Intérêt du métal trabéculaire dans les reprises de PTH : Étude rétrospective comparative des implants cotyloïdiens en métal trabéculaire par rapport aux implants classiques

peer reviewe

Clinical and radiological results with a 36-mm Cobalt-Chrome prosthetic head, cross-linked Durasul liners associated with Allofit cups: A more than 10-year follow-up period.

peer reviewedHighly cross-linked polyethylene is currently a common articulation surface used for THA. The aim of the present study is in-vivo assessment of highly cross-linked Durasul® polyethylene linear and volumetric wear when associated with a 36-mm prosthetic femoral head. We retrospectively reviewed clinical and radiographic data of 78 patients (81 hips) having primary THAs using Durasul® liner combined with a 36-mm CoCr prosthetic head. All of them were followed for more than 10 years. Patient outcome was assessed with the Harris Hip Score (HHS) preoperatively and at last follow-up. Two-dimensional prosthetic head penetration into polyethylene, three-dimensional wear rates and cup migration were evaluated. the preoperative and last follow-up HHS were 50.43 +/- 10.42 and 97.44 +/- 5.51 respectively. The annual penetration of the prosthetic head into Durasul® liner was 0.029 +/- 0.003 mm. The annual linear penetration and volumetric wear extrapolation rates using Charnley and Ilchmann formulas were 37.84% and 57.76% respectively of that seen with conventional polyethylene liner. At last follow-up, the total loss of material in Durasul® represents only 0.15% of the initial polyethylene mass. We did not observed any significant cup migration in the study group. Results are promising and we believe that these data authorize the continued use of highly cross-linked polyethylene liner associated with a 36-mm prosthetic head for total hip arthroplasties in older patients. More long-term follow-up studies are mandatory before we feel comfortable with the project of using cross-linked polyethylene in young and active patients instead of ceramic-on-ceramic bearings

Anterior Fracture - Dislocation of the Glenoid: Case report.

peer reviewe

Planification préopératoire d’une PTH : cette partie essentielle de la procédure doit-elle être nécessairement réalisée par le chirurgien orthopédiste ? Est-elle influencée par le design de l’implant ? Une étude prospective à propos de 200 arthroplasties totales de hanche.

Background Currently, patients who undergo total hip arthroplasty want a complete restoration of their hip function and not only pain relief. Templating in THA is essential for accurately predicting the optimal size of the implants required. It also reduces the risk of potential complications. Aim To check the reproducibility of our preoperative planning, to compare the accuracy of templating between orthopedic surgeon (OS), orthopedic resident (OR) and data manager (DM), to determine the learning curve between the different planners and to evaluate the effect of body mass index impact on digital templating for THA. Materials and methods The software used for templating was IMPAX-Orthopaedic-Tools. A calibration marker (28-mm ball) was used for calibration. All the anteroposterior pelvis radiographs were planned by three participants (OS, OR, DM). Results We systematically collected the precisely planned size measurements as well as the variation by 1 or 2 sizes of prostheses. At +/- 1 size, we did not find any significant difference between the participants with respectively 94%, 96% and 93% concordance for the cup, 88%, 90% and 90% for the stem and 85%, 84% and 83% for the neck. Conclusions Our preoperative templating was accurate in predicting the required implant size and results were similar to those available in the literature. We did not find any difference between the planners and we were unable to objectivate a learning curve period. We conclude that this essential part of the planning procedure can be performed by the surgeon himself or an orthopedic resident or data manager who has anatomical knowledge if the surgeon is unable to perform templating himself

Notre expérience du couple métal-métal (MoM) dans le resurfaçage (RTH) et les prothèses totales de hanche avec tête de grand diamètre (PTH-GD) présentant un suivi minimum de 10 ans : À propos de 215 cas.

peer reviewedIntroduction : Au début des années 2000, le couple métal-métal (MoM) a connu un regain d’intérêt pour les prothèses de resurfaçage (PR) ainsi que pour les prothèses totales de hanche (PTH) utilisant des megatêtes (> 36 mm) (MT). Depuis 2011, il n’a cessé d’alimenter les débats suite au taux d’échecs à court et moyen termes anormalement élevé dans certains études. Des prothèses particulières ont dès 2010 jeté le discrédit sur ce couple dans son ensemble, imposant un suivi radio-clinique et biologique attentif de ces patients. Matériel et méthodes : Entre 2003 et 2009, 215 prothèses MoM ont été implantées dans notre service. Nous avons revu avec un recul d’au-moins 10 ans (10 – 21 ans ; moyenne 15,2 ans) 142 patients porteurs d’implants DUROM (68 MT, 74 PR), 60 patients porteurs d’implants BHR (15 MT, 45 PR) et 13 patients porteurs d’implants ASR (12 MT, 1 PR). 38 patients perdus de vue ou décédés d’une cause sans relation avec les implants (27 DUROM, 8 BHR et 3 ASR) mais présentant un suivi minimum de 10 ans ont été inclus dans l’étude. Nous avons établi pour chaque groupe de prothèse le score de Harris (HHS) en préopératoire et au dernier suivi , le taux de survie des implants ainsi qu’un historique détaillé des complications ayant mené à une reprise chirurgicale. Résultats : Pour le groupe DUROM, les HHS étaient de 52,9 en préopératoire et 96,5 ; au dernier suivi, nous dénombrons 14 reprises, 7 sur méga-tête (10,3 %) et 7 sur resurfaçage (9,5 %). Pour le groupe BHR, les HHS étaient de 52,4 en préopératoire et 96,2 ; au dernier suivi, nous dénombrons 6 reprises, 1 sur méga-tête (6,7 %) et 5 sur resurfaçage (11,1 %). Pour le groupe ASR, les HHS étaient de 51,3 en préopératoire et 93,1 ; au dernier suivi, nous dénombrons 2 reprises sur méga-tête (15,4 %) et pas de reprise de notre unique resurfaçage (0,0 %). Les principales causes de reprise sont pour les PR une cobaltémie élevée sans symptôme clinique (2 cas), un descellement cotyloïdien (3 cas), un conflit antérieur (3 cas) et un cas de luxation ; pour les MT un descellement (3 cas), une infection (3 cas) et la présence d’une pseudotumeur (2 cas). Les autres indications de reprises étaient des ossifications hétérotopiques, une bursite trochantérienne, une fracture périprothétique ainsi qu’une suspicion d’allergie au métal. Discussion : Les résultats de notre étude semblent montrer un faible pourcentage d’échec lié spécifiquement à l’utilisation du couple MoM à grand diamètre : 3 % (7/215 cas). Selon notre expérience, toute une classe d’implants qui aurait pu conserver une place dans des indications bien spécifiques s’est vue condamnée probablement à tort. Conclusion : Il semble important d’étudier ces implants non pas en tant que classe globale mais en séparant resurfaçaces, mégatêtes et fabricants en raison de la spécificité des métallurgies

SUR QUELQUES CURIOSITÉS D'HISTOIRE NATURELLE DANS LES PERTUIS CHARENTAIS : FAUNE DES INVERTÉBRÉS MARINS

Eight invertebrate species, rediscovered, demographically expanding or newly observed are reported from the Pertuis Charentais Sea. They were sampled from intertidal rocky shores (Alpheus macrocheles, Aslia lefevrei, Epitonium clathrulatum and Haliotis tuberculata), intertidal sand flats (Africorchestia spinifera and Arcuatula senhousia) and subtidal bottoms (Aslia lefevrei and Rapana venosa). One species is pelagic (Lepas anatifera). Most of them are within their natural range. However, R. venosa, native to Southeast Asia, has been introduced in the Pertuis Charentais since the 2010s and its populations are currently expanding. The new northern limit of Africorchestia spinifera along the Atlantic coast is defined as the Ré Island. Phoresis of Crepidula fornicata on Carcinus maenas is noted but was already described in European waters whereas it is a hitherto undescribed and unexpected association with the gastropod R. venosa.Eight invertebrate species, rediscovered, demographically expanding or newly observed are reported from the Pertuis Charentais Sea. They were sampled from intertidal rocky shores (Alpheus macrocheles, Aslia lefevrei, Epitonium clathrulatum and Haliotis tuberculata), intertidal sand flats (Africorchestia spinifera and Arcuatula senhousia) and subtidal bottoms (Aslia lefevrei and Rapana venosa). One species is pelagic (Lepas anatifera). Most of them are within their natural range. However, R. venosa, native to Southeast Asia, has been introduced in the Pertuis Charentais since the 2010s and its populations are currently expanding. The new northern limit of Africorchestia spinifera along the Atlantic coast is defined as the Ré Island. Phoresis of Crepidula fornicata on Carcinus maenas is noted but was already described in European waters whereas it is a hitherto undescribed and unexpected association with the gastropod R. venosa

A Role for Glutamate Transporters in the Regulation of Insulin Secretion

In the brain, glutamate is an extracellular transmitter that mediates cell-to-cell communication. Prior to synaptic release it is pumped into vesicles by vesicular glutamate transporters (VGLUTs). To inactivate glutamate receptor responses after release, glutamate is taken up into glial cells or neurons by excitatory amino acid transporters (EAATs). In the pancreatic islets of Langerhans, glutamate is proposed to act as an intracellular messenger, regulating insulin secretion from beta-cells, but the mechanisms involved are unknown. By immunogold cytochemistry we show that insulin containing secretory granules express VGLUT3. Despite the fact that they have a VGLUT, the levels of glutamate in these granules are low, indicating the presence of a protein that can transport glutamate out of the granules. Surprisingly, in beta-cells the glutamate transporter EAAT2 is located, not in the plasma membrane as it is in brain cells, but exclusively in insulin-containing secretory granules, together with VGLUT3. In EAAT2 knock out mice, the content of glutamate in secretory granules is higher than in wild type mice. These data imply a glutamate cycle in which glutamate is carried into the granules by VGLUT3 and carried out by EAAT2. Perturbing this cycle by knocking down EAAT2 expression with a small interfering RNA, or by over-expressing EAAT2 or a VGLUT in insulin granules, significantly reduced the rate of granule exocytosis. Simulations of granule energetics suggest that VGLUT3 and EAAT2 may regulate the pH and membrane potential of the granules and thereby regulate insulin secretion. These data suggest that insulin secretion from beta-cells is modulated by the flux of glutamate through the secretory granules