Vertebral endplate defects: nomenclature, classification and measurement methods: a scoping review

Detection and Characterization of Endplate Structural Defects on CT: A Diagnostic Accuracy Study

STUDY DESIGN

Diagnostic test study.

OBJECTIVE

To determine the reliability and validity or diagnostic accuracy of two previously described endplate structural defect (EPSD) assessment methods.

SUMMARY OF BACKGROUND DATA

Studies of EPSD may further the understanding of pathoanatomic mechanisms underlying back pain. However, clinical imaging methods used to document EPSD have not been validated, leaving uncertainty about what the observations represent.

MATERIALS AND METHODS

Using an evaluation manual, 418 endplates on CT sagittal slices obtained from 19 embalmed cadavers (9 men and 10 women, aged 62-91 yr) were independently assessed by two experienced radiologists and a novice for EPSD using the two methods. The corresponding micro-CT (µCT) from the harvested T7-S1 spines were assessed by another independent rater with excellent intra-rater reliability (k=0.96).

RESULTS

Inter-rater reliability was good for the presence (k=0.60-0.69) and fair for specific phenotypes (k=0.43-0.58) of EPSD. Erosion, for which the Brayda-Bruno classification lacked a category, was mainly (82.8%) classified as wavy/irregular, while many notched defects (n=15, 46.9%) and Schmorl's nodes (n=45, 79%) were recorded as focal defects using Feng's classification. When compared to µCT, endplate fractures (n=53) and corner defects (n=28) were routinely missed on CT. Endplates classified as wavy/irregular on CT corresponded to erosion (n=29, 21.2%), jagged defects (n=21, 15.3%), calcification (n=19, 13.9%), and other phenotypes on µCT. Some focal defects on CT represented endplate fractures (n=21, 27.6%) on µCT. Overall, with respect to the presence of an EPSD, there was a sensitivity of 70.9% and a specificity of 79.1% using Feng's method, and 79.5% and 57.5% using Brayda-Bruno's method. Poor to fair inter-rater reliability (k=0.26-0.47) was observed for defect dimensions.

CONCLUSION

There was good inter-rater reliability and evidence of criterion validity supporting assessments of EPSD presence using both methods. However, neither method contained all needed EPSD phenotypes for optimal sensitivity, and specific phenotypes were often misclassified.

Thoracolumbar Vertebral Endplate Defect Morphology: A Descriptive Study of Human Cadaveric Spines Using Micro-Computed Tomography

STUDY DESIGN

A descriptive, cross-sectional cadaver study.

OBJECTIVE

This study aimed to provide a thorough depiction of vertebral endplate defects classified based on their morphologic features and reported with respect to size, location, and prevalence in the human cadaveric spines of older adults.

SUMMARY OF BACKGROUND DATA

Back pain has been associated with vertebral endplate defects; however, findings have been inconsistent. This is partially due to miscommunication surrounding the classification of endplate defects observed using clinical imaging, and limited knowledge of the types of defects present on the endplate and their prevalence. A comprehensive study of vertebral endplates is needed to clarify types of structural defects, their character, and prevalence.

MATERIALS AND METHODS

Using micro-computed tomography, 3-dimensional reconstructed images were created of 409 endplates from 19 cadaveric spines (9 men and 10 women; aged 62-91; T6-S1). Endplate defects were categorized based on their morphology, size, and location to investigate distribution patterns.

RESULTS

Seven types of endplate defects were identified: Schmorl nodes, corner fracture or limbus vertebra, other fractures, erosion, jagged surface, calcification, and depressions. Defects were identified on 63.6% of endplates. Multiple defects were present on 19.1% of endplates. Fracture and erosion were the most common defect types. Defects were more common on the endplate cranial to the intervertebral disc and in male specimens ( P = 0.01). Defects were larger in the lumbar spine and the "total area of endplate defect" was larger on the cranial than the caudal endplate in the thoracic spine ( P < 0.05).

CONCLUSION

This is the first study of which we are aware that provides a thorough depiction of the morphology and distribution of endplate defects across the entire lower thoracic and lumbar spine (T6-S1) using micro-computed tomography. Results support the presence of several distinct endplate defect phenotypes with different prevalence rates and provide a reference when considering endplate defects in the elderly.

The interrater reliability of Modic changes among a potential basivertebral nerve ablation population: Why AC1 may be preferred to kappa

Interrater reliability of Modic changes is subject to variables which affect consistency in reporting. Given the importance of Modic change identification for basivertebral nerve ablation (BVNA) candidacy, interrater reliability for this specific cohort has not yet been reported. Twenty lumbar magnetic resonance images of potential basivertebral nerve candidates were independently reviewed by two neuroradiologists and two interventional spine physiatrists for the presence and characterization of Modic changes. The kappa value of their agreement on the presence of Modic changes was 0.52 (95% confidence interval [CI] 0.37-0.67), whereas agreement on the type of Modic change was 0.51 (95% CI 0.37-0.65). Using an alternative methodology for measuring interrater reliability (Gwet's AC1) yielded the identification of the presence of Modic changes at AC1 0.51 (95% CI 0.36-0.66), whereas agreement on the type of Modic change was AC1 0.75 (95% CI 0.66-0.83). While less common, AC1 may be preferred in the appropriate cohort to kappa as it mitigates some of the pitfalls to which kappa values may be victim. Ultimately, our results are in-line with previous reports of interrater reliability results for Modic changes in other cohorts and should serve to caution those who perform BVNA regarding interrater agreement of the imaging crux of the procedure.

The interrater reliability of the novel Udby classification of Modic Changes: A first estimate

Background

Modic change grading is heterogeneous, inconsistent, and lacks a single nomenclature across the published literature. A new method of Modic change classification has been established by Dr. Peter Udby which hopes to unify how Modic changes are classified while also adding grading of the cranial/caudal extent of the Modic change across the vertebral body from the respective endplate involved to best capture the clinically relevant information of Modic changes.

Methods

Twenty magnetic resonance images of potential basivertebral nerve ablation candidates were independently reviewed by two board-certified and fellowship trained neuroradiologist and two board-certified and fellowship-trained interventional spine physiatrists for the presence and characterization of Modic changes using the newly described Udby classification. 100% agreement of all four reviewers of Modic change presence, Type, and Udby classification was required to be classified as agreement. There were 480 total data points each with 10 unique choices to compare across the four independent reviewers.

Results

The kappa value of their agreement was 0.5899 (95% CI 0.4860-0.6939).

Conclusion

This study, requiring unanimous agreement between 4 physicians in application of the Udby classification, demonstrated an interrater reliability score of 0.5899 (95% CI 0.4860-0.6939). While this figure provides a first estimate, larger scale research is necessary before definitive claims regarding the interrater agreement validity of the Udby characterization system may be made.

Schmorl's nodes: demystification road of endplate defects-a critical review

BACKGROUND

Schmorl's nodes (SN) were the first vertebral endplate defects described. Debate continues about their epidemiology, physiopathology, and clinical significance. The purpose of this work was to summarize and discuss available literature about SN.

METHODS

We have searched for relevant papers about SN until April 2020, with 104 articles have been reviewed.

RESULTS

More than half of the available literature described the epidemiological aspects of SN or reported rare clinical presentations and treatment options. The lack of a consensual definition of SN, among other endplate defects, contributed to difficulties in literature results' interpretation. Summing up, SN is a frequent vertebral defect at the thoracolumbar juncture, with ethnic and gender influence. Lumbar Schmorl's nodes were frequently associated with disc degenerative disease and back pain. Their physiopathology remains unknown. However, strain energy changes in the spine along with morphological aspects of the vertebra, the genetic background, and the osteoimmunology may constitute possible clues. New SN could be confused in malignancy context with bone metastasis. The literature describes some imaging techniques to differentiate them, avoiding invasive approaches. Treatment options for rare painful presentations remain few with low evidence. Further studies are needed to establish a consensual definition for SN, understand clinical aspects, and provide adequate therapeutic strategies.

A definition and clinical grading of Modic changes

To provide an up-to-date description of knowledge and pitfalls related to the classification, definition and grading of Modic changes (MC) visualized on magnetic resonance imaging (MRI). State-of-the-art review of current knowledge regarding the definition and grading of MC on MRI. MC on MRI have been reported to be associated with low back pain and disability. However, previous studies have shown heterogeneous results in regards to the impact of MC and its clinical relevance in patients with back pain. MC is a term used with considerable variation in the literature. No strict definition has been provided previously, this has contributed to varying diagnostic inclusion criteria, heterogeneous study populations, and discrepancy in results. A definition of MC and a proposal for grading is provided in this state-of-the-art review. MC are important, clinically relevant findings. However, issues with the nomenclature, definition and grading of these changes need to be addressed. Our current review highlights relevant issues related to MC, and provides a definition and grading score for the term MC that includes the Modic type and the extent of vertebral body involvement. Future studies should seek to validate the MC grading score in clinically relevant populations.

Cervical Disc Degeneration and Vertebral Endplate Defects After the Fused Operation

STUDY DESIGN

Longitudinal study of cervical MR in patients with degenerative disc disease (DDD).

OBJECTIVE

To evaluate the evolution of the degenerative changes in the C2-D1 cervical segments and to assess the association magnetic resonance imaging (MRI) parameters with clinical symptoms after surgical treatment in patients with DDD.

SUMMARY OF BACKGROUND DATA

The evolution of degenerative changes in the cervical spine is poorly understood. Endplate defects can be of great importance in progressive disc degeneration (DD). Clarification of this predictor may be important in determining the treatment tactics in patients with DDD.

METHODS

The study included patients who had 2-years' follow-up after cervical fusion for spondylotic radiculo- with/without myelopathy. Demographic data (age, sex, surgical data) were assessed; clinical data (visual analogue scale [VAS] neck, VAS arm, Neck Disability Index [NDI]) and cervical MRI (DD grades by Pfirrmann, Modic changes (MC), total endplate scores (TEPS) were compared to preoperative data.

RESULTS

The median follow-up term was 26.5 (18.9-33.1) months. All patients reported a decrease neck pain and arm pain at follow-up (P < 0.001). There was observed the change in MC types (P < 0.001) and an increase of TEPS (P < 0.05). 71.7% discs remained unchanged during the follow-up, but a significant number of discs went from Grade 2 to Grade 3 and from Grade 3 to Grade 4 by Pfirrmann (P < 0.001). Clinical scores (VAS neck, VAS arm, NDI) had no correlation with MRI changes (P > 0.05). DD was associated with TEPS (odds ratio [OR] 2.05-5.47, P < 0.05) and patients' age (OR 1.11-2.33, P < 0.05) at all cervical levels; with MC types, but only at C4-C5 and C6-C7 levels (OR = 2.91 and 2.79, respectively, P < 0.05). Receiver-operating characteristic analysis showed a TEPS threshold value of 7, above which the probability of DD significantly higher.

CONCLUSION

During 2 years' follow-up the significant increase of DD grades by Pfirrmann was observed at C4-C6 levels (P < 0.001). A significant association DD with TEPS and age at all cervical levels was determined.Level of Evidence: 3.

Clinical and Radiological Features Predicting Intervertebral Autofusion after Successful Antibiotic Therapy in Pyogenic Vertebral Osteomyelitis

Background: Pyogenic vertebral osteomyelitis (PVO) is a bacterial infection involving the intervertebral disc, vertebral body, and paravertebral soft tissues. Damaged intervertebral structure is a major cause of persistent back pain even after successful antibiotic therapy, which can be improved by achieving autofusion or via additional surgical fixation. In this study, we analyzed the clinical and radiological features predicting intervertebral autofusion after successful antibiotic therapy in lumbar PVO. Methods: This study was retrospectively conducted with 32 patients (20 men and 12 women) diagnosed with lumbar PVO that was completely cured with no recurrences after antibiotic therapy. They were divided into two groups with (group A, n = 18) and without (group B, n = 14) intervertebral autofusion at six-month follow-up. Differences in back pain, blood inflammatory markers, and radiological features of PVO on simultaneous ¹⁸F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (¹⁸F-FDG-PET/MRI) of the intervertebral structure between the two groups were analyzed. Results: The mean duration of antibiotic therapy was 41.44 ± 14.21 (21–89) days. Group A showed a statistically higher erythrocyte sedimentation ratio (ESR; 59.28 ± 32.33 vs. 33.93 ± 18.76 mm/h, p = 0.014; normal range of ESR < 25), maximum standardized ¹⁸F-FDG uptake (SUV_max; 5.56 ± 1.86 vs. 3.98 ± 1.40, p = 0.013), and sustained extensive edematous changes on T2-weighted fat saturation (T2FS) MRI (p = 0.015) immediately after successful antibiotic therapy. However, no significant differences were observed in back pain, C-reactive protein, or the distribution of ¹⁸F-FDG uptake/contrast enhancement on ¹⁸F-FDG-PET/MRI (p > 0.05). Conclusions: Higher ESR and SUV_max of the intervertebral structure and sustained extensive edematous change on T2FS MRI immediately after successful antibiotic therapy are related with subsequent intervertebral autofusion, which should be carefully considered when assessing therapeutic response in PVO.

The association between vertebral endplate structural defects and back pain: a systematic review and meta-analysis

PURPOSE

To clarify the current state of knowledge on the association of endplate structural defects and back pain.

METHODS

Five databases were searched for studies reporting on the association between endplate structural defects and back pain. Covidence and comprehensive meta-analysis software were used for article screening and selection and pooling of extracted data. Overall quality of evidence was assessed using GRADE.

RESULTS

Twenty-six studies comprised of 11,027 subjects met inclusion criteria. The presence of moderate heterogeneity (I² = 73%; p = 0.001) prevented the pooling of estimates across all studies. However, it was possible to pool studies of specific endplate defect phenotypes, such as erosion (OR: 2.69; 95% CI: 1.35-5.50) and sclerosis (OR: 1.97; 95% CI: 1.50-2.58), which yielded significant associations with back pain. Schmorl's nodes were also associated with most individual back pain phenotypes (OR: 1.53-1326, I² = 0-7.5%) and back pain overall (OR: 1.63, 95% CI: 1.37-1.94, I² = 26%) in general population samples. The pooling of data from all studies of specific back pain phenotypes, such as frequent back pain (OR: 2.83; 95% CI: 1.77-4.52) and back pain incidence (OR: 1.65; 95% CI: 1.30-2.10), each yielded significant association with endplate structural defects and was supported by low heterogeneity (I² =  < 7.5.%).

CONCLUSION

Overall, there is moderate quality evidence of an association between back pain and endplate structural defects, which is most evident for erosion, sclerosis and Schmorl's nodes. Going forward, research on specific endplate defect phenotypes and back pain case definitions using strong study designs will be important in clarifying the extent of associations and underlying mechanisms. The study was prospectively registered in Prospero (CRD42020170835) on 02/24/2020.

Intervertebral Disc and Adipokine Leptin-Loves Me, Loves Me Not

Leptin—the most famous adipose tissue-secreted hormone—in the human body is mostly observed in a negative connotation, as the hormone level increases with the accumulation of body fat. Nowadays, fatness is becoming another normal body shape. Fatness is burdened with numerous illnesses—including low back pain and degenerative disease of lumbar intervertebral disc (IVD). IVD degeneration and IVD inflammation are two indiscerptible phenomena. Irrespective of the underlying pathophysiological background (trauma, obesity, nutrient deficiency), the inflammation is crucial in triggering IVD degeneration. Leptin is usually depicted as a proinflammatory adipokine. Many studies aimed at explaining the role of leptin in IVD degeneration, though mostly in in vitro and on animal models, confirmed leptin’s “bad reputation”. However, several studies found that leptin might have protective role in IVD metabolism. This review examines the current literature on the metabolic role of different depots of adipose tissue, with focus on leptin, in pathogenesis of IVD degeneration.