Volume and fat infiltration of spino-pelvic musculature in adults with spinal deformity.

AIM: To investigate fat infiltration and volume of spino-pelvic muscles in adults spinal deformity (ASD) with magnetic resonance imaging (MRI) and 3D reconstructions. METHODS: Nineteen female ASD patients (mean age 60 ± 13) were included prospectively and consecutively and had T1-weighted Turbo Spin Echo sequence MRIs with Dixon method from the proximal tibia up to T12 vertebra. The Dixon method permitted to evaluate the proportion of fat inside each muscle (fat-water ratio). In order to investigate the accuracy of the Dixon method for estimating fat vs water, the same MRI acquisition was performed on phantoms of four vials composed of different proportion of fat vs water. With Muscl'X software, 3D reconstructions of 17 muscles or group of muscles were obtained identifying the muscle's contour on a limited number of axial images [Deformation of parametric specific objects (DPSO) Method]. Musclar volume (Vmuscle), infiltrated fat volume (Vfat) and percentage of fat infiltration [Pfat, calculated as follow: Pfat = 100 × (Vfat/Vmuscle)] were characterized by extensor or flexor function respectively for the spine, hip and knee and theirs relationship with demographic data were investigated. RESULTS: Phantom acquisition demonstrated a non linear relation between Dixon fat-water ratio and the real fat-water ratio. In order to correct the Dixon fat-water ratio, the non linear relation was approximated with a polynomial function of degree three using the phantom acquisition. On average, Pfat was 13.3% ± 5.3%. Muscles from the spinal extensor group had a Pfat significantly greater than the other muscles groups, and the largest variability (Pfat = 31.9% ± 13.8%, P < 0.001). Muscles from the hip extensor group ranked 2(nd) in terms of Pfat (14% ± 8%), and were significantly greater than those of the knee extensor (P = 0.030). Muscles from the knee extensor group demonstrated the least Pfat (12% ± 8%). They were also the only group with a significant correlation between Vmuscle and Pfat (r = -0.741, P < 0.001), however this correlation was lacking in the other groups. No correlation was found between the Vmuscle total and age or body mass index. Except for the spine flexors, Pfat was correlated with age. Vmuscle and Vfat distributions demonstrated that muscular degeneration impacted the spinal extensors most. CONCLUSION: Mechanisms of fat infiltration are not similar among the muscle groups. Degeneration impacted the spinal and hip extensors most, key muscles of the sagittal alignment

Spino-femoral muscles affect sagittal alignment and compensatory recruitment: a new look into soft tissues in adult spinal deformity

Objective To quantify muscle characteristics (volumes and fat infiltration) and identify their relationship to sagittal malalignment and compensatory mechanism recruitment. Methods Female adult spinal deformity patients underwent T1-weighted MRI with a 2-point Dixon protocol from the proximal tibia up to the T12 vertebra. 3D reconstructions of 17 muscles, including extensors and flexors of spine, hip and knee, were obtained. Muscle volume standardized by bone volume and percentage of fat infiltration (Pfat) were calculated. Correlations and regressions were performed. Results A total of 22 patients were included. Significant correlations were observed between sagittal alignment and muscle parameters. Fat infiltration of the hip and knee flexors and extensors correlated with larger C7-S1 SVA. Smaller spinal flexor/extensor volumes correlated with greater PI-LL mismatch (r = − 0.45 and − 0.51). Linear regression identified volume of biceps femoris as only predictor for PT (R2 = 0.34, p = 0.005) and Pfat of gluteus minimus as only predictor for SVA (R2 = 0.45, p = 0.001). Sagittally malaligned patients with larger PT (26.8° vs. 17.2°) had significantly smaller volume and larger Pfat of gluteus medius, gluteus minimus and biceps femoris, but similar values for gluteus maximus, the hip extensor. Conclusion This study is the first to quantify the relationship between degeneration of spino-femoral muscles and sagittal malalignment. This pathoanatomical study identifies the close relationship between gluteal, hamstring muscles and PT, SVA, which deepens our understanding of the underlying etiology that contributes to adult spinal deformity.The manuscript submitted does not contain information about medical device(s)/drug(s). This work received funding from Youth Fund of Natural Science Foundation of Jiangsu Province (BK20180122). This work received funding from Key Project supported by Medical Science and Technology Development Foundation, Nanjing Department of Health (YKK18092)

Estimation of spinopelvic muscles' volumes in young asymptomatic subjects: a quantitative analysis.

Purpose Muscles have been proved to be a major component in postural regulation during pathological evolution or aging. Particularly, spinopelvic muscles are recruited for compensatory mechanisms such as pelvic retroversion, or knee flexion. Change in muscles’ volume could, therefore, be a marker of greater postural degradation. Yet, it is difficult to interpret spinopelvic muscular degradation as there are few reported values for young asymptomatic adults to compare to. The objective was to provide such reference values on spinopelvic muscles. A model predicting the muscular volume from reduced set of MRI segmented images was investigated. Methods A total of 23 asymptomatic subjects younger than 24 years old underwent an MRI acquisition from T12 to the knee. Spinopelvic muscles were segmented to obtain an accurate 3D reconstruction, allowing precise computation of muscle’s volume. A model computing the volume of muscular groups from less than six MRI segmented slices was investigated. Results Baseline values have been reported in tables. For all muscles, invariance was found for the shape factor [ratio of volume over (area times length): SD \0.04] and volume ratio over total volume (SD \1.2 %). A model computing the muscular volume from a combination of two to five slices has been evaluated. The five-slices model prediction error (in % of the real volume from 3D reconstruction) ranged from 6 % (knee flexors and extensors and spine flexors) to 11 % (spine extensors). Conclusion Spinopelvic muscles’ values for a reference population have been reported. A new model predicting the muscles’ volumes from a reduced set of MRI slices is proposed. While this model still needs to be validated on other populations, the current study appears promising for clinical use to determine, quantitatively, the muscular degradation.The authors thank the ParisTech BiomecAM chair program on subject-specific musculoskeletal modelling, and in particular COVEA and Sociéte Générale. The authors thank the support received from the Anatomy association from Nice, France (Association d’Anatomie Nic¸oise). The authors also thank the support received from the Fulbright Program as a Fulbright PhD scholarship

Morphologie des articulations intervertébrales postérieures : Etude réalisée à partir de l'ostéothèque régionale LOMBONICE 2005

But de l'étude: Nos connaissances anatomiques sur le rachis lombaire reposent sur des dissections cadavériques rares, comprenant peu de sujets, très agés. La précision du scanner fait référence pour la morphologie articulaire. Une base de données scannographique (Lombonice 2005) a été crée puis 400 patients ont été mesurés. L'objectif est d'élaborer un Atlas biométrique de référence. Nous chercherons également à décrire la forme afin de concevoir une prothèse anatomique. Enfin, nous espérons dégager un dimorphisme sexuel et ainsi prédire l'âge ou le sexe d'un sujet en se basant ses articulations lombaires. Patients et méthodes : Nous avons mesuré 217 hommes et 183 femmes d'âge moyen 59 ans. Les coupes natives font 1,25 mm d'épaisseur (de L1 à S1). Nous crérons chaque plan de coupe puis nous positionnons des points de repères sur ces plans. Les coordonnées de ces points nous permettront de calculer des distances, des angles et le rayon des cercles mécaniques. Nous comparons ensuite les mesures obtenues avec l'âge, le côté, le sexe ou le niveau étudié. Résultats : De L1 à S1, les articulaires se rapprochent du mur postérieur mais s'éloignent l'une de l'autre. L'angle d'étrave postérieure augmente vers la caudalité. Le rayon des cercles mécaniques droit et gauche ne sont symétriques que dans 50% des cas et se confondent dans moins de 10 % des cas. Les mesures réalisées ne permettent pas de déterminer le sexe ou l'âge du sujet. Les mesures centrées sur le corps vertébral semblent plus discriminantes. Conclusion: La forme en 3D des articulaires postérieures est plus complexe qu'un fragment de sphère.Aim of the study: Our anatomical knowledge about lumbar spine is based on few cadaveric dissections with very few specimens of very old. The CT scan is very informative concerning about bony facets morphology. We have first created a database of lumbar CT called « Lombonice 2005 » and then we have made differents measureson 400 subjects. The aim of this study is to obtain a biometric atlas. Then, we wanted to create a new anatomic lumbar facet prosthesis. At least, we would like to determine the age or the sex of a sunject only with anatomic measures. Patients and methods : We have measured 217 men and 183 women of 59 years old on average. The native slices was 1,25 mm thick and goes from L1 to S1. We have created each cutting plan and we have placed many landmarks on them. The coordonates of these landmarks let us calculate differents distances, angles or mechanical circle radius which describe well the shape of the facets. We have compared then the measures obtained and the age, sex, side or level studied. Results : From L1 to S1, on transversal plan, the facets are getting closer to posterior wall but are getting away from each other. The posterior angle like a boat's bow increase from L1 to S1. The mechanical circle radius of each sides are symmetrical just in 50% of cases and unique in less than 10 % of cases. All the measures even in 3 dimensions does'nt let us determine the sex or the age of subjects. Measures on vertebral body seems to be more discriminant. Conclusion: We found that 3D shape of lumbar facets is more complicated than a spere fragment as expected. The side asymmetry makes it difficult to reproduce an anatomical facet's prosthesis

La prothèse discale lombaire (étude médico-économique)

NICE-BU Médecine Odontologie (060882102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

La réserve d'extension de la hanche et sa relation avec la colonne vertébrale

NICE-BU Médecine Odontologie (060882102) / SudocSudocFranceF

Sympathy-Empathy and the Radicalization of Young People

Background: The sympathy-empathy (SE) system is commonly considered a key faculty implied in prosocial behaviors, and SE deficits (also called callous-unemotional traits, CUTs) are associated with nonprosocial and even violent behaviors. Thus, the first intuitive considerations considered a lack of SE among young people who undergo radicalization. Yet, their identification with a cause, their underlying feelings of injustice and grievance, and the other ways in which they may help communities, suggest that they may actually have a lot of empathy, even an excess of it. As a consequence, the links between SE and radicalization remain to be specified. This critical review aims to discuss whether and how SE is associated with developmental trajectories that lead young people to radicalization. Method: We first recall the most recent findings about SE development, based on an interdisciplinary perspective informed by social neuroscience. Then, we review sociological and psychological studies that address radicalization. We will critically examine the intersections between SE and radicalization, including neuroscientific bases and anthropologic modulation of SE by social factors involved in radicalization. Results: This critical review indicates that the SE model should clearly distinguish between sympathy and empathy within the SE system. Using this model, we identified three possible trajectories in young radicalized individuals. In individuals with SE deficit, the legitimization of violence is enough to engage in radicalization. Concerning individuals with normal SE, we hypothesize two trajectories. First, based on SE inhibition/desensitization, individuals can temporarily join youths who lack empathy. Second, based on an SE dissociation, combining emotional sympathy increases for the in-group and cognitive empathy decreases toward the out-group. Conclusions: While confirming that a lack of empathy can favor radicalization, the counterintuitive hypothesis of a favorable SE development trajectory also needs to be considered to better specify the cognitive and affective aspects of this complex phenomenon

Do Radicalized Minors Have Different Social and Psychological Profiles From Radicalized Adults?

International audienceIntroduction: Radicalization is a major issue in Western societies. Supposedly, there is no predefined pathway leading to radicalization. However, youth appears to be at risk for radicalization. The aim of this study was to compare the social and psychological profiles of radicalized minors and radicalized adults.Methods: This cross-sectional study is based on the first large prospective sample of young French individuals (N = 150) who aimed to join the Islamic State (IS) between 2014 and 2016. This sample included 70 adolescents (mean age 15.82 years old, SD 1.14) and 80 young adults (mean age 23.32 years, SD 4.99). We compared the two groups on their sociodemographic and psychological characteristics.Results: Radicalized minors and radicalized adults have different profiles and follow different paths in the radicalization process. Among the group of minors, there are significantly more female subjects (81.4% versus 55.0%, adj. p = 0.007) and more self-harm history before radicalization (44.3% versus 16.2%, p <0.001). In addition, there are significantly less attempts to radicalize the entourage (24.3% versus 50.0%, adj. p = 0.007), and a tendency to show less cases of radicalization among the entourage (32.9% versus 52.5%, adj. p = 0.075) and less radicalization through physical encounter (45.7% versus 65%, adj. p = 0.082).Discussion: Overall, radicalized minors appear to be more psychologically vulnerable individuals than radicalized adults. These differences highlight the importance of tailored interventions in order to prevent radicalization among vulnerable adolescents

Analyse biométrique de l'anneau pelvien en 3 dimensions - à propos de 100 scanners

National audienceÀ l’instar de la chirurgie percutanée rachidienne, le traitement percutané du bassin traumatique instable par 2 vis polyaxiales canulées supra-acétabulaires et une tige précintrée sous-cutanée formant un fixateur interne pourrait se développer dans un futur proche. Ainsi nous avons voulu étudier les caractéristiques anatomiques des corridors osseux des hémi-bassins où se placent les vis et les distances transversales entre des repères osseux déterminés pour connaître les longueurs et les courbures requises pour les tiges.L'étude a consisté en une analyse de 100 scanners (48 femmes, 52 hommes) de sujets avec des bassins intacts. Les reconstructions 3D ont été réalisées sur le logiciel OSIRIX et le placement de 16 points sur le bassin modélisé en 3D a été réalisé par 3 chirurgiens selon un protocole commun. Les données ont été analysées par le laboratoire de recherche INRIA Sophia-Antipolis. Plusieurs distances et angles ont été mesurées dont celle correspondant à la longueur et au rayon de la tige antérieure cintrée du fixateur interne sous-cutané, celle des longueurs antéro-postérieures des corridors osseux pour les vis et l’angle entre les 2 vis supra-acétabulaires.La distance correspondant à la longueur de la tige antérieure du fixateur interne était en moyenne de 231 mm (200–267), celle du rayon était en moyenne de 117 mm (88–150). La distance correspondant à la longueur antéro-postérieure des corridors osseux pour les vis était en moyenne de 134 mm (102–157). L’angle entre les 2 vis supra-acétabulaire était en moyenne de 43 deg (31–56). L’analyse des rayons de courbure et des distances au scanner, montre une répartition large des données et ne permet pas de conclure sur une valeur standard. En effet les écarts types sont importants, mais on remarque que le sexe n’est pas un facteur influant sur les valeurs de nos mesures. Ceci peut sembler étonnant car les morphologies des bassins de l’homme et de la femme sont assez différentes.Le précintrage industrielle de la tige antérieur paraît impossible en raison des variations anatomiques inter-individuelles et devra être réalisé en peropératoire en fonction du patient. Des vis canulées d’une longueur suffisante restent à fabriquer