Computational Simulation of a Femoral Nail Fracture

Every year in the United States roughly 300,000 people over the age of 65 suffer from a hip fracture. Ninety five percent of which are the result from a fall. The resulting hip fracture can be classified into several categories of fracture. Depending on the damage the patient could be implanted with a femoral nail device to assist in their recovery. These devices can, however, have complications during recovery. In some cases, these nails can have a failure rate as high as 10%. When failure occurs, extensive investigations are needed to determine the causes of failure. These investigations involve physical examination, testing for material and chemical properties, and numerical computation with computer simulations. The results from this investigation show that the nail investigated may have accrued damage from the implantation process. There is evidence of internal crack propagation leading to device failure. Simulations performed indicate that if the nail was operating in a femur with a subtrochanteric fracture the internal forces may have been 50% higher than that of a normal femur, significantly more than any fracture type

Genetics of the Hippocampal Transcriptome in Mouse: A Systematic Survey and Online Neurogenomics Resource

Differences in gene expression in the CNS influence behavior and disease susceptibility. To systematically explore the role of normal variation in expression on hippocampal structure and function, we generated an online microarray database for a diverse panel of strains of mice, including most common inbred strains and numerous recombinant inbred lines (www.genenetwork.org). Using this resource, coexpression networks for families of genes can be generated rapidly to test causal models related to function. The data set is optimized for quantitative trait locus (QTL) mapping and was used to identify over 5500 QTLs that modulate mRNA levels. We describe a wide variety of analyses and novel synthetic approaches that take advantage of this resource, and demonstrate how both the data and associated tools can be applied to the study of gene regulation in the hippocampus and relations to structure and function

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Creating and curating an archive: Bury St Edmunds and its Anglo-Saxon past

This contribution explores the mechanisms by which the Benedictine foundation of Bury St Edmunds sought to legitimise and preserve their spurious pre-Conquest privileges and holdings throughout the Middle Ages. The archive is extraordinary in terms of the large number of surviving registers and cartularies which contain copies of Anglo-Saxon charters, many of which are wholly or partly in Old English. The essay charts the changing use to which these ancient documents were put in response to threats to the foundation's continued enjoyment of its liberties. The focus throughout the essay is to demonstrate how pragmatic considerations at every stage affects the development of the archive and the ways in which these linguistically challenging texts were presented, re-presented, and represented during the Abbey’s history

Computational Simulation of a Femoral Nail Fracture

Femoral nails are used to provide fixation for fractured long bones. These constructs simultaneously provide stability and union in nearly 10% of cases of premature failure. The goal of this investigation was to develop and test different models of the femur using cephalomedullary nail fixation. These models represent three different types of hip fractures (intracapsular, intertrochanteric, and subtrochanteric fractures). By testing the different fracture types, one can determine the fracture tolerance of the constructs from the resulting forces that occur due to the activities of daily living. Understanding the effects that the loads will have on the integrity of the nail-bone construct may help reduce the risks that could arise through its use. The computational simulations performed indicate that an undamaged femur can withstand the forces of 4.4&times; the body weight of the average adult male. A subtrochanteric femur fracture, however, can only withstand over 2.3&times; the same weight, nearly 50% lower than the normal femur. Regarding this lower amount, it is not impossible that an overloading scenario could occur. The data from the gait cycle show that, with a subtrochanteric fracture, the nail experiences stress that is just within the fatigue limit of the material. Given the collected data, subtrochanteric fractures are the most likely candidates for causing failures when comparing fracture types. In general, understanding the effects that different loads have on the integrity of the nail-bone construct may help reduce the risks that could arise through its use

Remarques Historiques Et Critiques Sur L'Histoire D'Angleterre De Mr. De Rapin Thoyras, Par Mr. N. Tindal ... Et Abregé Historique Du Recueil Des Actes Publics D'Angleterre, De Thomas Rymer

REMARQUES HISTORIQUES ET CRITIQUES SUR L'HISTOIRE D'ANGLETERRE DE MR. DE RAPIN THOYRAS, PAR MR. N. TINDAL ... ET ABREGÉ HISTORIQUE DU RECUEIL DES ACTES PUBLICS D'ANGLETERRE, DE THOMAS RYMER Remarques Historiques Et Critiques Sur L'Histoire D'Angleterre De Mr. De Rapin Thoyras, Par Mr. N. Tindal ... Et Abregé Historique Du Recueil Des Actes Publics D'Angleterre, De Thomas Rymer Qui contient l'Abregé historique des douze derniers Volumes des Actes Publics (T. 2