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Bone Fragments (bone + fragment)
Selected AbstractsAccuracy and precision of radiostereometric analysis in the measurement of three-dimensional micromotion in a fracture model of the distal radiusJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2005Rami Madanat Abstract The purpose of the current study was to verify the feasibility of radiostereometric analysis (RSA) in monitoring three-dimensional fracture micromotion in fractures of the distal radius. The experimental set-up consisted of a simulated model of an extra-articular Colles' fracture, including metallic beads inserted into the bone on either side of the fracture site. The model was rigidly fixed to high precision micrometer stages allowing controlled translation in three axes and rotation about the longitudinal and transverse axes. The whole construct was placed inside a RSA calibration cage with two perpendicular radiographic film cassettes. Accuracy was calculated as the 95% prediction intervals from the regression analyses between the micromotion measured by RSA and actual displacements measured by micrometers. Precision was determined as the standard deviation of five repeated measurements of a 200 ,m displacement or a 0.5° rotation along a specific axis. Translations from 25 ,m to 5 mm were measured with an accuracy of ±6,m and translations of 200,m were measured with a precision of 2,6 ,m. Rotations ranging from 1/6° to 2° were measured with an accuracy of ±0.073° and rotations of 1/2° were measured with a precision of 0.025°,0.096°. The number of markers and their configuration had greater impact on the accuracy and precision of rotation than on those of translation. Aside from the unknown rate of clinical marker loosening, the current results favor the use of at least four markers in each bone fragment in distal radius fractures. These results suggest a strong rationale for the use of RSA as an objective tool for comparing different treatment modalities and novel bone graft substitutes aimed at stabilization of fractures of the distal radius. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Taphonomy and zooarchaeology of the Upper Palaeolithic cave of Dzudzuana, Republic of GeorgiaINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 2 2008G. Bar-Oz Abstract We present the results of a detailed taphonomic and zooarchaeological study of the faunal remains from the Upper Palaeolithic layers of Dzudzuana Cave, Republic of Georgia. This study presents the first carefully analysed Upper Palaeolithic faunal assemblage from the southern Caucasus and thus serves as a significant point of reference for inter-regional studies of Upper Palaeolithic subsistence in Eurasia. A series of intra-site taphonomic comparisons are employed to reconstruct the depositional history of the bone assemblages within the different occupational phases at the site and to investigate subsistence, meat procurement and bone-processing strategies. Caucasian tur (Capra caucasica), aurochs (Bos primigenius) and steppe bison (Bison priscus) were the major prey species throughout the Upper Palaeolithic. Their frequencies do not change significantly over time, and nor does bone preservation vary by layer. The assemblage is characterised by significant density-mediated biases, caused by both human bone-processing behaviours and in situ post-burial bone attrition. Bone marrow extraction produced large numbers of unidentified bone fragments, many exhibiting green bone fractures. The density and size of bone assemblages and the extent of fragmentation indicate that Dzudzuana Cave was repeatedly occupied by Upper Palaeolithic foragers over many years. Skeletal part representation and butchery marks from all stages of carcass processing suggest that prey occasionally underwent field butchery. Intra-site taphonomic comparisons highlight uniform patterns of cultural and economic behaviours related to food procurement and processing strategies. Copyright © 2007 John Wiley & Sons, Ltd. [source] Differentiating Human Bone from Animal Bone: A Review of Histological MethodsJOURNAL OF FORENSIC SCIENCES, Issue 2 2007Maria L. Hillier M.Sc. ABSTRACT: This review brings together a complex and extensive literature to address the question of whether it is possible to distinguish human from nonhuman bone using the histological appearance of cortical bone. The mammalian species included are rat, hare, badger, racoon dog, cat, dog, pig, cow, goat, sheep, deer, horse, water buffalo, bear, nonhuman primates, and human and are therefore not exhaustive, but cover those mammals that may contribute to a North American or Eurasian forensic assemblage. The review has demonstrated that differentiation of human from certain nonhuman species is possible, including small mammals exhibiting Haversian bone tissue and large mammals exhibiting plexiform bone tissue. Pig, cow, goat, sheep, horse, and water buffalo exhibit both plexiform and Haversian bone tissue and where only Haversian bone tissue exists in bone fragments, differentiation of these species from humans is not possible. Other primate Haversian bone tissue is also not distinguishable from humans. Where differentiation using Haversian bone tissue is undertaken, both the general microstructural appearance and measurements of histological structures should be applied. Haversian system diameter and Haversian canal diameter are the most optimal and diagnostic measurements to use. Haversian system density may be usefully applied to provide an upper and lower limit for humans. [source] Multilineage mesenchymal differentiation potential of human trabecular bone-derived cellsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2002Ulrich Nöth Abstract Explant cultures of adult human trabecular bone fragments give rise to osteoblastic cells, that are known to express osteoblast-related genes and mineralize extracellular matrix. These osteoblastic cells have also been shown to undergo adipogenesis in vitro and chondrogenesis in vivo. Here we report the in vitro developmental potential of adult human osteoblastic cells (hOB) derived from explant cultures of collagenase-pretreated trabecular bone fragments. In addition to osteogenic and adipogenic differentiation, these cells are capable of chondrogenic differentiation in vitro in a manner similar to adult human bone marrow-derived mesenchymal progenitor cells. High-density pellet cultures of hOB maintained in chemically defined serum-free medium, supplemented with transforming growth factor-,1, were composed of morphologically distinct, chondrocyte-like cells expressing mRNA transcripts of collagen types II, IX and X, and aggrecan. The cells within the high-density pellet cultures were surrounded by a sulfated prote-oglycan-rich extracellular matrix that immunostained for collagen type II and proteoglycan link protein. Osteogenic differentiation of hOB was verified by an increased number of alkaline phosphatase-positive cells, that expressed osteoblast-related transcripts such as alkaline phosphatase, collagen type I, osteopontin and osteocalcin, and formed mineralized matrix in monolayer cultures treated with ascorbate, ,-glycerophosphate, and bone morphogenetic protein-2. Adipogenic differentiation of hOB was determined by the appearance of intracellular lipid droplets, and expression of adipocyte-specific genes, such as lipoprotein lipase and peroxisome proliferator-activated receptor ,2, in monolayer cultures treated with dexamethasone, indomethacin, insulin and 3-isobutyl-l-methylxanthine. Taken together, these results show that cells derived from collagenase-treated adult human trabecular bone fragments have the potential to differentiate into multiple mesenchymal lineages in vitro, indicating their developmental plasticity and suggesting their mesenchymal progenitor nature. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Conception of a navigation system controlling diaphyseal fracture reduction treated with external fixationTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 1 2009T. Leloup Abstract Background The reduction of long bone fractures treated with external fixation is usually performed with fluoroscopic images, which include several disadvantages: 2D information, distortions, and irradiation to the patient and the surgical team. This article presents a new navigation technique to control the reduction of such fractures while minimizing the irradiation. Methods Optically tracked markers are fixed to pins inserted into the bone fragments. These last are modelled using two initial calibrated radiographs. The models can be improved with several types of anatomical data and are displayed in real time. Results This navigation system was tested on dry bones and an anatomical specimen leg. Conclusions This new technique allows the visualization of the fracture in real time and from any viewpoint during the reduction. Irradiation is minimized using only two X-ray images. Copyright © 2009 John Wiley & Sons, Ltd. [source] Composite bows at ed-Dur (Umm al-Qaiwain, U.A.E.)ARABIAN ARCHAEOLOGY AND EPIGRAPHY, Issue 2 2005An De Waele This article discusses seven bone fragments excavated during the second Belgian archaeological campaign at ed-Dur (tomb G.3831, area N). Rather than weaving implements, these objects are identified as the reinforcing bone laths of composite bows. Information on the composite bow in general,origins, structural composition and technical advantages,will be given. Additionally, the question of which types of composite bows could have been present at ed-Dur and what role these weapons could have played at the site are discussed. [source] PHOSPHATES IN ARCHAEOLOGICAL FINDS: IMPLICATIONS FOR ENVIRONMENTAL CONDITIONS OF BURIAL,ARCHAEOMETRY, Issue 4 2004L. MARITAN The occurrence of coarse-grained vivianite and mitridatite aggregates in a potsherd, a grand ring and a timber imprint from the Second Iron Age site of Adria (Rovigo, northeastern Italy) suggest contrasting environmental conditions of burial. In particular, bone fragments were replaced by vivianite at relatively low pH and Eh, due to the presence of deteriorating organic matter, together with slag and iron flakes. Subsequent interactions with Ca-rich groundwater characterized by higher pH and Eh determined the growth of mitridatite after vivianite. Although phosphates crystallized after burial, the examined samples were not involved in pervasive chemical contamination. [source] | ||||||||||