Search results for " Bone"
showing 10 items of 933 documents
Comparison of three ultrasonic axial transmission methods for bone assessment.
2005
Abstract This study compared three approaches to bone assessment using ultrasonic axial transmission. In 41 fresh human radii, velocity of the first arriving signal was measured with a commercial device (Sunlight Omnisense ™ ) operating at 1.25 MHz, a prototype based on 1-MHz bidirectional axial transmission and a low-frequency (200 kHz) prototype, also measuring the velocity of a slower wave. Cortical and trabecular bone mineral density, cortical thickness and cross-sectional area were determined by peripheral quantitative computed tomography. Significant but modest correlation between velocities reflects differences in the nature of the propagating waves and methodological differences. Of…
Prediction of bone mechanical properties using QUS and pQCT: study of the human distal radius.
2007
Abstract The objective was to compare the prediction of bone mechanical properties provided by axial transmission to that provided by peripheral quantitative computed tomography (pQCT) at the distal radius. The distal radius is the location for Colles’ fractures, a common osteoporosis related trauma situation. Measurements of the radial speed of sound were performed using three axial transmission devices: a commercial device (Sunlight Omnisense, 1.25 MHz), a bi-directional axial transmission prototype (1 MHz), both measuring the velocity of the first arriving signal (FAS), and a low frequency (200 kHz) device, measuring the velocity of a slower wave. Co-localized pQCT measurements of bone m…
Immunohistochemical characteristics of the Implant-Hosted Bon : preliminary findings of 9 mandibular cores
2010
Objectives: The aims of this study were to investigate the biochemical topography of collagen types I and III and to describe the histological structure at the implant placement site to determine the clinical significance of the findings and their possible interaction with bone healing around dental implants. Material and Methods: Bone cores from 9 mandibles were taken from the site of placement of dental implants. The reliable technique for rapid preparation of fresh-frozen undecalcified bone sections and the indirect immunofluorescent technique as an immunohistochemical procedure were applied. All sections were viewed under U.V light. For comparative purposes the tissue blocks remaining w…
Medial buttressing of the quadrilateral surface in acetabular and periprosthetic acetabular fractures
2020
Background In geriatric acetabular fractures, the quadrilateral plate is often involved in the fracture pattern and medially displaced. Open reduction and internal fixation (ORIF) includes reduction of the quadrilateral plate and securing its position. In this study, the concept of medial buttressing in acute and periprosthetic acetabular fractures is evaluated. Materials and methods Patients, who sustained an acetabular fracture between 2012 and 2018, in whom ORIF with a specific implant for medial buttressing was performed, were included in the study. Patients were divided in two groups; acute acetabular fractures (group 1) and periprosthetic acetabular fractures (group 2). Demographics,…
Atlases with Arcuate Foramen Present Cortical Bone Thickening That May Contribute to Lower Fracture Risk.
2018
To date, no information about the cortical bone microstructural properties in atlas vertebrae with arcuate foramen has been reported. As a result, we aimed to test in an experimental model if there is a cortical bone thickening in an atlas vertebra which has an arcuate foramen that may play a protective role against bone fracture.We analyzed by means of micro-computed tomography the cortical bone thickness, the cortical volume, and the medullary volume (SkyScan 1172 Bruker micro-CT NV, Kontich, Belgium) in cadaveric dry atlas vertebrae with arcuate foramen and without arcuate foramen. We also reviewed a case series of 31 posterior atlas arch fractures to correlate the possible presence in t…
Cortical bone thickening in Type A posterior atlas arch defects: experimental report.
2017
Abstract Background Context To date, no information about the cortical bone microstructural properties in atlas vertebrae with posterior arch defects has been reported. Purpose To test if there is an increased cortical bone thickening in atlases with Type A posterior atlas arch defects in an experimental model. Study Design Micro-computed tomography (CT) study on cadaveric atlas vertebrae. Methods We analyzed the cortical bone thickness, the cortical volume, and the medullary volume (SkyScan 1172 Bruker micro-CT NV, Kontich, Belgium) in cadaveric dry vertebrae with a Type A atlas arch defect and normal control vertebrae. Results The micro-CT study revealed significant differences in cortica…
Temporobasal, Transsphenoidal Meningoencephalocele Becoming Symptomatic with Spontaneous Cerebrospinal Fluid Rhinorrhea: Diagnostic Work-up and Micro…
2012
Background We report the rare case of an adult transsphenoidal meningoencephalocele and outline the microneurosurgical strategy. Clinical history, the findings of computerized tomography (CT) scans and magnetic resonance imaging (MRI), the microsurgical procedure, and histopathology are reported. Case Report A 54-year-old female patient complained about cerebrospinal fluid (CSF) rhinorrhea; a transnasal biopsy of a mass in the maxillar sinus prior to diagnostic work-up was performed elsewhere. Persisting CSF leakage prompted CT and MRI, which showed brain tissue extending from the left middle cranial fossa into the left sphenoid sinus through several bony defects. The diagnosis of a trans…
Microsurgical treatment of midfacial tumours involving the skull base
1998
Various approaches to the base of the skull for the treatment of cranial base tumours are described in detail. Advantages and disadvantages of the particular approaches are discussed. This clinical experience is based on 303 neoplasms involving the base of the skull, operated on by the authors. Retrospective survival studies are presented and a review of the literature on the subject is discussed. Utilizing microsurgical techniques the 2-, 3- and 5-year survival rates were significantly improved. The functional and aesthetic outcomes were also dramatically superior compared with standard ablative procedures. Reconstructive postoperative strategies are suggested.
Repair of bone defect by nano-modified white mineral trioxide aggregates in rabbit: a histopathological study
2014
Background: Many researchers have tried to enhance materials functions in different aspects of science using nano-modification method, and in many cases the results have been encouraging. To evaluate the histopathological responses of the micro-/nano-size cement-type biomaterials derived from calcium silicate-based composition with addition of nano tricalcium aluminate (3CaO.Al 2 O 3 ) on bone healing response. Material and Methods: Ninety mature male rabbits were anesthetized and a bone defect was created in the right mandible. The rabbits were divided into three groups, which were in turn subdivided into five subgroups with six animals each based on the defect filled by: white mineral tri…
Evaluation of demineralized bone and bone transplantsin vitroandin vivowith cone beam computed tomography imaging
2010
The objective of this study was to determine the ability of two flat panel cone beam CT (CBCT) devices to identify demineralized bone and bone transplants in vivo and in vitro.Datasets from patients with autologous bone grafts (n = 9, KaVo 3DeXam (KaVo, Biberach, Germany); n = 38, Accuitomo 40 (Morita, Osaka, Japan)) were retrospectively evaluated. Demineralized and non-demineralized porcine cancellous bone blocks were examined with the two CBCT devices. A SawBone skull (Pacific Research Laboratories, Vashon, WA) was used as a positioning tool for the bone blocks. Descriptive evaluation and image quality assessment were conducted on the KaVo 3DeXam data (voxel size 0.3 mm) using the OsiriX …