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CORNELIA SCHERZER HENNING WINDHAGEN JENS NELLESEN HORST-ARTUR CROSTAK KARL ROHN FRANK WITTE FRITZ THOREY MICHAEL FEHR GREGOR HAUSCHILD 《Veterinary radiology & ultrasound》2009,50(4):404-411
The goal of this study was to examine the microarchitecture of the trabecular bone of the canine femoral head using microcomputed tomography (micro-CT) technology. Specifically, we assessed changes seen in the femoral head in dogs with Legg-Calvé-Perthes disease and compared this with changes seen in dogs with hip dysplasia and coxofemoral luxation. Femoral heads from healthy animals were examined as a control. In total, 38 femoral heads were studied. Rules for defining spherical volumes (region of interest) for determination of the structural parameters within the trabecular structure were established using micro-CT images. The following parameters were determined directly in three dimensions: bone volume fraction, surface volume fraction, trabecula thickness, trabecular count, trabecular spacing, and connectivity. Characteristic femoral head changes were found for each condition. An unexpected result was found that contradicts the prevailing understanding of Legg-Calvé-Perthes disease. Instead of observing a thickening of the bone trabeculae caused by layering of new bone matrix on top of necrotic trabeculae, we observed an increase in trabecular count and a smaller trabecular thickness. From this it may be concluded that trabecular regeneration is more prominent or prevails over the characteristically described layering processes in the revascularization and repair processes occurring in this illness. 相似文献
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JON CHEETHAM VetMB Diplomate ACVS THOMAS H. WITTE BVetMed PhD LEO V. SODERHOLM JOHN W. HERMANSON PhD NORM G. DUCHARME DMV MSc Diplomate ACVS 《Veterinary surgery : VS》2008,37(6):588-593
Objective— To develop an in vitro laryngeal model to mimic airflow and pressures experienced by horses at maximal exercise with which to test laryngoplasty techniques.
Study Design— Randomized complete block.
Sample Population— Cadaveric equine larynges (n=10).
Methods— Equine larynges were collected at necropsy and a bilateral prosthetic laryngoplasty suture was placed with #5 Fiberwire™ suture to achieve bilateral maximal arytenoid abduction. Each larynx was positioned in a flow chamber and subjected to static flow and dynamic flow cycling at 2 Hz. Tracheal pressure and flow, and pressure within the flow chamber were recorded at a sampling frequency of 500 Hz. Data obtained were compared with the published physiologic values for horses exercising at maximal exercise.
Results— Under static flow conditions, the testing system produced inspiratory tracheal pressures (mean±SEM) of −33.0±0.98 mm Hg at a flow of 54.48±1.8 L/s. Pressure in the flow chamber was −8.1±2.2 mm Hg producing a translaryngeal impedance of 0.56±0.15 mm Hg/L/s. Under dynamic conditions, cycling flow and pressure were reproduced at a frequency of 2 Hz, the peak inspiratory (mean±SEM) pharyngeal and tracheal pressures across all larynges were −8.85±2.5 and −35.54±1.6 mm Hg, respectively. Peak inspiratory flow was 51.65±2.3 L/s and impedance was 0.57±0.06 mm Hg/L/s.
Conclusions— The model produced inspiratory pressures similar to those in horses at maximal exercise when airflows experienced at exercise were used.
Clinical Relevance— This model will allow testing of multiple novel techniques and may facilitate development of improved techniques for prosthetic laryngoplasty. 相似文献
Study Design— Randomized complete block.
Sample Population— Cadaveric equine larynges (n=10).
Methods— Equine larynges were collected at necropsy and a bilateral prosthetic laryngoplasty suture was placed with #5 Fiberwire
Results— Under static flow conditions, the testing system produced inspiratory tracheal pressures (mean±SEM) of −33.0±0.98 mm Hg at a flow of 54.48±1.8 L/s. Pressure in the flow chamber was −8.1±2.2 mm Hg producing a translaryngeal impedance of 0.56±0.15 mm Hg/L/s. Under dynamic conditions, cycling flow and pressure were reproduced at a frequency of 2 Hz, the peak inspiratory (mean±SEM) pharyngeal and tracheal pressures across all larynges were −8.85±2.5 and −35.54±1.6 mm Hg, respectively. Peak inspiratory flow was 51.65±2.3 L/s and impedance was 0.57±0.06 mm Hg/L/s.
Conclusions— The model produced inspiratory pressures similar to those in horses at maximal exercise when airflows experienced at exercise were used.
Clinical Relevance— This model will allow testing of multiple novel techniques and may facilitate development of improved techniques for prosthetic laryngoplasty. 相似文献
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