Prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and early-phase DISH across the lifespan of an American population

OBJECTIVES

DISH is a common musculoskeletal disorder; however, the imaging features and disease continuum from early to advanced stages is poorly understood. The purpose of this study was to evaluate the prevalence of DISH and early-phase DISH in an American population and to assess the extent and pattern of ectopic mineralization across the thoracic spine.

METHODS

Data were retrieved in collaboration with the Rochester Epidemiology Project. We conducted a retrospective image evaluation of a sample of individuals over 19 years of age with CT of the thoracic spine from a Northern US catchment area. Stratified random sampling by age and sex was used to populate the study. We examined the prevalence and extent of ectopic mineralization along the thoracic spine using previously established criteria.

RESULTS

A total of 1536 unique images (766 female and 770 male individuals) including 16 710 motion segments were evaluated for imaging features of the continuum of DISH. Collectively, 40.5% of all motion segments evaluated displayed evidence of ectopic mineralization in the thoracic spine. The prevalence of early-phase DISH was 13.2% (10.4% of female and 15.8% of male individuals). The prevalence of established DISH was 14.2% (7.4% of female and 20.9% of male individuals). Remarkable heterogeneity was detected in individuals within each disease classification, based on the extent of the thoracic spine affected and degree of mineralization.

CONCLUSIONS

The continuum of imaging features associated with DISH is detected in more than one in four adults and both sexes in an American population.

Depression as a prognostic factor for lumbar spinal stenosis outcomes: a systematic review

PURPOSE

Lumbar spinal stenosis (LSS) is associated with increased levels of psychological distress, including depression; however, the prognostic value of depression remains unclear. The purpose of this systematic review was to synthesize the evidence on the prognostic value of depression for a range of outcomes in patients with LSS.

METHODS

Inclusion criteria were prospective cohort studies that investigated depression in patients diagnosed with LSS. Searches were conducted in 7 databases. Critical appraisal, data extraction, and judgement of cumulative evidence were conducted independently by two reviewers. A meta-analysis was not conducted due to a lack of unique cohorts for each outcome, varying follow-up times, and differences in measurements for both prognostic factors and outcomes.

RESULTS

Twenty-three articles were included. There was evidence for an association between preoperative depression and postoperative disability and symptom severity outcomes for patients with LSS. Odds ratios ranged from 1.15 to 2.94 for postoperative disability and 1.16-1.20 for symptom severity at various follow-up times. Using GRADE, evidence supporting depression as a prognostic factor for these LSS outcomes was deemed to be of moderate quality. Similarly strong evidence suggested depressive symptoms are of no prognostic value for postoperative walking capacity.

CONCLUSION

Depression appears to have small to moderate prognostic value for LSS outcomes, with the strongest evidence for postoperative disability and symptom severity. The prognostic value of depression for LSS outcomes should be further explored using standardized measures in additional cohorts, including patients managing their condition conservatively, who have been neglected in related research.

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 pathoanatomical mechanisms underlying back pain. However, clinical imaging methods used to document EPSD have not been validated, leaving uncertainty about what the observations represent.

METHODS

Using an evaluation manual, 418 endplates on CT sagittal slices obtained from 19 embalmed cadavers (9 men and 10 women, aged 62-91 y) 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 (Kappa=0.96).

RESULTS

Inter-rater reliability was good for presence (Kappa=0.60-0.69) and fair for specific phenotypes (Kappa=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 specificity of 79.1% using Feng's method, and 79.5% and 57.5% using Brayda-Bruno's. 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.

Lumbar disc herniation in juveniles: A case-control study of MRI characteristics and etiological insights

Lumbar disc herniation (LDH) is rare in juveniles. LDH occurring at age 20 years or younger is referred to as juvenile disc herniation (JDH). While adult LDH is regarded as an advanced stage of disc degeneration, it remains unclear why intervertebral discs rupture in youth. This study aimed to characterize magnetic resonance imaging (MRI) findings of JDH and investigate possible etiological factors. From 2013 to 2020, JDH patients and controls were identified and interviewed to assess demographics, general lifestyles, and family histories. MRIs were evaluated for disc degeneration, epiphyseal ring separation, Modic changes and endplate lesions. The relationships between JDH and suspected risk factors were examined. A total of 297 JDH patients (199 boys and 98 girls, age 17.3 ± 2.1 years) and 185 controls (age 17.1 ± 2.4 years) were studied. Age, body mass index, exposures to daily physical labor, regular exercise, and daily sitting time were similar between JDH cases and controls. A family medical history of serious back pain was more common in JDH patients than in controls (59.4% vs. 26.5%, p < 0.001), as well as family history of clinically established LDH (45.0% vs. 12.4%, p < 0.001). Epiphyseal ring separation was identified in 102 (29.2%) herniated discs in 91 (36.4%) JDH patients, while occurring in only 5 (1.4%) control participants (p < 0.001). Overall, severe disc degeneration was not a prominent finding in JDH patients. In conclusion, epiphyseal ring separation was a common magnetic resonance feature in JDH. Findings suggest a genetically mediated developmental model of JDH, rather than a model of premature disc degeneration.

Bone-GAN: Generation of virtual bone microstructure of high resolution peripheral quantitative computed tomography

BACKGROUND

Data-driven development of medical biomarkers of bone requires a large amount of image data but physical measurements are generally too restricted in size and quality to perform a robust training.

PURPOSE

This study aims to provide a reliable in silico method for the generation of realistic bone microstructure with defined microarchitectural properties. Synthetic bone samples may improve training of neural networks and serve for the development of new diagnostic parameters of bone architecture and mineralization.

METHODS

One hundred-fifty cadaveric lumbar vertebrae from 48 different male human spines were scanned with a high resolution peripheral quantitative CT. After prepocessing the scans, we extracted 10,795 purely spongeous bone patches, each with a side length of 32 voxels (5 mm) and isotropic voxel size of 164 μm. We trained a volumetric generative adversarial network (GAN) in a progressive manner to create synthetic microstructural bone samples. We then added a style transfer technique to allow the generation of synthetic samples with defined microstructure and gestalt by simultaneously optimizing two entangled loss functions. Reliability testing was performed by comparing real and synthetic bone samples on 10 well-understood microstructural parameters.

RESULTS

The method was able to create synthetic bone samples with visual and quantitative properties that effectively matched with the real samples. The GAN contained a well-formed latent space allowing to smoothly morph bone samples by their microstructural parameters, visual appearance or both. Optimum performance has been obtained for bone samples with voxel size 32 × 32 × 32, but also samples of size 64 × 64 × 64 could be synthesized.

CONCLUSIONS

Our two-step-approach combines a parameter-agnostic GAN with a parameter-specific style transfer technique. It allows to generate an unlimited anonymous database of microstructural bone samples with sufficient realism to be used for the development of new data-driven methods of bone-biomarkers. Particularly, the style transfer technique can generate datasets of bone samples with specific conditions to simulate certain bone pathologies.

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.

Reliability and validity of subjective radiologist reporting of temporal changes in lumbar spine MRI findings

BACKGROUND

The importance of lumbar findings on magnetic resonance imaging (MRI) remains controversial. Changes in lumbar MRI findings over time may provide important insights into the causes of low back pain. However, the reliability and validity of temporal changes are unknown.

OBJECTIVE

To (1) investigate the interrater reliability of subjective radiologist reporting of temporal changes in lumbar spine MRI findings and (2) determine how commonly temporal changes are reported when two scans are conducted 30 minutes apart (considered false positives).

DESIGN

Cross-sectional study.

SETTING

Radiology clinic.

PARTICIPANTS

Forty volunteers (mean age 40; 53% female) with current (n = 31) or previous (n = 9) low back pain underwent initial lumbar MRI on a single 3T scanner. Participants then lay on a bed for 30 minutes before undergoing an identical MRI. In addition, we purposely selected five participants from a previous study with repeat lumbar MRI scans where temporal changes were reported in at least one MRI finding (1-12 weeks after initial scan) and another five participants where no temporal change was reported. The 10 participants were included in analyses for aim 1 only.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Two blinded radiologists reported on temporal changes between the baseline and repeat scan for 12 different MRI findings (eg, disk herniation, annular fissure) at five levels.

RESULTS

The interrater reliability of subjective reporting of temporal changes was poor for all MRI findings based on Kappa values (≤ 0.24), but agreement was relatively high (≥ 90.8%). This is explained by the low prevalence of temporal changes as demonstrated by high values for Prevalence and Bias Adjusted Kappa (≥ 0.82). "False positive" temporal changes were reported by at least one radiologist for most MRI findings, but the rate was generally low.

CONCLUSIONS

Caution is required when interpreting temporal changes in lumbar MRI findings owing to low reliability and some false positive reporting.

The association between whole body vibration exposure and spine degeneration on imaging: A systematic review

BACKGROUND

Low frequency vibrations from motorized vehicles and heavy equipment have been associated with musculoskeletal disorders. Spine degeneration on diagnostic imaging provides direct and objective measures of the possible effects of such exposures on the spine.

OBJECTIVE

The objective of this systematic review was to evaluate the association of exposure to whole-body vibration (WBV) with spine degeneration on imaging.

METHODS

We conducted electronic searches in MEDLINE, CINAHL, EMBASE, and Web of Science to July 2021. Two reviewers independently screened search results, assessed quality, and extracted data. Studies evaluating the exposure to WBV and lumbar spine degeneration on imaging were included.

RESULTS

Fifteen studies (16 manuscripts) were included. Seven studies including a meta-demonstrated moderate quality evidence of no association between WBV and disc degeneration. There was also moderate quality evidence of no association between WBV and disc height narrowing and osteophytes. Overall, there was low level evidence of no association between WBV and other degenerations findings.

CONCLUSIONS

There was moderate to low quality evidence suggesting no association between WBV exposures with spine degeneration on imaging. The results of this study currently do not support assertion that motorized vehicle and WBV exposure accelerates degeneration and causes structural damage to the spine.

Consensus on a standardised treatment pathway algorithm for lumbar spinal stenosis: an international Delphi study

Background

Lumbar spinal stenosis (LSS) is a common degenerative spinal condition in older adults associated with disability, diminished quality of life, and substantial healthcare costs. Individual symptoms and needs vary. With sparse and sometimes inconsistent evidence to guide clinical decision-making, variable clinical care may lead to unsatisfactory patient outcomes and inefficient use of healthcare resources.

Methods

A three-phase modified Delphi study comprising four consensus rounds was conducted on behalf of the International Taskforce for the Diagnosis and Management of LSS to develop a treatment algorithm based on multi-professional international expert consensus. Participants with expertise in the assessment and management of people with LSS were invited using an international distribution process used for two previous Delphi studies led by the Taskforce. Separate treatment pathways for patients with different symptom types and severity were developed and incorporated into a proposed treatment algorithm through consensus rounds 1 to 3. Agreement with the proposed algorithm was evaluated in the final consensus round.

Results

The final algorithm combines stratified and stepped approaches. When indicated, immediate investigation and surgery is advocated. Otherwise, a stepped approach is suggested when self-directed care is unsatisfactory. This starts with tailored rehabilitation, then more complex multidisciplinary care, investigations and surgery options if needed. Treatment options in each step depend on clinical phenotype and symptom severity. Treatment response guides pathway entrance and exit points. Of 397 study participants, 86% rated their agreement ≥ 4 for the proposed algorithm on a 0–6 scale, of which 22% completely agreed. Only 7% disagreed. Over 70% of participants felt that the algorithm would be useful for clinicians in public healthcare (both primary care and specialist settings) and in private healthcare settings, and that a simplified version would help patients in shared decision-making.

Conclusions

International and multi-professional agreement was achieved for a proposed LSS treatment algorithm developed through expert consensus. The algorithm advocates different pathway options depending on clinical indications. It is not intended as a treatment protocol and will require evaluation against current care for clinical and cost-effectiveness. It may, however, serve as a clinical guide until evidence is sufficient to inform a fully stratified care model.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05485-5.

Traumatic vertebra and endplate fractures promote adjacent disc degeneration: evidence from a clinical MR follow-up study

OBJECTIVES

The integrity of endplate is important for maintaining the health of adjacent disc and trabeculae. Yet, pathological impacts of traumatic vertebra and endplate fractures were less studied using clinical approaches. This study aims to investigate their effects on the development of adjacent disc degeneration, segmental kyphosis, Modic changes (MCs), and high-intensity zones (HIZs).

MATERIALS AND METHODS

Magnetic resonance (MR) images of patients with acute traumatic vertebral compression fractures (T11-L5) were studied. On MR images, endplate fractures were evaluated as present or absent. Disc signal, height, bulging area, sagittal Cobb angle, MCs, and HIZs were measured on baseline and follow-up MR images to study the changes of the disc in relation to vertebra fractures and endplate fractures.

RESULTS

Ninety-seven patients were followed up for 15.4 ± 14.0 months. There were 123 fractured vertebrae, including 79 (64.2%) with endplate fractures and 44 (35.8%) without. Both the adjacent and control discs decreased in signal and height over time (p < 0.001), and the disc adjacent to vertebral fractures had greater signal and height loss than the control disc (p < 0.05). In the presence of endplate fractures, the adjacent discs had greater signal decrease in follow-up (p < 0.05), as compared to those without endplate fractures. Sagittal Cobb angle significantly increased in segments with endplate fractures (p < 0.05). Vertebra fractures were associated with new occurrence of MCs in the fractured vertebra (p < 0.001) but not HIZs in the adjacent disc.

CONCLUSIONS

Traumatic vertebral fractures were associated with accelerated adjacent disc degeneration, which appears to be further promoted by concomitant endplate fractures. Endplate fractures were associated with progression of segmental kyphosis.

Paraspinal muscle imaging measurements for common spinal disorders: review and consensus-based recommendations from the ISSLS degenerative spinal phenotypes group

PURPOSE

Paraspinal muscle imaging is of growing interest related to improved phenotyping, prognosis, and treatment of common spinal disorders. We reviewed issues related to paraspinal muscle imaging measurement that contribute to inconsistent findings between studies and impede understanding.

METHODS

Three key contributors to inconsistencies among studies of paraspinal muscle imaging measurements were reviewed: failure to consider possible mechanisms underlying changes in paraspinal muscles, lack of control of confounding factors, and variations in spinal muscle imaging modalities and measurement protocols. Recommendations are provided to address these issues to improve the quality and coherence of future research.

RESULTS

Possible pathophysiological responses of paraspinal muscle to various common spinal disorders in acute or chronic phases are often overlooked, yet have important implications for the timing, distribution, and nature of changes in paraspinal muscle. These considerations, as well as adjustment for possible confounding factors, such as sex, age, and physical activity must be considered when planning and interpreting paraspinal muscle measurements in studies of spinal conditions. Adoption of standardised imaging measurement protocols for paraspinal muscle morphology and composition, considering the strengths and limitations of various imaging modalities, is critically important to interpretation and synthesis of research.

CONCLUSION

Study designs that consider physiological and pathophysiological responses of muscle, adjust for possible confounding factors, and use common, standardised measures are needed to advance knowledge of the determinants of variations or changes in paraspinal muscle and their influence on spinal health.

Statistical morphological analysis reveals characteristic paraspinal muscle asymmetry in unilateral lumbar disc herniation

Growing evidence suggests an association of lumbar paraspinal muscle morphology with low back pain (LBP) and lumbar pathologies. Unilateral spinal disorders provide unique models to study this association, with implications for diagnosis, prognosis, and management. Statistical shape analysis is a technique that can identify signature shape variations related to phenotypes but has never been employed in studying paraspinal muscle morphology. We present the first investigation using this technique to reveal disease-related paraspinal muscle asymmetry, using MRIs of patients with a single posterolateral disc herniation at the L5-S1 spinal level and unilateral leg pain. Statistical shape analysis was conducted to reveal disease- and phenotype-related morphological variations in the multifidus and erector spinae muscles at the level of herniation and the one below. With the analysis, shape variations associated with disc herniation were identified in the multifidus on the painful side at the level below the pathology while no pathology-related asymmetry in cross-sectional area (CSA) and fatty infiltration was found in either muscle. The results demonstrate higher sensitivity and spatial specificity for the technique than typical CSA and fatty infiltration measures. Statistical shape analysis holds promise in studying paraspinal muscle morphology to improve our understanding of LBP and various lumbar pathologies.

Innervation of the Human Intervertebral Disc: A Scoping Review

OBJECTIVE

Back pain is an elusive symptom complicated by a variety of possible causes, precipitating and maintaining factors, and consequences. Notably, the underlying pathology remains unknown in a significant number of cases. Changes to the intervertebral disc (IVD) have been associated with back pain, leading many to postulate that the IVD may be a direct source of pain, typically referred to as discogenic back pain. Yet despite decades of research into the neuroanatomy of the IVD, there is a lack of consensus in the literature as to the distribution and function of neural elements within the tissue. The current scoping review provides a comprehensive systematic overview of studies that document the topography, morphology, and immunoreactivity of neural elements within the IVD in humans.

METHOD

Articles were retrieved from six separate databases in a three-step systematic search and were independently evaluated by two reviewers.

RESULTS

Three categories of neural elements were described within the IVD: perivascular nerves, sensory nerves independent of blood vessels, and mechanoreceptors. Nerves were consistently localized within the outer layers of the annulus fibrosus. Neural ingrowth into the inner annulus fibrosus and nucleus pulposus was found to occur only in degenerative and disease states.

CONCLUSION

While the pattern of innervation within the IVD is clear, the specific topographic arrangement and function of neural elements in the context of back pain remains unclear.

Could compression and traction loading improve the ability of magnetic resonance imaging to identify findings related to low back pain?

BACKGROUND

Diagnostic imaging is routinely used to depict structural abnormalities in people with low back pain (LBP), but most findings are prevalent in people with and without LBP. It has been suggested that LBP is related to changes induced in the spine due to loading. Therefore, new imaging measurements are needed to improve our ability to identify structures relating to LBP.

OBJECTIVES

To investigate the response of the lumbar spine to compression and traction in participants with and without chronic LBP using MRI T₂-mapping.

METHOD

Fifteen participants with chronic LBP were matched for age, weight, and gender with 15 healthy volunteers. All participants underwent MRI under three loading conditions maintained for 20 min each: resting supine, followed by compression and traction, both using 50% body weight. Participants were imaged in the last 5 min of each loading condition. Disc morphometric and fluid-based measurements from T₂-maps were obtained.

RESULTS

Traditional MRI measurements (i.e. disc height, width and mean signal intensity) were not able to capture any differences in the changes measured in response to loading between individuals with and without pain. The location of the T₂ weighted centroid (WC) was able to capture the difference between groups in response to compression in the horizontal (p < 0.01) and vertical direction (p < 0.01), and in response to traction in the vertical direction (p < 0.01). While the location of T₂WC moved anteriorly (Effect Size (ES): 0.44) and inferiorly with compression in those with pain (ES: 0.34), it moved posteriorly (ES: -0.14) and superiorly (ES: -0.05) in the group without pain. In response to traction, the vertical location of T₂WC moved superiorly in both groups but the change was larger in those with pain (ES _Pain = -0.52; ES _{No Pain}: -0.13).

CONCLUSION

The novel measurements of the location of the T₂WC in the intervertebral discs were the only measurements capturing differences in response to loading between those with and without low back pain.

Vascularization of the human intervertebral disc: A scoping review

Intervertebral discs (IVDs) are often referred to as the largest avascular structures of the human body, yet a collective resource characterizing the vascularization of the IVD does not exist. To address this gap, the objective of this study was to conduct a comprehensive search of the literature to review and summarize current knowledge of the prevalence and localization of blood supply in human IVDs, with a scoping review. A comprehensive search of peer-reviewed publications on the topic of IVD vascularization in humans was conducted across six electronic databases: PubMed, EMBASE, MEDLINE, Scopus, Web of Science, and BIOSIS Previews. Studies of humans were included regardless of age, sex, ethnicity, and health status, with the exception of IVD herniation. Two independent reviewers screened titles and abstracts and full-texts according to eligibility criteria. The review was conducted and reported according to Preferred Reporting Items for Systematic Reviews Extension for Scoping Reviews guidelines. Our search yielded 3122 articles, with 22 articles meeting the inclusion criteria. The study samples ranged in age from fetal to >90 years and included both sexes, various health statuses, and used different methodologies (eg, histology, medical imaging, and gross dissection) to assess vasculature. Overall, consistent observations were that (a) the nucleus pulposus of the IVD is avascular throughout life, (b) both the cartilage endplates and annulus fibrosus receive considerable blood supply early in life that diminishes over the lifespan, and (c) vascular ingrowth into the cartilage endplates and inner layers of the annulus fibrosus is commonly associated with damaged or disrupted tissue, irrespective of age. Histology and immunohistochemistry are often used to report vascularization of the IVD. The body of the current literature suggests that the IVD should not be generalized as an avascular tissue. Instead, vascularization of the IVD differs based on the constituent tissues, their age, and state of degeneration or damage.

Functional Recovery after Surgery for Lumbar Spinal Stenosis in Patients with Hypertension

Hypertension is a prevalent condition that is associated with lower health status in patients with lumbar spinal stenosis. The study determined whether hypertension is a prognostic factor associated with functional recovery after spine surgery for lumbar spinal stenosis. This was a secondary analysis of the Alberta Lumbar Spinal Stenosis Study in which patients were identified as participants at the time of lumbosacral magnetic resonance imaging or computed tomography in Calgary, Alberta, Canada. Multivariable linear regression analyses were performed to examine hypertension as a prognostic factor of functional recovery after surgery (Oswestry Disability Index, the Swiss Spinal Stenosis (SSS)-Symptom Severity and SSS-Physical Function scales). Of the 97 surgical participants, 49 who were hypertensive were older (76.8, SD 11.4 years) than the 48 non-hypertensive participants (66.7, SD 12.4 years) (p < 0.001). No significant associations between hypertension and post-operative function in any of the three multivariable models were seen. The Oswestry Disability Index mean score improved after surgery (effect size: 1.73; 95%CI: 1.39, 2.06), with no differences seen between those with and without hypertension (p = 0.699). Large changes were seen after surgery for the SSS-Symptom Severity (effect size: 1.0, 95%CI 0.7, 1.3) and SSS-Physical Function (effect size: 0.9, 95%CI 0.6, 1.2) scales. Hypertension alone does not negatively impact functional recovery following surgery.

What Motivates Engagement in Work and Other Valued Social Roles Despite Persistent Back Pain?

Purpose The prognosis of persistent back pain is variable, with some individuals adjusting poorly and others continuing to actively engage in work and other valued social roles. The aim of this study was to better understand why some individuals, despite persistent back pain, continue to actively engage in work and other valued social roles. Methods Individuals with persistent back pain, who were participating in their regular duties as a full-time employee, homemaker, student or any combination of these, were recruited from a multidisciplinary pain centre and orthopedic physical therapy clinics in Alberta, Canada. A qualitative study was conducted using semi-structured interviews of 15 participants and a thematic analysis to analyze the data. Results There were two motivators identified for participating in the work role: (1) participation formed part of the participant's self-schema (a cognitive framework that includes one's beliefs about oneself) and (2) participation made it possible to achieve a valued outcome. Conclusions Further understanding of important motivators for maintaining engagement in work and other valued social roles despite persistent back pain can help inform the development of more successful disability and pain management programs.

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.

Degenerative Disc Disease: What is in a Name?

STUDY DESIGN

A systematic search and review OBJECTIVE.: The aim of this study was to investigate the term, degenerative disc disease, to elucidate its current usage and inform clinical, research, and policy recommendations.

SUMMARY OF BACKGROUND DATA

Degenerative disc disease has long been a dominant concept in common, painful spinal disorders. Yet, despite its pervasiveness and important clinical consequences and controversies, there has not been a systematic examination of its use and meaning in the scientific literature.

METHODS

We conducted a systematic search of publications using the term degenerative disc disease from 2007 through 2016 in Ovid MEDLINE (R), Embase, CINAHL, and Scopus. Two investigators independently reviewed all publications in the primary sample. Publication and author identifiers, and qualitative study descriptors were extracted. Finally, the definition of degenerative disc disease was placed in one of eight categories. Data were summarized using descriptive statistics.

RESULTS

Degenerative disc disease appeared in the titles of 402 publications in the primary sample and increased in frequency by 189% from the first to the last 3 years of the decade. No single definition was used in the majority of publications, and most frequently, the term was used without any definition provided (30.1%). In other cases, degenerative disc disease specifically included radiculopathy or myelopathy (14.4%), or only back or neck pain (5.5%), or was equated with disc degeneration regardless of the presence of symptoms (15.4%), or with discogenic pain or disc degeneration as a presumed cause of axial pain (12.7%). Another 7.2% comprised a mix of broad ranging findings and diagnoses. The most notable differences in definitions occurred between surgeons and other disciplines, and when applied to cervical versus lumbar regions.

CONCLUSION

Despite longstanding use and important consequences, degenerative disc disease represents an underdeveloped concept, with greatly varying, disparate definitions documented. Such inconsistencies challenge clear, accurate communication in medicine and science, create confusion and misconceptions among clinicians, patients and others, and hinder the advancement of related knowledge.

LEVEL OF EVIDENCE

4.

The association between occupational loading and spine degeneration on imaging - a systematic review and meta-analysis

Background

There are inconsistencies in findings regarding the relationship of occupational loading with spinal degeneration or structural damage. Thus, a systematic review was conducted to determine the current state of knowledge on the association of occupational loading and spine degeneration on imaging.

Methods

We performed electronic searches on MEDLINE, CINAHL and EMBASE. We included cross-sectional, case control and cohort studies evaluating occupational loading as the exposure and lumbar spine structural findings on imaging as the outcomes. When possible, results were pooled.

Results

Seventeen studies were included in the review. Ten studies evaluated the association of occupational loading with disc degeneration (signal intensity), four of which were pooled into a meta-analysis. Of the 10 studies, only two did not identify a relationship between occupation loading and disc degeneration. A meta-analysis including four of the studies demonstrated an association between higher loading and degeneration for all spinal levels, with odds ratios between 1.6 and 3.3. Seven studies evaluated disc height narrowing and seven evaluate disc bulge, with six and five identifying an association of loading and with imaging findings respectively. Three studies evaluated modic changes and one identified and association with occupational load.

Conclusions

There was moderate evidence suggesting a modest association between occupational loading and disc degeneration (signal intensity), and low-quality evidence of an association between occupational loading and disc narrowing and bulging.

Measuring and reporting of vertebral endplate bone marrow lesions as seen on MRI (Modic changes): recommendations from the ISSLS Degenerative Spinal Phenotypes Group

PURPOSE

The positive association between low back pain and MRI evidence of vertebral endplate bone marrow lesions, often called Modic changes (MC), offers the exciting prospect of diagnosing a specific phenotype of chronic low back pain (LBP). However, imprecision in the reporting of MC has introduced substantial challenges, as variations in both imaging equipment and scanning parameters can impact conspicuity of MC. This review discusses key methodological factors that impact MC classification and recommends guidelines for more consistent MC reporting that will allow for better integration of research into this LBP phenotype.

METHODS

Non-systematic literature review.

RESULTS

The high diagnostic specificity of MC classification for a painful level contributes to the significant association observed between MC and LBP, whereas low and variable sensitivity underlies the between- and within-study variability in observed associations. Poor sensitivity may be owing to the presence of other pain generators, to the limited MRI resolution, and to the imperfect reliability of MC classification, which lowers diagnostic sensitivity and thus influences the association between MC and LBP. Importantly, magnetic field strength and pulse sequence parameters also impact detection of MC. Advances in pulse sequences may improve reliability and prove valuable for quantifying lesion severity.

CONCLUSIONS

Comparison of MC data between studies can be problematic. Various methodological factors impact detection and classification of MC, and the lack of reporting guidelines hinders interpretation and comparison of findings. Thus, it is critical to adopt imaging and reporting standards that codify acceptable methodological criteria. These slides can be retrieved under Electronic Supplementary Material.

Reliability and validity of lumbar disc height quantification methods using magnetic resonance images

Disc height has been a focus of research on disc degeneration and low back pain (LBP). However, choosing an appropriate method to quantify disc height remains controversial. The aim of the present study was to determine the reliability and construct validity of disc height quantification methods. Repeated semi-automatic measurements of L4-5 and L5-S1 discs were obtained from 43 T2-weighted mid-sagittal 3T magnetic resonance (MR) images of 22 subjects with LBP (43±13 years), blinded to prior measurements. Heights were calculated with area-based methods (using 60%, 80% and 100% of the disc width), and point-based methods (Hurxthal's, Dabbs' and combining the two). Intra-class correlation coefficients (ICC) and standard error of measurement (SEM) were estimated. Construct validity was assessed using correlation coefficients. Intra-rater ICC(3,1) of the area-based disc height measurements ranged from 0.84 to 0.99 with an inter-rater ICC(2,1) of 0.99. Measurements with point-based methods had lower intra- and inter-rater reliability ranging between 0.76 and 0.96 and between 0.84 and 0.98, respectively. Inter-rater SEM varied between 0.2 and 0.3 mm for area-based methods and between 0.3 and 0.7 mm for point-based methods. Excluding Dabbs', high correlations (r>0.9) were observed between methods. Area-based height measurements using partial disc width demonstrated excellent reliability and construct validity and outperformed point-based methods.

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

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

Population-averaged MRI atlases for automated image processing and assessments of lumbar paraspinal muscles

PURPOSE

Growing evidence suggests an association between lumbar paraspinal muscle degeneration and low back pain (LBP). Currently, time-consuming and laborious manual segmentations of paraspinal muscles are commonly performed on magnetic resonance imaging (MRI) axial scans. Automated image analysis algorithms can mitigate these drawbacks, but they often require individual MRIs to be aligned to a standard "reference" atlas. Such atlases are well established in automated neuroimaging analysis. Our aim was to create atlases of similar nature for automated paraspinal muscle measurements.

METHODS

Lumbosacral T2-weighted MRIs were acquired from 117 patients who experienced LBP, stratified by gender and age group (30-39, 40-49, and 50-59 years old). Axial MRI slices of the L4-L5 and L5-S1 levels at mid-disc were obtained and aligned using group-wise linear and nonlinear image registration to produce a set of unbiased population-averaged atlases for lumbar paraspinal muscles.

RESULTS

The resulting atlases represent the averaged morphology and MRI intensity features of the corresponding cohorts. Differences in paraspinal muscle shapes and fat infiltration levels with respect to gender and age can be visually identified from the population-averaged data from both linear and nonlinear registrations.

CONCLUSION

We constructed a set of population-averaged atlases for developing automated algorithms to help analyze paraspinal muscle morphometry from axial MRI scans. Such an advancement could greatly benefit the fields of paraspinal muscle and LBP research. These slides can be retrieved under Electronic Supplementary Material.

Methodology and cohort profile for the Hangzhou Lumbar Spine Study: a study focusing on back health in a Chinese population

Back pain is a worldwide health problem, adding a tremendous burden to modern societies. However, little information on back health is available in China, even though a quarter of the world's population is Chinese. To enhance knowledge in this area, we designed and initiated the Hangzhou Lumbar Spine Study, which is a cross-sectional study of a general sample of mainland Chinese with focusing on disc degeneration, Modic changes, endplate lesions, and back pain. The study consists of a structured questionnaire to measure back pain history and lifetime exposure to suspected risk factors, magnetic resonance imaging of the lumbar spine, bone mineral density study of the spine and hip, and DNA sample analysis. Here we briefly introduce the study methodology, report the test-retest reliability of the questionnaire, and describe the cohort profile to date. Since May 2014, 301 randomly selected subjects (male/female, 122/179; mean age, 51.0 years; range, 20-87 years) have been recruited. Tests-retests of the questionnaire, completed by 40 participants, revealed good reliability. To our knowledge, the Hangzhou Lumbar Spine Study is the first population-based epidemiological study conducted to characterize lumbar spinal phenotypes and back pain, their interaction, and their associations with lifetime environmental exposure, in mainland Chinese. Epidemiological information obtained from a reliable questionnaire, magnetic resonance (MR) imaging data, dual energy X-ray absorptiometry (DXA) measurements, and DNA analysis may serve as a valuable reference for future studies on back health, particularly for mainland Chinese.

MRI evaluation of the effects of extension exercises on the disc fluid content and location of the centroid of the fluid distribution

BACKGROUND

McKenzie prone press-up exercises have been hypothesised to reduce intradiscal pressure, allowing fluid to be reabsorbed into the disc, which could improve the internal stability and local chemical milieu of the disc, potentially reducing symptoms.

OBJECTIVE

To investigate the immediate effects of prone press-up exercises on lumbar disc fluid content and movement.

DESIGN

Quantification of MRI changes before and after a single exercise session.

METHODS

The mid-sagittal T₂-weighted MR images of 22 volunteers with low back pain were obtained before and immediately after performing press-up exercises. The whole disc and nucleus regions of the L4-5 and L5-S1 discs were then segmented, and their mean signal intensity (MSI) and signal intensity weighted centroid (SIWC) were computed to estimate disc fluid content and displacement.

RESULTS

There were no significant differences between the MSI and the vertical position of the SIWC of the whole disc before and after extension at either disc level (effect size [ES]: -0.23 to 0.09). There was a significant anterior displacement (0.1 ± 5.4 mm) of the location of the SIWC of the disc after extension exercise at L4-5 (ES: 0.22), but not at L5-S1 (ES: 0.00) or at either level for the nucleus region (ES: -0.06; 0.16).

CONCLUSION

Little evidence was found supporting the hypothesis that press-up exercises affect disc fluid content and distribution. Novel parameters reflecting fluid distribution detected similar or larger effects of the extension than MSI. If such exercises are effective in reducing symptoms, it is likely through other mechanisms than by changing fluid content or distribution.

MRI-based hip cartilage measures in osteoarthritic and non-osteoarthritic individuals: a systematic review

Osteoarthritis is a common hip joint disease, involving loss of articular cartilage. The prevalence and prognosis of hip osteoarthritis have been difficult to determine, with various clinical and radiological methods used to derive epidemiological estimates exhibiting significant heterogeneity. MRI-based methods directly visualise hip joint cartilage, and offer potential to more reliably define presence and severity of osteoarthritis, but have been underused. We performed a systematic review of MRI-based estimates of hip articular cartilage in the general population and in patients with established osteoarthritis, using MEDLINE, EMBASE and SCOPUS current to June 2016, with search terms such as ‘hip’, ‘femoral head’, ‘cartilage’, ‘volume’, ‘thickness’, ‘MRI’, etc. Ultimately, 11 studies were found appropriate for inclusion, but they were heterogeneous in osteoarthritis assessment methodology and composition. Overall, the studies consistently demonstrate the reliability and potential clinical utility of MRI-based estimates. However, no longitudinal data or reference values for hip cartilage thickness or volume have been published, limiting the ability of MRI to define or risk-stratify hip osteoarthritis. MRI-based techniques are available to quantify articular cartilage signal, volume, thickness and defects, which could establish the sequence and rate of articular cartilage changes at the hip that yield symptomatic osteoarthritis. However, prevalence and rates of progression of hip osteoarthritis have not been established in any MRI studies in the general population. Future investigations could fill this important knowledge gap using robust MRI methods in population-based cross-sectional and longitudinal studies.

Cranio-caudal asymmetries in trabecular architecture reflect vertebral fracture patterns

Clinically, vertebral fractures often occur in the upper lumbar spine and involve the superior endplate of a vertebra (which is immediately caudal to a disc). Knowledge that the cranial endplate of a disc is thicker and has greater bone mineral density (BMD) than the corresponding caudal endplate helps to explain this phenomenon. In this study, we investigated structural differences in vertebral trabeculae on either side of a lumbar disc to provide further insight into vertebral fracture risk. As the focus is trabecular difference within a spinal motion segment, we define cranial and caudal vertebral trabeculae relative to the disc. Ninety-two spinal motion segments from 46 cadaveric lumbar spines (males, mean age 50years, range 21-63years) were studied. Disc narrowing on radiography and spread of barium sulfate (BaSO₄) on discography were measured to indicate disc degeneration. Micro-computed tomography (μCT) images were obtained at a resolution of 82μm for each vertebra and processed to include only vertebral trabeculae. Using image processing, the vertebral trabeculae were divided into superior and inferior halves, and then into central and peripheral regions which were approximately opposite to the disc pulposus and annulus, and further into anterior and posterior sub-regions. Microarchitecture measurements for each vertebral region were obtained to determine the differences between the cranial and caudal trabeculae (relative to disc) and their associations with age and disc degeneration within each spinal motion segment. Data from the upper (L1/2-L3/4) and lower (L4/5) lumbar segments were analyzed separately. In the upper lumbar region, the trabeculae cranial to a disc on average had 5.3% greater BMD and trabecular bone volume, 3.6% greater trabecular number, 9.7% greater connectivity density, and 3.7% less trabecular separation than the corresponding caudal trabeculae (P<0.05 for all). Similar trends were observed in peripheral, anterior and posterior regions, but not in central region. No structural difference was observed in the trabeculae of L4/5 segment. Structural asymmetries of vertebral trabeculae were not associated with age, disc degeneration, or disc narrowing. Vertebral trabecular parameters cranial to the disc were greater than caudally in the upper but not in the lower lumbar region. Findings further explain why vertebral fractures are more common in the upper lumbar region and more frequently involve the endplate caudal to a disc.

ISSLS Prize Winner: Consensus on the Clinical Diagnosis of Lumbar Spinal Stenosis: Results of an International Delphi Study

STUDY DESIGN

Delphi.

OBJECTIVE

The aim of this study was to obtain an expert consensus on which history factors are most important in the clinical diagnosis of lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

LSS is a poorly defined clinical syndrome. Criteria for defining LSS are needed and should be informed by the experience of expert clinicians.

METHODS

Phase 1 (Delphi Items): 20 members of the International Taskforce on the Diagnosis and Management of LSS confirmed a list of 14 history items. An online survey was developed that permits specialists to express the logical order in which they consider the items, and the level of certainty ascertained from the questions. Phase 2 (Delphi Study) Round 1: Survey distributed to members of the International Society for the Study of the Lumbar Spine. Round 2: Meeting of 9 members of Taskforce where consensus was reached on a final list of 10 items. Round 3: Final survey was distributed internationally. Phase 3: Final Taskforce consensus meeting.

RESULTS

A total of 279 clinicians from 29 different countries, with a mean of 19 (±SD: 12) years in practice participated. The six top items were "leg or buttock pain while walking," "flex forward to relieve symptoms," "feel relief when using a shopping cart or bicycle," "motor or sensory disturbance while walking," "normal and symmetric foot pulses," "lower extremity weakness," and "low back pain." Significant change in certainty ceased after six questions at 80% (P < .05).

CONCLUSION

This is the first study to reach an international consensus on the clinical diagnosis of LSS, and suggests that within six questions clinicians are 80% certain of diagnosis. We propose a consensus-based set of "seven history items" that can act as a pragmatic criterion for defining LSS in both clinical and research settings, which in the long term may lead to more cost-effective treatment, improved health care utilization, and enhanced patient outcomes.

LEVEL OF EVIDENCE

2.

The relation of social support and depression in patients with chronic low back pain

PURPOSE

Depression is a common condition in adults with low back pain (LBP), and is associated with poorer patient outcomes. Social support is a modifiable factor that may influence depressive symptoms in people with LBP and, if so, could be a consideration in LBP management when depression is an issue. The aim of this study was to examine social support as a prognostic factor for depressive symptoms and recovery from depression in patients with LBP.

METHOD

Patients with LBP (n = 483), recruited from four imaging centers in Canada, completed an initial survey following imaging and a follow-up survey one year later, including the Medical Outcomes Study (MOS) Social Support Survey and the Center for Epidemiologic Studies Depression Scale. Multivariable regression analyses were used to examine the relationship between social support and depression.

RESULTS

More social support (overall functional social support) at baseline was associated with recovery from depression (OR = 0.24; 95% CI 0.10, 0.55) and less depressive symptoms (β = 1.68; 95% CI = 0.36, 3.00) at one-year follow-up. In addition, associations were found between specific aspects (subscales) of social support and the two depression outcomes.

CONCLUSIONS

Functional social support as a prognostic factor for depression and possible target of LBP management warrants further investigation. Implications for Rehabilitation Depression is a common condition in adults with low back pain (LBP), and is associated with poorer patient outcomes. This study provides evidence for social support as a prognostic factor for depressive symptoms and recovery from depression in patients with LBP problems. Management of pain conditions may be enhanced by a better understanding of modifiable risk factors for depression, such as social support.

A comparison of two methods to evaluate a narrow spinal canal: routine magnetic resonance imaging versus three-dimensional reconstruction

BACKGROUND CONTEXT

In routine clinical practice, the presence of lumbar spinal stenosis (LSS) is assessed on axial magnetic resonance images (MRI) typically acquired using a preselected spine sagittal angle. Given the natural lordosis of the lumbar spine, not all axial slices will be parallel to the disc and perpendicular to the spinal canal and, thus, are not optimal for the assessment of dural sac cross-sectional area (DCSA).

PURPOSE

The objective of this study was to compare DCSA measurements from routinely acquired clinical images with three-dimensional (3D)-reconstructed images.

STUDY DESIGN

This is a cross-sectional study.

PATIENT SAMPLE

The sample consists of 390 patients referred for lumbar imaging with some aspect of anatomical LSS found, with no prior back surgery, 40 years of age or older, and with available volumetric MR images to allow 3D reconstruction of the spine.

OUTCOME MEASURES

The outcome of interest in this study was dural sac cross sectional area.

METHODS

Spine images were 3D reconstructed at the level of the disc, perpendicular to the spinal canal. Dural sac cross-sectional area was measured for both 3D-reconstructed and routinely acquired clinical images using the slice orientation captured.

RESULTS

Dural sac cross-sectional area for the lower lumbar levels (L4-L5 and L5-S1) was significantly different between routinely acquired clinical images and 3D-reconstructed images, with a standard error of measurement of 12.98 and 19.73 mm(2), respectively.

CONCLUSIONS

When canal size is of interest, particularly when LSS affecting the lower lumbar levels is of concern, 3D reconstruction of clinical images should be considered.

The distribution of bone mass in the lumbar vertebrae: are we measuring the right target?

BACKGROUND CONTEXT

The ideal target of bone mineral density (BMD) measurements of the spine is the trabecula-rich vertebral body. Yet, spine BMD measurements routinely obtained with dual-energy X-ray absorptiometry also include the posterior elements of the vertebra, which are mainly cortical bone and insensitive to bone loss.

PURPOSE

We compared the bone mass of the vertebral body and posterior elements to determine the contributions of vertebral components to vertebral BMD measurements.

STUDY DESIGN

A micro-computed tomography study of lumbar vertebral bone.

METHODS

From a spine archive, 144 cadaveric lumbar vertebrae (L1-L5) from 48 male human spines (mean age, 50 years) were scanned in air using micro-computed tomography to measure bone volume, bone mineral content (BMC) and BMD of the vertebral body, posterior elements, and entire vertebra. The contributions of the vertebral components to the total vertebral BMC and volume were compared, and the correlations between the BMC and BMD of the vertebrae and their components were examined.

RESULTS

Overall, the vertebral body contributed about one-third of the total vertebral BMC and two-thirds of the total vertebral volume, and the posterior elements contributed the remainder. The vertebral body BMC and BMD were poorly correlated to those of the posterior elements (r=0.39 for BMC and r=0.34 for BMD, p<.0001) and moderately correlated to the whole vertebra (r=0.77 and 0.75, respectively, p<.0001). The BMC and BMD of the posterior elements and whole vertebra were more strongly correlated (r=0.89 and 0.84, respectively, p<.0001).

CONCLUSIONS

The posterior elements are the primary contributor to vertebral BMC and BMD measurements. Dual-energy X-ray absorptiometry spine BMD measurements are likely to be more representative of the posterior elements than the targeted vertebral body. The findings elucidate the extent of the limitation of dual-energy X-ray absorptiometry spine BMD measurements.

Lumbar spinal stenosis is a highly genetic condition partly mediated by disc degeneration

Objective. Lumbar spinal stenosis is one of the most commonly diagnosed spinal disorders in older adults. Although the pathophysiology of the clinical syndrome is not well understood, a narrow central canal or intervertebral foramen is an essential or defining feature. The aim of the present study was to estimate the magnitude of genetic versus environmental influences on central lumbar spinal stenosis and to investigate disc degeneration and stature or bone development as possible genetic pathways.Methods. A classic twin study with multivariate analyses considering lumbar level and other covariates was conducted. The study sample comprised 598 male twins (147 monozygotic and 152 dizygotic pairs), 35-70 years of age, from the population-based Finnish Twin Cohort. The primary phenotypes were central lumbar stenosis as assessed qualitatively on magnetic resonance imaging (MRI) and quantitatively measured dural sac cross-sectional area. Additional phenotypes (to examine possible genetic pathways) included disc bulging and standing height, as an indicator of overall skeletal size or development.Results. The heritability estimate (h²) for qualitatively assessed central lumbar spinal stenosis on MRI was 66.9% (95% confidence interval [95% CI] 56.8,74.5). The broad-sense heritability estimate for dural sac cross-sectional area was 81.2% (95% CI 74.5, 86.1),with a similar magnitude of genetic influences across lumbar levels (h²=72.4–75.6). The additive genetic correlation of quantitatively assessed stenosis and disc bulging was extremely high. There was no indication of shared genetic influences between stenosis and stature.Conclusion. Central lumbar spinal stenosis and associated dural sac dimensions are highly genetic, and disc degeneration (bulging) appears to be one pathway through which genes influence spinal stenosis.

Pathoanatomical characteristics of clinical lumbar spinal stenosis

BACKGROUND

There is no clear picture of pathoanatomy in clinically diagnosed LSS. Findings in the literature regarding imaging in LSS are heterogeneous.

OBJECTIVE

Characterize the pathoanatomy of LSS, as reported in the radiology reports, for a large community-based sample of patients with the clinical diagnosis of LSS.

METHODS

Retrospective review of clinical radiology reports. The sample comprised patients 40 years of age or older, with clinically diagnosed LSS. Radiology reports for lumbar MRI were obtained and data were extracted pertaining to the type and location of LSS.

RESULTS

173 subjects with a mean age of 66.2 ± 11.7 years were included (61% women). 68.2% had mixed stenosis, 19.1% had central stenosis only, and 12.7% had lateral stenosis only. By level, the most prevalent findings were at L4/5 (93%), L3/4 (66%) and L5/S1 (49%). This pattern was different in those with lateral stenosis only, where the proportion of findings at L5/S1 was higher than at L3/4. 156 subjects (90.2%) had findings of at least moderate severity. Considering moderate-severe findings only, 31% had mixed stenosis and 40.0% had multi-level findings (90.5% at adjacent segments). When mild findings were included for subjects with at least one moderate-severe finding the rate of mixed stenosis increased to 59%, and multi-level stenosis to 68.6%. The most common multi-level combinations were L3/4 and L4/5 for two-level stenosis and L2/3 through L4/5 for three-level.

CONCLUSION

Results of this study confirm a number of pathoanatomical patterns in people diagnosed with LSS, including a high proportion of stenosis at L4/5, followed by L3/4 and L5/S1. Results also suggest a high prevalence of multi-level stenosis at adjacent segments. The prevalence of mixed stenosis varied from 31% to 68.2%; inclusion of mild findings resulted in a higher rate of both mixed and multi-level stenosis, compared to analysis of moderate-severe findings only. These results may guide future studies on LSS pathophysiology, by focusing attention toward the most prevalent radiological findings.

A cluster randomized clinical trial comparing functional capacity evaluation and functional interviewing as components of occupational rehabilitation programs

PURPOSE

Functional capacity evaluations (FCE) are used to identify work abilities and are commonly integrated into rehabilitation programs. We studied whether integrating FCE into rehabilitation leads to better outcomes for injured workers.

METHODS

A cluster randomised controlled trial was conducted at a workers' compensation rehabilitation facility (registration ISRCTN61284905). Clinicians were randomised into 2 groups: 1 group used FCE while another conducted semi-structured functional interviews. Outcomes included recommendations following assessment, rehabilitation program outcomes including functional work levels and pain intensity, as well as compensation outcomes at 1, 3, and 6 months after assessment. Analysis included Mann-Whitney U, Chi square and t tests.

RESULTS

Subjects included 225 claimants of whom 105 were tested with FCE. Subjects were predominantly employed (84 %) males (63 %) with sub-acute musculoskeletal conditions (median duration 67 days). Claimants undergoing FCE had ~15 % higher average functional work levels recommended at time of assessment (Mann-Whitney U = 4,391.0, p < 0.001) but differences at other follow-up times were smaller (0-8 %), in favour of functional interviewing, and not statistically significant. Clinically important improvement during rehabilitation in functional work level (0.9/4, SRM = 0.94), pain intensity (2.0/10, SRM = 0.88) and self-reported disability (21.8/100, SRM = 1.45) were only observed in those undergoing the functional interview.

CONCLUSIONS

Performance-based FCE integrated into occupational rehabilitation appears to lead to higher baseline functional work levels compared to a semi-structured functional interview, but not improved RTW rates or functional work levels at follow-up. Functional interviewing has potential for efficiency gains and higher likelihood of clinically important improvement following rehabilitation, however further research is needed.

Paraspinal muscle morphology and composition: a 15-yr longitudinal magnetic resonance imaging study

PURPOSE

The purposes of this study were to define the natural progression of age-related changes of the lumbar paraspinal muscles during adulthood and to investigate the influence of lifestyle and individual factors (e.g., physical activity levels at work and leisure, body mass index, and low back pain [LBP]).

METHODS

This population-based longitudinal study included a sample of 99 adult male twins. Data were collected through a structured interview, physical examination, and magnetic resonance imaging. Measurements of the lumbar multifidus and erector spinae muscles were obtained from T2-weighted axial images at L3-L4 and L5-S1 at baseline and 15-yr follow-up. Muscle cross-sectional area (CSA), functional CSA (FCSA) (fat-free mass), and FCSA/CSA (composition) as well as CSA and FCSA asymmetry and FCSA/CSA side-to-side differences were measured.

RESULTS

Subjects' mean ± SD age was 47.3 ± 7.4 yr at baseline and 62.3 ± 8.0 yr at follow-up. During the 15-yr period, both muscles exhibited a decrease in CSA and FCSA and an increase in fatty infiltration and side-to-side differences in size and composition at both spinal levels. Both muscles displayed greater changes at L5-S1 than L3-L4. Age and BMI were found to be significantly associated with the degree of paraspinal muscle changes over time. However, there was no association between the change in paraspinal muscle size, composition, or asymmetry with the level of physical demands at work or leisure or LBP history.

CONCLUSIONS

The present longitudinal study suggests that over adulthood, the multifidus and erector spinae undergo similar morphological changes. Moreover, our findings suggest that the long-term progression of lumbar paraspinal muscle changes evaluated through magnetic resonance imaging are not associated with the range of physical demand levels as were typical of Finnish men or LBP history.

Longitudinal construct validity and responsiveness of measures of walking capacity in individuals with lumbar spinal stenosis

BACKGROUND CONTEXT

Walking capacity is a primary outcome indicator for individuals with lumbar spinal stenosis (LSS). Therefore, there is a demand for psychometrically sound measures of walking that are responsive to change.

PURPOSE

The primary objective of this study was to examine longitudinal construct validity of the Physical Function Scale of the Swiss Spinal Stenosis Questionnaire (PF Scale), the Oswestry Disability Index (ODI), and the walking capacity items from these scales specifically for the assessment of walking capacity in LSS using the objective Self-Paced Walking Test (SPWT) as the external standard. A secondary objective was to examine responsiveness of measures of walking using a self-reported walking capacity change scale as the external criterion standard.

STUDY DESIGN

Patients were prospectively enrolled.

PATIENT SAMPLE

Twenty-six patients were included in this study (17 women and 9 men), with an average age of 68.5 years (SD, 9.2). All participants had LSS diagnosed by a spine specialist surgeon based on both clinical examination and imaging, as well as self-reported walking limitations (neurogenic claudication).

OUTCOME MEASURES

The self-reported outcome measures included in this study were PF Scale, ODI, and self-reported walking capacity change score.

FUNCTIONAL MEASURES

The functional measure used in the study was SPWT.

METHODS

Longitudinal construct validity was assessed using the correlational method. Internal responsiveness was examined using Guyatt responsiveness index and external responsiveness using receiver operating characteristic analysis. Change in the SPWT and the self-reported walking capacity change score were used as external criteria for the analysis.

RESULTS

The highest correlations with change in the SPWT were 0.78 for the ODI walking item and 0.78 for the walking capacity change score. Changes in the PF Scale and ODI score were correlated with change in the criterion SPWT at r=0.56 and r=0.70, respectively. There were no differences observed between the PF Scale and ODI for any of the responsiveness indices.

CONCLUSIONS

The PF Scale, ODI, and walking capacity change score are able to detect changes in walking capacity in people with LSS. The individual walking capacity item from the ODI appears to be the most valid and responsive to changes in measured walking and may be a reasonable alternative for measuring walking when an objective test such as the SPWT is not feasible.

Do variations in paraspinal muscle morphology and composition predict low back pain in men?

This longitudinal study aimed to clarify the longstanding controversy over whether variations in paraspinal muscle morphology (e.g., size, composition and asymmetry) are predictors of low back pain (LBP). A sample of 99 Finnish men were included in this population-based longitudinal study. Data were collected through a structured interview, physical examination and magnetic resonance imaging (MRI). Baseline measurements of the lumbar multifidus and erector spinae muscles were obtained from T2-weighted axial images at L3-L4 and L5-S1, and interview data were obtained at baseline, 1- and 15-year follow-ups. Few of the paraspinal muscle parameters investigated were predictors of change in LBP frequency, intensity or sciatica at 1- and 15-year follow-ups in the population-based sample, and findings were not consistent across muscles and spinal levels. However, greater multifidus and erector spinae fatty infiltration at L5-S1 was associated with a higher risk of having continued, frequent, persistent LBP at 1-year follow-up. None of the relationships observed was confounded by body mass index or the amount of physical activity at work or leisure. This longitudinal study provided evidence that variations in paraspinal muscle morphology on MRI have a limited, if not uncertain, role in the short- and long-term predictions of LBP in men.

Predictors of objectively measured walking capacity in people with degenerative lumbar spinal stenosis

BACKGROUND

Identifying factors associated with walking capacity in people with lumbar spinal stenosis (LSS) may provide a better understanding of neurogenic claudication and inform future rehabilitation research.

OBJECTIVE

To examine factors associated with objectively measured walking capacity in a sample of people with LSS and self-reported walking limitations.

METHODS

Participants included 49 individuals (65.8 years ± 10) who were at least 45 years of age with clinically diagnosed lumbar spinal stenosis (LSS) confirmed on MRI or CT imaging. All participants completed a Self-Paced Walking Test with visual analog pain scales and body diagrams before and immediately after walking. Questionnaires included the Physical Function and Symptom Severity Scales of the Swiss Spinal Stenosis Questionnaire, the Oswestry Disability Index (ODI) and the Health Utilities Index. Univariate linear relationships were examined, followed by development of a multivariate linear regression model with walking distance (m) as the dependent variable. A post-hoc analysis was also conducted including post-test symptom variables.

RESULTS

Variables retained from univariate analyses included years of leg pain, pre-test leg pain severity, the ODI, balance problems, and quality of life. When these variables were considered for a final model, only the ODI and balance problems were retained (R2=0.33). Other than balance, none of the pre-test symptom variables entered into the final model. Post-hoc analysis including post-test symptom variables found the presence and severity of post-test leg pain to be most highly associated with walking distance. In an explanatory model considering the ODI, balance and these two post-walking factors, only presence of post-test leg pain added to the model (R2=0.42).

CONCLUSIONS

Factors found to be most highly associated with walking capacity in LSS were self-reported, pain-related function (ODI), balance problems, and presence of leg pain immediately following walking.

Regional variations in trabecular architecture of the lumbar vertebra: associations with age, disc degeneration and disc space narrowing

Previous studies suggest that age and disc degeneration are associated with variations in vertebral trabecular architecture. In particular, disc space narrowing, a severe form of disc degeneration, may predispose the anterior portion of a vertebra to fracture. We studied 150 lumbar vertebrae and 209 intervertebral discs from 48 cadaveric lumbar spines of middle-aged men to investigate regional trabecular differences in relation to age, disc degeneration and disc narrowing. The degrees of disc degeneration and narrowing were evaluated using radiography and discography. The vertebrae were dried and scanned on a μCT system. The μCT images of each vertebral body were processed to include only vertebral trabeculae, which were first divided into superior and inferior regions, and further into central and peripheral regions, and then anterior and posterior regions. Structural analyses were performed to obtain trabecular microarchitecture measurements for each vertebral region. On average, the peripheral region had 12-15% greater trabecular bone volume fraction and trabecular thickness than the central region (p<0.01). Greater age was associated with better trabecular structure in the peripheral region relative to the central region. Moderate and severe disc degeneration were associated with higher trabecular thickness in the peripheral region of the vertebral trabeculae (p<0.05). The anterior region was of lower bone quality than the posterior region, which was not associated with age. Slight to moderate narrowing was associated with greater trabecular bone volume fraction in the anterior region of the inferior vertebra (p<0.05). Similarly, greater disc narrowing was associated with higher trabecular thickness in the anterior region (p<0.05). Better architecture of peripheral trabeculae relative to central trabeculae was associated with both age and disc degeneration. In contrast to the previous view that disc narrowing stress-shields the anterior vertebra, disc narrowing tended to associate with better trabecular architecture in the anterior region, as opposed to the posterior region.

Disc degeneration-related clinical phenotypes

The phenotype, or observable trait of interest, is at the core of studies identifying associated genetic variants and their functional pathways, as well as diagnostics. Yet, despite remarkable technological developments in genotyping and progress in genetic research, relatively little attention has been paid to the equally important issue of phenotype. This is especially true for disc degeneration-related disorders, and the concept of degenerative disc disease, in particular, where there is little consensus or uniformity of definition. Greater attention and rigour are clearly needed in the development of disc degeneration-related clinical phenotypes if we are to see more rapid advancements in knowledge of this area. When selecting phenotypes, a basic decision is whether to focus directly on the complex clinical phenotype (e.g. the clinical syndrome of spinal stenosis), which is ultimately of interest, or an intermediate phenotype (e.g. dural sac cross-sectional area). While both have advantages, it cannot be assumed that associated gene variants will be similarly relevant to both. Among other considerations are factors influencing phenotype identification, comorbidities that are often present, and measurement issues. Genodisc, the European research consortium project on disc-related clinical pathologies has adopted a strategy that will allow for the careful characterisation and examination of both the complex clinical phenotypes of interest and their components.

Genetics of disc-related disorders: current findings and lessons from other complex diseases

Disc-related disorders are highly genetic conditions with heritability estimates of up to 75 % and yet, few genomic locations have been moderately associated with the disorders. Candidate gene studies have shown possible disease associations on loci and genes of 1p21.1 (COL11A1), 6q27 (THBS2), 9q22.31 (ASPN), 10p12.31 (SKT), 20q11.2 (GDF5) and 20q13.12 (MMP9). More recently, in 2012, the first genome-wide association study revealed variants on loci and genes of 3p26.2, 6p21.32 (HLA region) and 6q26 (PARK2) that associate with disc-related disorders. In many other complex diseases, large meta-analyses of hundreds of thousands of study subjects and loci have revealed remarkable pathways. As methodology is evolving rapidly, we have already stepped into the era of routinely sequencing all bases in all human exons and we are approaching the era of sequencing the entire genome of study subjects with common diseases. The past decade has taught us that the common variants seen throughout populations seem to have low effects in many common diseases, explain relatively little of the overall heritability of the diseases and demand thousands of study subjects to identify associations. It seems that familial rare variants play an important role in many common diseases leading us back to valuing studies with large families and isolated populations. Moreover, careful characterization of environmental conditions are needed to explore and determine gene-environment interactions as genes that increase disease risk in one context may not do so under another context.

Morphometrics and lesions of vertebral end plates are associated with lumbar disc degeneration: evidence from cadaveric spines

BACKGROUND

Prior studies have suggested that vertebral end plate morphometrics and lesions may play a role in disc degeneration. However, most prior end plate studies have been based on radiographic images, and findings of associations between end plate morphometrics (measurements of size and shape) and disc degeneration remain controversial. The present study investigated the prevalence of vertebral end plate lesions and determined end plate morphometrics through direct measurements of cadaveric spines, and it examined the association of these factors with disc degeneration.

METHODS

We studied 600 vertebral end plates and 313 intervertebral discs from the cadaveric lumbosacral spines of seventy-six men (mean age, fifty-one years). Discography was performed to evaluate disc degeneration as indicated by disruption of the anulus fibrosus. The shape of the vertebral end plate and the presence of any lesions were visually evaluated. Lesions were rated as absent, small to moderate, or large. In addition, each end plate was digitized to quantify its area, circularity, and concavity. The association of end plate morphometrics and lesions with disc degeneration was examined.

RESULTS

Vertebral end plate lesions were found in 72% (fifty-five) of the seventy-six lumbar spines and in 32.8% (197) of the 600 end plates. The presence of end plate lesions was associated with disc degeneration, with larger lesions being associated with more severe disc degeneration (odds ratio, 2.31 for small to moderate lesions [p < 0.01] and 3.54 for large lesions [p < 0.001]). Greater end plate area was also associated with more severe disc degeneration (odds ratio, 1.2 per cm2 [p < 0.05]).

CONCLUSIONS

Vertebral end plate lesions were common and were associated with adjacent disc degeneration, with greater lesion size being associated with more severe disc degeneration. End plate morphometrics, particularly greater end plate size, may also play a role in the pathogenesis of disc degeneration.

Is level- and side-specific multifidus asymmetry a marker for lumbar disc pathology?

BACKGROUND CONTEXT

Several reports suggest that level- and side-specific multifidus atrophy or fat infiltration may be related to localized spinal pathology and symptoms. In particular, a study using a porcine model reported rapid level- and side-specific multifidus atrophy and adipocyte enlargement resulting from anterolateral disc or nerve root lesions.

PURPOSE

To investigate asymmetry in cross-sectional area (CSA) and fat infiltration in multifidus and other paraspinal muscles in patients with acute or subacute unilateral symptoms of radiculopathy and concordant posterolateral disc herniation. If multifidus asymmetry is indeed related to local pathology, this may serve as a marker for helping to target the search for less clearly identifiable pathology responsible for low back-related symptoms, which currently remains elusive in approximately 85% of those seeking care.

STUDY DESIGN

Cross-sectional observational study.

PATIENT SAMPLE

Subjects were patients referred to magnetic resonance imaging (MRI) with unilateral leg symptoms of less than 6 weeks onset suggestive of radiculopathy, with a consistent posterolateral lumbar disc herniation verified on imaging.

METHODS

Using T2-weighted axial MRI, measurements were obtained for total muscle CSA and signal intensity, functional (fat-free) CSA, and the ratio of functional CSA to total CSA.

RESULTS

Forty-three subjects met the inclusion criteria. The ratio of functional CSA to total muscle CSA was smaller on the side of the herniation than on the unaffected side, both below (mean 0.69 vs. 0.72, p=.007) and at the level of herniation (mean 0.78 vs. 0.80, p=.031). Multifidus signal intensity (fat infiltration) was greater on the side of the herniation at the level below the herniation (p=.014). Contrary to expectation, greater total multifidus CSA was found ipsilateral to the pathology at the level of herniation (p=.033). No asymmetries were found at the level above the herniation or in any other paraspinal muscles, with the exception of higher signal in the erector spinae at the level and side of herniation.

CONCLUSIONS

Multifidus may be particularly responsive to, or indicative of, localized lumbar disc or nerve root pathology within the first 6 weeks of symptoms as expressed through fat infiltration, but not through CSA asymmetry on MRI. However, such measurements are not reliable markers of lumbar pathology on an individual basis for use in clinical or research settings.

A morphological study of lumbar vertebral endplates: radiographic, visual and digital measurements

PURPOSE

Clinical observations suggest that endplate shape and size are related to complications of disc arthroplasty surgery. Yet, the morphology of the vertebral endplate has not been well defined. This study was conducted to characterize the morphology of lumbar vertebral endplates and to quantify their morphometrics using radiographic, visual and digital measures.

METHODS

A total of 591 vertebral endplates from 76 lumbosacral spines of men were studied (mean age 51.3 years). The shape of the vertebral endplates was classified as concave, flat and irregular, and was evaluated from both radiographs and cadaveric samples. Each endplate was further digitized using a laser scanner to quantify diameters, surface area and concavity for the whole endplate and its components (central endplate and epiphyseal rim). The morphological characteristics and morphometrics of the vertebral endplates were depicted.

RESULTS

In both radiographic and visual assessments, more cranial endplates (relative to the disc) were concave and more caudal endplates were flat at all disc levels (p < 0.001). On average, the mean concavity depth was 1.5 mm for the cranial endplate and 0.7 mm for the caudal endplate. From L1/2 down to L5/S1 discs, the vertebral endplate gradually changed into a more oval shape. The central endplate was approximately 70% of the diameter of the whole endplate and the width of the epiphyseal rim varied from 3 to 7 mm.

CONCLUSIONS

There is marked morphological asymmetry between the two adjacent endplates of a lumbar intervertebral disc: the cranial endplate is more concave than the caudal endplate. The size and shape of the vertebral endplate also vary considerably between the upper and lower lumbar regions.

Modic changes: prevalence, distribution patterns, and association with age in white men

BACKGROUND CONTEXT

Suspected as a cause of back pain, Modic changes (MCs) have received increasing attention in spine research and care. Yet, epidemiologic knowledge of MCs based on the general population, which may provide an important clinical reference, is limited.

PURPOSE

To investigate the prevalence and distribution patterns of MCs in the lumbosacral spine and their associations with age in a large population-based sample of men.

STUDY DESIGN

An epidemiologic investigation of lumbar magnetic resonance images (MRIs).

PATIENT SAMPLE

This study was based on the Twin Spine Study database, comprising a sample of male twins shown to be largely representative of the base Finnish population. Lumbar spine MRIs (1.5 Tesla Magnetom; Siemens AG, Erlangen, Germany) of 561 subjects (mean age, 49.8 years; range, 35-70 years) were included in the present study.

METHODS

For each spine, all 11 end plates (L1-S1) in the lumbar region were evaluated using both T1- and T2-weighted images to identify MCs, which were classified into Type 1, 2, 3, and mixed types. Furthermore, the number and location of MCs were recorded, as well as the anteroposterior (AP) and transverse sizes, to explore the prevalence and distribution pattern of MCs in the lumbar region and associations with age.

RESULTS

Modic changes were identified in 55.6% (312) of individuals and 13.5% (830) of end plates studied. Among these MCs, 64.2% (533) were Type 2, 16.0% (133) were Type 1, 18.1% (150) were Mixed Type 1/2, and the remaining 1.6% (13) were noted as Type 3 or Mixed Type 2/3. Modic changes were more common in the lower (74.5%) than in the upper lumbar region (25.5%), and 77.9% (642) of MCs presented in pairs at opposing end plates of a disc. Moreover, the specific type of MCs on opposing end plates was usually concordant. The presence of MCs in the lumbar region was associated with age (odds ratio=1.05-1.08 for each additional year of age, depending on type of MCs, p<.001). In addition, greater age was associated with a greater number of end plates affected and MCs of larger size (p<.001).

CONCLUSIONS

Modic changes are common MRI findings in the lumbar spines of middle-aged white men, with Type 2 MCs predominating. Mainly present in the lower lumbar region, MCs tend to affect both end plates adjacent to a disc simultaneously, and they commonly involve the entire AP diameter of the vertebral end plate. The presence and size of MCs are clearly related to age, suggesting that aging or associated factors may play an essential role in the pathogenesis of MCs.

Health-related quality of life and comorbidities associated with lumbar spinal stenosis

BACKGROUND CONTEXT

Spinal stenosis is one of the most commonly diagnosed pathologies of the lumbar spine and the leading indication for spine surgery in adults aged 65 years and older. Yet, the burden of lumbar spinal stenosis (LSS) alone, and in combination with common comorbidities, on health-related quality of life (HRQL) is unknown as are comorbidities specifically associated with this chronic condition.

PURPOSE

To estimate the illness burden of LSS on HRQL, adjusting for the effects of specific comorbidities, age, and gender, and investigate whether specific comorbidities are associated with the condition.

STUDY DESIGN/SETTING

A community-based cohort of 245 patients diagnosed with LSS was assembled and compared with a representative sample of 7,489 adults from the base population of Albertans responding to the Canadian Community Health Survey on HRQL and comorbidities.

METHODS

Health-related quality-of-life data were acquired through interviews for both groups using the Health Utilities Index Mark 3 (HUI3). Both groups were also queried about the presence of 13 specific chronic conditions. Linear regression was used to model HUI3 scores as a function of group, age, gender, and specific comorbid conditions. Logistic regression was used to compare the odds of having particular comorbid conditions between the LSS and general population groups.

RESULTS

The mean unadjusted overall HUI3 scores were 0.60 for the LSS group and 0.85 for the general population (1=perfect health). After adjustment, HRQL deficits four times that deemed a clinically important difference remained between the groups. Controlling age and gender, the prevalence of arthritis, migraines, hypertension, and incontinence was significantly greater in the LSS group as compared with the general population sample.

CONCLUSIONS

Diagnosed LSS is associated with a very substantial burden of illness that is compounded by associated comorbidities, with implications for clinical care, health-care policy decisions, and research. Attention to comorbidities is particularly important in LSS.