Editorial: Immunological imbalance: What is its role in intervertebral disc degeneration?

Low back pain (LBP) is a major cause of disability worldwide (GBD, 2017 Disease and Injury Incidence and Prevalence Collaborators, 2018) and belongs to the most urgent priorities to identify novel therapies, especially for the elderly (Teichtahl et al., 2015; Chen et al., 2020; Lee et al., 2021). Global health costs are generally rising but in the field of orthopedics and mostly for spine, the costs are exploding in recent years compared to other diseases (Wieser et al., 2011; Martin et al., 2019). Surgical options to treat LBP efficiently are very limited; clinical outcome is often non-satisfactory for the patients with very high re-operation rates (Nachemson et al., 1996; Knezevic et al., 2021).

Radiographic cervical spine degenerative findings: a study on a large population from age 18 to 97 years

AbstractPurposeThe aims of this study were (1) to determine the prevalence of radiographic cervical disc degeneration in a large population of patients aged from 18 to 97 years; (2) to investigate individually the prevalence and distribution of height loss, osteophyte formation, endplate sclerosis and spondylolisthesis; and (3) to describe the patterns of cervical disc degeneration.MethodsA retrospective study was performed. Standard lateral cervical spine radiographs in standing, neutral position of 1581 consecutive patients (723 males, 858 females) with an average age of 41.2 ± 18.2 years were evaluated. Cervical disc degeneration was graded from C2/C3 to C6/C7 based on a validated quantitative grading system. The prevalence and distribution of radiographic findings were evaluated and associations with age were investigated.Results53.9% of individuals had radiographic disc degeneration and the most affected level was C5/C6. The presence and severity of disc degeneration were found to be significantly associated with age both in male and female subjects. The most frequent and severe occurrences of height loss, osteophyte formation, and endplate sclerosis were at C5/C6, whereas spondylolisthesis was most observed at C4/C5. Age was significantly correlated with radiographic degenerative findings. Contiguous levels degeneration pattern was more likely found than skipped level degeneration. The number of degenerated levels was also associated with age.ConclusionsThe presence and severity of radiographic disc degeneration increased with aging in the cervical spine. Older age was associated with greater number of degenerated disc levels. Furthermore, the correlations between age and the degree of degenerative findings were stronger at C5/C6 and C6/C7 than at other cervical spinal levels

Reliability of quantifying the spatial distribution of fatty infiltration in lumbar paravertebral muscles using a new segmentation method for T1-weighted MRI

Background: To our knowledge, there are no methods allowing for quantification of the spatial distribution of lumbar paravertebral muscle fatty infiltration (FI) in the transverse plane. There is an increasing emphasis on muscle tissues as modifiable factors in lumbar spine health. Population datasets based on conventional T1-weighted (T1-W) magnetic resonance imaging (MRI) represent a valuable resource for examining all spinal tissues, and methods with reliability are needed. The aim of our study was to determine the reliability of a novel method quantifying lumbar paravertebral muscle fat content based on conventional T1-W MRI. Methods: Axial 3-Tesla T1W MRIs from ten adult subjects (3W, 7M; mean age 52.8 ± SD 7.2 years) were randomly selected from the large prospective cross-sectional Hong Kong Population-based Disc Degeneration Cohort study examining lumbar spine degeneration. The selected sample included subjects with mixed imaging-determined disc degeneration and low back pain history. Two raters with MRI lumbar paravertebral muscle analysis experience (R1 > 250 h and R2 > 1000 h) repeat-measured the image-set a week apart. Multifidus and erector spinae (spinalis, longissimus and iliocostalis) were manually outlined together on a single-slice from the inferior vertebral end-plates of L1 to L5 using a semi-automated, quartile-defining (Q1-4 (medial to lateral) and Qmean) MatLab-based programme. Bland-Altman plots and intra-class correlation coefficients (ICC) with 95 % confidence intervals (CI) describe intra- and inter-rater reliability according to lumbar level, quartile, and side, and combined level and quartile. Results: There was good intra- (ICC = 0.88; CI: 0.87-0.90) and inter-rater agreement (ICC = 0.82; CI: 0.80-0.84). Intra-rater values for Qmean (ICC; CI) were higher at L5 (0.89; 0.79-0.94) than L1 (0.61; 0.37-0.78). Higher intra-rater values for L1-5 were shown at Q1 (0.93; 0.91-0.95) than Q3 (0.83; 0.78-0.87) or Q4 (0.81; 0.76-0.85), and on the right (0.91; 0.90-0.93) than left (0.85; 0.83-0.88). Similar observations were made for inter-rater values in terms of lumbar level and quartile, with no differences between sides shown. Conclusions: In our study of ten cases we demonstrate a reliable method to quantify the spatial distribution of fat content in lumbar paravertebral muscles based on T1W MRI. Understanding the geography of fat content in these muscles may offer additional insight in determining and improving spinal health. The clinical relevance and application of this method require testing across various populations to build on the early feasibility established in this study

Sagittal wedging of intervertebral discs and vertebral bodies in the cervical spine and their associations with age, sex and cervical lordosis: A large-scale morphological study

AbstractMany recent studies have focused on the functional and clinical importance of cervical lordosis. However, there is little accurate knowledge of the anatomical parameters that constitute cervical lordosis (i.e., the sagittal wedging angles of intervertebral discs and vertebral bodies) and their associations with age and sex. Standing lateral cervical radiographs of 1020 subjects (424 males, 596 females) with a mean age of 36.6 ± 17.0 years (range 7–95 years) were evaluated retrospectively. Cervical lordosis, the sum of intervertebral disc wedging angles from C2/C3 to C6/C7 and the sum of vertebral body wedging angles from C3 to C7 were measured. The sum of intervertebral disc wedging and the sum of vertebral body wedging were 20.6° ± 14.7° and −12.8° ± 10.3°, respectively. The sum of intervertebral disc wedging increased significantly with age and was significantly greater in males than females, whereas there was no sex‐related difference in the sum of vertebral body wedging. The sum of intervertebral disc wedging was negatively correlated with sum of vertebral body wedging. Wedging of discs contributed to C2–C7 cervical lordosis more significantly than wedging of vertebral bodies. There were moderate positive correlations between cervical lordosis and intervertebral disc wedging angles at C3/C4, C4/C5 and C5/C6; weak correlations were observed at C2/C3 and C6/C7. This study constitutes the largest currently available analysis comprehensively documenting the anatomical characteristics of sagittal wedging of intervertebral discs and vertebral bodies in the cervical spine. The findings could improve understanding of the internal architecture of cervical lordosis among clinicians

Reproducibility of thoracic kyphosis measurements in patients with adolescent idiopathic scoliosis

BACKGROUND: Current surgical treatment for adolescent idiopathic scoliosis (AIS) involves correction in both the coronal and sagittal plane, and thorough assessment of these parameters is essential for evaluation of surgical results. However, various definitions of thoracic kyphosis (TK) have been proposed, and the intra- and inter-rater reproducibility of these measures has not been determined. As such, the purpose of the current study was to determine the intra- and inter-rater reproducibility of several TK measurements used in the assessment of AIS. METHODS: Twenty patients (90% females) surgically treated for AIS with alternate-level pedicle screw fixation were included in the study. Three raters independently evaluated pre- and postoperative standing lateral plain radiographs. For each radiograph, several definitions of TK were measured as well as L1–S1 and nonfixed lumbar lordosis. All variables were measured twice 14 days apart, and a mixed effects model was used to determine the repeatability coefficient (RC), which is a measure of the agreement between repeated measurements. Also, the intra- and inter-rater intra-class correlation coefficient (ICC) was determined as a measure of reliability. RESULTS: Preoperative median Cobb angle was 58° (range 41°–86°), and median surgical curve correction was 68% (range 49–87%). Overall intra-rater RC was highest for T2–T12 and nonfixed TK (11°) and lowest for T4–T12 and T5–T12 (8°). Inter-rater RC was highest for T1–T12, T1-nonfixed, and nonfixed TK (13°) and lowest for T5–T12 (9°). Agreement varied substantially between pre- and postoperative radiographs. Inter-rater ICC was highest for T4–T12 (0.92; 95% CI 0.88–0.95) and T5–T12 (0.92; 95% CI 0.88–0.95) and lowest for T1-nonfixed (0.80; 95% CI 0.72–0.88). CONCLUSIONS: Considerable variation for all TK measurements was noted. Intra- and inter-rater reproducibility was best for T4–T12 and T5–T12. Future studies should consider adopting a relevant minimum difference as a limit for true change in TK. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13013-017-0112-4) contains supplementary material, which is available to authorized users

APSS-ASJ Best Clinical Research Award: Predictability of Curve Progression in Adolescent Idiopathic Scoliosis Using the Distal Radius and Ulna Classification

Study DesignProspective study.PurposeTo determine the risk of clinically significant curve progression in adolescent idiopathic scoliosis (AIS) based on the initial Cobb angle and to test the utility of the distal radius and ulna (DRU) classification in predicting these outcomes.Overview of LiteratureDetermining the remaining growth potential in AIS patients is necessary for predicting prognosis and initiating treatment. Limiting the maturity Cobb angle to <40° and <50° reduces the risk of adulthood progression and need for surgery, respectively. The risk of curve progression is the greatest with skeletally immature patients and thus warrants close monitoring or early intervention. Many parameters exist for measuring the skeletal maturity status in AIS patients, but the DRU classification has been shown to be superior in predicting peak growth and growth cessation. However, its predictive capabilities for curve progression are unknown.MethodsTotally, 513 AIS patients who presented with Risser 0–3 were followed until either skeletal maturity or the need for surgery, with a minimum 2-year follow-up period. Outcomes of 40° and 50° were used for probability analysis based on the cut-offs of adulthood progression risk and surgical threshold, respectively.ResultsAt the R6/U5 grade, most curves (probability of ≥48.1%–55.5%) beyond a Cobb angle of 25° progressed to the 40° threshold. For curves of ≥35°, there was a high risk of unfavorable outcomes, regardless of skeletal maturity. Most patients with the R9 grade did not progress, regardless of the initial curve magnitude (probability of 0% to reach the 50° threshold for an initial Cobb angle of ≥35°).ConclusionsThis large-scale study illustrates the utility of the DRU classification for predicting curve progression and how it may effectively guide the timing of surgery. Bracing may be indicated for skeletally immature patients at an initial Cobb angle of 25°, and those with a scoliosis ≥35° are at an increased risk of an unfavorable outcome, despite being near skeletal maturity

Geography of lumbar paravertebral muscle fatty infiltration

Study Design: Cross-sectional Objective: We quantified fatty infiltration (FI) geography of the lumbar spine to identify whether demographics, temporal low back pain (LBP), and disability influence FI patterns. Summary of Background Data: Lumbar paravertebral muscle FI has been associated with age, sex, LBP, and disability; yet, FI accumulation patterns are inadequately described to optimise interventions. Methods: This cross-sectional study employed lumbar axial T1-weighted MRI in 107 Southern-Chinese adults (54 females, 53 males). Single-slices at the vertebral inferior end-plate per lumbar level were measured for quartiled-FI, and analysed against demographics, LBP, and disability (ODI: Oswestry Disability Index). Results: Mean FI% was higher in females, on the right, increased per level caudally, and from medial to lateral in men (p 0.05). Conclusions: Lumbar paravertebral muscle FI predominates in the lower lumbar spine, notably for those aged 40-65, and depends more on sagittal than transverse distribution. Higher FI in females and differences of mean FI between sexes for BMI, LBP, and disabling ODI suggest sex-differential accumulation patterns. Our study contradicts pain models rationalising lumbar muscle FI and may reflect a normative sex-dependent feature of the natural history of lumbar paravertebral muscles

A Riemann solver at a junction compatible with a homogenization limit

We consider a junction regulated by a traffic lights, with n incoming roads and only one outgoing road. On each road the Phase Transition traffic model, proposed in [6], describes the evolution of car traffic. Such model is an extension of the classic Lighthill-Whitham-Richards one, obtained by assuming that different drivers may have different maximal speed. By sending to infinity the number of cycles of the traffic lights, we obtain a justification of the Riemann solver introduced in [9] and in particular of the rule for determining the maximal speed in the outgoing road.Comment: 19 page

Tracking Cyber Adversaries with Adaptive Indicators of Compromise

A forensics investigation after a breach often uncovers network and host indicators of compromise (IOCs) that can be deployed to sensors to allow early detection of the adversary in the future. Over time, the adversary will change tactics, techniques, and procedures (TTPs), which will also change the data generated. If the IOCs are not kept up-to-date with the adversary's new TTPs, the adversary will no longer be detected once all of the IOCs become invalid. Tracking the Known (TTK) is the problem of keeping IOCs, in this case regular expressions (regexes), up-to-date with a dynamic adversary. Our framework solves the TTK problem in an automated, cyclic fashion to bracket a previously discovered adversary. This tracking is accomplished through a data-driven approach of self-adapting a given model based on its own detection capabilities. In our initial experiments, we found that the true positive rate (TPR) of the adaptive solution degrades much less significantly over time than the naive solution, suggesting that self-updating the model allows the continued detection of positives (i.e., adversaries). The cost for this performance is in the false positive rate (FPR), which increases over time for the adaptive solution, but remains constant for the naive solution. However, the difference in overall detection performance, as measured by the area under the curve (AUC), between the two methods is negligible. This result suggests that self-updating the model over time should be done in practice to continue to detect known, evolving adversaries.Comment: This was presented at the 4th Annual Conf. on Computational Science & Computational Intelligence (CSCI'17) held Dec 14-16, 2017 in Las Vegas, Nevada, US