The pathogenesis of Schmorl's nodes

Schmorl's nodes in two 19th-20th century Spanish osteological collections from Valladolid and Granada

OBJECTIVE

This study examines how age at death, sex, and socio-historical context relate to the frequency, location, and severity of Schmorl's nodes.

MATERIALS

The sample comprised thoracic and lumbar vertebrae of 192 skeletons from two contemporary documented osteological collections from Spain, in Valladolid and Granada, both of which contain individuals who died during the second half of the 20th century.

METHODS

Schmorl's nodes were recorded on the superior and inferior surfaces of vertebral bodies and their location was categorized in one of three areas: center, canal, and periphery.

RESULTS

The prevalence of Schmorl's nodes was 57.42 % for the Valladolid collection and 67.39 % for Granada, with no significant differences between collections. Statistically significant differences were found between the sexes, but age at death did not correlate with the presence of the lesion.

CONCLUSIONS

This analysis supports the absence of a direct relationship between the pathology and the aging process, but shows a greater predisposition in male individuals, suggesting that vertebral morphology and/or physical activity might be key etiological factors.

SIGNIFICANCE

This research enhances our understanding of the etiology of Schmorl's nodes by highlighting sex as a key variable and suggesting a lack of association with age.

LIMITATIONS

The absence of data on occupational activity prevents correlating this variable with the presence of Schmorl's nodes.

SUGGESTIONS FOR FURTHER RESEARCH

Conduct studies on geometric morphometric data to corroborate the evolutionary hypothesis proposed by other authors.

Experimentally Dissociating the Acute Mechanisms of Endplate Fracture Lesions and Schmorl's Node Injuries Using a Porcine Cervical Spine Model

STUDY DESIGN

This is an in vitro biomechanical study.

OBJECTIVE

This study evaluated the influence of localized trabecular bone strength deficits and loading rate as determinants of Schmorl's node and fracture lesion incidence. The failure load (ultimate compression tolerance [UCT]), loading stiffness, and failure morphology were assessed after acute compression loading and failure.

SUMMARY OF BACKGROUND DATA

The cartilaginous endplate is vulnerable to injuries such as Schmorl's nodes and fracture lesions. While both injuries are associated with acute compression traumas, the factors that distinguish their incidence are poorly understood.

METHODS

Forty-eight porcine spinal units (domestic hog, 5-10 mo, ~110 kg) were assigned to one of eight experimental groups that differed by initial condition (control, sham, experimentally produced chemical fragility, and structural void) and loading rate (3 kN/s, 9kN/s). A servo-hydraulic materials testing system was used to perform acute compression testing until observed failure in the specimen. Post-loading dissection was performed to classify injury morphologies. Between group differences in UCT and loading stiffness were evaluated using a general linear model and injury distributions were evaluated using chi-squared statistics.

RESULTS

Schmorl's nodes occurred exclusively in chemical fragility (63%) and structural void groups (37%) and were more prevalent with a 9 kN/s (75%) loading rate compared with 3 kN/s (25%). In contrast, fracture lesions occurred in all FSUs assigned to the control groups (100%) and the majority of those assigned to the sham groups (92%). No between-group differences were observed for UCT and loading stiffness.

CONCLUSION

Pre-existing strength deficits of the subchondral trabecular bone can alter endplate injury morphology, particularly when coupled with high loading rates, but the localized strength deficits that were associated with Schmorl's nodes did not appreciably influence measured joint properties.

From structure to therapy: the critical influence of cartilaginous endplates and microvascular network on intervertebral disc degeneration

The intervertebral disc (IVD) is the largest avascular structure in the human body. The cartilaginous endplate (CEP) is a layer of translucent cartilage located at the upper and lower edges of the vertebral bodies. On one hand, CEPs endure pressure from within the IVD and the tensile and shear forces of the annulus fibrosus, promoting uniform distribution of compressive loads on the vertebral bodies. On the other hand, microvascular diffusion channels within the CEP serve as the primary routes for nutrient supply to the IVD and the transport of metabolic waste. Degenerated CEP, characterized by increased stiffness, decreased permeability, and reduced water content, impairs substance transport and mechanical response within the IVD, ultimately leading to intervertebral disc degeneration (IDD). Insufficient nutrition of the IVD has long been considered the initiating factor of IDD, with CEP degeneration regarded as an early contributing factor. Additionally, CEP degeneration is frequently accompanied by Modic changes, which are common manifestations in the progression of IDD. Therefore, this paper comprehensively reviews the structure and physiological functions of CEP and its role in the cascade of IDD, exploring the intrinsic relationship between CEP degeneration and Modic changes from various perspectives. Furthermore, we summarize recent potential therapeutic approaches targeting CEP to delay IDD, offering new insights into the pathological mechanisms and regenerative repair strategies for IDD.

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.

Bone cement distribution may significantly affect the efficacy of percutaneous vertebroplasty in treating symptomatic Schmorl's nodes

PURPOSE

Percutaneous vertebroplasty(PVP) has been widely used in treating symptomatic Schmorl's nodes(SNs). However, there were still some patients with poor pain relief. At present, there is a lack of research to analyze the reasons for poor efficacy.

METHODS

Review the SNs patients treated with PVP in our hospital from November 2019 to June 2022, collect their baseline data. Reverse reconstruction software was used to calculate the filling rate of bone edema ring(R_f). NRS score was used to evaluate pain and ODI to evaluate function. The patients were divided into remission group(RG) and non remission group(n-RG) according to symptom. In addition, according to the R_f, they were divided into excellent, good and poor groups. Differences between groups were investigated.

RESULTS

A total of 26 vertebrae were included in 24 patients. When grouped according to symptoms, patients in n-RG were older, and surgical segments were tend to locate in lower lumbar spine. The proportion of Poor distribution was significantly higher. When grouped according to the cement distribution, the preoperative NRS and ODI of the three groups were comparable, but the NRS and ODI of Poor group were significantly worse than the Excellent and Good groups postoperatively and at the last follow-up.

CONCLUSIONS

The cement distribution may significantly affect the efficacy of PVP in treating symptomatic SNs. We suggest that the bone edema ring should be filled as fully as possible to ensure the efficacy. In addition, advanced age and low lumbar lesions are also adverse factors for clinical outcomes.

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.

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 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.

Percutaneous vertebroplasty (PVP) to treat specialized type of endplate fractures around the Schmorl's node: a prospective study of 65 patients

BACKGROUND

The Schmorl's nodes (SNs) are defined as the herniation of the intervertebral disc into the vertebral body. Endplate fractures around the Schmorl's node could result in severe back pain that is similar to vertebral compression fractures. The objective of this study was to prospectively analyze the surgical effectiveness and safety of percutaneous vertebroplasty (PVP) for endplate fractures around the SNs.

METHODS

Seventy-one consecutive patients with the fresh endplate fracture around SNs from October 2017 to February 2018 were enrolled in this study. The visual analog scale (VAS) and Oswestry disability index (ODI) scores of low back pain were evaluated in all patients preoperatively, postoperatively, and at 1 month, 6 months, and 1 year after primary single level PVP. Surgery-related data including duration of the operation, injected cement volumes, and surgical complications were recorded.

RESULTS

Sixty-five patients with fresh endplate fractures around the SNs were treated successfully via percutaneous vertebroplasty. Our study showed that the VAS scores and ODI scores of patients were obviously improved after operation. Cement leakage into the disc space occurred in 5 patients (7.7%), and adjacent segment refractures occurred in 2 patients (3.1%). No other surgical complications, including infections or nerve root injuries were encountered.

CONCLUSIONS

Based on the results of this prospective study, PVP was an effective and safe procedure for endplate fractures around the SNs.

TRIAL REGISTRATION

ChiCTR, ChiCTR1800016453 . Registered 2 June 2018-retrospectively registered, http://www.chictr.org.cn/com/25/historyversionpuben.aspx?regno=ChiCTR1800017602.

Paraspinal pseudoneoplasms: a series of 58 consultation cases emphasizing the importance of pathology-radiology correlation

A variety of non-neoplastic diseases of the spine, including herniated/sequestered intervertebral discs, synovial cysts, and degenerative or post-traumatic changes, may present as mass lesions. Over the past several years, we have seen a large number of such paraspinal pseudoneoplasms in consultation, referred out of concern for malignancy on the part of the clinician, pathologist, or both. Herein, we report our experience with these specimens, emphasizing the clinical, radiologic, and histopathological features that allow their confident distinction from various mesenchymal tumors. Fifty-eight cases were identified within our consultation archives, referred in consultation to exclude malignancy and diagnosed as non-neoplastic disease involving the intervertebral disc, ligamentum flavum, or paraspinal soft tissues (2006-2019). Available radiologic studies were reviewed by 2 musculoskeletal radiologists. The histologic features of all cases were re-evaluated. Available clinical records were reviewed. The masses occurred in adults (median age 62 years, range 20-86 years) with a male predominance (35 males and 23 females). Sites included lumbar spine (N = 33), thoracic spine (N = 15), cervical spine (N = 6), paraspinal region (N = 3), and sacral spine (N = 1). In 44 cases (76%), the referring pathologist regarded the specimen as representing a benign or malignant neoplasm, either primary or metastatic. Fifteen cases (26%) were sent for second opinion at the request of the treating clinician, following an initial malignant diagnosis. Advanced imaging studies were available for re-review in 37 cases (64%) and showed herniated/extruded disc (N = 17), compression fracture (N = 9), synovial cyst (N = 8), and degenerative joint disease (N = 7). Multiple radiologic findings were seen in 9 patients. Histologically, the specimens showed a spectrum of often florid reactive changes involving degenerating disc material, ligamentum flavum, and bone. Awareness that non-neoplastic spinal processes may form pseudoneoplastic mass lesions, and careful clinical-radiologic-pathologic correlation should allow their confident distinction from potential morphologic mimics.

Thoracolumbar meningeal fibrosis in pugs

Background

Thoracolumbar myelopathies associated with spinal cord and vertebral column lesions, with a similar clinical phenotype, but different underlying etiologies, occur in pugs.

Objectives

To further characterize the clinical and neuropathological characteristics of pugs with longstanding thoracolumbar myelopathy.

Animals

Thirty client‐owned pure‐bred pugs with a history of more than a month of ataxia and paresis of the pelvic limbs, suggesting a myelopathy localized to the thoracolumbar spinal cord, were included in the study.

Methods

Prospective clinicopathological study. Included pugs underwent a complete neurological examination and gross and histopathologic postmortem studies with focus on the spinal cord. Computed tomography (n = 18), magnetic resonance imaging (n = 17), and cerebrospinal fluid analysis (n = 27) were performed before or immediately after death.

Results

Twenty male and 10 female pugs had a median age at clinical onset of 84 months (interquartile range, 66‐96). Affected pugs presented with a progressive clinical course and 80% were incontinent. There was circumferential meningeal fibrosis with concomitant focal, malacic, destruction of the neuroparenchyma in the thoracolumbar spinal cord in 24/30 pugs. Vertebral lesions accompanied the focal spinal cord lesion, and there was lympho‐histiocytic inflammation associated or not to the parenchymal lesion in 43% of the pugs.

Conclusions and Clinical Importance

Meningeal fibrosis with associated focal spinal cord destruction and neighboring vertebral column lesions were common findings in pugs with long‐standing thoracolumbar myelopathy.

Association between parity and lumbar spine degenerative disorders in young women

Introduction: Estrogen helps to maintain the health of collagen-containing tissues including the intervertebral disc. Estrogen deficiency after menopause negatively affects the quality of vertebral end plates and induces development of degenerative disc disease (DDD). However, there is no study examining the relationship between parity and spinal degeneration in young women. The aim of this study was to define the relationship between parity and development of vertebral endplate signal changes and DDD in young premenopausal women.Materials and methods: This case-control case study included 224 patients aged 20-40 years with a history of low back pain for at least 3 months. Pfirrmann's grade, Modic changes (MCs), and Schmorl's nodes (SNs) were graded based on magnetic resonance images. Patients' parity, demographics, body mass index, physical activity level, and disability scores were assessed using a questionnaire.Results: The prevalence of abnormal total Pfirrmann's score (>10) and MCs was higher in primiparous patients than multiparous and grand-multiparous; however, it was not statistically significant. The presence of SN was statistically significantly associated with low parity. According to multivariate logistic regression analysis, it was found that the number of births increases by 1 unit, the abnormality in Pfirrmann's score decreases by 1.36 times.Conclusions: This cross-sectional study shows that parity is associated with DDD and vertebral end plate changes. SNs were significantly associated with parity. Modic changes and DDD were less common in grand multipara and multipara young women than in primipara women. These results indicate that low parity may possibly be associated with the development of spinal degeneration.

Percutaneous Full Endoscopic Management of Lumbar Posterior Edge Separation in Adolescents

PURPOSE

Lumbar posterior edge separation is a common disorder with lumbar disc herniation (LDH) in adolescents. Over the years, there has been a lack of an acknowledged assessment and plan. The purpose of this study was to elucidate the feasibility of all sufferers who have received percutaneous full endoscopic treatment for lumbar posterior edge separation in adolescents.

METHODS

Case series of sufferers with lumbar posterior edge separation who underwent surgery in the Affiliated Hospital Qingdao University between February 2017 and December 2018 were reviewed, including 15 males and 9 females. Preoperative and postoperative visual analogue scale (VAS) scores and the Korean Version of the Oswestry disability index (K-ODI) scores were used to evaluate the clinical outcomes.

RESULTS

All sufferers were followed up for 6 to 12 months, with an average time of 10.7 months. The postoperative VAS scores of low back pain and leg pain and ODIs were significantly different from the preoperative scores (p < 0.05). According to the modified Mac Nab criteria, the results were excellent in 17 cases and good in 7 cases.

CONCLUSIONS

Percutaneous full endoscopic treatment can effectively achieve neurological functional recovery in sufferers with favorable efficacy and safety.

In the quest for degenerative lumbar spinal stenosis etiology: the Schmorl's nodes model

BACKGROUND

Degenerative lumbar spinal stenosis (DLSS) is a common health problem in the elderly and usually associated with three-joint complex degeneration. Schmorl's nodes (SNs) are described as vertical herniation of the disc into the vertebral body through a weakened part of the end plate that can lead to disc degeneration. Since SNs can harm the spine unit stability, the association between DLSS and SNs is expected. The aim of this study is to shed light on the relationship between degenerative lumbar spinal stenosis and SNs.

METHODS

Two groups of individuals were studied: the first included 165 individuals with DLSS (age range: 40-88, sex ratio: 80 M/85 F) and the second 180 individuals without spinal stenosis related symptoms (age range: 40-99, sex ratio: 90 M/90 F). The presence or absence of SNs on the cranial and caudal end plate surfaces at the lumbosacral region (from L1 to S1 vertebra) was recorded, using CT images (Brilliance 64 Philips Medical System, Cleveland Ohio, thickness of the sections was 1-3 mm and MAS, 80-250). Chi-Square test was taken to compare the prevalence of SNs between the study groups (control and stenosis) by lumbar disc level, for each gender separately. Multivariable logistic regression analysis was also used to determine the association between DLSS and SNs.

RESULTS

The prevalence rate of SNs was significantly greater in the stenosis males (L1-2 to L5-S1) and females (L4-5 and L4-S1) compared to their counterparts in the control (P < 0.001). In addition, the presence of SNs in both males and females was found to increase the likelihood for DLSS.

CONCLUSIONS

Our results indicate that SNs prevalence is significantly greater in the DLSS group compared to the control. Furthermore, SNs are strongly associated with DLSS.

Schmorl Nodes Can Cause Increased 68Ga DOTATATE Activity on PET/CT, Mimicking Metastasis in Patients With Neuroendocrine Malignancy

Schmorl node (SN) is the herniation of the nucleus pulposus through the cartilaginous and bony endplate into the adjacent vertebral body. It is documented that SNs produce areas of moderately increased F-FDG uptake. We present a case of a patient with history of neuroendocrine tumor, who underwent Ga DOTATATE PET/CT for follow-up, showing increased focal vertebral uptake suggestive of bone metastasis. CT revealed typical findings of an SN. The presented case indicates that SNs should be considered when encountering focally increased skeletal uptake in Ga DOTATATE PET/CT studies, which can mimic metastasis in patients with history of neuroendocrine tumors.

Classification of Schmorl's nodes of the lumbar spine and association with disc degeneration: a large-scale population-based MRI study

OBJECTIVE

Schmorl's nodes (SN) are highly associated with lumbar disc degeneration (DD). However, SN present with different morphologies/topographies that may be associated with varying degrees of DD. This study proposed a classification of SN to determine their morphological/topographical prevalence and association with the severity of DD.

METHODS

Sagittal T2-weighted MRIs were assessed to identify SN and additional imaging findings from L1-S1 in 2,449 individuals. SN characteristics were classified by six criteria: disc level; endplate involvement; shape; size; location of endplate zone; and the presence of marrow changes. Hierarchical clustering was performed to identify distinct SN characteristics with endplate patterns.

RESULTS

Good to excellent observer classification reliability was noted. SN most commonly presented at the L1 and L2 disc levels, and entailed one-third of the endplate, predominantly the middle zone. Round shape (39.2%) was the most common SN shape. Four specific SN and endplate linkage patterns were identified. 8.3% of identified SN (n = 960) were "Atypical SN". Multivariable regression showed that "Typical SN" and "Atypical SN", depending on levels, were associated with an adjusted 2- to 4-fold and a 5- to 13-fold higher risk of increased severity of DD, respectively (p < 0.05).

CONCLUSIONS

This is the first large-scale magnetic resonance imaging (MRI) study to propose a novel SN classification. Specific SN-types were identified, which were associated with more severe DD. This study further broadens our understanding of the role of SN and degrees of DD, further expanding on the SN phenotyping that can be internationally adopted for utility assessment.

Evaluation of the disco-vertebral junction using ultrashort time-to-echo magnetic resonance imaging: inter-reader agreement and association with vertebral endplate lesions

OBJECTIVE

To evaluate ultrashort time to echo (UTE) magnetic resonance (MR) morphology of the cartilaginous endplates (CEP) in cadaveric lumbar spines with bony vertebral endplate (VEP) lesions, to determine inter-reader agreement as well as associations between the CEP morphology and VEP lesions as well as other abnormalities.

MATERIALS AND METHODS

MR imaging of cadaveric lumbar spines from 10 donors was performed at 3T using a UTE MR sequence. Two musculoskeletal radiologists identified the location of vertebral endplate lesions in consensus. The morphology of the CEP overlying the lesions and in the adjacent normal regions was assessed individually. A total of 55 vertebral lesions and 55 normal regions were assessed. The presence of osteophytosis, morphological changes of the anterior and posterior longitudinal ligament, and intervertebral disc signal and morphology was also assessed. Agreement between observers was determined using Cohen's kappa analysis, and association between CEP and vertebral endplate lesions was determined using the chi square test.

RESULTS

Fifty-five vertebral endplate lesions were identified and the morphology of CEP evaluated by two readers was in substantial agreement with Cohen's kappa of 0.78. The presence of vertebral endplate abnormality was associated with the presence of osteophytes (39 out of 55 levels), altered morphology and signal of the anterior longitudinal ligament (23 out of 55 levels) and intervertebral discs (30 out of 55 levels).

CONCLUSION

UTE MRI enables evaluation of the CEP with substantial inter-reader agreement. Abnormal changes of the CEP may facilitate formation of lesions of vertebral endplate over time and are associated with degenerative changes of the lumbar spine.

Lumbar spine endplate fractures: Biomechanical evaluation and clinical considerations through experimental induction of injury

Lumbar endplate fractures were investigated in different experimental scenarios, however the biomechanical effect of segmental alignment was not outlined. The objectives of this study were to quantify effects of spinal orientation on lumbar spine injuries during single-cycle compressive loads and understand lumbar spine endplate injury tolerance. Twenty lumbar motion segments were compressed to failure. Two methods were used in the preparation of the lumbar motion segments. Group 1 (n = 7) preparation maintained pre-test sagittal lordosis, whereas Group 2 (n = 13) specimens had a free-rotational end condition for the cranial vertebra, allowing sagittal rotation of the cranial vertebra to create parallel endplates. Five Group 1 specimens experienced posterior vertebral body fracture prior to endplate fracture, whereas two sustained endplate fracture only. Group 2 specimens sustained isolated endplate fractures. Group 2 fractures occurred at approximately 41% of the axial force required for Group 1 fracture (p < 0.05). Imaging and specimen dissection indicate endplate injury consistently took place within the confines of the endplate boundaries, away from the vertebral periphery. These findings indicate that spinal alignment during compressive loading influences the resulting injury pattern. This investigation identified the specific mechanical conditions under which an endplate breach will take place. Development of endplate injuries has significant clinical implication as previous research identified internal disc disruption (IDD) and degenerative disc disease (DDD) as long-term consequences of the axial load-shift that occurs following a breach of the endplate. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1084-1091, 2016.

MR imaging of Schmorl's nodes: Imaging characteristics and epidemio-clinical relationships

PURPOSE

The purpose of our prospective study was to assess the presentation of Schmorl's nodes (SN) on magnetic resonance imaging (MRI) and investigate their possible association with demographic and clinical findings.

MATERIALS AND METHODS

Three hundred and thirty-three patients were prospectively included. Thirteen (3.9%) patients were excluded because of contraindication to MRI and/or Scheuermann's disease. The final study population included 320 patients. T1-weighted and short TI inversion recovery sequences were performed to assess SN prevalence, the vertebral level and their anatomical distribution in vertebra. Medical history was recorded focusing on previous diseases including degenerative, rheumatoid and neoplastic disease, and any existing spinal traumatism. Epidemiological information was also obtained, including age, gender, ethnicity, professional and sporting activity.

RESULTS

The final study population included 320 patients (172 men, 148 women) with a mean age of 54 years±17.5 (SD) (range: 19-87 years). A total of 421 SN were found in 158/320 patients (49.4%). SN were localized in thoracic spine for 48%, in lumbar spine for 46% and cervical spine for 6%. The middle part of the thoracic vertebra was the most affected area (80%), mostly in the middle superior endplate (41%). SN were more frequently observed in manual workers who worked more than 10 years (P<0.0001) and less frequently in patients of the 30-39-year-old age group (P=0.0048). No significant associations were found with gender (P=0.17) and remarkable medical history (P=0.21). SN were less frequently observed in patients with sport activities of 1-5hours/week (P=0.04) and those with an African origin (P<0.0001).

CONCLUSION

Our study suggests a potential role for ethnical and physical factors in the pathogenesis of SN. Furthers studies are mandatory to evaluate their clinical relevance, especially in patients such as Caucasian manual workers in whom SN have a high prevalence.

THE SEVERAL FACES OF SCHMORL'S NODE: PICTORIAL ESSAY

The aim of this review is to present the imaging features of Schmorl's node (SN) occurring in conjunction with several etiologies. The SN is a relatively common finding in diagnostic spinal imaging. This condition is usually asymptomatic and its etiology is not always clear. Any disorder that weakens the subchondral bone of the vertebral body may lead to endplate disruption and consequent intravertebral disc herniation. SN is a common finding among asymptomatic patients, but may possibly be accompanied by symptoms in cases of trauma, hemispherical spondylosclerosis, calcific discitis with intravertebral migration, inflammatory diseases and neoplasms. Even though SN is generally associated with benign diseases, its presence does not exclude the possibility of concomitant malignancy in the vertebral body. Radiologists and spine surgeons must be aware of uncommon conditions that might be associated with SNs, as well as related radiological findings, in order to avoid misdiagnosis.

Coming together is a beginning: the making of an intervertebral disc

The intervertebral disc (IVD) is a complex fibrocartilaginous structure located between the vertebral bodies that allows for movement and acts as a shock absorber in our spine for daily activities. It is composed of three components: the nucleus pulposus (NP), annulus fibrosus, and cartilaginous endplate. The characteristics of these cells are different, as they produce specific extracellular matrix (ECM) for tissue function and the niche in supporting the differentiation status of the cells in the IVD. Furthermore, cell heterogeneities exist in each compartment. The cells and the supporting ECM change as we age, leading to degenerative outcomes that often lead to pathological symptoms such as back pain and sciatica. There are speculations as to the potential of cell therapy or the use of tissue engineering as treatments. However, the nature of the cells present in the IVD that support tissue function is not clear. This review looks at the origin of cells in the making of an IVD, from the earliest stages of embryogenesis in the formation of the notochord, and its role as a signaling center, guiding the formation of spine, and in its journey to become the NP at the center of the IVD. While our current understanding of the molecular signatures of IVD cells is still limited, the field is moving fast and the potential is enormous as we begin to understand the progenitor and differentiated cells present, their molecular signatures, and signals that we could harness in directing the appropriate in vitro and in vivo cellular responses in our quest to regain or maintain a healthy IVD as we age.

The ancestral shape hypothesis: an evolutionary explanation for the occurrence of intervertebral disc herniation in humans

Background

Recent studies suggest there is a relationship between intervertebral disc herniation and vertebral shape. The nature of this relationship is unclear, however. Humans are more commonly afflicted with spinal disease than are non-human primates and one suggested explanation for this is the stress placed on the spine by bipedalism. With this in mind, we carried out a study of human, chimpanzee, and orangutan vertebrae to examine the links between vertebral shape, locomotion, and Schmorl’s nodes, which are bony indicators of vertical intervertebral disc herniation. We tested the hypothesis that vertical disc herniation preferentially affects individuals with vertebrae that are towards the ancestral end of the range of shape variation within Homo sapiens and therefore are less well adapted for bipedalism.

Results

The study employed geometric morphometric techniques. Two-dimensional landmarks were used to capture the shapes of the superior aspect of the body and posterior elements of the last thoracic and first lumbar vertebrae of chimpanzees, orangutans, and humans with and without Schmorl’s nodes. These data were subjected to multivariate statistical analyses.

Canonical Variates Analysis indicated that the last thoracic and first lumbar vertebrae of healthy humans, chimpanzees, and orangutans can be distinguished from each other (p<0.028), but vertebrae of pathological humans and chimpanzees cannot (p>0.4590). The Procrustes distance between pathological humans and chimpanzees was found to be smaller than the one between pathological and healthy humans. This was the case for both vertebrae. Pair-wise MANOVAs of Principal Component scores for both the thoracic and lumbar vertebrae found significant differences between all pairs of taxa (p<0.029), except pathological humans vs chimpanzees (p>0.367). Together, these results suggest that human vertebrae with Schmorl’s nodes are closer in shape to chimpanzee vertebrae than are healthy human vertebrae.

Conclusions

The results support the hypothesis that intervertebral disc herniation preferentially affects individuals with vertebrae that are towards the ancestral end of the range of shape variation within H. sapiens and therefore are less well adapted for bipedalism. This finding not only has clinical implications but also illustrates the benefits of bringing the tools of evolutionary biology to bear on problems in medicine and public health.

Electronic supplementary material

The online version of this article (doi:10.1186/s12862-015-0336-y) contains supplementary material, which is available to authorized users.

Endplate changes following discectomy: natural history and associations between imaging and clinical data

PURPOSE

Some patients will experience post-operative back pain following lumbar discectomy, and the potential sources for that pain are poorly understood. One potential source is the vertebral endplates. The goal of this study was to document the changes that occur in lumbar endplates following discectomies, and to assess associations between endplate changes and clinical outcomes.

METHODS

Changes in lumbar endplates and discs were assessed from X-rays, CT and MRI exams by comparing preoperative imaging with imaging obtained at yearly intervals up to 5 years. 260 endplates in 137 patients with single-level herniation and discectomy were analyzed. The geometry of osseous defects in the endplates was measured from the CT exams, and marrow and disc changes adjacent to endplates were assessed from the MRI exams. Clinical outcome assessments were collected at each time point. Descriptive statistics were used to describe endplate defect sizes, and logistic regression and analysis of variance were used to identify potential associations between endplate and vertebral body changes and clinical outcomes.

RESULTS

Approximately 14 % of the endplates had osseous defects prior to surgery. After surgery, 24 % of inferior and 43 % of superior endplates had defects. Change occurred within the first year and remained relatively constant over the next few years. Disc signal intensity worsened and disc height decreased following surgery. New Modic changes were also observed. None of these changes were associated with having achieved a clinically significant improvement in outcome scores. The follow-up rates were low at the later time points and significant associations cannot be ruled out.

CONCLUSIONS

This study documents lesion characteristics in detail and supports that osseous defects in the endplates at the level of a lumbar discectomy may be a relatively common finding following surgery, along with disc height loss, loss of disc signal intensity, and Modic changes. The clinical significance of these imaging findings could not be conclusively determined in this study.

The role of the vertebral end plate in low back pain

End plates serve as the interface between rigid vertebral bodies and pliant intervertebral disks. Because the lumbar spine carries significant forces and disks don't have a dedicated blood supply, end plates must balance conflicting requirements of being strong to prevent vertebral fracture and porous to facilitate transport between disk cells and vertebral capillaries. Consequently, end plates are particularly susceptible to damage, which can increase communication between proinflammatory disk constituents and vascularized vertebral bone marrow. Damaged end plate regions can be sites of reactive bone marrow lesions that include proliferating nerves, which are susceptible to chemical sensitization and mechanical stimulation. Although several lines of evidence indicate that innervated end plate damage can be a source of chronic low back pain, its role in patients is likely underappreciated because innervated damage is poorly visualized with diagnostic imaging. This literature review summarizes end plate biophysical function and aspects of pathologic degeneration that can lead to vertebrogenic pain. Areas of future research are identified in the context of unmet clinical needs for patients with chronic low back pain.

Ultrashort time-to-echo MRI of the cartilaginous endplate: technique and association with intervertebral disc degeneration

INTRODUCTION

The purpose of this study was to report the feasibility of the ultrashort time-to-echo (UTE) MRI technique to assess cartilaginous endplate (CEP) defects in humans in vivo and to assess their relationship with intervertebral disc (IVD) degeneration.

METHODS

Nine volunteer subjects (mean age = 43.9 years; range = 22-61 years) were recruited, representing 54 IVDs and 108 CEPs. The subjects underwent T2-weighted and UTE MRI to assess for the presence and severity of IVD degeneration, and for the presence of CEP defects, respectively, from T12 to S1. IVD degeneration was graded according to the Schneiderman et al. classification on T2-weighted MRI. CEP defects were defined on UTE MRI as discontinuity of high signal over four consecutive images and were independently assessed by two observers.

RESULTS

Thirty-seven out of 108 (34.3%) CEPs had defects, which mainly occurred at T12/L1, L1/L2 and L4/L5 (P = 0.008). Multivariate logistic regression revealed that lower body mass index (P = 0.009) and younger (P = 0.034) individuals had a decreased likelihood of having CEP defects. A statistically significant association was found to exist between the presence of CEP defects and IVD degeneration (P = 0.036). A higher prevalence of degenerated IVDs with CEP defects was found at L4/5 and L5/S1, while degenerated IVDs with no CEP defects were found throughout the whole lumbar region. Mean IVD degeneration scores of the L4/5 and L5/S1 levels with CEP defects were higher in comparison with those with no CEP defects.

CONCLUSIONS

Our study demonstrates the feasibility of using UTE MRI in humans in vivo to assess the integrity of the CEP. A statistically significant association was found to exist between the presence of CEP defects and IVD degeneration. In the lower lumbar region, more severe degeneration was found to occur in the IVDs with CEP defects than in those without defects.

Image-guided percutaneous spinal biopsy

The purpose of this article is to discuss the role of imaging in the diagnosis and management of spinal disorders, with particular attention to that of image-guided percutaneous spinal biopsy. We discuss the indications, general principles, pre-procedural steps and specific techniques used for image-guided percutaneous spinal biopsy in the context of our experience and the wider literature. Percutaneous spinal biopsy is a safe and diagnostically accurate procedure when appropriately selected for further evaluation in the multidisciplinary team setting.

Vertebral morphology influences the development of Schmorl's nodes in the lower thoracic vertebrae

Schmorl's nodes are the result of herniations of the nucleus pulposus into the adjacent vertebral body and are commonly identified in both clinical and archaeological contexts. The current study aims to identify aspects of vertebral shape that correlate with Schmorl's nodes. Two-dimensional statistical shape analysis was performed on digital images of the lower thoracic spine (T10-T12) of adult skeletons from the late medieval skeletal assemblages from Fishergate House, York, St. Mary Graces and East Smithfield Black Death cemeteries, London, and postmedieval Chelsea Old Church, London. Schmorl's nodes were scored on the basis of their location, depth, and size. Results indicate that there is a correlation between the shape of the posterior margin of the vertebral body and pedicles and the presence of Schmorl's nodes in the lower thoracic spine. The size of the vertebral body in males was also found to correlate with the lesions. Vertebral shape differences associated with the macroscopic characteristics of Schmorl's nodes, indicating severity of the lesion, were also analyzed. The shape of the pedicles and the posterior margin of the vertebral body, along with a larger vertebral body size in males, have a strong association with both the presence and severity of Schmorl's nodes. This suggests that shape and/or size of these vertebral components are predisposing to, or resulting in, vertically directed disc herniation.

Acute Schmorl's Node during Strenuous Monofin Swimming: A Case Report and Review of the Literature

Study Design This case report describes an acute Schmorl's node (SN) in an elite monofin athlete during exercise. The patient presented with severe back pain and leg numbness and was managed successfully with conservative treatment. Objective The aim of our communication was to describe a rare presentation of a common pathological condition during an intense sport. Background Swimming is not generally considered to be a sport activity that leads to spinal injuries. SNs are usually asymptomatic lesions, incidentally found on imaging studies. There is no correlation between swimming and symptomatic SN formation. Case Report A 16-year-old monofin elite athlete suffered from an acute nonradiating back pain during extreme exercise. His back pain was associated with a fracture of the superior L5 end plate and an acute SN at the L5 vertebral body with perilesional bone marrow edema. The pain resolved with nonsteroidal anti-inflammatory drugs and bed rest. The athlete had an excellent outcome and returned to his training activities 6 months after his incident. Conclusion SN should be considered in the differential diagnosis of severe back pain, especially in sport-related injuries. SNs present with characteristic imaging findings. Due to the benign nature of these lesions, surveillance-only management may be the best course of action.

Surgical management of a Schmorl's node in an Airedale Terrier and review of the literature

OBJECTIVE

To describe a clinical case of Schmorl's node affecting the lumbosacral disc in an Airedale Terrier including surgical management, short-term outcome, and review of the literature.

METHODS

A five-year-old male Airedale Terrier with signs of chronic spinal pain and right hindlimb muscle fasciculation was diagnosed with a Schmorl's node with computed tomography. Repeat imaging performed two months later identified enlargement of the defect in the seventh lumbar vertebra (L7) and herniation of the lumbosacral disc into the spinal canal.

RESULTS

Dorsal laminectomy and discectomy were performed and the defect was treated with curettage and stabilization of the L7 and first sacral vertebra disc space with pins and bone cement. Immediately postoperatively, the patient had proprioception deficits in the hindlimbs and decreased right patellar reflex. Over the next four months the dog's neurological condition improved and no neurological or gait deficits were present six months postoperatively.

CLINICAL SIGNIFICANCE

Schmorl's node may be a cause of signs of chronic pain in dogs. Successful management may be achieved surgically, although in the case reported here, recovery was prolonged. To the authors' knowledge, this is the first report of progressive enlargement of a Schmorl's node in a dog.

Temporal interactions of degenerative changes in individual components of the lumbar intervertebral discs: a sequential magnetic resonance imaging study in patients less than 40 years of age

STUDY DESIGN

A retrospective longitudinal observational study using baseline and follow-up magnetic resonance imaging (MRI).

OBJECTIVE

To study the natural history of disc degeneration, focusing on the significance of changes affecting the individual components of the intervertebral disc.

SUMMARY OF BACKGROUND DATA

The natural history of the degenerative disc disease is poorly understood. Focusing on the relative prevalence, temporal evolution, and interactions of pathology in the anulus fibrosus, nucleus pulposus, and the end plates can help in better understanding of this process.

METHODS

MRIs of the lumbar spine in 63 patients, obtained at a mean interval of 30 months, were evaluated independently by two neuroradiologists to assess the temporal evolution of degeneration changes in 378 discs between T12 through S1 segments. In addition, a direct side-by-side comparison of two studies was also performed. Statistical analysis was performed to assess the association between the degeneration of individual disc components and to find the predictors of future degeneration.

RESULTS

Radial anular tears and end plate defects were associated with worse nuclear degeneration at the time of the initial study. Both end plate defects and nuclear degeneration were rare in the absence of radial tears. Multiple nominal logistic regression analysis showed that radial tears and herniation at the time of the initial study, along with the duration between the two imaging studies were the significant predictors of worsening nuclear degeneration. Age, sex, and the segmental disc level did not show any significant association with temporal progression of nuclear degeneration.

CONCLUSION

Radial tears and herniation are significant predictors of progressive nuclear degeneration, which was not seen in the absence of radial tears. End plate defects also frequently occur before nuclear degeneration but rarely in the absence of anular tears.

ISSLS prize winner: prevalence, determinants, and association of Schmorl nodes of the lumbar spine with disc degeneration: a population-based study of 2449 individuals

STUDY DESIGN

A cross-sectional population-based magnetic resonance imaging study of Schmorl nodes (SN) in the lumbar spine.

OBJECTIVE

To determine the prevalence and potential determinants of SN, and their association with intervertebral disc degeneration.

SUMMARY OF BACKGROUND DATA

SN represent intravertebral disc herniation and are commonly seen in the spine. Their reported prevalence and determinants vary, and their association with disc degeneration remains uncertain. Data based on this large scale population-based study of intervertebral disc degeneration would provide important information for understanding SN and their pathomechanism.

METHODS

Sagittal T2-weighted magnetic resonance imagings of the lumbar spine were analyzed in 2449 volunteers. Two independent observers assessed the images for the presence of SN, and scored for additional radiologic features (e.g., severity of degeneration, presence of disc bulge/extrusion). Subject demographics were assessed by standardized questionnaire.

RESULTS

SN were found in 16.4% (n = 401; 219 males, 182 females; mean age = 42.3) of our study population (981 males, 1468 females; mean age = 40.4), being most common at L1/2 and L2/3 (54.1%). Multivariate logistic regression revealed that males, taller and heavier individuals had an increased likelihood of SN (P < 0.005), but association between SN and age were not discerned. Overall presence of SN was associated with disc degeneration (P < 0.001), and linearly correlated (R = 0.97) with increase in severity of degeneration. SN were particularly associated with severe disc degeneration at L1/2 and L2/3 with 22- to 15-fold increased odds, respectively (P < 0.0001), but less than 5-fold increased odds (P < 0.001) were noted in the lower lumbar spine.

CONCLUSION

In a population-based cohort, 16.4% of Southern Chinese subjects had SN at 1 or more lumbar levels. Males, taller and heavier individuals had increased likelihood of SN. Interestingly, SN were highly associated with severity of disc degeneration.

Lumbar disc herniation in young children

AIM

This article explores lumbar disc herniation in young children through focusing on matters relevant to patient presentation, physical examination, differential diagnosis, imaging and treatment.

METHODS

Major databases were searched for studies that addressed lumbar disc herniation in young children.

RESULTS

Diagnosis of lumbar disc herniation in young children is usually delayed because of the rarity and lack of experience with this entity and the difficulty in extracting a reliable medical history. Nevertheless, lumbar disc herniation should be considered in the differential diagnosis of any young child presenting with a chief complaint of back pain and/or radiculopathy, especially in the setting of recent trauma. This should be coupled with a directed physical examination to elicit signs and narrow the differential diagnosis. Imaging studies, mainly magnetic resonance imaging, will help establish a diagnosis; yet radiographs are still required to exclude other spinal lesions. The initial management of lumbar disc herniation in children is the same as that in adults and consists of conservative treatment unless lumbar disc herniation affects the patient's motor and neurological functions in which case, early surgical treatment must be undertaken. Although the latter remains more difficult, current experience suggests a favourable outcome.

CONCLUSION

Awareness of lumbar disc herniation will help the paediatrician extract a relevant medical history, perform a directed physical examination, and order appropriate imaging studies. This will aid in initiating early intervention, be it conservative or operative, and achieving a favourable outcome.

Diagnosis and surgical treatment of back pain originating from endplate

Twenty-one patients with back pain originating from the endplate injuries were selected to explore the methods of diagnosis and surgical treatment. All patients underwent examinations using radiography, CT, and MR imaging. Pain level of disc was determined through discography in each patient. The principal outcome judgments were pain and disability, and the efficacy of surgical treatment was assessed through the use of the visual analog scale (VAS) for pain and the Oswestry disability index (ODI) for functional recovery. All 21 patients with a diagnosis of back pain originating from endplate injuries according to discography were treated with anterior or posterior fusion surgery. The mean follow-up period was 3 years and 5 months (range, 2-6 years). Of the 21 patients, 20 (20/21) reported a disappearance or marked alleviation of low back pain and experienced a definite improvement in physical function. Statistically significant and clinically meaningful improvements in the VAS and ODI scores were obtained after treatment in the patients with chronic low back pain originating from the endplate injuries (P = 0.0001). The study suggests that discography and fusion surgery may be very effective methods for the diagnosis and treatment, respectively, of chronic back pain originating from the endplate injuries.

Demographical aspects of Schmorl nodes: a skeletal study

STUDY DESIGN

A descriptive study of the association between Schmorl nodes (SNs) and gender, ethnic origin, and age in a normal skeletal population.

OBJECTIVES

To gain reliable data on behavioral patterns of SNs in various human groups shedding light on its etiology.

SUMMARY OF BACKGROUND DATA

Opinions regarding SNs prevalence in human populations vary greatly (from 5% to 70%). This caveat greatly reduced our ability to recognize the etiology of the phenomenon and understand its clinical significance.

METHODS

Two hundred forty human skeleton vertebrae (T4-L5) from a normal adult population (divided by gender, ethnicity, and age) were examined for SNs. SNs were defined as depressions with sclerotic margins appearing on the vertebral body surface.

RESULTS

One hundred sixteen individuals (48.3%) of the 240 studied manifested SNs along their thoracolumbar spine. SNs are age independent and gender and ethnicity dependent, are significantly more common in males (54.2%) versus females (43%) and more common in European-Americans (60.3%) versus African-Americans (36.7%).

CONCLUSION

SNs are a common phenomenon in the normal adult populations with almost half of the individuals in our sample manifesting at least 1 vertebra with SN. Its demographic characteristics suggest that the phenomenon is not of occupational origin, promoting the notion of genetic background.

Fracture-associated and idiopathic subchondral vertebral lesions: a magnetic resonance study in autopsy specimens with histologic correlation

OBJECTIVE

The aim of this study was to describe and compare the magnetic resonance (MR) and histological appearance of subchondral vertebral lesions that are idiopathic or that develop with vertebral fractures.

MATERIALS AND METHODS

T1- and T2-weighted spin-echo images and radiographs were obtained in 81 cadaveric spine specimens. All subchondral vertebral lesions that were considered to be idiopathic or associated with vertebral end plate fractures were selected. Lesions due to growth disturbance were excluded. Radiographs and MR images were analyzed in consensus by two radiologists, and sampled specimens were analyzed by a pathologist.

RESULTS

Eleven idiopathic and ten fracture-associated vertebral lesions were available. On T1-weighted images, all lesion signal intensity was low and homogeneous. On T2-weighted images, all idiopathic lesions showed a heterogeneous signal with a central low or intermediate signal component and a peripheral high or intermediate component. All but one fracture-related lesions showed a homogeneous intermediate to high signal intensity. Histological analysis of idiopathic lesions showed a central acellular fibrous connective tissue in all cases surrounded by loose connective tissue in nine cases. Herniated disk material and cartilage metaplasia were found in one lesion only. Fracture-associated lesions contained herniated disk material, necrotic tissue, and loose connective tissue with a peripheral component of loose fibrovascular connective tissue in four cases only.

CONCLUSION

MR and histological appearance of idiopathic and fracture-associated subchondral vertebral lesions differ, suggesting that they might have a different origin.

[Dorso-lumbar pain caused by a schmorl hernia]

Thoracic and lumbar spine conditions cause primarily mechanical back pain, although the clinician has to ensure that the symptoms are not from another etiology. We present the case of a patient with thoracic and lumbar non mechanical pain, resistant to treatment, diagnosed with a herniation of the intervertebral disc through the vertebral end-plate. We also performed a literature review.

Pediatric disk disease

Intervertebral disk herniation in pediatric patients is a rare but potentially disabling entity that is frequently difficult to diagnose. This article reviews the fundamentals of pediatric intervertebral disk herniation with the intention of presenting a rational and simple strategy for the evaluation and treatment of disk herniation in children, with specific emphasis on how it differs from adult disk disease in presentation, pathologic findings, and treatment options.