLUSION

LESS is safe and effective in treating patients with PGAD/GPD who are diagnosed with lumbosacral annular tear-induced sacral radiculopathy.

Enhancing Annular Fissures and High-Intensity Zones: Pain, Internal Derangement, and Anesthetic Response at Provocation Lumbar Discography

BACKGROUND AND PURPOSE

A high-intensity zone identified on preprocedural MR imaging is known to correlate with pain at provocation lumbar discography. The correlation between enhancing annular fissures and pain at provocation lumbar discography has not been comprehensively evaluated. The purpose of this study was to assess the pain response and imaging features at enhancing annular fissure nonoperated disc levels identified on preprocedural MR imaging with comparison with the high-intensity zone and nonenhancing disc levels in patients referred for provocation lumbar discography.

MATERIALS AND METHODS

One-hundred nonoperated discs in 44 patients were retrospectively evaluated for an enhancing annular fissure on sagittal postcontrast T1-weighted pre-discogram MR imaging. Enhancing annular fissure discs were graded on the sagittal T2-weighted sequence (Grade 4: like CSF to Grade 1: negative/barely visible) for high-intensity-zone conspicuity. High-intensity-zone detection was performed independently. In the primary assessment, enhancing annular fissure and high-intensity zones were associated with pain response at provocation lumbar discography. Additional analysis included intradiscal anesthetic response and postdiscogram CT appearance.

RESULTS

Thirty-nine discs demonstrated an enhancing annular fissure, with 23/39 demonstrating a high-intensity zone. The presence of a high-intensity zone predicted severe pain (concordant + nonconcordant; P = .005, sensitivity of 40%, specificity of 94%) and concordant pain (P = .007, sensitivity of 39%, specificity of 86%) at provocation lumbar discography. Enhancing annular fissures without a detected high-intensity zone were more frequently observed among severely painful (50%) and concordant (36%) discs than among discs negative for pain (9%; P = .01). This finding resulted in a substantially greater overall sensitivity of enhancing annular fissures for severe (P < .001, 64%) and concordant pain (P = .008, 61%), significantly improving the overall predictive ability of a high-intensity zone alone. A high-intensity zone went undetected in 9/11 Grade 1 disc levels with concordant pain present in 7/9.

CONCLUSIONS

Consideration of enhancing annular fissures on preprocedural MR imaging substantially improves the prediction of severe/concordant pain in provocation lumbar discography.

The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Computed tomography (CT) and magnetic resonance imaging (MRI) have replaced conventional radiography in the study of many spinal conditions, it is essential to know when these techniques are indicated instead of or as complementary tests to radiography, which findings can be expected in different clinical settings, and their significance in the diagnosis of different spinal conditions. Proper use of CT and MRI in spinal disorders may facilitate diagnosis and management of spinal conditions. An adequate clinical approach, a good understanding of the pathological manifestations demonstrated by these imaging techniques and a comprehensive report based on a universally accepted nomenclature represent the indispensable tools to improve the diagnostic approach and the decision-making process in patients with spinal pain. Several guidelines are available to assist clinicians in ordering appropriate imaging techniques to achieve an accurate diagnosis and to ensure appropriate medical care that meets the efficacy and safety needs of patients. This article reviews the clinical indications of CT and MRI in different pathologic conditions affecting the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumor disorders, as well as their main imaging features. It is intended to be a pictorial guide to clinicians involved in the diagnosis and treatment of spinal disorders.

Imaging Analysis of the High-Intensity Zone on Lumbar Spine Magnetic Resonance Images: Classification, Features and Correlation with Low Back Pain

Aim

Early studies suggested that the high-intensity zone (HIZ) on lumbar MRI was a diagnostic sign of painful internal disc disruption (IDD). However, recent studies have questioned its diagnostic value. This study is conducted to explore imaging features of HIZ and to investigate the correlation between these characteristics and low back pain (LBP), further studying the predictive value of HIZ.

Methods

A retrospective study of 1188 cases was performed. MR images were read and analyzed by two experienced, blinded radiologists.

Results

A total of 575 (48.4%) individuals exhibited HIZ. The prevalence of posterior HIZ (32.3%) was significantly higher than that of anterior HIZ (23.6%; P < 0.01). Round type was the most common shape (61.0%) on sagittal view. Only 37 HIZs (4.6%) were identified on axial views. A total of 263 HIZ discs (32.5%) were found to have additional diagnostic signs of IDD, which is difficult to distinguish from the annulus fibrosus. In subjects with consecutive slides showing HIZ, the incidence of LBP was significantly higher than in single-slide HIZ individuals (58.0% vs 48.6%, P < 0.05).

Conclusion

MRI-visualized HIZ is a highly valuable method of screening for lumbar IDD. It is demonstrated that consecutive-slide HIZ was a more reliable indicator for discogenic LBP than single-slide HIZ.

Motion Characteristics of the Functional Spinal Unit During Lumbar Disc Injection (Discography) Including Comparison Between Normal and Degenerative Levels

OBJECTIVE

While provocation lumbar discography has been used to identify discs responsible for low back pain, the biomechanical effects of disc injection have received little attention. The purpose of this study was to assess the motion of the functional spinal unit including the endplate and facet/pedicle region during disc injection including comparison between normal and degenerative discs.

SUBJECTS

Subjects represent 91 consecutive patients referred for discography with chronic low back pain.

METHODS

Lateral projection vertebral motion was retrospectively analyzed at 232 levels (normal: 76 [32.8%], degenerative: 156 [67.2%]). Pre- and postinjection fluoroscopic images were size scaled, and lower endplates were superimposed on separate PowerPoint images. Upper endplate and facet/pedicle motion was separately and independently analyzed on toggled PowerPoint images, subjectively graded as prominent, intermediate, questionable/uncertain, or no motion. Disc morphology was graded using the anteroposterior/lateral postinjection disc appearance (Adams criteria).

RESULTS

Prominent or intermediate endplate and facet/pedicle motion was identified at most lumbar levels with substantial overall agreement (degenerative: κ = 0.93, 95% confidence intervals [CI] = 0.87-1.00; normal: κ = 0.80, 95% CI = 0.61-1.00). Degenerative levels were strongly associated with a lower degree of endplate and facet/pedicle motion compared with normal: ("prominent" motion grade: endplate: 61% [95/156] vs 89% [68/76], P < 0.001; facet/pedicle: 60% [93/156] vs 88% [67/76], P < 0.001).

CONCLUSION

Disc injection expands the disc space inducing endplate motion, pedicle motion, and facet translation in almost all normal and most degenerate levels. Disc injection therefore biomechanically "provokes" the entire functional spinal unit. When provoked pain is encountered during lumbar discography, contribution from the associated facet joint and myotendinous insertions should be considered.

Factors Predicting the Clinical Outcome After Trans-sacral Epiduroscopic Laser Decompression for Lumbar Disc Herniation

Objective

Previous literatures have demonstrated widely variable clinical results after transsacral epiduroscopic laser decompression (SELD) and the factors predicting outcomes are not yet established. Therefore, we analyzed the clinical outcome and associated predictive factors of SELD in patients with lumbar disc herniation.

Methods

Between 2015 and 2018, 82 patients who underwent single-level SELD and followed up at least 6 months were enrolled. The overall success rate (excellent or good results at final follow-up) was 58.5% according to Odom’s criteria. Based on this result, patients were divided to 2 groups: a favorable group (n = 48) and an unfavorable group (n = 34). A retrospective review of the baseline characteristics and clinical outcome were conducted to reveal the predictive factors.

Results

As expected, improvement of pain and patient satisfaction, was more favorable in the favorable group (p < 0.05). Moreover, the rate of additional procedure was lower in the favorable group (4.2%, 2 of 48 patients) than in the unfavorable group (35.3%, 12 of 34 patients) (p = 0.011). Among the various baseline characteristics, the only significant predictive factor for favorable outcome was the presence of a high-intensity zone (HIZ) on preoperative magnetic resonance imaging (50.0% [24 of 48 patients] in the favorable group vs. 11.8% [4 of 34 patients] in the unfavorable group; odds ratio, 15.67; p = 0.024).

Conclusion

Although SELD for lumbar disc herniation resulted in a less favorable clinical outcome than that reported in previous studies, in patients with a HIZ, SELD can be an effective minimally invasive surgery to relieve low back pain and/or leg pain.

Anterior High-Intensity Zone in Lumbar Discs: Prevalence and Association with Low Back Pain

OBJECTIVES

To explore the features of high-intensity zone (HIZ) in anterior annulus fibrosus and assess the association of anterior HIZ with low back pain (LBP).

DESIGN, SETTING, AND SUBJECTS

A retrospective study of 5,940 discs in 1,188 individuals was conducted.

METHODS

Subjects' information and LBP symptoms confirmed by an orthopedic surgeon were acquired from the medical record. Magnetic resonance (MR) image reading and analysis were performed by two experienced blinded radiologists.

RESULTS

Two hundred eighty individuals exhibited 355 anterior HIZs in 355 discs. The prevalence was 23.57%; 88.45% were located in the inferior part of the annulus fibrosus. It frequently occurred in the middle and upper segments of lumbar spine, especially at L3/4 (45.63%). Of the 355 anterior HIZs, only 79 (22.25%) were consecutive-slides HIZ. Round type (63.38%) was the most common shape of anterior HIZs. The highest prevalence was found in individuals aged 60-69 years. LBP was confirmed in 141 anterior-HIZ individuals. The incidence of LBP in anterior-HIZ individuals was significantly higher than in non-HIZ subjects (50.36% vs 35.24%, χ2 = 18.314, P < 0.001).

CONCLUSIONS

Anterior HIZ is a lower-prevalence, age-related sign on lumbar MR images. The spatial distribution of anterior HIZ can be distinguished from posterior HIZ. The number of consecutive anterior HIZ slides might suggest fewer Dallas grade 4 anterior annular disruptions in this sample. Anterior HIZ was correlated with LBP.

The Relationship between Diabetes Mellitus Type II and Intervertebral Disc Degeneration in Diabetic Rodent Models: A Systematic and Comprehensive Review

The number of diabetic patients grows constantly worldwide. Many patients suffer simultaneously from diabetes mellitus type 2 (T2DM) and intervertebral disc disease (IVDD), suggesting a strong link between T2DM and IVDD. T2DM rodent models provide versatile tools to study this interrelation. We hypothesized that the previously achieved studies in rodents approved it. Performing a search in the publicly available electronic databases according to our inclusion (e.g., experimental study with clearly outlined methods investigating IVDD in diabetic rodent models) and exclusion (e.g., non-experimental) criteria, we included 23 studies from 1992 to 2020 analyzing different aspects of IVDD in diabetic rodents, such as on pathogenesis (e.g., effects of hyperglycemia on IVD cells, sirtuin (SIRT)1/p53 axis in the interrelation between T2DM and IVDD), risk factors (e.g., high content of advanced glycation end-products (AGEs) in modern diets), therapeutical approaches (e.g., insulin-like growth factor (IGF-I)), and prophylaxis. Regarding their quality, 12 studies were classified as high, six as moderate, and five as low. One strong, 18 moderate, and three mild evidences of the link between DM and IVDD in rodents were found, while only one study has not approved this link. We concluded that T2DM has a devastating effect on IVD, particularly in advanced cases, which needs to be further evaluated.

Lumbar high-intensity zones on MRI: imaging biomarkers for severe, prolonged low back pain and sciatica in a population-based cohort

BACKGROUND CONTEXT

There is often discrepancy between clinical presentation and lumbar magnetic resonance imaging (MRI) findings.

PURPOSE

The purpose of this study was to assess the relationship of high-intensity zones (HIZs) on MRI with low back pain (LBP), sciatica, and back-related disability.

STUDY DESIGN

Cross-sectional, population-based Southern Chinese cohort study.

PATIENT SAMPLE

Of 1,414 possible participants, data from 1,214 participants (453 males, 761 females; mean age of 48.1±6.3 years) were included.

OUTCOME MEASURES

Presence of single-level, homogeneous multilevel (same type HIZs of morphology and topography) and heterogeneous multilevel (mixed type HIZs of morphology and topography) HIZs and other MRI phenotypes were assessed at each level with T2-weighted 3T sagittal MRI of L1-S1. Associations with LBP, sciatica and Oswestry Disability Index were correlated with HIZ profiles.

RESULTS

In all, 718 individuals had HIZs (59.1%). Disc degeneration/displacement were more prevalent in HIZ individuals (p<.001). HIZ subjects experienced prolonged severe LBP more frequently (39.6% vs. 32.5%; p<.05) and had higher Oswestry Disability Index scores (10.7±13.7 vs. 8.9±11.3; p<.05). Posterior multilevel HIZ were significantly associated with prolonged severe LBP (OR: 2.18; 95% CI:1.42-3.37; p<.05) in comparison to anterior only, anterior/posterior or other patterns of HIZ. Multilevel homogeneous or heterogeneous HIZs were significantly associated with prolonged, severe LBP (OR: 1.53-1.57; p<.05). Individuals with homogeneous HIZs had a higher risk of sciatica (OR: 1.51, 95% CI: 1.01-2.27; p<.05).

CONCLUSIONS

This is the first large-scale study to note that lumbar HIZs, and specific patterns therein, are potentially clinically-relevant imaging biomarkers that are independently and significantly associated with prolonged/severe LBP and sciatica. HIZs, especially homogenous multilevel HIZ, should be noted in the global pain imaging phenotype assessment.

Abnormal Conditions of the Diskovertebral Segment: MRI With Anatomic-Pathologic Correlation

OBJECTIVE. The purpose of this article is to review the appearance of various abnormalities that affect the lumbar intervertebral disk and diskovertebral segment through anatomic-pathologic correlation in cadavers. CONCLUSION. Familiarity with the pathologic conditions in and around the intervertebral disk is important in recognizing such conditions as a potential source of symptoms. We revisit the principal role of MRI in evaluating these abnormalities and excluding other sources of significant clinical manifestations.

Reoccurring discogenic low back pain (LBP) after discoblock treated by oblique lumbar interbody fusion (OLIF)

Objective

To determine the efficacy of OLIF in the treatment of reoccurring discogenic low back pain (LBP) after discoblock

Methods

We included 108 patients with LBP that was suspected to be discogenic (such as high intensity zone, Schmorl’s nodes, Modic changes Type I, etc.), from August 2015 to August 2017. All patients underwent discography, and patients whose LBP was confirmed to be discogenic received discoblock. Patients who had reoccurring pain after discoblock underwent OLIF. Perioperative parameters and complications were recorded. The VAS and Oswestry Disability Index (ODI) were assessed at preoperation, and 1 week and 1, 3, 6, and 12 months after the surgery. The fusion rate was evaluated.

Results

Of 108 patients, 89 were confirmed to have discogenic LBP, and 32/89 patients with reoccurring LBP pain after discoblock underwent OLIF. Twenty-eight patients were followed up for ≥ 1 year. The OLIF operation lasted for 92 ± 34 min. Blood loss during the operation was 48 ± 15 ml. The mean incision length was 3.0 ± 0.6 cm. The average length of stay was 4.8 ± 1.9 days. The VAS and ODI scores decreased from 8.1 ± 1.7 preoperatively to 0.9 ± 0.4, and from 71.2 ± 11.3 to 9.3 ± 3.1, 12 months postoperatively, respectively. The total incidence of complications was 15.6%, including 2 cases of cage subsidence, 2 cases of ipsilateral hip flexor weakness, and 1 case of ipsilateral anterior thigh pain. All symptoms relieved or disappeared during follow-up. The fusion rate was 96.9%.

Conclusions

Reoccurring discogenic LBP after discoblock should be considered as a suitable group for treatment by OLIF.

Advanced trends in magnetic resonance imaging in assessment of lumbar intervertebral degenerative disk disease

Abstract

Background

T2 mapping and DWI are newly quantitated method for disk degeneration assessment; they were used in the determination of an early stage of intervertebral disk degeneration. T2 mapping was quantitatively sensitive for detecting the early stage and aging-related changes in intervertebral disk degeneration. Furthermore, T2 mapping and apparent diffusion coefficient values (ADC) in lumbar intervertebral disks indirectly correlated with the Pfirrmann grades in IVDD and age-related disk degeneration. The aim of this study is to evaluate the sensitivity of T2 mapping and apparent diffusion coefficient in the determination of an early stage of intervertebral disk degeneration.

Results

T2 relaxometry values were found to decrease with the increased disk degeneration except in grade V where it was found to be increased again. There was a negative correlation between T2 values and semi-quantitative grading (Pfirrmann Grading) of disk degeneration and T2 values were significantly different when comparing grade I to V. A T2 value of nucleus pulposus (NP) was more sensitive than annulus fibrosus (AF) and entire of the disk. ADC values were found to decrease with the increased degree of disk degeneration; there was a weakly significant negative correlation between age and T2 mapping values, ADC values of nucleus pulposus, and entire of disk.

Conclusion

T2 mapping was significantly different when comparing grade I to V while ADC value had a significant weak negative correlation with age, so T2 mapping and to a little extent ADC can be used for quantitative analysis of early disk generation seeking for early diagnosis and better management.

Low-Pressure Lumbar Provocation Discography According to Spine Intervention Society/International Association for the Study of Pain Standards Does Not Cause Acceleration of Disc Degeneration in Patients With Symptomatic Low Back Pain: A 7-Year Matched Cohort Study

STUDY DESIGN

Retrospective matched cohort study.

OBJECTIVE

To determine if low-pressure lumbar provocation discography (PD) results in long-term accelerated disc degeneration, internal disc disruption, or disc herniation in patients with symptomatic low back pain (LBP).

SUMMARY OF BACKGROUND DATA

Study of subjects without clinically-significant LBP suggests that high-pressure PD may accelerate disc degeneration.

METHODS

Consecutive patients with symptomatic LBP who underwent magnetic resonance imaging (MRI), PD, and repeat MRI more than 7 years later, but did not undergo subsequent spinal fusion surgery, were included. Punctured discs were matched (1:2 to 1:4) to corresponding discs in a control cohort by age, BMI, Pfirrmann score (±2), and presence of disc herniation; control cohort inclusion required MRIs for symptomatic LBP, separated by more than 7 years. The primary outcome of the study was a progression in Pfirrmann score category (I-II, III-IV, V). MRI disc-to-CSF T2 signal-intensity ratio, disc height, disc herniations, high intensity zones (HIZs), and Modic changes were assessed.

RESULTS

Baseline and follow-up MRIs were available for 77 discs exposed to PD, and for 260 discs in the matched control cohort. There was no difference in the proportion of punctured discs that advanced in Pfirrmann score category in the PD group (17%, 95% CI 9-27%) compared with corresponding discs in the Control group (21%, 95% CI 17-27%), P = 0.3578, or in non-punctured discs in the PD group (35%, 95% CI 21-51%) compared with corresponding discs in the Control group (34%, 95% CI 27-42%), P = 0.1169. There were no differences in disc-to-CSF T2 signal-intensity ratio, presence of disc herniations, HIZs, or Modic changes following puncture in the PD versus matched cohort discs or in the non-punctured PD cohort discs versus corresponding control cohort discs (P > 0.05).

CONCLUSION

Patients with symptomatic LBP who underwent low-pressure PD, but who did not undergo a subsequent spinal fusion surgery, developed disc degeneration and new disc herniations at a similar rate to corresponding discs in matched control patients.

LEVEL OF EVIDENCE

3.

Spondylodiscitis due to Cutibacterium acnes following lumbosacral intradiscal biologic therapy: a case report

A 40-year-old woman with a history of chronic low back pain underwent a fluoroscopically guided intradiscal platelet-rich plasma injection (PRP) at the L5-S1 level. She subsequently developed progressive low back pain, night sweats and decreased ability to ambulate. Laboratory work-up revealed elevated acute phase reactants and imaging revealed L5-S1 intervertebral disc and vertebral end-plate abnormalities highly suggestive of spondylodiscitis. Computed tomography-guided aspiration and biopsy cultures grew Cutibacterium acnes and the patient was subsequently treated with intravenous antibiotics without surgical management. To the best of our knowledge, this is the first published case of lumbar spondylodiscitis following an intradiscal PRP injection, and brings to the forefront several clinically relevant issues including the antimicrobial effects of PRP, the role of C. acnes in spine infections and the ideal treatment protocol for intradiscal biologics in order to minimize morbidity and optimize functional outcomes.

High Prevalence of Spinal Magnetic Resonance Imaging Findings in Asymptomatic Young Adults (18-22 Yrs) Candidate to Air Force Flight

STUDY DESIGN

Cross-sectional, retrospective, magnetic resonance (MR) imaging study, performed during cadets' selection procedures of the Italian Air Force Academy.

OBJECTIVE

To assess the prevalence of spinal MR imaging findings in asymptomatic young adults (18-22 yrs) candidate to Air Force Flight.

SUMMARY OF BACKGROUND DATA

Spinal MR imaging findings are frequently detected in asymptomatic subjects. Literature prevalence data come from studies that analyze different patient populations, in a wide age range and in different spinal tracts. Chronic degenerative disease of the vertebral column often occurs in pilots exposed to high flight acceleration forces, thus resulting crucial for Air Force Academy to exclude vertebral disease in cadets.

METHODS

Three hundred fifty asymptomatic young adults underwent a 3T MR examination of the entire spine. A structured radiological report was set up to classify and calculate the prevalence of spinal MR imaging findings.

RESULTS

Two hundred seventy of 350 subjects (77%) presented spinal MR findings, while 80 of 350 candidates (23%) had no detectable MR imaging findings. One hundred six of 350 (30%) candidates had at least one disc desiccation and 47 of 350 (13%) presented at least one disc narrowing. Disc bulging was found in 176 of 350 (49%) cadets. Sixty-two of 350 (18%) subjects showed disc protrusion while 28 of 350 (8%) had disc extrusion. Forty-five of 350 (13%) candidates presented low grade intervertebral spondylosis and of these 12 had also facet joints spondylosis. Asymptomatic vertebral fractures were observed in 2 of 350 (<1%) cadets.

CONCLUSION

A high rate of MR spinal imaging findings, similar to that of the adult population, was detected in our population of young asymptomatic subjects. Our results suggest that the process of aging spine, which is supposed to begin in the second decade of life, is morphologically appreciable in the immediate postadolescent period and this issue is of crucial importance when selecting military pilots.

LEVEL OF EVIDENCE

4.

Low Back Pain in Adolescent Athletes: Comparison of Diagnoses Made by General Orthopedic Surgeons and Spine Surgeons

Background

Nonspecific low back pain (NSLBP) is a term used to describe low back pain of unknown origin with no identifiable generators. Over a decade ago, it was reported to account for about 85% of all cases of low back pain, although there is some doubt about the frequency. The purpose of this study was to determine the frequency of NSLBP in adolescent athletes diagnosed by general orthopedic surgeons and by spine surgeons.

Materials and Methods

A total of 69 adolescent athletes consulted our sports spine clinic to seek a second opinion for low back pain. Data on age, sex, type of sport played, the previous diagnosis made by general orthopedic surgeons, and the final diagnosis made by spine surgeons were collected retrospectively from medical records.

Results

The frequency of NSLBP diagnosed by general orthopedic surgeons was 18.9% and decreased to 1.4% after careful imaging and functional nerve block examination by spine surgeons. The final diagnoses made by spine surgeons for those patients previously diagnosed as having NSLBP by general orthopedic surgeons were as follows: early-stage lumbar spondylolysis, discogenic low back pain, facet joint arthritis, lumbar disc herniation, and lumbar apophyseal ring fracture.

Conclusions

In adolescent athletes, the rate of NSLBP diagnosed by general orthopedic surgeons decreased markedly when the diagnosis was made by spine surgeons. A thorough medical interview, careful physical examination, appropriate diagnostic imaging, and selective nerve block examination can effectively identify the cause of low back pain.

Discogenic Back Pain: Literature Review of Definition, Diagnosis, and Treatment

Discogenic back pain is multifactorial; hence, physicians often struggle to identify the underlying source of the pain. As a result, discogenic back pain is often hard to treat—even more so when clinical treatment strategies are of questionable efficacy. Based on a broad literature review, our aim was to define discogenic back pain into a series of more specific and interacting pathologies, and to highlight the need to develop novel approaches and treatment strategies for this challenging and unmet clinical need. Discogenic pain involves degenerative changes of the intervertebral disc, including structural defects that result in biomechanical instability and inflammation. These degenerative changes in intervertebral discs closely intersect with the peripheral and central nervous systems to cause nerve sensitization and ingrowth; eventually central sensitization results in a chronic pain condition. Existing imaging modalities are nonspecific to pain symptoms, whereas discography methods that are more specific have known comorbidities based on intervertebral disc puncture and injection. As a result, alternative noninvasive and specific diagnostic methods are needed to better diagnose and identify specific conditions and sources of pain that can be more directly treated. Currently, there are many treatments/interventions for discogenic back pain. Nevertheless, many surgical approaches for discogenic pain have limited efficacy, thus accentuating the need for the development of novel treatments. Regenerative therapies, such as biologics, cell‐based therapy, intervertebral disc repair, and gene‐based therapy, offer the most promise and have many advantages over current therapies. © 2019 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research

Is the location of the signal intensity weighted centroid a reliable measurement of fluid displacement within the disc?

Degenerated discs have shorter T2-relaxation time and lower MR signal. The location of the signal-intensity-weighted-centroid reflects the water distribution within a region-of-interest (ROI). This study compared the reliability of the location of the signal-intensity-weighted-centroid to mean signal intensity and area measurements. L4-L5 and L5-S1 discs were measured on 43 mid-sagittal T2-weighted 3T MRI images in adults with back pain. One rater analysed images twice and another once, blinded to measurements. Discs were semi-automatically segmented into a whole disc, nucleus, anterior and posterior annulus. The coordinates of the signal-intensity-weighted-centroid for all regions demonstrated excellent intraclass-correlation-coefficients for intra- (0.99-1.00) and inter-rater reliability (0.97-1.00). The standard error of measurement for the Y-coordinates of the signal-intensity-weighted-centroid for all ROIs were 0 at both levels and 0 to 2.7 mm for X-coordinates. The mean signal intensity and area for the whole disc and nucleus presented excellent intra-rater reliability with intraclass-correlation-coefficients from 0.93 to 1.00, and 0.92 to 1.00 for inter-rater reliability. The mean signal intensity and area had lower reliability for annulus ROIs, with intra-rater intraclass-correlation-coefficient from 0.5 to 0.76 and inter-rater from 0.33 to 0.58. The location of the signal-intensity-weighted-centroid is a reliable biomarker for investigating the effects of disc interventions.

The relevance of high-intensity zones in degenerative disc disease

PURPOSE

The purpose of this study was to review the current understanding of high-intensity zones (HIZ) in the lumbar spine with particular attention to its imaging phenotype and clinical relevance.

METHODS

A review was conducted of studies related to HIZ. Particular attention was made to imaging phenotypes and classification, and its relationship with discogenic low back pain (LBP).

RESULTS

The most current classification system of HIZ is based on location (anterior and posterior), morphology (round, fissure, vertical, rim, or giant types), and its appearance on both T1- and T2-weighted magnetic resonance imaging (MRI). HIZ are commonly manifested with disc degeneration. Hence, both conditions share similar risk factors such as the effect of frequent and prolonged disc loading. The clinical significance of HIZ however is not conclusive. Provocative discography is not sensitive (~ 70%) for eliciting a concordant pain response. Population-based studies have conflicting results regarding the prevalence (14-63%) of HIZ and its correlation with LBP.

CONCLUSIONS

HIZ are likely a risk factor for discogenic LBP. However, its etiology and pathophysiology are not well understood. Some clinical studies suggest a link between its occurrence and LBP. However, the results are not consistent as a result of studies which are underpowered and based on heterogeneous study populations, lacking control groups, and without standardized imaging phenotypes. HIZ may be an important pain biomarker that should be further studied. With more modern MRI technology and a detailed classification system, future large-scale population studies will improve our knowledge on its role in the disc degeneration cascade and development of LBP.

The association of high-intensity zones on MRI and low back pain: a systematic review

Background

Magnetic resonance imaging (MRI) of the lumbar spine is commonly used to identify the source of low back pain (LBP); however, its use has been questionable. Throughout the years, numerous lumbar phenotypes (e.g., endplate abnormalities, Modic changes, black disc) have been studied as possible pain generators. High-intensity zones (HIZs) are of particular interest as they may represent annular tears. However, for over three decades, there has been heated debate as to whether these imaging biomarkers are synonymous with LBP. Therefore, the following study addressed a systematic review of the reported literature addressing the relationship of HIZs and LBP.

Methods

A systematic review was conducted via MEDLINE, SCOPUS, Cochrane, PubMed, PubMed Central, EMBASE via Ovid, and Web of Science with the following search terms: "HIZ," "high intensity zone," or "high intensity zones" and "low back pain," "pain," "lumbago," and/or "sciatica." Specific exclusion criteria were also maintained. Two independent reviewers searched the literature, selected the studies, and extracted the data.

Results

We identified six studies from our search strategy that met the inclusion criteria from a total of 756 possible studies. One cross-sectional population-based study and five comparison studies were identified, which provided information regarding the prevalence of HIZs. The prevalence of HIZs was 3 to 61% in subjects with LBP and 2 to 3% in subjects without LBP. Only three studies suggested a significant association between the presence of HIZ and LBP with or without sciatica.

Conclusions

Our systematic review has found evidence that HIZs may be a possible risk factor for LBP; however, a mismatch of the clinical relevance of HIZs between studies still remains. The available evidence is limited by small sample size, heterogeneous study populations, and lack of standardized imaging methods for phenotyping. HIZs may be important lumbar biomarkers that demand further investigation and should be considered in the global imaging assessment of the spine, which may have immense clinical utility. Further large-scale studies with standardized imaging and classification techniques as well as the assessment of patterns of HIZs are necessary to better understand their role with LBP development.

Tidemark Avulsions are a Predominant Form of Endplate Irregularity

STUDY DESIGN

Descriptive histologic and magnetic resonance imaging study of human cadaveric spines.

OBJECTIVE

To identify and characterize common endplate pathologies to form a histologic foundation for an etiology-based classification system.

SUMMARY OF BACKGROUND DATA

Irregularities at the spinal disc-vertebra interface are associated with back pain and intervertebral disc herniation injuries. However, there is currently a lack of consensus regarding terminology for classification. This limits the potential for advancing understanding of back pain mechanisms, and prohibits meaningful comparisons for identifying priorities for prevention and treatment. Prior classification systems largely rely on observations from clinical imaging, which may miss subtle pathologic features.

METHODS

Fifteen cadaveric spines with moderate to severe disc degeneration were obtained and scanned with MRI in the sagittal plane using two-dimensional T1-weighted and T2-weighted fast spin-echo sequences. Eighty-nine lumbar and lower thoracic bone-disc-bone motion segments were extracted, fixed, sectioned, and stained for histologic evaluation. Focal endplate irregularities were identified and categorized based on features that inferred causation. The presence, type, and anatomic location were recorded. A classification system with three major categories of focal endplate irregularities was created.

RESULTS

Disc-vertebra avulsion and vertebral rim degeneration were more common than subchondral nodes: 50% of irregularities were classified as rim degeneration (75/150), 35% were classified as avulsions (52/150), and 15% were classified as nodes (23/150). Ninety percent of avulsions were subclassified as "tidemark avulsions," a highly prevalent form of endplate irregularity in which the outer annulus separates from the vertebra at the tidemark. These tidemark avulsions have not been previously described, yet are visible on T2-weighted MRI as high-intensity regions.

CONCLUSION

This study provides histologic basis for a system to classify focal endplate irregularities. Included is a previously unidentified but prevalent finding of tidemark avulsions, which are visible with both histology and magnetic resonance imaging. These observations will help clinicians better organize patients into meaningful groups to facilitate diagnosis, treatment, and clinical research.

LEVEL OF EVIDENCE

3.

Prevalence of High-Intensity Zones in the Lumbar Spine According to Age and Their Correlation with Other Degenerative Findings on Magnetic Resonance Imaging

Introduction

A high-intensity zone (HIZ) in an intervertebral disc of the lumbar spine is a high-intensity signal located in the posterior annulus fibrosus on T2-weighted magnetic resonance imaging (MRI). There is limited information on the prevalence of HIZ in the lumbar spine according to age. The aim of this cross-sectional study was to investigate the prevalence of HIZ in the lumbar spine by age and the correlation between HIZ and other degenerative findings, such as disc degeneration, disc bulging and herniation, and changes in adjacent vertebral endplates on lumbar MRI.

Methods

We retrospectively reviewed MRI studies of 305 patients (1525 discs) with low back pain, leg pain, or numbness. The prevalence of HIZ was calculated in 5 age groups (<20, 20-39, 40-59, 60-79, 80-91 years).

Results

The number of patients in the 5 age groups was 19, 38, 69, 145, and 36, respectively. The prevalence of HIZ in the 5 age groups was 11.8%, 47.3%, 52.2%, 42.8%, and 50.0%, respectively. Disc degeneration was observed in 58.1% and 39.2% of discs with and without HIZ, respectively; disc bulging and herniation was observed in 63.9% and 41.1% and intensity changes at adjacent end plates in 11.6% and 10.0%, respectively.

Conclusions

Prevalence of HIZ from the third decade of life onward was around 50%, with no significant change in prevalence beyond the age of 20 years. HIZ was correlated with disc degeneration, disc bulging, and disc herniation in patients with LBP, leg pain, or numbness.

The Global Spine Care Initiative: a narrative review of psychological and social issues in back pain in low- and middle-income communities

PURPOSE

The purpose of this review was to describe psychological and social factors associated with low back pain that could be applied in spine care programs in medically underserved areas and low- and middle-income countries.

METHODS

We performed a narrative review of cohort, cross-sectional, qualitative and mixed methods studies investigating adults with low back pain using Medline and PubMed were searched from January 2000 to June 2015. Eligible studies had at least one of the following outcomes: psychological, social, psychosocial, or cultural/ethnicity factors. Studies met the following criteria: (1) English language, (2) published in peer-reviewed journal, (3) adults with spinal disorders, (4) included treatment, symptom management or prevention.

RESULTS

Out of 58 studies, 29 were included in this review. There are few studies that have evaluated psychological and social factors associated with back pain in low- and middle-income communities, therefore, adapting recommendations from other regions may be needed until further studies can be achieved.

CONCLUSION

Psychological and social factors are important components to addressing low back pain and health care providers play an important role in empowering patients to take control of their spinal health outcomes. Patients should be included in negotiating their spinal treatment and establishing treatment goals through careful listening, reassurance, and information providing by the health care provider. Instruments need to be developed for people with low literacy in medically underserved areas and low- and middle-income countries, especially where psychological and social factors may be difficult to detect and are poorly addressed. These slides can be retrieved under Electronic Supplementary Material.

The associations between magnetic resonance imaging findings and low back pain: A 10-year longitudinal analysis

PURPOSE

To conduct a 10-year longitudinal analysis of the relationship between magnetic resonance imaging (MRI) findings and low back pain (LBP).

MATERIALS AND METHODS

Ninety-one volunteers with a history of LBP, but without current LBP were recruited between 2005 and 2006. Participants' baseline demographics and MRI findings were recorded. All volunteers were invited for a follow-up MRI in 2016; of these, 49 volunteers (53.8%) participated in the follow-up. We enquired whether they had LBP history during the 10 years between the baseline and follow-up examinations. Sagittal T1 and T2-weighted MRI were used to assess the intervertebral space from T12/L1 to L5/S1. We evaluated the presence of disc degeneration by Pfirrmann's grading system, disc bulging, high intensity zone (HIZ), spondylolisthesis, and any type of Modic changes in the follow-up MRIs. We compared the follow-up MRI findings with the baseline findings; the progress of each finding over the 10 years were also compared between the groups with (n = 36) and without (n = 13) LBP.

RESULTS

Average age of the study participants at follow-up was 44.8 years; 25 were female and 24 were male. Average age, sex, body mass index, and smoking habits of those who did and did not participate in the follow-up study, as well as the demographic characteristics of those who did and did not have LBP history during the 10 years, were not significantly different. Compared with the group without LBP history, the group that had LBP history during the 10 years did not have a significantly increased prevalence of disc degeneration, disc bulging, and HIZ in the follow-up and baseline MRIs. Spondylolisthesis and any type of Modic changes were also not associated with LBP history during the 10 years.

CONCLUSIONS

Follow-up MRI findings consistent with Pfirrmann grading ≥4, disc bulging, HIZ, spondylolisthesis, and any type of Modic changes were not associated with LBP history during the 10 years between the baseline and follow-up study. The progresses of these findings were also not associated with the LBP history. In addition, baseline MRI findings were not associated with LBP history during the 10 years; therefore, our data suggest that baseline MRI findings cannot predict future LBP.

MRI histogram analysis enables objective and continuous classification of intervertebral disc degeneration

PURPOSE

Magnetic resonance imaging (MRI) is the best diagnostic imaging method for low back pain. However, the technique is currently not utilized in its full capacity, often failing to depict painful intervertebral discs (IVDs), potentially due to the rough degeneration classification system used clinically today. MR image histograms, which reflect the IVD heterogeneity, may offer sensitive imaging biomarkers for IVD degeneration classification. This study investigates the feasibility of using histogram analysis as means of objective and continuous grading of IVD degeneration.

METHODS

Forty-nine IVDs in ten low back pain patients (six males, 25-69 years) were examined with MRI (T2-weighted images and T2-maps). Each IVD was semi-automatically segmented on three mid-sagittal slices. Histogram features of the IVD were extracted from the defined regions of interest and correlated to Pfirrmann grade.

RESULTS

Both T2-weighted images and T2-maps displayed similar histogram features. Histograms of well-hydrated IVDs displayed two separate peaks, representing annulus fibrosus and nucleus pulposus. Degenerated IVDs displayed decreased peak separation, where the separation was shown to correlate strongly with Pfirrmann grade (P < 0.05). In addition, some degenerated IVDs within the same Pfirrmann grade displayed diametrically different histogram appearances.

CONCLUSIONS

Histogram features correlated well with IVD degeneration, suggesting that IVD histogram analysis is a suitable tool for objective and continuous IVD degeneration classification. As histogram analysis revealed IVD heterogeneity, it may be a clinical tool for characterization of regional IVD degeneration effects. To elucidate the usefulness of histogram analysis in patient management, IVD histogram features between asymptomatic and symptomatic individuals needs to be compared.

The Degenerative Spine

Degenerative disease of the spine is a leading cause of back pain and radiculopathy, and is a frequent indication for spine MR imaging. Disc degeneration, disc protrusion/herniation, discarhtrosis, spinal canal stenosis, and facet joint arthrosis, as well as interspinous processes arthrosis, may require an MR imaging workup. This review presents the MR imaging patterns of these diseases and describes the benefit of the MR imaging in these indications compared with the other imaging modalities like plain radiographs or computed tomography scan.

Correlation between high-intensity zone on MRI and discography in patients with low back pain

The aim of this study was to analyze the correlation between high-intensity zone (HIZ) on magnetic resonance imaging (MRI) of a lumbar disc and positive pain response assessed by discography for the diagnosis and treatment of discogenic low back pain (LBP). Thirty-seven patients aged 21 to 59 years with chronic LBP but without any neurological symptoms or lumbar disc herniation who underwent MRI and subsequent discography were included in this study. During discography, concordant pain was regarded as positive, whereas discordant pain and no pain were regarded as negative. X-ray and computed tomography (CT) after discography with positive pain response were analyzed to correlate with HIZ on MRI. A total of 98 discs underwent discography in 37 patients; 21 discs presented positive pain response, including 10 with HIZ (47.6%). Seventy-seven discs presented negative pain response, including 29 with HIZ (37.6%). The high grade of annular disruption group shows a high proportion of HIZ on MRI. A positive correlation between HIZ and degree of annular disruption was observed. However, no correlation between HIZ and positive pain response was established on discography. The findings confirm that the presence of HIZ on MRI is only a suggestive and screening iconography indication for the diagnosis of discogenic LBP and cannot replace the gold standard of the discography. MRI should be closely integrated with those of discography, and thus, they play a crucial role in selecting operative segments of multilevel lumbar degenerative disk disease.

The correlation between the high-intensity zone on a T2-weighted MRI and positive outcomes of discography: a meta-analysis

BACKGROUND

This meta-analysis aimed to assess the correlation between the high-intensity zone (HIZ) of a lumbar MRI and discography.

METHODS

We conducted an electronic search of the PubMed, MEDLINE, Embase, and ScienceDirect databases from their respective inceptions to October 2016 using the following search terms: "low back pain," "discogenic low back pain," "HIZ or high-intensity zone," and "discography". Relevant journals and conference proceedings were manually searched. Two reviewers independently assessed the quality of the studies, extracted data from the included studies, and analyzed the data.

RESULTS

Eleven studies were included. The results of the meta-analysis indicated that outstanding relativity and statistically significant correlations were observed between the HIZ and abnormal disc morphology (OR = 47.79; 95% CI: 17.07 to 133.77; P < 0.00001), HIZ and pain reproduction (OR = 8.65, 95% CI: 6.01 to 15.23, P < 0.00001), and HIZ and abnormal morphology pain reproduction (OR = 11.74, 95% CI: 1.99 to 69.36, P = 0.007).

CONCLUSIONS

The presence of an HIZ on a lumbar MRI T2-weighted image indicates abnormal disc morphology. There is a strong relationship between the HIZ and pain reproduction. The HIZ can be an effective index for prediction of discogenic low back pain.

Clinical Significance of High-intensity Zone for Discogenic Low Back Pain: A Review

High-intensity zone (HIZ) was originally described as a high-intensity signal on T2-weighted magnetic resonance (MR) images, located in the posterior annulus fibrosus, clearly separated from the nucleus pulposus. Among symptomatic patients with low back pain, HIZ is present in 28-59% of cases. In morphologically abnormal discs, high sensitivity and specificity of 81% and 79%, respectively, were reported for HIZs and concordant pain during discography. In contrast, another report indicated low rates. Although most papers reported high sensitivity and specificity for this relationship, it remains controversial. Regarding the pathology of HIZs, inflammatory granulation tissues are found at sites showing HIZs. Such inflammatory tissues produce pro-inflammatory cytokines and mediators, which sensitize the nociceptors within the disc and cause pain. An effective treatment for this condition is yet to be established. Recently, minimally invasive surgery using percutaneous endoscopic discectomy (PED) under local anesthesia was introduced. After removal of the degenerated disc material, the HIZ is identified with the endoscope and then coagulated and modulated with a bipolar radio pulse. This technique is called thermal annuloplasty. In conclusion, HIZs is an important sign of painful intervertebral disc disruption, if identified precisely based on factors such as location and intensity.

The relationship between findings on magnetic resonance imaging and previous history of low back pain

The objective of this study was to evaluate the relationship between magnetic resonance imaging (MRI) findings and previous low back pain (LBP) in participants without current LBP. Current LBP was defined as LBP during the past month. Previous LBP was defined as a history of medical consultation for LBP. Ninety-one participants without current LBP were included. Sagittal T2-weighted MRI was used to assess the intervertebral space from T12/L1 to L5/S1. These images were classified into five grades based on the Pfirrmann grading system. Furthermore, we evaluated the presence of disk bulging, high-intensity zone, and spondylolisthesis. We compared the MRI findings between groups with (27 participants) and without (64 participants) previous LBP without current LBP. Intraobserver and interobserver kappa values were evaluated. Participants had an average age of 34.9 years; 47 were female and 44 were male; and their average body mass index was 21.8 kg/m². Compared to the group of participants without previous LBP, the group of participants with previous LBP had a significantly higher incidence of disk degeneration such as a Pfirrmann grade ≥3, disk bulging, and high-intensity zone in the analyses adjusted by age and sex. There were no significant differences in spondylolisthesis between the groups. An odds ratio of >10 was only found for Pfirrmann grade ≥3, ie, a Pfirrmann grade ≥3 was strongly associated with a history of previous LBP in participants without current LBP.

Nucleoplasty for treating lumbar disk degenerative low back pain: an outcome prediction analysis

Purpose

Nucleoplasty is a minimally invasive technique that is considered efficacious in alleviating lumbar disk degenerative low back pain (LBP). The efficacy of nucleoplasty and identified variables that can predict pain relief for nucleoplasty was reported.

Patients and methods

Between December 2013 and November 2015, 47 nucleoplasty procedures on 47 lumbar disks in 31 consecutive patients were performed. The outcome was evaluated using a visual analog scale (VAS) score. Improvements of ≥50% in VAS scores were considered substantial pain relief. The variables associated with pain relief after nucleoplasty included: 1) age; 2) sex; 3) body mass index; 4) hyperintensity zone at the rear of the disk; 5) hypointensity of the disk; 6) Modic changes of the end plates; 7) spinal instability pain; and 8) discography results.

Results

Twenty-one patients (67.7%) experienced substantial pain relief. The most common side effects following nucleoplasty were soreness at the needle puncture site (64.5%), numbness in the lower leg (12.9%), and increased intensity of back pain (9.7%). All side effects were transient. Multivariate analysis revealed that the discography results were the most critical predictor for substantial pain relief of nucleoplasty (P=0.03). The sensitivity and specificity of discography were 92.8% and 62.5%, respectively.

Conclusion

Discography results could improve the success rate of nucleoplasty in the treatment of disk degenerative LBP.

Fluoroscopy-guided Bipolar Radiofrequency Thermocoagulation Treatment for Discogenic Low Back Pain

Background:

The efficacy of percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) for the treatment of discogenic low back pain (LBP) remains controversial. However, all the PIRFT studies utilized monopolar radiofrequency thermocoagulation (RFTC). The aim of this study was to investigate the safety and efficacy of bipolar RFTC for the treatment of discogenic LBP.

Methods:

A total of 23 patients with discogenic LBP were treated with single-level bipolar RFTC. The patients were assessed before the procedure and at 1 week, 1 month, 3 months, 6 months, and 1 year after the procedure. The primary outcome included the visual analog scale (VAS) score and the Oswestry Disability Index (ODI) score. The secondary outcome included pain relief, reduction of analgesic dose, and patient satisfaction.

Results:

The VAS and ODI scores were significantly decreased after bipolar RFTC treatment at all time points of follow-up (P < 0.05). Bipolar RFTC treatment also resulted in a significant change in all secondary measures, such as pain relief, reduction of analgesic dose, and patient satisfaction. No serious complications or neurological sequelae were observed in any of the patients.

Conclusions:

Bipolar RFTC treatment can significantly attenuate pain and improve the function of patients with discogenic LBP.

Classification of High Intensity Zones of the Lumbar Spine and Their Association with Other Spinal MRI Phenotypes: The Wakayama Spine Study

INTRODUCTION

High intensity zones (HIZ) of the lumbar spine are a phenotype of the intervertebral disc noted on MRI whose clinical relevance has been debated. Traditionally, T2-weighted (T2W) magnetic resonance imaging (MRI) has been utilized to identify HIZ of lumbar discs. However, controversy exists with regards to HIZ morphology, topography, and association with other MRI spinal phenotypes. Moreover, classification of HIZ has not been thoroughly defined in the past and the use of additional imaging parameters (e.g. T1W MRI) to assist in defining this phenotype has not been addressed.

MATERIALS AND METHODS

A cross-sectional study of 814 (69.8% females) subjects with mean age of 63.6 years from a homogenous Japanese population was performed. T2W and T1W sagittal 1.5T MRI was obtained on all subjects to assess HIZ from L1-S1. We created a morphological and topographical HIZ classification based on disc level, shape type (round, fissure, vertical, rim, and enlarged), location within the disc (posterior, anterior), and signal type on T1W MRI (low, high and iso intensity) in comparison to the typical high intensity on T2W MRI.

RESULTS

HIZ was noted in 38.0% of subjects. Of these, the prevalence of posterior, anterior, and both posterior/anterior HIZ in the overall lumbar spine were 47.3%, 42.4%, and 10.4%, respectively. Posterior HIZ was most common, occurring at L4/5 (32.5%) and L5/S1 (47.0%), whereas anterior HIZ was most common at L3/4 (41.8%). T1W iso-intensity type of HIZ was most prevalent (71.8%), followed by T1W high-intensity (21.4%) and T1W low-intensity (6.8%). Of all discs, round types were most prevalent (anterior: 3.6%, posterior: 3.7%) followed by vertical type (posterior: 1.6%). At all affected levels, there was a significant association between HIZ and disc degeneration, disc bulge/protrusion and Modic type II (p<0.01). Posterior HIZ and T1W high-intensity type of HIZ were significantly associated with disc bulge/protrusion and disc degeneration (p<0.01). In addition, posterior HIZ was significantly associated with Modic type II and III. T1W low-intensity type of HIZ was significantly associated with Modic type II.

CONCLUSIONS

This is the first large-scale study reporting a novel classification scheme of HIZ of the lumbar spine. This study is the first that has utilized T2W and T1W MRIs in differentiating HIZ sub-phenotypes. Specific HIZ sub-phenotypes were found to be more associated with specific MRI degenerative changes. With a more detailed description of the HIZ phenotype, this scheme can be standardized for future clinical and research initiatives.

Operative Management of Lumbar Degenerative Disc Disease

Lumbar degenerative disc disease is extremely common. Current evidence supports surgery in carefully selected patients who have failed non-operative treatment and do not exhibit any substantial psychosocial overlay. Fusion surgery employing the correct grafting and stabilization techniques has long-term results demonstrating successful clinical outcomes. However, the best approach for fusion remains debatable. There is some evidence supporting the more complex, technically demanding and higher risk interbody fusion techniques for the younger, active patients or patients with a higher risk of non-union. Lumbar disc arthroplasty and hybrid techniques are still relatively novel procedures despite promising short-term and mid-term outcomes. Long-term studies demonstrating superiority over fusion are required before these techniques may be recommended to replace fusion as the gold standard. Novel stem cell approaches combined with tissue engineering therapies continue to be developed in expectation of improving clinical outcomes. Results with appropriate follow-up are not yet available to indicate if such techniques are safe, cost-effective and reliable in the long-term.

Efficacy and cost-effectiveness of intradiscal methylene blue injection for chronic discogenic low back pain: study protocol for a randomized controlled trial

BACKGROUND

Low back pain (LBP) is a common health problem and a substantial part of LBP is presumed to be attributable to degeneration of the intervertebral disc. For patients suffering from intractable discogenic LBP, there are few evidence-based effective interventional treatment options available. In 2010, the results of a randomized controlled trial (RCT) were published concerning "intradiscal methylene blue injection" (IMBI), in which this intervention appeared to be very successful in relieving discogenic pain. Therefore, we decided to repeat this study to investigate whether we could replicate the published results. The results of our preliminary feasibility study gave reason to set up an RCT. The aim of this RCT is to evaluate if IMBI is a more effective treatment of discogenic low back pain as an intradiscal placebo intervention, and furthermore, to assess the cost-effectiveness of this intervention.

METHODS/DESIGN

Consecutive discogenic low back pain patients referred to four specialized pain treatment facilities are being screened for eligibility. After a positive standardized provocation discography and informed consent, patients are randomized into two groups. The treatment group receives an intradiscal injection with methylene blue, lidocaine, and contrast, and the control group receives intradiscal isotonic saline with lidocaine and contrast. Main outcome measures are pain at the 6-month follow-up, patient's global impression of change, cost-effectiveness, quality of life, disability, and analgesic intake.

DISCUSSION

The importance of this study is emphasized by the fact that for intractable discogenic low back pain patients, evidence-based effective pain treatments are rare. If this study establishes clinical success and cost-effectiveness, IMBI could become the "pain treatment of choice" for a selected group of patients with chronic discogenic low back pain for whom noninvasive treatment options have failed.

TRIAL REGISTRATION

National Trial register NTR2547 Registered at 29 September 2010 and 31 March 2014.