A key parameter in the mechanical environment created in distraction osteogenesis is the axial stiffness of the external fixator. Mechanical testing of the frames with wire and half pins has been used to estimate the stiffness contributions of wires based on the span length and of half pins based on the offset length. A summation of the wire and half pin contributions appears to represent a suitable estimate for the axial stiffness of frames composed of a mixture of wires and half pins. Using this estimate, clinicians can make informed decisions regarding frame construction, and it may be possible to investigate the rate of bone formation relative to axial frame stiffness in the clinical setting.
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Sci Rep
January 2025
Department of Mechanical Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
This study investigates the nonlinear dynamics of a system with frequency-dependent stiffness using a MEMS-based capacitive inertial sensor as a case study. The sensor is positioned directly on a rotating component of a machine and consists of a microbeam clamped at both ends by fixed supports with a fixed central proof mass. The nonlinear behavior is determined by electrostatic forces, axial and bending motion coupling, and frequency-dependent stiffness.
View Article and Find Full Text PDFEur Heart J Imaging Methods Pract
January 2025
Department of Radiology, University of Michigan, 1500 E Medical Center Drive, CVC 5581, Ann Arbor, MI 48109, USA.
Aims: Aortic wall stiffening in ascending thoracic aortic aneurysm (aTAA) is common. However, the spatial and temporal relationships between stiffness, aortic size, and growth in aTAA remain unclear.
Methods And Results: In this single-centre retrospective study, we utilized vascular deformation mapping to extract multi-directional aortic motion, aortic distensibility, and aortic growth in a multi-planar fashion from multi-phasic ECG-gated computed tomography angiograms.
Eur J Neurol
January 2025
Groupe Hospitalier Pitié-Salpêtrière, Institut de Myologie, AP-HP, Sorbonne Université, Paris, France.
Background: Monoclonal gammopathy (MG) has been reported in association with numerous neurological disorders but the spectrum of MG-associated myopathies remains poorly described.
Objective: To report a newly acquired myopathy associated with MG.
Methods: Three adult patients with the same phenotype from two French referral centers were prospectively analyzed.
JOR Spine
March 2025
Beijing Key Laboratory for Design and Evaluation Technology of Advanced Implantable & Interventional Medical Devices, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering Beihang University Beijing China.
Background: Growth rods are the gold standard for treating early-onset scoliosis (EOS). However, current treatments with growth rods do not optimize spinal growth in EOS patients, and frequent distraction surgeries significantly increase complications, imposing considerable economic and psychological burdens on patients. An improved growth rod is urgently required to address the need for dynamic growth and external regulation.
View Article and Find Full Text PDFLancet
January 2025
Rheumazentrum Ruhrgebiet Herne, Ruhr-University Bochum, Germany.
Axial spondyloarthritis manifests as a chronic inflammatory disease primarily affecting the sacroiliac joints and spine. Although chronic back pain and spinal stiffness are typical initial symptoms, peripheral (ie, enthesitis, arthritis, and dactylitis) and extra-musculoskeletal (ie, uveitis, inflammatory bowel disease, and psoriasis) manifestations are also common. Timely and accurate diagnosis is challenging and relies on identifying a clinical pattern with a combination of clinical, laboratory (HLA-B27 positivity), and imaging findings (eg, structural damage on pelvic radiographs and bone marrow oedema on MRI of the sacroiliac joints).
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