Aims: A pilon fracture is a severe ankle joint injury caused by high-energy trauma, typically affecting men of working age. Although relatively uncommon (5% to 7% of all tibial fractures), this injury causes among the worst functional and health outcomes of any skeletal injury, with a high risk of serious complications and long-term disability, and with devastating consequences on patients' quality of life and financial prospects. Robust evidence to guide treatment is currently lacking.
View Article and Find Full Text PDFGrignard reagents undergo conjugate addition to thiochromones catalyzed by copper salts to afford 2-substituted-thiochroman-4-ones, both 2-alkylthiochroman-4-ones and thioflavanones (2-arylthiochroman-4-ones), in good yields with trimethylsilyl chloride (TMSCl) as an additive. The best yields of 1,4-adducts can be attained with CuCN∙2LiCl as the copper source. Excellent yields of 2-alkyl-substituted thiochroman-4-ones and thioflavanones (2-aryl substituted) are attained with a broad range of Grignard reagents.
View Article and Find Full Text PDFPurpose: Older people with dementia are at risk of adverse events associated with potentially inappropriate prescribing.
Aim: to describe (1) how international tools designed to identify potentially inappropriate prescribing have been used in studies of older people with dementia, (2) the prevalence of potentially inappropriate prescribing in this cohort and (3) advantages/disadvantages of tools METHODS: Systematic literature review, designed and reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). MEDLINE, EMBASE, PsychInfo, CINAHL, the Cochrane Library, the Social Science Citation Index, OpenGrey, Base, GreyLit, Mednar and the National Database of Ageing Research were searched in April 2016 for studies describing the use of a tool or criteria to identify potentially inappropriate prescribing in older people with dementia.
The aim of this study was to determine the effect of the induced stress and restraint provided by the underlying bone on the frequency-dependent storage and loss stiffness (for bone restraint) or modulus (for induced stress) of articular cartilage, which characterise its viscoelasticity. Dynamic mechanical analysis has been used to determine the frequency-dependent viscoelastic properties of bovine femoral and humeral head articular cartilage. A sinusoidal load was applied to the specimens and out-of-phase displacement response was measured to determine the phase angle, the storage and loss stiffness or modulus.
View Article and Find Full Text PDFAntimicrobial silver nanoparticle coatings have attracted interest for reducing prosthetic joint infection. However, few studies report in vivo investigations of the biotransformation of silver nanoparticles within the regenerating tissue and its impact on bone formation. We present a longitudinal investigation of the osseointegration of silver nanoparticle-coated additive manufactured titanium implants in rat tibial defects.
View Article and Find Full Text PDFA T-handle has been designed to be used for minimally invasive implantation of a dynamic hip screw to repair fractures of the proximal femur. It is capable of being used in two actions: (i) push and hold (while using an angle guide) and (ii) application of torque when using the insertion wrench and lag screw tap. The T-handle can be held in a power or precision grip.
View Article and Find Full Text PDFThis study evaluated the effect of pulsed low-intensity ultrasound on cell proliferation, collagen production and glycosaminoglycan deposition by human dermal fibroblasts encapsulated in alginate. Hoechst 33258 assay for cell number, hydroxyproline assay for collagen content, dimethylmethylene blue assay for glycosaminoglycan content and scanning electron microscopy were performed on the encapsulated cells treated with pulsed low-intensity ultrasound and a control group that remained untreated. Pulsed low-intensity ultrasound showed a significant effect on cell proliferation and collagen deposition but no consistent pattern for glycosaminoglycan content.
View Article and Find Full Text PDFJ Back Musculoskelet Rehabil
August 2016
Background: Static radiographic techniques are unable to capture the wealth of kinematic information available from lumbar spine sagittal plane motion.
Objective: Demonstration of a viable non-invasive technique for acquiring and quantifying intervertebral motion of the lumbar spine in the sagittal plane.
Methods: Videofluoroscopic footage of sagittal plane lumbar spine flexion-extension in seven symptomatic volunteers (mean age = 48 yrs) and one asymptomatic volunteer (age = 54 yrs) was recorded.
The viscoelastic properties of cylinders (diameter 5 mm, height 2.2 ± 0.2 mm) of Nagor silicone elastomer of medium hardness, were investigated before and after the specimens had undergone accelerated aging in saline solution at 70°C for 38, 76 and 114 days (to simulate aging at 37°C, for 1, 2 and 3 years, respectively).
View Article and Find Full Text PDFThe Charité(®) lumbar intervertebral disc replacement was subjected to wear testing in an electro-mechanical spine simulator. Sinusoidally varying compression (0.6-2 kN, frequency 2 Hz), rotation (±2°, frequency 1 Hz), flexion-extension (6° to -3°, frequency 1 Hz) and lateral bending (±2°, frequency 1 Hz) were applied out of phase to specimens immersed in diluted calf serum at 37 °C.
View Article and Find Full Text PDFThis study presents a method for measuring the low volumetric wear expected in ceramic total disc replacements, which can be used to replace intervertebral discs in the spine, using non-contacting optical methods. Alumina-on-alumina ball-on-disc tests were conducted with test conditions approximating those of cervical (neck region of the spine) total disc replacement wear tests. The samples were then scanned using a three-dimensional non-contacting optical profilometer and the data used to measure surface roughness and develop a method for measuring the wear volume.
View Article and Find Full Text PDFMixtures of silicone elastomer and silicone oil were prepared and the values of their Young's moduli, E, determined in compression. The mixtures had volume fractions, [Formula: see text], of silicone oil in the range of 0-0.73.
View Article and Find Full Text PDFBackground: The knee is an incongruent joint predisposed to developing osteoarthritis, with certain regions being more at risk of cartilage degeneration even in non-osteoarthrosed joints.At present it is unknown if knee regions prone to cartilage degeneration have similar storage and/or loss stiffness, and frequency-dependent trends, to other knee joint cartilage. The aim of this study was to determine the range of frequency-dependent, viscoelastic stiffness of articular cartilage across the bovine knee joint.
View Article and Find Full Text PDFBackground: Nonadherence to antiepileptic drugs (AEDs) can result in suboptimal outcomes for patients.
Aim: This study aimed to assess the utility of a theory-based approach to understanding patient perspectives on AEDs and adherence.
Method: Patients with epilepsy, identified by a GP case note review, were mailed validated questionnaires assessing their perceptions of AEDs and their adherence to them.
Proc Inst Mech Eng H
September 2013
Some designs of total disc replacement devices have articulating bearing surfaces, and these devices are tested in vitro with a lubricant of diluted calf serum. It is believed that the lubricant found in total disc replacement devices in vivo is interstitial fluid that may have properties between that in Ringer's solution and diluted calf serum. To investigate the effect of lubricants, a set of friction tests were performed on a generic model of a metal against metal ball-and-socket total disc replacement device.
View Article and Find Full Text PDFThe wear of a model metal-on-metal ball-and-socket total disc arthroplasty was measured in a simulator. The ball had a radius of 10 mm, and there was a radial clearance between ball and socket of 0.015 mm.
View Article and Find Full Text PDFThis study investigated the friction between surgical instruments and bone to aid improvements to instrument design. The bases of orthopaedic surgical instruments are usually made of metal, especially stainless steel. Silicone elastomer was chosen as an alternate biocompatible material, which would be compliant on the bone surface when used as the base of an instrument.
View Article and Find Full Text PDFThis community-based survey of people with epilepsy who were divided into adherent and non-adherent groups used validated scales to determine factors associated with medicine non-adherence and self-management of epilepsy to identify those people at risk of poor self-management behavior or medicines non-adherence. Using demographic characteristics, it is possible to identify those people at risk during a regular epilepsy review. Adults with epilepsy were identified from general practices using clinical and drug searches with the diagnosis confirmed by case notes analysis.
View Article and Find Full Text PDFThis article reviews the current knowledge of the intervertebral disc (IVD) and its association with low back pain (LBP). The normal IVD is a largely avascular and aneural structure with a high water content, its nutrients mainly diffusing through the end plates. IVD degeneration occurs when its cells die or become dysfunctional, notably in an acidic environment.
View Article and Find Full Text PDFProc Inst Mech Eng H
January 2012
The mineral content of cancellous bone from sheep and pig vertebral bodies was determined by ashing at 800 degrees C. The results were compared with published results for human vertebral cancellous bone. The results for sheep (0.
View Article and Find Full Text PDFA surgical instrument to aid implantation of a range of lumbar spinal fusion cages has been developed. Once the cage is in position, the entrance to screw holes is partially blocked by the edge of the vertebral body. In order to insert fixation screws to secure the cage between the vertebrae, some part of the blocking edge has to be removed.
View Article and Find Full Text PDFIn this study, the effect of pulsed-low intensity ultrasound on cell proliferation, collagen production and glycosaminoglycan deposition by 3T3 fibroblasts encapsulated in alginate was evaluated. Hoechst 33258 assay for cell number, hydroxyproline assay for collagen content and dimethylamine blue assay for glycosaminoglycan content were performed on samples from cell cultures treated with pulsed-low intensity ultrasound and a control group. Pulsed-low intensity ultrasound shows no effect on cell proliferation, while collagen and glycosaminoglycan contents were consistently higher in the samples treated with pulsed-low intensity ultrasound, showing a statistically significant difference (p < 0.
View Article and Find Full Text PDFComput Methods Biomech Biomed Engin
March 2015
A transient multi-physics model of the mitral heart valve has been developed, which allows simultaneous calculation of fluid flow and structural deformation. A recently developed contact method has been applied to enable simulation of systole (the stage when blood pressure is elevated within the heart to pump blood to the body). The geometry was simplified to represent the mitral valve within the heart walls in two dimensions.
View Article and Find Full Text PDFRepair of the mitral valve is defined (loosely) as a procedure that alters the valve structure, without replacement, enabling the natural valve itself to continue to perform under the physical conditions to which it is exposed. As the mitral valve is driven by flow and pressure, it should be feasible to analyse and assess its function, failure and repair as a mechanical system. This article reviews the current state of mechanical evaluation of surgical repairs of the failed mitral valve of the heart.
View Article and Find Full Text PDFStudy Design: Mechanical testing of total disc arthroplasty (TDA).
Objective: To compare the friction between a polymer socket-on-metal ball and metal socket-on-polymer ball TDA.
Summary Of Background Data: A degenerate intervertebral disc can be replaced by TDA.