J Am Acad Orthop Surg Glob Res Rev
May 2023
We present a case of a 61-year-old healthy man who had bilateral femoral neck insufficiency fractures attributed to repeated iron transfusions, causing iron-induced hypophosphatemic rickets, requiring surgical intervention. Atraumatic insufficiency fractures present a diagnostic dilemma in orthopaedics. Chronic fractures with no acute precipitating trigger can often go unrecognized until complete fracturing or displacement occurs.
View Article and Find Full Text PDFThe earliest reports of atypical femur fractures (AFF) emerged from Asia. In the West, epidemiologic studies report a greater incidence of AFFs among subjects of Asian background. Asian ethnicity is an established risk factor for AFF, but clear mechanisms to explain this risk and implications for the general development of AFF are open questions.
View Article and Find Full Text PDFAtypical femur fractures (AFF) are a rare but serious complication of long-term bisphosphonate use. Although clearly defined by ASBMR criteria, a proportion of patients with AFFs may go unrecognized and the use of qualitative fracture criteria may lead to uncertainty in AFF diagnosis, with significant therapeutic implications. A score that rapidly and accurately identifies AFFs among subtrochanteric femur fractures using quantitative, measurable parameters is needed.
View Article and Find Full Text PDFBackground: Iatrogenic injury to the femoral neurovascular bundle is not uncommon during primary and revision total hip replacement (THR) and can result in permanent weakness, pain and poor function. Prevention of injury to these structures relies on a sound knowledge of their relationships to the hip joint.
Methods: We studied 115 consecutive hip magnetic resonance imaging (MRI) results in order to identify objective relationships between these structures and the hip joint that can be used intraoperatively.
Eight Thiel embalmed hips were dissected. The distance between the sciatic nerve and the femoral neck was measured before and after hip dislocation, and before and after release of the gluteus maximus tendon. There was a significant reduction in the mean distance between the neck of femur and the sciatic nerve in both the gluteus maximus tendon release and the unreleased groups at 60° and 90° of hip flexion, p < 0.
View Article and Find Full Text PDFPredictive models play an important role in the design of post-combustion processes for the capture of carbon dioxide (CO) emitted from power plants. A rate-based absorber model is presented to investigate the reactive capture of CO using aqueous monoethanolamine (MEA) as a solvent, integrating a predictive molecular-based equation of state: SAFT-VR SW (Statistical Associating Fluid Theory-Variable Range, Square Well). A distinctive physical approach is adopted to model the chemical equilibria inherent in the process.
View Article and Find Full Text PDFBackground: The common peroneal nerve (CPN) is an important structure of the lower limb and is at risk of injury during total knee arthroplasty. The aim of this study was to use a tibial reference system to determine the position of the CPN relative to the knee center and popliteus.
Methods: Two hundred consecutive knee magnetic resonance images at the level of a standard tibial arthroplasty cut were evaluated for (1) distance of the CPN from the posterolateral capsule; (2) angle of the CPN from the center of the tibial anteroposterior axis; and (3) location of CPN with respect to the popliteus.
The effect of two colorant particles with different surface geometries on the stability of shear-induced precursors in isotactic polypropylene was studied after the cessation of shear flow at 140 °C. In the absence of particles, the shear-induced precursors survived for at least 100 s after the shear flow ended. The presence of particles was found to stabilize lower molecular weight chains assisting in the formation of additional shear-induced precursors.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
November 2009
The effects of two seeds on the melt crystallization of isotactic polypropylene were experimentally investigated. The seed, which has the flat surface full of a nonuniform size distribution, has provided a right surface pattern to activate effectively the heterogeneous nucleation. In contrast, the seed, which has the curved surface full of a uniform size distribution, has failed to induce the heterogeneous nucleation.
View Article and Find Full Text PDFIntroduction: The incidence of rotational malalignment after femoral nailing has been reported to be at least 20%. If the deformity is recognised early, it can be corrected by changing the distal locking screw and rotating the bone prior to fracture union. It is common practice to use the same distal locking screw of the nail if this surgery is performed, however, there is a risk of the new drill hole "cutting out" into the old screw hole.
View Article and Find Full Text PDFThis work investigates the fatigue behaviour and the mechanism of fatigue failure of an epoxy resin with a dispersion of modified layered silicates in the polymer matrix. The fatigue properties are very important for structural application of nanocomposite materials. Clay-epoxy nanocomposites were successfully synthesized with a commercially available 1-Methylimidazole curing agent.
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