Next generation of growth-sparing techniques: preliminary clinical results of a magnetically controlled growing rod in 14 patients

Session 3A - Early Onset Scoliosis: Paper no. 33SUMMARY: Growth-sparing techniques are commonly used for the treatment of progressive EOS. The standard growing rod (GR) technique requires multiple surgeries for lengthening. The preliminary results of MCGR has shown the comparable outcomes to standard GR without the need for repeated surgery which can be expected to reduce the overall complication rate in GR surgery. INTRODUCTION: The growing rod (GR) technique for management of progressive Early-Onset Scoliosis (EOS) is a viable alternative but with a high complication rate attributed to frequent surgical lengthenings. The safety and efficacy of a non-invasive Magnetically Controlled Growing Rod (MCGR) has been previously reported in a porcine model. We are reporting the preliminary results of this technique in EOS. METHODS: Retrospective review of prospectively collected multi-center data. Only patients who underwent MCGR surgery and at least 3 subsequent spinal distractions were included in this preliminary review. Distractions were performed in clinic without anesthesia or analgesics. T1-T12 and T1-S1 height and the distraction distance inside the actuator were analyzed in addition to conventional clinical and radiographic data. RESULTS: Patients (N=14; 7 F and 7 M) had a mean age of 8y+10m (3y+6m to 12y+7m) and underwent a total of 14 index surgeries (SR: index single rod in 5 and DR: dual rod in 9) and 91 distractions. There were 5 idiopathic, 4 neuromuscular, 2 congenital, 2 syndromic and one NF. Mean follow-up (FU) was 10 months (5.8-18.2). Mean Cobb changed from 57° pre-op to 35° post-op and correction was maintained (35°) at latest FU. T1-T12 increased by 4 mm for SR and 10 mm for DR with mean monthly gain of 0.5 and 1.39, respectively. T1-S1 gain was 4 mm for SR and 17 mm for DR with mean monthly gain of 0.5 mm for SR and 2.35 mm for DR. The mean interval between index surgery and the first distraction was 66 days and thereafter was 43 days. Complications included one superficial infection in (SR), one prominent implant (DR) and minimal loss of initial distraction in three after index MCGR (all SR). Overall, partial loss of distraction was observed following 14 of the 91 distractions (one DR and 13 SR). This loss was regained in subsequent distractions. There was no neurologic deficit or implant failure. CONCLUSION: MCGR appears to be safe and provided adequate distraction similar to the standard GR technique without the need for repeated surgeries. DR patients had better initial curve correction and greater spinal height. No major complications were observed during the short follow-up period. The FDA has not cleared the drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an ‘off label’ use).postprin

CONSTITUTIVE EQUATION, QUASI-STATIC AND DYNAMIC BUCKLING OF 2024-T3 PLATES - EXPERIMENTAL RESULT AND ANALYTICAL MODELLING

Nos travaux expérimentaux statistiques et dynamiques sur des éprouvettes en AU4G1 ont permis d'aboutir à une modélisation statique et dynamique de la variation de σcr = f (Ɗ) et de montrer, à partir du statique, l'influence de la vitesse de choc (V0) et de la vitesse de déformation (ε) sur les valeurs des contraintes critiques de flambage.Our experimental work allowed us to design a static and dynamic model of σcri = f (Ɗ), and to show from quasistatic, the effect of impact velocity V0, strain rate ε on the critical stress buckling

CLASSIFICATION DE LA TENUE AU CHOC DES RESINES ORGANIQUES LORS D'ESSAIS EN COMPRESSION DYNAMIQUE ET D'IMPACT SUR PANNEAUX DES COMPOSITES A FIBRES DE VERRE

Cette recherche a permis de classer les résines organiques (époxyde, vinylester, polyester) utilisées dans la fabrication des composites à fibres de verre par rapport à deux types de sollicitations : monoaxiale (compression statique et dynamique dans le sens parallèle aux fibres et perpendiculaire aux fibres) et triaxiale (impact sur panneaux).This research have permitted to classify the resins (epoxyde, vinylester, polyester) used in glass fibre composite manufacturing, with regard to two type of test : static and dynamic compression in the parallel and perpendicular direction to the fibres, and impact panels

CISAILLEMENT DYNAMIQUE MONO-AXIAL NOUVELLE MÉTHODE - PARTIE I

Une nouvelle méthode de l'étude du cisaillement mono-axial a été créée pour compléter celles déjà existantes (voir CAMPBELL, DOWLING, HARTMANN, STELLY et DORMEVAL...).A new method to study uni-axial shear has been developed in addition to the already existing ones (see CAMPBELL, DOWLING, HARTMANN, STELLY and DORMEVAL...)

Finite time blow-up for damped wave equations with space–time dependent potential and nonlinear memory

In this paper, we consider the Cauchy problem in Rn, n≥ 1 , for semilinear damped wave equations with space–time dependent potential and nonlinear memory. A blow-up result under some positive data in any dimensional space is obtained. Moreover, the local existence in the energy space is also studied. © 2018, Springer Nature Switzerland AG

INFLUENCE DU CHOC RÉPÉTÉ SUR LE COMPORTEMENT EN COMPRESSION ET TRACTION DYNAMIQUE DE L'ACIER XC18

L'influence du choc répété sur le comportement plastique de l'acier XC18S en compression et traction dynamique a été étudiée, où on montre l'évolution de la loi de comportement (σ = f(ε)) en fonction du nombre de chocs. Le réarrangement des dislocations dépend du temps entre deux chocs et agit sur la valeur du coefficient de sensibilité de la contrainte à la vitesse de déformation ainsi que sur la valeur du saut de contrainte Ɗσ.The plastic behaviour of the mild steel (XC18S) have been studied in compression or tensile repetitive shocks. The stress-strain relation, [(σ = f(ε)], was discussed as a function of time and the number of shocks. The duration between two shots yields some effects on the dislocation arrangement. This changes the strain-rate sensitivity of the materials and also the value of stress increment Ɗσ after the previous shocks

Intégration des caractéristiques des soudures dans les calculs de crash

Cet article s'inscrit dans le cadre d'une tentative d'amélioration des simulations numériques de structures mécano-soudés. Plusieurs chemins de modélisation d'une structure sont proposés en intégrant les éléments simulant la soudure. Ainsi complété, le modèle numérique devient plus physique et, par la même occasion, moins sensible aux paramètres numériques et conditions aux limites. Les déformées initiales dues au soudage sont simulées pour évaluer la sensibilité du modèle aux imperfections géométriques.This article describes an attempt to improve the numerical simulation of welded structures. Several ways of modeling a structure are proposed by integrating finite elements simulating welding beads. Hence, the FE model becomes more physical and less sensitive to numerical parameters and boundary conditions. Initial unevenness induced by welding processes is simulated so as to assess the sensitivity of the model to geometric imperfections

Finite time blow-up for damped wave equations with space–time dependent potential and nonlinear memory

In this paper, we consider the Cauchy problem in Rn, n≥ 1 , for semilinear damped wave equations with space–time dependent potential and nonlinear memory. A blow-up result under some positive data in any dimensional space is obtained. Moreover, the local existence in the energy space is also studied. © 2018, Springer Nature Switzerland AG

Incidence of kidney stones with topiramate treatment in pediatric patients.

Purpose: We ran this study to assess the incidence of nephrolithiasis in a group of children on topiramate (TPM) therapy for at least 1 year. Methods: In this retrospective observational surveillance study, we reviewed the medical charts of children on TPM for at least 1 year seen at the pediatric neurology department during the period from 2005 to 2010 at King Fahad Medical City. Children with a normal baseline ultrasound report were included. Follow-up ultrasound reports after at least 1 year were collected. However, patients with any evidence of chronic illness or medications that may affect the kidney functions in addition to those who are not compliant with the prescribed dose were excluded. Family history of renal stones, symptoms suggestive of urologic disorders, and comorbidities were recorded. Key Findings: Medical charts of 96 children on TPM with a mean age of 6.9 (±3.8) years were reviewed; 52 (54.2%) of the children were male. The follow-up ultrasound showed that five children (5.2%) had developed kidney stones. The occurrence of kidney stones was found in four female patients (80%) versus one male (20%) (p > 0.05). Significance: Long-term use of TPM may result in increased incidence of asymptomatic kidney stones in the pediatric population. Hence, routine baseline and follow-up ultrasound of the urinary system should be recommended during the use of TPM in children