Blade-plate fixation for distal femoral fractures: A case-control study

AbstractBackgroundThe blade-plate is the earliest of the contemporary internal fixation devices introduced for distal femoral fractures. The recent development of dedicated, fixation devices has considerably limited its use. The objective of this study was to evaluate outcomes after blade-plate fixation and after fixation using other devices.HypothesisOutcomes after blade-plate fixation are similar to those after condylar screw-plate, distal femoral nail, or locking condylar plate fixation.Material and methodsWe reviewed outcomes after 62 patients managed with blade-plate fixation and included in a multicentre retrospective study (n=57) or a multicentre prospective study (n=5) and we compared them to outcomes after fixation using condylar screw-plates (n=82), distal femoral nail (n=219), or locking condylar plates (n=301). The four groups were comparable for age, gender distribution, occupational status, prevalence of skin wounds, patient-related factors, type of accident, and type of fracture. The evaluation relied on the clinical International Knee Society (IKS) score and on radiographs.ResultsNo significant differences existed across the four groups for operative time, blood transfusion use, complications, need for bone grafting, non-union rate, or IKS score values. The early surgical revision rate for removal of the fixation material was 4% with the blade-plate and 16% with the other three fixation devices (P=0.02). Post-operative fracture deformity was similar in the four groups with, however, a higher proportion of residual malalignment in the screw-fixation group. The final anatomic axis was 3.3±1.4° with the blade-plate versus 2.3±3.7° with the other three fixation devices. The blade-plate group had few patients with axial malalignment, and the degree of malalignment was limited to 3° of varus and 10° of valgus at the most, compared to 10° and 18° respectively, with the other three fixation devices.ConclusionDespite the now extremely limited use and teaching of blade-plate fixation, as well as the undeniable technical challenges raised by the implantation of this device, the blade-plate is a simple, strong, and inexpensive fixation method. It remains reliable for the fixation of distal femoral fractures. The disfavour into which the blade-plate is currently falling is not warranted.Level of evidenceIII, case-control study

Process Design and Integration of Shale Gas to Methanol

Recent breakthroughs in horizontal drilling and hydraulic fracturing technology have made huge reservoirs of previously untapped shale gas and shale oil formations available for use. These new resources have already made a significant impact on the United States chemical industry and present many opportunities for new capital investments and industry growth. As in conventional natural gas, shale gas contains primarily methane, but some formations contain significant amounts of higher molecular weight hydrocarbons and inorganic gases such as nitrogen and carbon dioxide. These differences present several technical challenges to incorporating shale gas with current infrastructure designed to be used with natural gas. However, each shale presents opportunities to develop novel chemical processes that optimize its composition in order to more efficiently and profitably produce valuable chemical products. This paper is aimed at process synthesis, analysis, and integration of different processing pathways for the production of methanol from shale gas. The composition of the shale gas feedstock is assumed to come from the Barnett Shale Play located near Fort Worth, Texas, which is currently the most active shale gas play in the US. Process simulation and published data were used to construct a base-case scenario in Aspen Plus. The impact of different processing pathways was analyzed. Key performance indicators were assessed. These include overall process targets for mass and energy, economic performance, and environmental impact. Finally, the impact of several factors (e.g., feedstock composition, design and operating variables) is studied through a sensitivity analysis. The results show a profitable process above a methanol selling price of approximately $1.50/gal. The sensitivity analysis shows that the ROI depends much more heavily on the selling price of methanol than on the operating costs. Energy integration leads to a savings of$30.1 million per year, or an increase in ROI of 2% points. This also helps offset some of the cost required for the oxygen necessary for syngas generation through partial oxidation. For a sample shale gas composition with high levels of impurities, preprocessing costs require a price differential of $0.73/MMBtu from natural gas. The process is also environmentally desirable because shale gas does not lead to higher GHG emissions than conventional natural gas. More water is required for hydraulic fracturing, but some of these concerns can be abated through conservation techniques and regulation

Early prediction of femoral head avascular necrosis following neck fracture

SummaryFemoral neck fracture puts at risk functional prognosis in young patients and can be life-threatening in the elderly. The present study reviews methods of femoral head vascularity assessment following neck fracture, to address the following issues: what is the risk of osteonecrosis? And what, in the light of this risk, is the best-adapted treatment to avoid iterative surgery? Femoral head vascularity depends on retinacular vessels and especially the lateral epiphyseal artery, which contributes from 70 to 80% of the femoral head vascular supply. Fracture causes vascular lesions, which are in turn the prime cause of necrosis. Other factors combine with this: hematoma tamponade effect, reduced joint space and increased pressure due to lower extremity positioning in extension/internal rotation/abduction during surgery. Head deformity is not due to direct cell death but to the repair process originating from the surrounding living bone. In post-traumatic necrosis, proliferation rapidly invades the head, with significant osteogenesis. Pathologic fractures occur at the boundary between the new and dead bone. Many techniques have been reported to help assess residual hemodynamics and risk of necrosis. Some are invasive: superselective angiography, intra-osseous oxygen pressure measurement, or Doppler-laser hemodynamic measurement; others involve imaging: scintigraphy, conventionnal or dynamic MRI. The future seems to lie with dynamic MRI, which allows a new classification of femoral neck fractures, based on a non-invasive assessment of femoral head vascularity

Complex fractures of the distal humerus in the elderly: Is primary total elbow arthroplasty a valid treatment alternative? A series of 20 cases

SummaryIntroductionDistal humerus fractures are fairly rare. But as our population ages, these fractures become more complex and the choice of treatment more delicate. Poor bone quality results in many technical problems and the fixation hardware stability remains at risk. The goal of this study was to evaluate the functional recovery and morbidity of complex distal humerus fractures in elderly patients when treated with elbow prosthesis.HypothesisGood functional recovery can be achieved with a total joint replacement.Patients and methodsThis series consisted of 20 patients (18 women and two men) having an average age of 80years (range 65–93, median 80). Based on the AO classification, there were two Type A2 fractures, two Type B fractures, 15 Type C fractures and one fracture that could not be classified because of previous rheumatoid disease history at this elbow. Two fractures were open. In two cases, the olecranon was also fractured. Treatment consisted of the implantation of a Coonrad-Morrey, hinge-type total elbow prosthesis (Zimmer®, Warsaw, IN, USA). The Mayo Clinic surgical approach was used 17 times and the transolecranon approach was used three times. Primary arthroplasty was performed in 19 cases and the surgery was performed after six weeks of conservative treatment (diagnostic delay) in one case. Unrestricted motion was allowed after surgery, but a maximum of 0.5kg could be carried during the first 3months; this was subsequently increased to 2.5kg.ResultsFifteen of the 20 patients were available for reevaluation with an average follow-up of 3.6years (range 1.7–5.5, median 3.4). Four patients had died and one was lost to follow-up. The average range of motion was 97° (range 60–130°), comprising an average flexion of 130° (range 110–140°) and average loss of extension of 33° (range 0–80°). Pronation and supination were normal. The average Mayo Elbow Performance Score (MEPS) was 83 (range 60–100, median 80). X-rays revealed seven cases of radiolucent lines, with two being progressive. There was no visible wear of the polyethylene bushings at the hinge. Six patients had moderate periarticular heterotopic ossification. The two cases of olecranon osteotomy and one case of olecranon fracture had healed. There were no surgical site infections but two cases of ulnar compression, one of which required neurolysis. There was one case of humeral component loosening after 6years, but the implant was not changed.DiscussionThe clinical range of motion results were comparable to published data. The functional scores were slightly lower, mainly because of the pain factor. The initial results were encouraging and consistent with published data as long as the indications were well-chosen. Based on this retrospective study, total elbow arthroplasty can be a valid alternative in the surgeon's treatment armamentarium for complex distal humerus fractures in elderly patients who have moderate functional demands. Our results support our hypothesis, since we found good functional recovery without associated morbidity.Level of evidenceLevel IV retrospective study without comparator

Trochanteric locking nail versus arthroplasty in unstable intertrochanteric fracture in patients aged over 75 years

SummaryIntroductionIn trochanteric fracture, whatever its anatomic type, internal fixation is currently the standard attitude, with arthroplasty as a relatively unusual option.HypothesisHip implants are an excellent alternative to osteosynthesis in unstable trochanteric fracture in patients aged over 75 years.Patients and methodsA non-randomised prospective multicenter study compared osteosynthesis by trochanteric nailing (n=113) to hip arthroplasty (n=134) in unstable trochanteric fracture (AO types 31 A2.2 and 3 and A3.3) in 247 patients over the age of 75 years. The series was recruited during 2007 in seven centres, four of which included only arthroplasties, two only osteosyntheses and one both. The two groups were comparable in age, sex, preoperative Parker score, pre-fracture place of residence, fracture type, time to surgery and preoperative comorbidity. The sole difference was in operators, with more senior surgeons in arthroplasty (62% versus 27%).ResultsThree-month mortality was identical in the two groups (21.2% versus 21%). General complications did not differ, although mechanical complications were more frequent in the nailing group (12.5% versus 2.8%). Functional results (Parker and PMA scores) were better in the implant than in the nail group.DiscussionThe present study validated hip arthroplasty in these indications. Cemented stems associated to a dual-mobility acetabular component gave the best results.Type of studyProspective, level of evidence III

Survivor of a traumatic atlanto-occipital dislocation

AbstractAtlanto-occipital dislocation is a devastating ligamentous injury that most often turns fatal. However, because of on-site resuscitation improvements, the emergency teams are increasingly dealing with this condition. We report a rare case of atlanto-occipital dislocation (AOD) in a surviving patient with more than one-year follow-up. The mechanism of injury appears to be an extreme hyperextension applied to the head. This injury occurs more frequently in children since they are anatomically predisposed (flat articulation between the occiput and the atlas, increased ligamentous laxity). The diagnosis should be suggested by severe neurological injury after high trauma but also post-traumatic cardiorespiratory deficit. There have been reports of atlanto-occipital dilocations without neurologic impairment. A radiographic examination must be performed and lateral cervical radiographs should be acquired. However, additional imaging with CT or MRI may be required to aid diagnosis of AOD in cases in which radiographic findings are equivocal. Once the diagnosis of AOD has been confirmed, an anatomical classification should be made according to the magnitude of displacement. Fatal lesions are of neurological and vascular origin and some authors advocate the systematic use of angiography. Consensus regarding the management of AOD in adults has been achieved. Occipito-cervical arthrodesis is the recommended treatment option. We advocate a two-stage surgery: the patient is initially fitted with a halo vest then occipitocervical fusion is performed. Surgical treatment should be combined with cardiorespiratory management. The emergency teams should get familiar with this injury since they will be increasingly confronted to it. Early recognition and standard appropriate management is essential to avoid delayed treatment and complications

Human Innate Mycobacterium tuberculosis–Reactive αβTCR+ Thymocytes

The control of Mycobacterium tuberculosis (Mtb) infection is heavily dependent on the adaptive Th1 cellular immune response. Paradoxically, optimal priming of the Th1 response requires activation of priming dendritic cells with Th1 cytokine IFN-γ. At present, the innate cellular mechanisms required for the generation of an optimal Th1 T cell response remain poorly characterized. We hypothesized that innate Mtb-reactive T cells provide an early source of IFN-γ to fully activate Mtb-exposed dendritic cells. Here, we report the identification of a novel population of Mtb-reactive CD4− αβTCR+ innate thymocytes. These cells are present at high frequencies, respond to Mtb-infected cells by producing IFN-γ directly ex vivo, and display characteristics of effector memory T cells. This novel innate population of Mtb-reactive T cells will drive further investigation into the role of these cells in the containment of Mtb following infectious exposure. Furthermore, this is the first demonstration of a human innate pathogen-specific αβTCR+ T cell and is likely to inspire further investigation into innate T cells recognizing other important human pathogens

Impact of Vaccination and Pathogen Exposure Dosage on Shedding Kinetics of Infectious Hematopoietic Necrosis Virus (IHNV) in Rainbow Trout

Vaccine efficacy in preventing clinical disease has been well characterized. However, vaccine impacts on transmission under diversefied conditions, such as variable pathogen exposure dosages, are not fully understood. We evaluated the impacts of vaccination on disease-induced host mortality and shedding of infectious hematopoietic necrosis virus (IHNV) in Rainbow Trout Oncorhynchus mykiss. Fish, in up to three different genetic lines, were exposed to different dosages of IHNV to simulate field variability. Mortality and viral shedding of each individual fish were quantified over the course of infection. As the exposure dosage increased, mortality, number offish shedding virus,daily virus quantity shed, and total amount of virus shed also increased. Vaccination significantly reduced mortality but had a much smaller impact on shedding, such that vaccinated fish still shed significant amounts of virus, particularly at higher viral exposure dosages. These studies demonstrate that the consideration of pathogen exposure dosage and transmission are critical for robust inference of vaccine efficacy

A Novel Resource Polymorphism in Fish, Driven by Differential Bottom Environments: An Example from an Ancient Lake in Japan

Divergent natural selection rooted in differential resource use can generate and maintain intraspecific eco-morphological divergence (i.e., resource polymorphism), ultimately leading to population splitting and speciation. Differing bottom environments create lake habitats with different benthos communities, which may cause selection in benthivorous fishes. Here, we document the nature of eco-morphological and genetic divergence among local populations of the Japanese gudgeon Sarcocheilichthys (Cyprinidae), which inhabits contrasting habitats in the littoral zones (rocky vs. pebbly habitats) in Lake Biwa, a representative ancient lake in East Asia. Eco-morphological analyses revealed that Sarcocheilichthys variegatus microoculus from rocky and pebbly zones differed in morphology and diet, and that populations from rocky environments had longer heads and deeper bodies, which are expected to be advantageous for capturing cryptic and/or attached prey in structurally complex, rocky habitats. Sarcocheilichthys biwaensis, a rock-dwelling specialist, exhibited similar morphologies to the sympatric congener, S. v. microoculus, except for body/fin coloration. Genetic analyses based on mitochondrial and nuclear microsatellite DNA data revealed no clear genetic differentiation among local populations within/between the gudgeon species. Although the morphogenetic factors that contribute to morphological divergence remain unclear, our results suggest that the gudgeon populations in Lake Biwa show a state of resource polymorphism associated with differences in the bottom environment. This is a novel example of resource polymorphism in fish within an Asian ancient lake, emphasizing the importance and generality of feeding adaptation as an evolutionary mechanism that generates morphological diversification

Evidence Based Development of a Novel Lateral Fibula Plate (VariAx Fibula) Using a Real CT Bone Data Based Optimization Process During Device Development

Development of novel implants in orthopaedic trauma surgery is based on limited datasets of cadaver trials or artificial bone models. A method has been developed whereby implants can be constructed in an evidence based method founded on a large anatomic database consisting of more than 2.000 datasets of bones extracted from CT scans. The aim of this study was the development and clinical application of an anatomically pre-contoured plate for the treatment of distal fibular fractures based on the anatomical database