Measurement of implant deployment and related forces in kyphoplasty by percutaneous approach

BACKGROUND: The treatment of osteoporotic vertebral compression fractures using a transpedicular approach and cement injection has grown significantly over the last two decades. METHODS: The aim was to study the deployment of an implant dedicated to the vertebral augmentation by percutaneous approach (kyphoplasty). Its kinematics and the related forces have been investigated. A theoretical model of deployment has been proposed and the ancillary was instrumented with strain gauges and Hall effect sensors to measure kinematics and force in the deployment actuator (tensile rod). The methodology was first evaluated ex-vivo in a test-bench with boundary conditions monitored by a tensile machine. Then, a cadaver study was carried out in three lumbar and thoracic vertebral segments of normal and osteoporotic spines. FINDINGS: The relationships between ancillary internal forces, deployment, and cranio-caudal pushing force have been obtained. The test-bench experiment showed quasi-proportional relationship between force distribution and kinematics during the deployment. Ex-vivo cranio-caudal pushing forces were measured. Cadaver studies showed cranio-caudal pushing forces comprised between 100N and 200N. These forces were dependent upon the implant location in the vertebral body and bone stock. INTERPRETATION: The methodology was related to the analysis of load distribution and kinematics of a deployable implant for vertebral augmentation. The ancillary instrumentation contributed to the objective quantification of the surgical technique. The cadaver study in normal and osteoporotic spines exhibited the role of bone properties and implant location in implant deployment. This pilot study showed a methodology to improve the kyphoplasty surgery and patient comfort in clinical routine

Les itinéraires parisiens du commissaire Maigret

On a dit de Simenon qu’il était un romancier de l’espace, et Maigret apparaît comme un enquêteur éminemment parisien, qui aime flâner et arpenter les rues de sa ville. La célèbre atmosphère de Simenon résulte de courtes descriptions, où l’espace est surtout nommé et structuré par des oppositions binaires. Aussi l’espace de Maigret est-il avant tout un espace abstrait, celui du plan et de l’itinéraire, dont les valeurs géographiques, sociales et psychologiques donnent leur épaisseur aux personnages.Space is important in Georges Simenon’s novels, especially in the detective stories where commissaire Maigret likes to stroll through the streets of Paris. The famous Simenon atmosphere becomes from short descriptions, with streets names and binary structures. Maigret’s space is thus abstract, and to solve the enigma is to map out a route, where geographical, sociological and psychological values give their depth to the characters

MRI evaluation of the hydration status of non-pathological lumbar intervertebral discs in a pediatric population

Introduction The intervertebral disc (IVD) is made up of the annulus fibrosus (AF) and the nucleus pulposus (NP) – an inert hydrated complex. The ability of the IVD to deform is correlated to that of the NP and depends on its hydration. As the IVD ages, its hydration decreases along with its ability to deform. In adolescent idiopathic scoliosis, one of the etiological hypotheses pertains to the IVD, thus making its condition relevant for the diagnosis and monitoring of this pathology. Hypothesis IVD hydration depends on sex, age and spine level in an asymptomatic pediatric population. The corollary is data on a control group of healthy subjects. Material and methods A cohort of 98 subjects with normal spine MRI was enrolled; their mean age was 13.3 years. The disc volume and hydration of each IVD was evaluated on T2-weighted MRI sequences, using previously validated image processing software. This evaluation focused on the lumbar spine, from the thoracolumbar junction to the lumbosacral junction. It was assumed that IVD hydration was related to the ratio of NP and AF volumes. A mixed multivariate linear analysis was used to explore the impact of age, sex and spinal level on disc hydration. Results Disc hydration was higher overall in boys than in girls, but this difference was not significant. Hydration increased with age by +0.005 for each additional year (p = 0.0213). Disc hydration appears to be higher at the thoracolumbar junction than the lumbar spine, although this difference was not significant. Conclusion Through this MRI study, we established a database of non-pathological lumbar disc hydration as a function of age, sex and spinal segment along with 95% confidence intervals

« Hamlet » à Chaillot

Bolzinger André, Bolzinger Claudie. « Hamlet » à Chaillot. In: Bulletin de psychologie, tome 37 n°363, 1983. Théorie psychanalytique des groupes. pp. 239-242

Dépression et amour du censeur. À propos d'« Ivanov »

Bolzinger André, Bolzinger Claudie. Dépression et amour du censeur. À propos d'« Ivanov ». In: Bulletin de psychologie, tome 37 n°366, 1984. Psychologie sociale. pp. 897-901

René Diatkine, Janine Simon. — La psychanalyse précoce. Paris, P.U.F., Coll. Le fil rouge, 1972

Bolzinger André. René Diatkine, Janine Simon. — La psychanalyse précoce. Paris, P.U.F., Coll. Le fil rouge, 1972. In: Bulletin de psychologie, tome 27 n°312, 1974. pp. 788-789