Schmorl's nodes: Common, highly heritable, and related to lumbar disc disease

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.

Epidemiology of Schmorl's Node in the Thoracic Spine: A Subtype Analysis

STUDY DESIGN

Retrospective observational study.

OBJECTIVE

To describe the epidemiology of Schmorl's nodes (SN) of primarily developmental cause (SNd) and SN of primarily acquired cause (SNa) separately in the thoracic spine in subjects aged 35 to 90 years old.

SUMMARY OF BACKGROUND DATA

The epidemiology of SN and its relationship with age and gender remain controversial. On the basis of a pathophysiological hypothesis and the different morphologic characteristics, two subtypes of SN may exist and should be considered separately.

PATIENTS AND METHODS

Chest CT scans of subjects who came to our institution for health checks aged 35 to 90 years old were retrospectively reviewed. The presence or absence of SN was recorded for each thoracic vertebra. The SNs were further classified into SNd and SNa. The prevalence, location, and relationship with age, gender, and bone mineral density (BMD) were evaluated separately for the two subtypes.

RESULTS

Of the 848 subjects (407 female, mean age: 53±12.2 yr) included, 15.7% had SNs. Of the 303 SNs, 49.2% were SNd, and 48.5% were SNa. Aging increased the prevalence of SNa, while it was not related to the prevalence of SNd. Males had significantly more SNd than females (11.3% vs. 4.7%, P <0.001), while the prevalence of SNa was not different between the two genders (10.2% vs. 9.1%, P =0.666). A similar distribution of SNd and SNa among thoracic vertebral levels was appreciated, with T9 most frequently involved. Subjects with SNa had lower lumbar BMD than controls ( P =0.006), while no significant difference in BMD was found between subjects with SNd and controls ( P =0.166).

CONCLUSIONS

The clinical characteristics of SN differ based on the developmental and acquired subtypes, including the relationship with age, gender, and BMD. The subtypes may be considered distinct clinical entities as a result.

Prevalence and distribution of Schmorl node and endplate signal change, and correlation with disc degeneration in a population-based cohort: the Wakayama Spine Study

PURPOSE

Degenerative spinal conditions, including disc degeneration (DD), Schmorl nodes (SN), and endplate signal changes (ESC), are pervasive age-associated phenomena that critically affect spinal health. Despite their prevalence, a comprehensive exploration of their distribution and correlations is lacking. This study examined the prevalence, distribution, and correlation of DD, SN, and ESC across the entire spine in a population-based cohort.

METHODS

The Wakayama Spine Study included 975 participants (324 men, mean age 67.2 years; 651 women, mean age 66.0 years). Magnetic resonance imaging (MRI) was used to evaluate the intervertebral space from C2/3 to L5/S1. DD was classified using Pfirrmann's system, ESC was identified by diffuse high-intensity signal changes on the endplates, and SN was defined as a herniation pit with a hypointense signal. We assessed the prevalence and distribution of SN, ESC, and DD across the entire spine. The correlations among these factors were examined.

RESULTS

Prevalence of ≥ 1 SN over the entire spine was 71% in men and 77% in women, while prevalence of ≥ 1 ESC was 57.9% in men and 56.3% in women. The prevalence of ESC and SN in the thoracic region was the highest among the three regions in both sexes. Positive linear correlations were observed between the number of SN and DD (r = 0.41, p < 0.001) and the number of ESC and DD (r = 0.40, p < 0.001), but weak correlations were found between the number of SN and ESC (r = 0.29, p < 0.001).

CONCLUSION

The prevalence and distribution of SN and ESC over the entire spine were observed, and correlations between SN, ESC, and DD were established. This population-based cohort study provides a comprehensive analysis of these factors.

Management of low back pain accompanying sagittal plane pathologies in children: Spondylolysis/spondylolisthesis and Scheuermann's disease

Background

Low back pain in childhood was underappreciated for a long time, but recent studies report higher prevalences, up to 70%. Two of the common causes are spondylolyis/spondylolisthesis and Scheuermann's disease. These disorders are relevant in a way they both cause significant back pain, and may disrupt the sagittal spinal balance.

Purpose

To present the current evidence on the diagnosis, natural history and treatment of these disorders with a special focus on sagittal spinal alignment.

Methods

This study is conducted as a literature review.

Results and Conclusions

Spondylolysis and low-grade spondylolisthesis have a benign course and are typically treated conservatively. When pars repair is indicated, pedicle screw-based techniques achieve more than 90% fusion with acceptable complication rates. High-grade spondylolisthesis, however, is frequently progressive. Surgical treatment involves fusion, which can be done in situ or after reduction. Reduction is useful for "unbalanced" patients to acquire sagittal spinopelvic balance, and it is important to distinguish these patients. Despite lowering the risk for pseudoarthrosis, reduction brings a risk for neurologic complications. With re-operation rates as high as 40%, these patients definitely require careful preoperative planning. Scheuermann's disease generally causes back pain in addition to cosmetic discomfort during adolescence. If the kyphosis is lower than 60°, symptoms typically resolve into adulthood with conservative measures only. However, it must be kept in mind that these patients may experience problems with physical performance and have a lower quality of life even when the problem seems to have "resolved". Severe kyphosis and intractable back pain are the most frequently referred surgical indications, and surgery typically involves fusion. Proper utilization of osteotomies and proper selection of the upper and lower fusion levels are of utmost importance to prevent complications in these patients.

A comparison of radiographic degeneration features of older Chinese women and older Italian Caucasian women with a focus on thoracic spine

BACKGROUND

Compared with Caucasians, East Asians have a lower incident of back pain, lower prevalence and severity of osteoporotic vertebral fracture and lumbar spine degeneration.

AIM

This study compares radiographic spine degeneration features of older Chinese women (as an example of East Asians) and older Italian women (as an example of Caucasians) with a focus on the thoracic spine.

METHODS

From two population-based epidemiological studies conducted in Hong Kong, China and Rome, Italy, 297 pairs (mean age: 73.6 years) age-matched older community women's lateral spine radiographs were sampled. Existence (or absence) of seven degeneration features were assessed including: (1) hyper-kyphosis, (2) disc space narrowing (T3/T4 ~ T11/T12), (3) osteoarthritic (OA) wedging (T4 ~ T12), (4) generalised osteophyte formation (T4 ~ T12); (5) acquired short vertebrae (T4 ~ T12), (6) Schmorl node (T4 - L5), (7) disc calcification (T4-L5).

RESULTS

Italian women were more likely to have hyper-kyphosis (53.4% vs 25.6%), disc space narrowing (34.4% vs. 17.2%), OA wedging (6.4% vs. 0.67%), Schmorl node (19.5% vs. 4.4%, all P < 0.001). However, there was no statistically significant difference in osteophyte formation (7.7% vs. 9.4%, P > 0.1) and acquired short vertebrae (8.0% vs. 10.4%, P > 0.1). Disc calcification was uncommon among both Chinese and Italians.

DISCUSSION AND CONCLUSION

For the first time, this study documented a lower prevalence of a number of thoracic spine degeneration features among Chinese. This study further affirms the concept of a generally healthier spine in older Chinese relative to older Caucasians. The observed differences may reflect a foundational background influence of genetic predisposition that represents an important line of future research.

Percutaneous Vertebroplasty in a Patient with Chronic Back Pain Caused by Multiple Schmorl's Nodes: A Case Report

Background and Objectives: Schmorl's nodes (SNs), formed by the herniation of intervertebral discs into adjacent vertebral bodies, are generally asymptomatic and do not require treatment. However, certain types of SNs can cause intractable back pain. Case Presentation: A 63-year-old man presented to our hospital with back pain after a fall 1 month prior. Physical examination revealed back pain that worsened with movement and paraspinal tenderness. Magnetic resonance imaging (MRI) performed immediately after presentation revealed subacute to chronic compression fractures with SNs at the upper endplates of the 11th and 12th thoracic and 1st lumbar vertebrae. Pain (numeric rating scale (NRS), 7-8/10) persisted despite 6 months of conservative treatment and MRI revealed increased signal intensity in T2-weighted images in the regions around the SNs. Based on these findings, an epidural nerve block was performed, and then repeated; however, no significant improvement was observed. Percutaneous vertebroplasty (PVP) was performed at the 11th and 12th thoracic and 1st lumbar vertebrae. Pain levels decreased substantially 1 week after PVP (NRS, 3-4/10). Subsequent treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and steroids for two weeks further reduced pain levels (NRS, 1-2/10), following which steroid use was discontinued and NSAID use became intermittent. At the six-month follow-up, pain levels remained low and the patient reported an improvement in activity levels of 90% or more. Conclusions: This case report demonstrates that PVP safely and effectively improved symptoms in a patient with multiple SNs and intractable back pain. Nevertheless, further research, particularly large-scale randomized prospective studies, is necessary to validate the long-term efficacy and safety of this intervention.

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 association between low virulence organisms in different locations and intervertebral disc structural failure: A meta-analysis and systematic review

Many factors may trigger intervertebral disc (IVD) structural failure (intervertebral disc degeneration (IDD) and endplate changes), including inflammation, infection, dysbiosis, and the downstream effects of chemical factors. Of these, microbial diversity in the IVD and elsewhere in the body has been considered as one of the potential reasons for disc structural failure. The exact relationships between microbial colonization and IVD structural failure are not well understood. This meta-analysis aimed to investigate the impact of microbial colonization and its location (such as skin, IVD, muscle, soft tissues, and blood) on IVD structural failure and corresponding low back pain (LBP) if any. We searched four online databases for potential studies. The potential relationships between microbial colonization in different sample sources (such as skin, IVD, muscle, soft tissues, and blood) and IDD and endplate change were considered as primary outcomes. Odds ratio (OR) and 95% confidence intervals (CI) for direct comparisons were reported. Grading of Recommendations Assessment, Development and Evaluation (GRADE) scale was used to assess the quality of evidence. Twenty-five cohort studies met the selection criteria. Overall pooled prevalence of microbial colonization in 2419 patients with LBP was 33.2% (23.6%-43.6%). The pooled prevalence of microbial colonization in 2901 samples was 29.6% (21.0%-38.9%). Compared with the patients without endplate change, the patients with endplate changes had higher rates of microbial colonization of disc (OR = 2.83; 95% CI = 1.93-4.14; I 2 = 37.6%; p = 0.108). The primary pathogen was Cutibacterium acnes which was present in 22.2% of cases (95% CI = 13.3%-32.5%; I 2 = 96.6%; p = 0.000). This meta-analysis and systematic review found low-quality grade evidence for an association between microbial colonization of disc with endplate changes. The primary pathogen was C. acnes. Due to lack of enough high-quality studies and methodological limitations of this review, further studies are required to improve our understanding of the potential relationships and mechanisms of microbiota, dysbiosis, IVD colonization and IVD structural failure.

Living with lower limb traumas and below-knee amputation in a Jordanian Late Ottoman nomadic community

OBJECTIVE

Paleopathological analysis is combined with ethnohistorical, ethnographic and ethnomedical reports to assess the sociocultural implications for a historical nomadic Bedouin female following her survival of a below-knee amputation and multiple injuries to the stump.

MATERIALS

A middle-aged female recovered from a nomadic-style burial dated to the Late Ottoman Period (1789-1918) in Jordan's Wadi ath-Thamad region.

METHODS

Macroscopic and radiographic assessment.

RESULTS

A supracondylar femur (Hoffa) fracture, knee complex injury and lower leg amputation were observed on the right lower limb. Other pathological lesions that may have affected movement included bilateral os acromiale, intervertebral disc disease, osteoarthritis and right hook of hamate fracture.

CONCLUSIONS

The individual survived a below-knee amputation, two injuries to the stump, and likely experienced lower back pain. Mobility may have been painful, but she likely functioned within the community performing gender-specific daily tasks within the family tent and designated community female workspaces. Ethnohistoric and ethnographic reports suggest that marital demotion by other wives or a return to her father's tent may have occurred.

SIGNIFICANCE

Healed multiple injuries and amputation affecting one limb are rare in paleopathological literature.

LIMITATIONS

It is uncertain whether the amputation or either of the stump injuries occurred during the same event. If they resulted from separate events, slight hip joint osteoarthritis suggests that the amputation preceded the other injuries.

SUGGESTIONS FOR FURTHER RESEARCH

Full pathological assessment of individuals with amputations may provide additional insight into impairment resolution, health problems and injury arising from impairment following amputation.

Experimentally dissociating the overuse mechanisms of endplate fracture lesions and Schmorl's node injuries using the porcine cervical spine model

BACKGROUND

Compared to the documented overuse mechanisms of endplate fracture lesions, the cause of Schmorl's node injuries remains unknown, despite existing hypotheses. Therefore, this study aimed to examine and dissociate the overuse injury mechanisms of these spinal pathologies.

METHODS

Forty-eight porcine cervical spinal units were included. Spinal units were randomly assigned to groups that differed by initial condition (control, sham, chemical fragility, structural void) and loading posture (flexed, neutral). Chemical fragility and structural void groups involved a verified 49% reduction in localized infra-endplate trabecular bone strength and removal of central trabecular bone, respectively. All experimental groups were exposed to cyclic compression loading that was normalized to 30% of the predicted tolerance until failure occurred. The cycles to failure were examined using a general linear model and the distribution of injury types were examined using chi-squared statistics.

FINDINGS

The incidence of fracture lesions and Schmorl's nodes was 31(65%) and 17(35%), respectively. Schmorl's nodes were exclusive to chemical fragility and structural void groups and 88% occurred in the caudal joint endplate (p = 0.004). In contrast, 100% of control and sham spinal units sustained fracture lesions, with 100% occurring in the cranial joint endplate (p < 0.001). Spinal units tolerated 665 fewer cycles when cyclically loaded in flexed postures compared to neutral (p = 0.015). Furthermore, the chemical fragility and structural void groups tolerated 5318 fewer cycles compared to the control and sham groups (p < 0.001).

INTERPRETATION

These findings demonstrate that Schmorl's node and fracture lesion injuries can result from pre-existing differences in the structural integrity of trabecular bone supporting the central endplate.

Radiographic evaluation of lumbar intervertebral disc height index: An intra and inter-rater agreement and reliability study

PURPOSE

To evaluate intra- and inter-rater agreement and reliability of seven reported disc height index (DHI) measurement methods on standing lateral X-ray of lumbar spine.

METHODS

The adult patients who had standing lateral X-ray of lumbar spine were recruited. Seven methods were used to measure DHI of each lumbar intervertebral disc level, including a ratio of sum of anterior and posterior disc height (DH) to disc diameter (Method 1), a ratio of middle DH to mid-vertebral body height (Method 2), a ratio of middle DH to disc diameter (Method 3), a ratio of the mean of anterior, middle, and posterior DH to the sagittal diameter of the proximal vertebral body (Method 4), a ratio of DH to vertebral height which cross the centre of adjacent vertebral bodies (Method 5), a ratio of the mean of anterior, middle, and posterior DH to the mean of proximal and distal vertebral body height (Method 6), and a ratio of the sum of anterior and posterior DH to the sum of superior and inferior disc depth (Method 7). Two raters conducted the measurements (one medical student (SS) and the other an experienced spine surgeon (XC)). Bland and Altmańs Limits of Agreement (LOA) with standard difference were calculated to examine intra- and inter-rater agreements between two out of seven methods for DHI. Intra-class correlations (ICC) with 95% confidence intervals were calculated to assess intra- and inter-rater reliability.

RESULTS

The intra-rater reliability in DHI measurements for 288 participants were ICCs from 0.807 (0.794, 0.812) to 0.922 (0.913, 0.946) by rater 1 (SS) and from 0.827 (0.802, 0.841) to 0.918 (0.806, 0.823) by rater 2 (XC). Method 2, 3, and 5 on all segmental levels had bias (95 % CI does not include zero) or/and out of the acceptable cut-off proportion (>50 %). A total of 609 outliers in 9174 segmental levels' LOA range. Inter-rater reliability was good-to-excellent in all but method 2 (0.736 (0.712, 0.759)) and method 5 (0.634 (0.598, 0.667)). ICCs of related lines to good-to-excellent reliability methods was excellent in all but only indirect lines in method 1 and 4 (ICCs lie in the range from 0.8 to 0.9).

CONCLUSION

Following a structured protocol, intra- and inter-rater reliability was good-to-excellent for most DHI measurement methods on X-ray. However, the complicated methods (more indirect lines) and IVD degeneration (nucleus pulposus degeneration and disc herniation) potentially affected the agreement on inter-rater measurements. Method 7 is the best reproducible method to measure disc height index for all intervertebral disc segmental levels with a good-to-excellent intra- and inter-rater reliability and agreement.

A Influência dos nódulos de Schmorl no equilíbrio sagital de adultos jovens

Objectives  The present study aims to characterize the spinal balance (SB) in young adults with Schmorl nodes (SN).

Methods  A cross-sectional study was conducted on a sample of 47 young adults. Lumbar magnetic resonance imaging (MRI) was used to divide the patients into an SN group and a control group. Standing full spine radiographs were used to compare the spinopelvic SB parameters between groups: sagittal vertical axis, thoracic kyphosis, lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS).

Results  The LL and SS values were significantly lower in patients with SN when compared with the control group (54.5° versus 64.3°; 36.2° versus 41.4°, respectively). No significant differences were observed for the other parameters. Significant correlations were found in both groups between LL and SS; PI and PT; and PI and SS.

Conclusions  Young adults with SN have associated SB modifications, particularly lower LL and SS values, when compared with a control group. This flatter profile resembles that observed in patients with lower back pain and early disc pathology. We believe that SNs are relevant clinical findings that should prompt the study of the SB of a patient, as it may uncover variations associated with early disc degeneration.

Level of Evidence III

The prevalence of Schmorl's nodes in osteoporotic vs normal patients: a Middle Eastern population study

The study was conducted to establish the association of Schmorl's nodes and osteoporosis in a Middle Eastern cohort. The prevalence of SN in this sample was 41.1%. It was most frequent in the lumbar spine typically solitary central lesions. Over 88% Schmorl's node cases were osteoporotic/osteopenic and only 11.6% normal.

INTRODUCTION

This study aims to identify the prevalence of Schmorl's nodes (SNs) in a cohort of Omani nationals, and also to determine any relation between osteoporosis and Schmorl's nodes.

METHODS

This retrospective observational study was conducted on Omani nationals. One thousand three hundred and forty-eight DEXA scan patients were included. Of these, 545 patients had complete X-rays and MRI scans that would help determine the SN status. The X-rays and sagittal, coronal, and axial T2-weighted MR images were used to identify the presence and exact location of the Schmorl nodes by one orthopedic trainee and confirmed by the senior author. The correlation of each parameter with the presence of SN was analyzed by the independent-samples T test and one-way ANOVA.

RESULTS

The overall prevalence of SN in this population sample appeared to be 41.1%. Over 88% of the SN-positive cases were either osteopenic or frankly osteoporotic by the WHO definition. Vast majority of SNs (87.1%) occurred in the lumbar spine and were central in location and mostly solitary. Statistical analysis of the data revealed significant correlation between osteopenia or osteoporosis and the presence of SNs.

CONCLUSIONS

The prevalence of SN in the sample of Omanis studied was 41.1% and was most frequently seen in older men in the lumbar spine. It is strongly associated with osteoporosis/osteopenia (88.4%) and frequently presents as solitary central lesions.

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.

Schmorl's nodes could be associated with intervertebral disc degeneration at upper lumbar levels and end-plate disease at lower lumbar level in patients with low back pain

Schmorl's nodes (SNs) have increasingly been recognized on vertebral end-plates using advanced imaging techniques. Even though vertebral end-plates are the closest structures to discs, their pathologies are underestimated in the etiology of low back pain (LBP). We aimed to detect the prevalence of SNs and other end-plate defects in subjects with/without LBP and to understand whether SNs were associated with LBP and spinal degeneration. Subjects were evaluated in terms of end-plate defects, intervertebral disc degeneration (IVDD), and vertebral end-plate changes (Modic changes) at all lumbar levels on lumbar spine magnetic resonance imagings (MRI). Control subjects were compared to patients with LBP. Higher Pfirrmann scores (OR: 2.696) and higher SN scores (OR: 8.076) were significantly associated with Modic changes at L4-L5 disc level. Patients with higher SN scores at L1-L2 or L2-L3 levels had approximately 7-fold increased risk of severe IVDD at the corresponding levels. The most significant factor associated with presence of SNs was body weight of the patients (OR: 1.417). The most significant factor associated with intensity of LBP was severe IVDD at L5-S1 level (OR: 3.670). Having higher total SN score had an OR of 1.230 (95% CI: 1.003-1.509; p = 0.047) for predicting LBP. Schmorl's nodes were seen in 33.1% of patients and 11.5% of asymptomatic subjects. Body weight was the most significant factor associated with SNs. The most significant factor associated with LBP was severe IVDD at L5-S1 level.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Effects of endplate healing morphology on intervertebral disc degeneration after pedicle screw fixation for thoracolumbar fractures

ABSTRACT

The cartilage endplate plays an important role in the stress distribution and nutrition metabolism of the intervertebral disc. The healing morphology of the endplate after spinal fracture and its effect on the intervertebral disc degeneration are still unclear.This was a retrospective study. Patients with traumatic single-level thoracolumbar fractures treated in our orthopedic trauma service center from June 2011 to May 2019 were included and the relevant data were collected from the medical records. Based on combined computed tomography and MRI images, the endplate injury status was determined (no endplate injury, unilateral and bilateral endplate injury). According to the location of the injury, endplate injury was further divided into endplate central injury and endplate peripheral injury. The degree of posttraumatic disc lesions and disc degeneration during follow-up were classified based on the Sander classification and the Pfirrmann classification, respectively. According to the T1 image of MRI at the final follow-up, the healing morphology of endplates was determined and classified. Univariate analyses and correlation analyses were performed to evaluate the within- and between-group differences.There were in total 51 patients included in this study. Cartilage endplate fracture was significantly closely related to the degree of degeneration of the intervertebral disc (P = .003). Injuries in different parts of the endplate have no significant effect on the intervertebral disc degeneration (P = .204). The healing morphology after endplate fracture significantly affected the degree of intervertebral disc degeneration (P = .001). The comparisons of groups showed that the effects of irregular healing and traumatic Schmorl nodes on disc degeneration were not statistically significant, but were significantly significant with increased curvature.These results suggest that the irregular healing and the traumatic Schmorl nodes are closely related to intervertebral disc degeneration. The presence and severity of the endplate injury can provide valuable information for individualized clinical decision-making processes.

Back Pain in Children and Adolescents

Back pain has long been considered an uncommon complaint in the pediatric population. When present, teaching had been that pediatric back pain almost always has a diagnosable cause, many of which are progressive and potentially debilitating. Recent evidence has suggested that pediatric back pain is not only more common than once thought but also, within certain populations, benign and idiopathic. This, in turn, places an increasing amount of pressure on pediatricians to accurately assess and manage their patients presenting with complaints of back pain. The aim of this article is to serve as a review of the current literature on pediatric back pain. The article reviews the epidemiology, basic anatomy, and important elements of a history and examination, which should be considered when a child presents complaining of back pain. Last, a common differential diagnosis with evaluation and management is also given to help guide pediatricians through their medical decision making.

Cervical Spine Endplate Abnormalities and Association With Pain, Disability, and Adjacent Segment Degeneration After Anterior Cervical Discectomy and Fusion

STUDY DESIGN

A retrospective study with prospectively-collected data.

OBJECTIVE

To determine how type, location, and size of endplate lesions on magnetic resonance imaging (MRI) may be associated with symptoms and clinical outcomes after anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Structural endplate abnormalities are important, yet understudied, phenomena in the cervical spine. ACDF is a common surgical treatment for degenerative disc disease; however, adjacent segment degeneration/disease (ASD) may develop.

METHODS

Assessed the imaging, symptoms and clinical outcomes of 861 patients who underwent ACDF at a single center. MRI and plain radiographs of the cervical spine were evaluated. Endplate abnormalities on MRI were identified and stratified by type (atypical, typical), location, relation to operative levels, presence at the adjacent level, and size. These strata were assessed for association with presenting symptoms, patient-reported, and postoperative outcomes.

RESULTS

Of 861 patients (mean follow-up: 17.4 months), 57.3% had evidence of endplate abnormalities, 39.0% had typical abnormalities, while 18.2% had atypical abnormalities. Patients with any endplate abnormality had greater odds of myelopathy irrespective of location or size, while sensory deficits were associated with atypical lesions (P = 0.016). Typical and atypical abnormalities demonstrated differences in patient-reported outcomes based on location relative to the fused segment. Typical variants were not associated with adverse surgical outcomes, while atypical lesions were associated with ASD (irrespective of size/location; P = 0.004) and reoperations, when a large abnormality was present at the proximal adjacent level (P = 0.025).

CONCLUSION

This is the first study to examine endplate abnormalities on MRI of the cervical spine, demonstrating distinct risk profiles for symptoms, patient-reported, and surgical outcomes after ACDF. Patients with typical lesions reported worsening postoperative pain/disability, while those with atypical abnormalities experienced greater rates of ASD and reoperation. This highlights the relevance of a degenerative spine phenotypic assessment, and suggests endplate abnormalities may prognosticate clinical outcomes after surgery.

LEVEL OF EVIDENCE

3.

Schmorl Node-A Cause of Acute Thoracic Pain: A Case Report and Pathophysiological Mechanism

Purpose

We report a case of a patient with an acute symptomatic Schmorl node (SN) that spontaneously resolved with characteristic imaging findings. The extensive hematological investigations also allow some insight as to the likely pathophysiology of the painful lesion.

Methods

Case report of an acute symptomatic SN.

Results

A fit and athletic 44-year-old female participant in a competitive paddling event developed atypical thoracic pain and was admitted for further investigation. Normal blood results included complete blood cell count, clotting, and D-dimer. Creatine phosphokinase was 63 U/L (reference < 167 U/L) and troponin I levels were not raised. Her only hematological abnormality was an elevated C-reactive protein (CRP) at 60.2 mg/L (reference < 5 mg/L). Magnetic resonance imaging (MRI) scan showed signal hyperintensity involving T7 vertebral body, surrounding an enlarged SN. Patient was given oral nonsteroidal anti-inflammatory drugs, opioid analgesia, and gradually mobilized. After 3 days, the pain had sufficiently subsided and CRP was 17.8 mg/L. Follow-up MRI scan showed some reduction in the T2 hyperintensity and size of the intraosseous herniation. Patient gradually returned to full activities and had no recurrence of symptoms. MRI scan 8 months after the initial scan showed almost complete resolution of the T2 hyperintensity and pan-vertebral marrow edema.

Conclusion

Symptomatic SN should be part of the differential diagnosis of unexplained thoracolumbar pain. Modality of choice for diagnosis would be MRI. Once diagnosed, several treatment options are available with the most likely being spontaneous resolution of symptoms and bone healing within a few months. The conservative approach is recommended when the symptoms can be medically well controlled.

The comparison analysis of clinical and radiological features in SAPHO syndrome

OBJECTIVES

The aim was to comparatively assess the clinical and imaging features in patients with SAPHO syndrome.

METHODS

The clinical data, laboratory results, imaging data of forty-six SAPHO patients were reviewed and the SAPHO patients were divided into spinal involvement group and non-spinal involvement group. Fifty patients with ankylosing spondylitis were recruited as control group. The clinical and radiological features of them were analyzed and compared.

RESULTS

Thirty-four of 46 (73.9%) of all the SAPHO patients had spinal involvement. The lesions exhibited as abnormal hyper-intensity signal in vertebral bodies, vertebral body erosion or collapse, bone marrow edema, endplate inflammation, spondyldiscitis, paravertebral ossification, and facet joint involvement. Compared with patients in non-spinal involvement group, the age at disease onset was older (P = 0.033), the disease duration was longer (P = 0.048), and CRP level was elevated (P = 0.047) in patients in spinal involvement group. Compared with patients with ankylosing spondylitis, SAPHO patients were more likely to have cervical vertebra involvement (P = 0.024), endplate inflammation (P = 0.019), and spondyldiscitis (P = 0.001), but less multiple vertebral body and facet joint involvement (P = 0.002). Patients regularly received DMARDS or biologics treatment had symptoms relieved and lesions turned into chronic stage or better than before.

CONCLUSIONS

A total of 73.9% of the SAPHO patients had spinal involvement and the involvement could affect any part of the spine. Cervical vertebral involvement, endplate inflammation, and sponlypodiscitis were more common in SAPHO than in patients with ankylosing spondylitis. In SAPHO patients with spinal involvement, the disease duration was longer and the inflammatory reaction was more intensive. DMARDs and biologics may help to prevent the disease progress.

KEY POINTS

• To the best of our knowledge, this paper is the first one to comparatively study the clinical and radiological features of SAPHO syndrome, especially the characteristics of spinal involvement.

The effect of bone mineral density on development of Schmorl's nodes in young patients

OBJECTIVE

The aim of this study was to detect the relationship between the development of Schmorl's nodes (SNs) and bone mineral density (BMD) in young patients.

METHODS

Computerized tomography (CT) images of the thoracolumbar vertebral column were retrospectively examined by two experienced radiologists for SNs. The diagnostic criterion for SN was defined as a node size larger than one-third but not more than two-thirds of the relevant vertebral endplate. Considering the eligibility criteria, a total of 74 individuals (60 males and 14 females; mean age: 24.3 years; age range: 18-40 years) with SN at the thoracolumbar vertebrae were included in the patient group, and a total of 38 age- and gender-matched individuals (30 males and 8 females; mean age: 25 years) with no evidence of SN were included in the control group. All these individuals were younger than 40 years. In the patient group, SNs were assessed in terms of the distribution of the thoracolumbar vertebrae, the location of the upper and lower endplates, and the total number of lesions. In all individuals included in the study, BMD was measured from the axial CT sections by quantitative CT and then compared between the two groups.

RESULTS

The distribution of age and gender was comparable between the two groups (p=0.438). A total of 208 SNs were identified in the patient group. Of these, 92 (44%) were located at the thoracic vertebrae and 116 (56%) at the lumbar vertebrae. The mean BMD was 131.6 g/cm3 in the patient group and 140.7 g/cm3 in the control group (p=0.03). There was no significant relationship between the total number of SNs per patient and the mean BMD (p=0.156).

CONCLUSION

Evidence from this study revealed that low BMD may be a predisposing factor for the development of SNs in patients younger than 40 years.

LEVEL OF EVIDENCE

Level III, Diagnostic Study.

Relevance between Schmorl's Node and Lumbar Intervertebral Disc Degeneration Quantified with Magnetic Resonance Imaging T2 Mapping in Chronic Low Back Pain

Study Design

Cross-sectional study.

Purpose

The purpose of this study was to elucidate the relevance among Schmorl’s node (SN), chronic low back pain (CLBP), and intervertebral disc degeneration (IVDD) with the use of magnetic resonance imaging T2 mapping.

Overview of Literature

SN may be combined with CLBP and/or IVDD; however, their relationship has not been determined to date.

Methods

A total of 105 subjects were included (48 men and 57 women; mean age, 63.2±2.7 years; range, 22–84 years). We analyzed five functional spinal unit levels (L1–S1) and evaluated the T2 values of the anterior annulus fibrosus (AF), nucleus pulposus, and posterior AF. We compared the low back pain (LBP) Visual Analog Scale (VAS) scores and the T2 values in each decade with or without SN.

Results

There were no remarkable differences in SN prevalence rate regarding age decade or gender. SNs were more prevalent in the upper 2 levels (70.3%). LBP VAS scores with and without SN were 64.7±4.3 mm and 61.9±2.8 mm, respectively, with no significant differences between the groups (p=0.62). The T2 values of anterior AF with SN were significantly lower than those without SN in patients in their 50s, 60s, 70s, and 80s (p<0.01).

Conclusions

SN presence is not itself a risk factor for CLBP; however, it indicates IVDD of the anterior AF in subjects with SN who are ≥50 years old.

Lumbar vertebral endplate defects on magnetic resonance images: prevalence, distribution patterns, and associations with back pain

BACKGROUND CONTEXT

Although the roles of Modic Changes (MCs) and disc degeneration in back pain remain controversial, clues from cadaveric studies suggest that lumbar vertebral endplate lesions may be important in back pain. Endplate lesions can be detected on magnetic resonance (MR) images as various endplate defects, including focal, corner, and erosive defects. Yet, the clinical significance of such endplate defects remains unknown.

PURPOSE

To determine the prevalence and distribution patterns of lumbar vertebral endplate defects and their associations with back pain in a population-based sample.

STUDY DESIGN

Cross-sectional study.

PATIENT SAMPLE

Subjects were randomly selected from a typical community in Hangzhou Eastern China, regardless of back pain status.

OUTCOME MEASURES

Each subject underwent a structured interview and lumbar MR imaging. Back pain history, including today, over the past 4 weeks, 12 months, and lifetime, were acquired. Endplate defects, MCs, and disc degeneration were evaluated on MRIs. Age, gender and body mass index (kg/m²), as well as lifetime exposures, including smoking history, riding in motorized vehicles and associated vibration, and occupational physical demands were assessed.

METHODS

Descriptive statistics were used to depict prevalence and distribution patterns of endplate defects in the lumbar spine. Logistic regressions were used to examine associations of endplate defects with back pain. The research grant was obtained from the National Natural Science Foundation of China (115,000 USD), Key Platform Project of the Health Department of Zhejiang Province (14,000 USD), Technology Program of Traditional Chinese Medicine Department of Zhejiang Province (21,000 USD), and 2015 Qianjiang Talent Program of Zhejiang Province (7,000 USD) toward this work. There is no conflict to disclose.

RESULTS

There were 478 subjects (53.3±14.4 years, range 20-88 years) studied. Endplate defects presented in 301 (63.0%) subjects and 842 (16.0%) endplates. The presence of endplate defects, but not MCs and disc degeneration, was associated with lifetime back pain (odds ratio=1.64, p=.026) in multivariate analyses. Focal and erosive endplate defects were associated with lifetime back pain history (odds ratio=1.74-2.23, p<.05 for both), whereas all three types of defects were associated with intensity of worst back pain over the past 12 months (Coef=5.84-7.19, p<.05 for all).

CONCLUSIONS

Endplate defects are common findings on lumbar MRIs in adults. Specific types of endplate defects were associated with back pain history. Endplate defects may be an independent risk factor for back pain.

PLS3 Mutations Cause Severe Age and Sex-Related Spinal Pathology

Objective: Mutations in the X-chromosomal PLS3-gene, encoding Plastin 3, lead to severe early-onset osteoporosis, suggesting a major role for PLS3 in bone metabolism. However, the consequences of abnormal PLS3 function in bone and other tissues remain incompletely characterized. This study evaluated spinal consequences of aberrant PLS3 function in patients with PLS3 mutations. Design: A cross-sectional cohort study with spinal magnetic resonance imaging of 15 PLS3 mutation-positive (age range 9-77 years) and 13 mutation-negative (9-70 years) subjects. Images were reviewed for spinal alignment, vertebral heights and morphology, intervertebral disc changes and possible endplate deterioration. Results: Vertebral changes were significantly more prevalent in the mutation-positive subjects compared with the mutation-negative subjects; they were most abundant in upper thoracic spine, and in all age groups and both sexes, although more prominent in males. Difference in anterior vertebral height reduction was most significant in T5 and T6 (p = 0.046 and p = 0.041, respectively). Mid-vertebral height reduction was most significant in T3 and T5 (p = 0.037 and p = 0.005, respectively), and, for male mutation-positive subjects only, in T4 and T6-10 (p = 0.005-0.030 for each vertebra). Most of the abnormal vertebrae were biconcave in shape but thoracic kyphosis or lumbar lordosis were unchanged. Vertebral endplates were well-preserved in the mutation-positive subjects with even fewer Schmorl nodes than the mutation-negative subjects (10 vs. 16). Conclusions: Compromised PLS3 function introduces severe and progressive changes to spinal structures that are present already in childhood, in both sexes and most abundant in upper thoracic spine. Cartilaginous structures are well-preserved.

3D shape analyses of extant primate and fossil hominin vertebrae support the ancestral shape hypothesis for intervertebral disc herniation

BACKGROUND

Recently we proposed an evolutionary explanation for a spinal pathology that afflicts many people, intervertebral disc herniation (Plomp et al. [2015] BMC Evolutionary Biology 15, 68). Using 2D data, we found that the bodies and pedicles of lower vertebrae of pathological humans were more similar in shape to those of chimpanzees than were those of healthy humans. Based on this, we hypothesized that some individuals are more prone to intervertebral disc herniation because their vertebrae exhibit ancestral traits and therefore are less well adapted for the stresses associated with bipedalism. Here, we report a study in which we tested this "Ancestral Shape Hypothesis" with 3D data from the last two thoracic and first lumbar vertebrae of pathological Homo sapiens, healthy H. sapiens, Pan troglodytes, and several extinct hominins.

RESULTS

We found that the pathological and healthy H. sapiens vertebrae differed significantly in shape, and that the pathological H. sapiens vertebrae were closer in shape to the P. troglodytes vertebrae than were the healthy H. sapiens vertebrae. Additionally, we found that the pathological human vertebrae were generally more similar in shape to the vertebrae of the extinct hominins than were the healthy H. sapiens vertebrae. These results are consistent with the predictions of the Ancestral Shape Hypothesis. Several vertebral traits were associated with disc herniation, including a vertebral body that is both more circular and more ventrally wedged, relatively short pedicles and laminae, relatively long, more cranio-laterally projecting transverse processes, and relatively long, cranially-oriented spinous processes. We found that there are biomechanical and comparative anatomical reasons for suspecting that all of these traits are capable of predisposing individuals to intervertebral disc herniation.

CONCLUSIONS

The results of the present study add weight to the hypothesis that intervertebral disc herniation in H. sapiens is connected with vertebral shape. Specifically, they suggest that individuals whose vertebrae are towards the ancestral end of the range of shape variation within H. sapiens have a greater propensity to develop the condition than other individuals. More generally, the study shows that evolutionary thinking has the potential to shed new light on human skeletal pathologies.

Lumbar spine Schmorl's nodes; prevalence in adults with back pain, and their relation to vertebral endplate degeneration

Background

In 1927, Schmorl described a focal herniation of disc material into the adjacent vertebral body through a defect in the endplate, named as Schmorl’s node (SN). The aim of the study is to reveal the prevalence and distribution of Schmorl’s nodes (SNs) in the lumbar spine and their relation to disc degeneration disease in Kirkuk city population.

Results

A cross-sectional analytic study was done for 324 adults (206 females and 118 males) with lower back pain evaluated as physician requests by lumbosacral MRI at the Azadi Teaching Hospital, Kirkuk city, Iraq. The demographic criteria of the study sample were 20–71 years old, 56–120 kg weight, and 150–181 cm height. SNs were seen in 72 patients (22%). Males were affected significantly more than the females (28.8% vs. 18.8%, P = 0.03). SNs were most significantly affecting older age groups. L1–L2 was the most affected disc level (23.6%) and the least was L5–S1 (8.3%). There was neither a significant relationship between SN and different disc degeneration scores (P = 0.76) nor with disc herniation (P = 0.62, OR = 1.4), but there was a significant relation (P = 0.00001, OR = 7.9) with MC.

Conclusion

SN is a frequent finding in adults’ lumbar spine MRI, especially in males; it is related to vertebral endplate bony pathology rather than discal pathology.

Imaging in Spine Surgery: Current Concepts and Future Directions

OBJECTIVE

To review and highlight the historical and recent advances of imaging in spine surgery and to discuss current applications and future directions.

METHODS

A PubMed review of the current literature was performed on all relevant articles that examined historical and recent imaging techniques used in spine surgery. Studies were examined for their thoroughness in description of various modalities and applications in current and future management.

RESULTS

We reviewed 97 articles that discussed past, present, and future applications for imaging in spine surgery. Although most historical approaches relied heavily upon basic radiography, more recent advances have begun to expand upon advanced modalities, including the integration of more sophisticated equipment and artificial intelligence.

CONCLUSIONS

Since the days of conventional radiography, various modalities have emerged and become integral components of the spinal surgeon's diagnostic armamentarium. As such, it behooves the practitioner to remain informed on the current trends and potential developments in spinal imaging, as rapid adoption and interpretation of new techniques may make significant differences in patient management and outcomes. Future directions will likely become increasingly sophisticated as the implementation of machine learning, and artificial intelligence has become more commonplace in clinical practice.

Bony stress in the lumbar spine is associated with intervertebral disc degeneration and low back pain: a retrospective case-control MRI study of patients under 25 years of age

PURPOSE

Abnormal stress in the lumbar vertebra, also known as bony stress, can be a precursor to degenerative changes which may manifest as low back pain (LBP). However, the prevalence of bony stress in the lumbar spine and its relationship with degenerative changes and LBP is unclear. The purpose of this study was to evaluate the prevalence of bony stress in the lumbar spine and its relationship with intervertebral disc (IVD) degeneration, facet osteoarthritis and LBP in patients under 25 years of age.

METHODS

A retrospective case-control study of 130 patients under 25 years of age was conducted from a population of 493 patients who had lumbar MRI across three imaging centres over three years. A cohort of 55 consecutive patients with bony stress was identified. A control group of consecutive patients (n = 75) without bony stress was also selected from the population.

RESULTS

Bony stress was prevalent in 11% (95% CI [8.4-14.5%]) of patients and was not diagnosed in 36% (95% CI [22-55%]) of these cases. Patients with bony stress had over twofold (OR 2.3, 95% CI [1.1-4.8]) and fivefold (OR 5.3, 95% CI [2.11-13.3]) higher likelihood of having IVD degeneration and LBP, respectively, when compared with the control group. Bony stress was not found to be associated with facet osteoarthritis.

CONCLUSION

Bony stress in the lumbar spine was prevalent in 11% of patients under 25 years of age. It was commonly undiagnosed in radiology reports (not reported in 36% of the cases). Being significantly associated and with an increased likelihood of IVD degeneration and LBP, we posit that bony stress is likely a symptomatic and clinically meaningful diagnostic entity in the assessment of LBP. These slides can be retrieved under Electronic Supplementary Material.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A longitudinal investigation of the endplate cystic lesion effect on oblique lumbar interbody fusion

OBJECTIVE

To determine longitudinal effects of changes in endplate cystic lesions on oblique lumbar interbody fusion (OLIF), the relationship between bone healing and endplate cystic lesion changes, and clinical significance of cyst formation.

PATIENTS AND METHODS

A total of 107 segments in 67 patients who underwent OLIF between January 2013 and July 2016 were examined in this retrospective study. Using computed tomography, radiographic examinations of endplate cystic lesion, positive or negative cyst formation, cage subsidence, and fusion status were performed. Clinical outcomes were measured using visual analogue scale (VAS) pain scores, Oswestry disability index (ODI), and modified Macnab criteria. Outcomes were compared with preoperatively and postoperatively. A logistic regression analysis was performed to evaluate the relationship between measurements for endplate cysts.

RESULTS

The fusion rate after OLIF was 94.4% at 2-year follow-up, with 86% of cases reporting satisfactory outcome (based on modified Macnab criteria). A significantly higher (P <  0.01) VAS score for back pain was observed in the cystic lesion group than non-cystic lesion group at 6-month follow-up. Cage subsidence significantly increased the risk of non-union (odds ratio [OR]: 17.24; 95% confidence interval [CI]: 1.67-178.09). Positive cyst sign was a significant risk factor for cage subsidence (OR: 8.52; 95% CI: 2.73-26.62) while cage subsidence was also a significant risk factor for positive cyst formation (OR: 8.37; 95% CI: 2.71-25.89).

CONCLUSIONS

Cystic lesion may increase back pain in the early postoperative period. However, the preoperative cystic lesion does not aggravate a positive cyst formation or affect the final clinical result. Positive cyst formation was a significant risk factor for cage subsidence. In addition, cage subsidence was a significant predictor of non-union. Thus, the authors can speculate that positive cyst sign was potentially an indirect predictor of non-union.

Multidimensional vertebral endplate defects are associated with disc degeneration, modic changes, facet joint abnormalities, and pain

The aim of the current study was to investigate the multi-dimensional characteristics of lumbar endplate defects in humans in relation to disc degeneration and other MRI phenotypes as well as their role with pain and disability. A total of 108 subjects were recruited and underwent 3T MRI of the lumbar spine. Structural endplate defects were identified and their dimensions were measured in terms of maximum width and depth, and were then standardized to the actual width of the endplate and depth of the vertebral body, respectively. Both width and depth of all endplate defects in each subject were added separately and scores were assigned on the basis of size from 1 to 3. Combining both scores provided "cumulative endplate defect scores." Disc degeneration scores, Modic changes, disc displacement, HIZ, and facet joint changes were assessed. Subject demographics, pain profile, and Oswestry Disability Index (ODI) were also obtained. Endplate defects were observed in 67.5% of the subjects and in 13.5% of the endplates. All dimensions of endplate defects showed significance with disc degenerative scores, Modic changes, and posterior disc displacement (p < 0.05). Maximum width (p = 0.009) and its standardized value (p = 0.02), and cumulative endplate defect scores (p = 0.004) increased with narrow facet joints. Cumulative endplate defect scores showed a strong positive association with ODI (p < 0.05) compared to disc degenerative scores. Large size endplate defects were strongly associated with degenerative spine changes and more back-related disability. Findings from this study stress the need to assess endplate findings from a multi-dimensional perspective, whose role may have clinical utility. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

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

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

Evolution of a Schmorl's Node and a Degenerative Osteophyte on Sequential 68Ga-DOTATATE PET/CT Scans: Potential Pitfalls in Neuroendocrine Tumor Imaging

Schmorl's node (SN) arises from the herniation of the nucleus pulposus of the disc through the cartilaginous endplate into the body of the vertebra. Our report describes a patient with carcinoid tumor who underwent a series of Ga-DOTATATE PET/CT scans for follow-up, demonstrating gradually increasing focal vertebral uptake in absence of CT abnormality, suspicious for a metastasis. Both CT and MRI eventually revealed classical findings of a SN. Also observed in the same vertebra is a degenerative osteophyte showing intense Ga-DOTATATE uptake. This interesting case shows 2 benign spinal lesions, which potentially can simulate bone metastasis in patients with neuroendocrine tumors.

Lumbar Schmorl's Nodes and Their Correlation with Spine Configuration and Degeneration

The aim of this study was to reveal whether demographic aspect, vertebral morphometry, and spine degeneration are associated with lumbar Schmorl's nodes (SNs). A retrospective cross-sectional study was performed using data from the Department of Radiology (Carmel, Medical Center, Israel) for 180 individuals: age range between 40 and 99 years; 90 males and 90 females. All participants had undergone high-resolution CT scans for abdominal diagnostic purposes in the same supine position prior to our study, which enabled the processing of the scans in all planes and allowed a 3D reconstruction of the lower lumbar region. Eighty individuals (44.4%) had at least one SN along the lumbar spine, particularly at L3-4 level (30%). Vertebral body length (L1 to L3) and width (L1 and L4) were significantly greater in the SNs group compared to non-SNs group. On contrast, disc height (L3-4 and L4-5) was significantly lesser in SNs group than non-SNs group. SNs was significantly associated with smoking (X²= 4.436, P=0.02) and degenerative lumbar spinal stenosis (X²= 5.197, P=0.038). Moreover, the prevalence of SN was significantly greater in individuals with vacuum phenomenon and osteophytes formation (L1-2 to L4-5 levels). This study indicates that vacuum phenomenon on L3-4 (OR: 4.7, P=0.034), smoking habit (OR: 3.2, P=0.003), disc height loss of L4-5 (OR: 0.798, P=0.008), vertebral body length of L1 (OR: 1.37, P<0.001), and age (OR: 1.05, P=0.002) increase the probability of developing lumbar SNs.

Lumbar Vertebral Endplate Defects on Magnetic Resonance Images: Classification, Distribution Patterns, and Associations with Modic Changes and Disc Degeneration

STUDY DESIGN

A cross-sectional magnetic resonance (MR) imaging study.

OBJECTIVE

To classify and characterize endplate defects using routine lumbar MR images and to determine associations of endplate defects with Modic changes (MCs) and disc degeneration.

SUMMARY OF BACKGROUND DATA

Previously, a cadaveric study revealed that endplate lesions were common and associated with back pain history. New in vivo approaches appropriate for clinical studies are needed to further this potentially important line of research on the clinical significance of endplate lesions, including their relation with MCs, disc degeneration, and back pain.

METHODS

Using a MRI archive, 1564 endplates of 133 subjects (59 men and 74 women, mean age 58.9 ± 11.9 years) with the presence of MCs were retrospectively collected from April of 2014 to June of 2015. On the basis of morphological characteristics, a protocol was proposed to identify three distinct types of endplate defects, including focal, corner, and erosive defects. The location, size, and distribution patterns of various endplate lesions were characterized. MCs and disc degeneration were measured to examine their associations with endplate defects.

RESULTS

Endplate defects were observed in 27.8% of endplates studied. Greater age was associated with the presence of endplate defects. Focal defects were the most common (13.5%), followed by erosive defects (11.1%) and corner defects (3.2%). Defect types also differed in size and distribution patterns. Endplate defects and MCs had similar distribution patterns in the lumbar spine. The presence of endplate defects were associated with the presence of MCs (odds ratio = 4.29, P < 0.001), and associated with less disc signal intensity and disc height, and greater disc bulging (P < 0.05).

CONCLUSION

The three endplate defects identified on routine MR images appear to represent different pathologies and may play a key role in the pathogenesis of MCs. This classification system may facilitate clinical studies on endplate defects.

LEVEL OF EVIDENCE

4.

From the international space station to the clinic: how prolonged unloading may disrupt lumbar spine stability

BACKGROUND CONTEXT

Prolonged microgravity exposure is associated with localized low back pain and an elevated risk of post-flight disc herniation. Although the mechanisms by which microgravity impairs the spine are unclear, they should be foundational for developing in-flight countermeasures for maintaining astronaut spine health. Because human spine anatomy has adapted to upright posture on Earth, observations of how spaceflight affects the spine should also provide new and potentially important information on spine biomechanics that benefit the general population.

PURPOSE

This study compares quantitative measures of lumbar spine anatomy, health, and biomechanics in astronauts before and after 6 months of microgravity exposure on board the International Space Station (ISS).

STUDY DESIGN

This is a prospective longitudinal study.

SAMPLE

Six astronaut crewmember volunteers from the National Aeronautics and Space Administration (NASA) with 6-month missions aboard the ISS comprised our study sample.

OUTCOME MEASURES

For multifidus and erector spinae at L3-L4, measures include cross-sectional area (CSA), functional cross-sectional area (FCSA), and FCSA/CSA. Other measures include supine lumbar lordosis (L1-S1), active (standing) and passive (lying) flexion-extension range of motion (FE ROM) for each lumbar disc segment, disc water content from T2-weighted intensity, Pfirrmann grade, vertebral end plate pathology, and subject-reported incidence of chronic low back pain or disc injuries at 1-year follow-up.

METHODS

3T magnetic resonance imaging and dynamic fluoroscopy of the lumbar spine were collected for each subject at two time points: approximately 30 days before launch (pre-flight) and 1 day following 6 months spaceflight on the ISS (post-flight). Outcome measures were compared between time points using paired t tests and regression analyses.

RESULTS

Supine lumbar lordosis decreased (flattened) by an average of 11% (p=.019). Active FE ROM decreased for the middle three lumbar discs (L2-L3: -22.1%, p=.049; L3-L4: -17.3%, p=.016; L4-L5: -30.3%, p=.004). By contrast, no significant passive FE ROM changes in these discs were observed (p>.05). Disc water content did not differ systematically from pre- to post-flight. Multifidus and erector spinae changed variably between subjects, with five of six subjects experiencing an average decrease 20% for FCSA and 8%-9% for CSA in both muscles. For all subjects, changes in multifidus FCSA strongly correlated with changes in lordosis (r²=0.86, p=.008) and active FE ROM at L4-L5 (r²=0.94, p=.007). Additionally, changes in multifidus FCSA/CSA correlated with changes in lordosis (r²=0.69, p=.03). Although multifidus-associated changes in lordosis and ROM were present among all subjects, only those with severe, pre-flight end plate irregularities (two of six subjects) had post-flight lumbar symptoms (including chronic low back pain or disc herniation).

CONCLUSIONS

We observed that multifidus atrophy, rather than intervertebral disc swelling, associated strongly with lumbar flattening and increased stiffness. Because these changes have been previously linked with detrimental spine biomechanics and pain in terrestrial populations, when combined with evidence of pre-flight vertebral end plate insufficiency, they may elevate injury risk for astronauts upon return to gravity loading. Our results also have implications for deconditioned spines on Earth. We anticipate that our results will inform new astronaut countermeasures that target the multifidus muscles, and research on the role of muscular stability in relation to chronic low back pain and disc injury.

High stature and body mass might affect the occurrence of Schmorl’s nodes

Schmorl’s nodes are vertical herniation of intervertebral discs into the body of neighbouring vertebral endplate. Notwithstanding extensive studies, no consensus has been reached in the subject of their possible etiology. It is hypothesized that physical stress, trauma and high axial loading are the key factors in the occurrence of this pathology. The main objective of the current work is to reevaluate the relationship between stature and body mass and Schmorl’s nodes. For this purpose, skeletal samples from Lithuania (44 males and 19 females) and Poland (97 males and 60 females) were used. The study confirmed that Schmorl’s nodes are age-independent, and more frequent in males (12.63% on the superior and 19.32% on the inferior surface of vertebrae) than in females (6.23% and 12.29% respectively). Obtained results also suggest that high stature (e.g. Spearmann correlation for superior: R=0.20 p=0.017, and inferior: R=0.31 p=0.000 surface of vertebrae) and body mass (R=0.25, p=0.002 and R=0.32, p<0.001, respectively) are factors that increase the risk of Schmorl’s nodes. Authors hypothesize that the afore-mentioned body size traits alter loadings acting on intervertebral discs, and rigidity of the spine.

Structural vertebral endplate nomenclature and etiology: a study by the ISSLS Spinal Phenotype Focus Group

PURPOSE

Vertebral endplate abnormalities may be associated with disc degeneration and, perhaps, pain generation. However, consensus definitions for endplate findings on spine MRI do not exist, posing a challenge to compare findings between studies and ethnic groups. The following survey was created to characterize the variability among the global spine community regarding endplate structural findings with respect to nomenclature and etiology.

METHODS

A working group within the International Society for the Study of the Lumbar Spine (ISSLS) Spinal Phenotype Focus Group was established to assess the endplate phenotype. A survey which consisted of 13 T2-weighted sagittal MRIs of the human lumbar spine illustrating the superior and inferior endplates was constructed based on discussion and agreement by the working group. A list of nomenclature and etiological terms with historical precedence was generated. Participants were asked to describe the endplates of each image and select from 14 possible nomenclatures and 10 etiological terms along with the option of free text response. The survey was entered into RedCap and was circulated throughout the ISSLS membership for data capture. Participants' demographics were also noted.

RESULTS

The survey was completed by 55 participants (87% males; 85% above 45 years of age, 39 clinicians, and 16 researchers). Sixty-eight percent of researchers and seventy-four percent of clinicians reported more than 16 and 20 years of research and clinical experience. Considerable variation existed in selection of nomenclature, etiology, and degree of severity of the endplate structural findings (reliability coefficients for single measures in each case were 0.3, 0.08, and 0.2, respectively). Sixty-seven percent regarded Modic changes as being a structural endplate finding. Approximately 84 and 80% of clinicians and researchers, respectively, agreed that a standardized endplate nomenclature and understanding the etiology is clinically important and needed.

CONCLUSIONS

This study found that variations exist with respect to endplate nomenclature and etiology between clinicians and basic scientists, and paves the way for a consensus process to formalize the definitions.

Impaired WNT signaling and the spine-Heterozygous WNT1 mutation causes severe age-related spinal pathology

BACKGROUND

WNT signaling plays a major role in bone and cartilage metabolism. Impaired WNT/β-catenin signaling leads to early-onset osteoporosis, but specific features in bone and other tissues remain inadequately characterized. We have identified two large Finnish families with early-onset osteoporosis due to a heterozygous WNT1 mutation c.652T>G, p.C218G. This study evaluated the impact of impaired WNT/β-catenin signaling on spinal structures.

METHODS

Altogether 18 WNT1 mutation-positive (age range 11-76years, median 49years) and 14 mutation-negative subjects (10-77years, median 43years) underwent magnetic resonance imaging (MRI) of the spine. The images were reviewed for spinal alignment, vertebral compression fractures, intervertebral disc changes and possible endplate deterioration. The findings were correlated with clinical data.

RESULTS

Vertebral compression fractures were present in 78% (7/9) of those aged over 50years but were not seen in younger mutation-positive subjects. All those with fractures had several severely compressed vertebrae. Altogether spinal compression fractures were present in 39% of those with a WNT1 mutation. Only 14% (2/14) mutation-negative subjects had one mild compressed vertebra each. The mutation-positive subjects had a higher mean spinal deformity index (4.0±7.3 vs 0.0±0.4) and more often increased thoracic kyphosis (Z-score>+2.0 in 33% vs 0%). Further, they had more often Schmorl nodes (61% vs 36%), already in adolescence, and their intervertebral discs were enlarged.

CONCLUSION

Compromised WNT signaling introduces severe and progressive changes to the spinal structures. Schmorl nodes are prevalent even at an early age and increased thoracic kyphosis and compression fractures become evident after the age of 50years. Therapies targeting the WNT pathway may be an effective way to prevent spinal pathology not only in those harboring a mutation but also in the general population with similar pathology.

[Low back pain and Modic changes]

Modic changes (MCh) are pathological changes in the bone marrow and the endplates of adjacent vertebrae characterized by bone marrow edema, fatty degeneration or osteosclerosis that are revealed by high-power field magnetic resonance imaging (MRI). The dominant disease pattern is a persistent back pain syndrome with varying intensity. It leads to difficulties in the interpretation of clinical data, evaluation of MRI data and treatment. The article presents a modern conception of the pathogenesis, classification, clinical implications and treatment of MCh based on national and foreign sources as well and the author's view on the osteogenic mechanism of the pathogenesis and treatment of MCh using intraosseous blockades.

A Retrospective Study of Percutaneous Balloon Kyphoplasty for the Treatment of Symptomatic Schmorl's Nodes: 5-Year Results

BACKGROUND Despite literature supporting the efficiency of percutaneous balloon kyphoplasty (PKP) in treating osteoporotic and malignant vertebral compression fractures, few reports exist that document its use for treatment of symptomatic Schmorl's nodes (SNs) refractory to conservative treatment. Patients with symptomatic SNs could have pain in the vertebrae similar to an acute vertebral compression fracture. MRI is very helpful in diagnosing symptomatic SNs when x-ray and CT scan are unremarkable. In painful cases, the vertebrae bone marrow around the SNs is hyperintense on T2-weighted subsequence. We evaluated the long-term safety and effectiveness of PKP for the treatment of symptomatic SNs not responding to conservative therapy. MATERIAL AND METHODS From January 2008 to December 2012, 32 patients suffering from symptomatic SNs underwent 43 PKP procedures. Outcome data, including mean height ratio of anterior and middle vertebral body, Visual Analog Scale (VAS score) for pain measurement, Oswestry Disability Indexes (ODI score) and SF-36 questionnaires for function measurement were recorded preoperatively, postoperatively, and at one month, six months, two years, and five years after treatment. RESULTS Thirty-two patients were treated successfully with PKP. Clinically asymptomatic cement leakage was observed in three (6.98%) of the treated vertebral bodies. The mean height ratio of anterior and middle vertebral bodies changed from 98.2±1.6% preoperatively to 98.5±1.4% postoperatively (p>0.05) and 98.3±1.5% preoperatively to 98.8±1.9% postoperatively (p>0.05). The mean VAS scores, ODI score, and SF-36 scores for physical function (PF), bodily pain (BF), social functioning (SF), and vitality (VT) all showed significant improvements (p<0.05). During the 5-year follow-up, the stabilization of the height of the vertebral body and functional improvements were all maintained. CONCLUSIONS PKP is a safe and effective procedure for the treatment of symptomatic SNs refractory to conservative therapy.