Genetics determine bone susceptibility to fluoride

Nowadays it is increasingly accepted that interactions with environmental factors must play an important role in determining bone quality and that these interactions must be influenced by genetics. Nevertheless, to date, only few animal studies explore an underlying genetic basis for extrinsic factors effect such as fluoride (F-) effect on bone metabolism. This study assessed the effect of increasing F- doses on the bone properties in three inbred mouse strains that demonstrate different susceptibilities to developing enamel fluorosis (A/J a “susceptible” strain, 129P3/J a “resistant” strain and SWR/J an “intermediate” strain). Fluoride concentrations were determined in femora and vertebral bodies. Bone mineral density was evaluating through DXA (Dual energy X-ray Absorptiometry). Three-point bend testing of femora, compression testing of vertebral bodies and femoral neck-fracture testing were performed to evaluate mechanical properties. Bone microarchitecture was quantified with microcomputed tomography and strut analysis. Bone formation was evaluated by static histomorphometry. Bone mineralization was quantified with backscattered electron (BSE) imaging and powder x-ray diffraction. Microhardness measurements were taken from the vertebral bodies (cortical and trabecular bone) and the cortex of the distal femur. Increasing doses of F- had different effects on the bone properties in the three inbred mouse strains. Although significant increases of bone F- concentration could be demonstrated, and no significant effects on bone macroarchitecture and BMD were found in the three strains, mechanical testing showed significant degradation of bone mechanical properties in the “susceptible” A/J strain, whereas moderate degradation in the “intermediate” SWR/J strain and no effect in the “resistant” 129P3/J strain were observed. Evaluation of the structural and material properties of the bone in the three strains showed that this different effect of F- on bone mechanical properties could be explained by an alteration of the mineral-organic interfacial bonding and/or bone matrix proteins, interfering with bone crystal growth inhibition on the crystallite faces as well as bonding between the mineral and organic interface. The smaller bone crystallites of the 129P3/J (resistant) strain may indicate a stronger organic-inorganic interface, reducing crystallite growth rate and increasing interfacial mechanical strength.(MED 3) -- UCL, 200

Clinical evaluation in pediatric orthopedic practice: What should the general practitioner know? [Examen clinique en orthopédie pédiatrique: Ce que le médecin généraliste doit savoir]

L’orthopédie pédiatrique est de nos jours une spécialité à part entière, qui se distingue de l’orthopédie adulte tant par ses pathologies que par son approche clinique. Cet article décrit l’examen clinique orthopédique « global » tel qu’il est réalisé par les auteurs dans leur pratique quotidienne, en mettant l’accent sur les aspects plus pertinents pour le médecin généraliste, l’objectif étant que ce dernier sache distinguer le normal du pathologique. Seule l’évaluation clinique de l’enfant ayant acquis la marche est décrite, selon une chronologie permettant de gagner progressivement la confiance de l’enfant

La toxine botulinique A dans le traitement de la spasticité dynamique en équin chez les enfants porteurs d'infirmité motrice d'origine cérébrale : étude préliminaire

Une étude clinique prospective a été réalisée afin d'évaluer l'efficacité desinjections intra-musculaires de toxine botulinique A dans le traitement des déformationsspastiques dynamiques en équin de la cheville retrouvées chez certains enfants atteintsd'infirmité motrice d'origine cérébrale. Dix enfants, âgés de 4 à 11 ans, ont étéinclus dans l'étude. Tous ces enfants présentaient des déformations spastiquesdynamiques en équin dans le cadre d'une infirmité motrice cérébrale et étaient touscapables de se déplacer avec ou sans aide. Deux unités de toxine botulinique A par kg depoids corporel étaient injectées dans les gastrocnémiens de chaque membre inférieurconcerné. Un examen clinique détaillé ainsi qu'une analyse vidéo de l'enfantdéambulant étaient réalisés avant les injections de toxine ainsi que 1, 3 et 6 moisaprès ces injections. Une analyse de la marche (par le système Elite) comprenant uneanalyse kinématique ainsi qu'une électromyographie dynamique de surface faisaientégalement partie du bilan réalisé avant et après les injections. Tous les patientsrepris dans l'étude ont présenté une amélioration clinique constatée par les parentset/ou les kinésithérapeutes ainsi que par le médecin lors de l'évaluation clinique.Ces améliorations consistaient essentiellement en une meilleure mobilité de la cheville,une plus grande tolérance du port des orthèses et des séances de kinésithérapie ainsiqu'une augmentation de l'endurance se manifestant par le fait qu'ils pouvaient marcherplus longtemps sans présenter de fatigue. L'amélioration clinique était évidente dansles 10 jours (3 à 10 jours) suivant l'injection. L'enregistrement vidéo ainsi quel'analyse de la marche ont confirmé ces constatations. Cette étude confirme la place dela toxine botulinique dans le traitement des déformations spastiques dynamiques en équinretrouvées chez certains enfants infirmes moteur cérébraux, à condition que lesindications soient posées de façon rigoureuse.[The use of botulinum-A toxin in spastic dynamic equinus deformities in children with cerebral palsy] Purpose of the study The purpose of this clinical prospective study is to better assess the efficacy of intramuscular injections of botulinum-A toxin in the treatment of spastic dynamic equinus deformities in children with cerebral palsy. Material Ten walking children (14 feet) with cerebral palsy were treated with botulinum-A, toxin (the American type, Botox) for spastic dynamic equinus, equinovalgus or equinovarus deformity of the foot. The mean age was 6 years (range 4 to 12 years of age). Method Two units of botulinum-A toxin per kilogram were injected in each involved extremity: the lateral and medial gastrocnemius were injected in equinus or equinovalgus foot and one more injection was done in the tibialis posterior in equinovarus foot. A clinical assessment (based on opinion of caretakers, functional evaluation-of gait, detailed orthopaedic clinical evaluation and video of the gait) and a gait analysis were performed prior to the first injections and then atl, 3 and 6 months afterwards. Results All patients showed a clinical improvement. The functional possibilities increased in 6 out of the 10 children. Five children showed a better endurance in their walking capacities. The clinical orthopaedic: exam showed improvement for 10 out of the 14 injected feet in passive dorsiflexion from 3 to 15 degrees at one month. Twelve feet improved their score on the Physician Rating Scale from 1 to 4 points. For gait analysis, 6 children (8 feet) had an improvement often minor of their curves in terms of improvement of the dorsal flexion of the ankle and the EMG of the gastrocnemius was improved in terms of decrease of spastic activity in 7 children (10 feet). The response to the injections was seen within 10 days (3 to 10 days) and lasted 3 to 6 months except in one child where it stopped already after 1 month. No side effect was noted. Discussion All ten patients of our study showed some type of improvement even if only minor or limited in time in some of them. These data corroborate previous studies performed by other authors. Since this study, the recommended dosage has greatly increased (from 2 U/kg up to; 10 U/kg or even more). The most interesting new element is that we noted that it seems to increase the endurance of the patient regarding walking distance. Conclusion The intramuscular injection of botulinum-A toxin in spastic dynamic equinus deformities in children with cerebral palsy is an useful treatment modality, but the indications have to be respected scrupulously: The subject needs more study with the higher dosage and clinical evaluation to confirm the possible increased indurance

A novel technique for treatment of progressive scoliosis in young children using a 3-hook and 2-screw construct (H3S2) on a single sub-muscular growing rod: Surgical technique

Introduction: Several different growing rod techniques have been described in the literature to treat progressive scoliosis in young children. Nevertheless, none of these techniques has shown a real superiority, and the rate of complications remains high. The purpose of this report is to describe an original fusionless method of treatment for this problem. Materials and methods: The 3 hooks-2 screws (H3S2) construct consists of a single 5.5 mm titanium rod with three hooks proximally and two monoaxial pedicle screws distally, and some extra length of rod located distally and/or proximally that can be used for future lengthenings. To date, a total of 103 H3S2 constructs have been performed in our institution. This paper reports the preliminary results on 38 patients, with a minimum follow-up of 2 years. Results: This procedure was found to be effective in maintaining scoliosis correction while allowing continued spinal growth and was associated with a low rate of complications. Conclusions: The H3S2 construct was found to have several advantages over the growing rod techniques as previously described in the literature. These include no need for post-operative bracing, fewer lengthening procedures and a lower rate of complications. © 2014 Springer-Verlag

Treatment of late-diagnosed DDH – Comparison of two treatments

Etude comparative de deux protocoles thérapeutiques pour luxations de hanche diagnostiquées tardivemen