keyword
MENU ▼
Read by QxMD icon Read
search

cortical bone

keyword
https://www.readbyqxmd.com/read/29140370/mandibular-bone-structure-analysis-using-cone-beam-computed-tomography-vs-primary-implant-stability-an-ex-vivo-study
#1
Ruben Pauwels, Somchai Sessirisombat, Soontra Panmekiate
PURPOSE: To evaluate the relationship between mandibular bone structure parameters measured on preimplant cone beam computed tomography (CBCT) images and primary implant stability. MATERIALS AND METHODS: Twenty-one hemimandibles were scanned on the 3D Accuitomo 170 CBCT. Next, an implant was placed in each hemimandible, after which insertion torque and implant stability quotient (ISQ) measurements were acquired. The following measurements were performed on the preimplant CBCT scans: bone surface, bone volume, fractal dimension, connectivity, trabecular thickness and spacing, and skeleton analysis...
November 2017: International Journal of Oral & Maxillofacial Implants
https://www.readbyqxmd.com/read/29137726/mineralized-collagen-fibril-network-spatial-arrangement-influences-cortical-bone-fracture-behavior
#2
Yaohui Wang, Ani Ural
Bone is a hierarchical material exhibiting different fracture mechanisms at each length scale. At the submicroscale, the bone is composed of mineralized collagen fibrils (MCF). At this scale, the fracture processes in cortical bone have not been extensively studied in the literature. In this study, the influence of MCF size and orientation on the fracture behavior of bone under both transverse and longitudinal loading was investigated using novel 3D models of MCF networks with explicit representation of extra-fibrillar matrix...
November 4, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/29137724/simplified-boundary-conditions-alter-cortical-trabecular-load-sharing-at-the-distal-radius-a-multiscale-finite-element-analysis
#3
Joshua E Johnson, Karen L Troy
High-resolution peripheral quantitative computed tomography (HR-pQCT) derived micro-finite element (FE) modeling is used to evaluate mechanical behavior at the distal radius microstructure. However, these analyses typically simulate non-physiologic simplified platen-compression boundary conditions on a small section of the distal radius. Cortical and trabecular regions contribute uniquely to distal radius mechanical behavior, and various factors affect these regions distinctly. Generalized strength predictions from standardized platen-compression analyses may not adequately capture region specific responses in bone...
November 4, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/29137563/stem-anteversion-mismatch-to-the-anatomical-anteversion-causes-loss-of-periprosthetic-bone-density-after-tha
#4
Shinya Hayashi, Shingo Hashimoto, Tomoyuki Matsumoto, Koji Takayama, Kotaro Nishida, Kazunari Ishida, Ryosuke Kuroda
The short tapered-wedge stem is popular worldwide because it potentially preserves more bone stock during total hip arthroplasty (THA). However, stem version mismatch may affect physiological stress distribution. In this study, we analyzed the correlations between periprosthetic bone mineral density (BMD) changes and anteversion mismatch in patients who underwent THA using a short tapered-wedge stem. The study included 44 patients (44 joints) who underwent THA with a Tri-Lock stem. At baseline and at 6 and 24 months postoperatively, the BMDs in the seven Gruen zones were evaluated using dual-energy X-ray absorptiometry...
September 2017: Journal of Orthopaedic Surgery
https://www.readbyqxmd.com/read/29137065/primary-leiomyosarcoma-of-the-bone-a-case-report-and-a-review-of-the-literature
#5
Federica Recine, Alberto Bongiovanni, Roberto Casadei, Federica Pieri, Nada Riva, Alessandro De Vita, Laura Mercatali, Chiara Liverani, Chiara Spadazzi, Giacomo Miserocchi, Valentina Fausti, Dino Amadori, Toni Ibrahim
RATIONALE: Leiomyosarcoma (LMS) is a malignant sarcoma that can occur in different anatomic sites, including the bone, showing similar histological characteristics but heterogeneous clinical behavior and prognosis. Primary bone LMS was first described in 1965. It is a very rare sarcoma, accounting for <0.7% of all primary malignant bone tumors. PATIENT CONCERNS: We report the case of a 52-year-old male with primary bone LMS who presented with a solitary osteolytic lesion with focal cortical destruction in the left clavicle, seen on an x-ray and subsequent computed tomography (CT) scan...
November 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29134242/serum-parathyroid-hormone-is-associated-with-increased-cortical-porosity-of-the-inner-transitional-zone-at-the-proximal-femur-in-postmenopausal-women-the-troms%C3%A3-study
#6
M Osima, T T Borgen, M Lukic, G Grimnes, R M Joakimsen, E F Eriksen, Å Bjørnerem
Serum parathyroid hormone (PTH) was associated with increased bone turnover markers and cortical porosity of the inner transitional zone at the proximal femur. These results suggest that PTH through increased intracortical bone turnover leads to trabecularisation of inner cortical bone in postmenopausal women. INTRODUCTION: Vitamin D deficiency leads to secondary hyperparathyroidism and increased risk for fractures, whereas its association with cortical porosity is less clear. We tested (i) whether serum 25-hydroxyvitamin D (25(OH)D) and PTH were associated with cortical porosity and (ii) whether the associations of 25(OH)D) and PTH with fracture risk are dependent on cortical porosity...
November 14, 2017: Osteoporosis International
https://www.readbyqxmd.com/read/29133279/effect-of-17%C3%AE-estradiol-on-estrogen-receptor-negative-breast-cancer-cells-in-an-osteolytic-mouse-model
#7
D Joshua Cohen, Vaidehi Patel, Anjali Verma, Barbara D Boyan, Zvi Schwartz
17β-Estradiol (E2) promotes metastasis of triple negative breast cancer cells to bone. Recent studies show many triple negative breast cancer cell lines lacking the 66 kDa estrogen receptor (ER) alpha (ERα66) or its splice variant ERα46, express another splice variant, ERα36 associated with membrane-mediated rapid actions of the hormone. qPCR and western blot confirmed that MCF7 cells possessed ERα splice variants ERα66, ERα46 and ERα36, while ER-negative breast cancer cells MDA-MB-231 possessed only ERα36...
November 10, 2017: Steroids
https://www.readbyqxmd.com/read/29133259/loss-of-pit-2-results-in-abnormal-bone-development-and-decreased-bone-mineral-density-and-length-in-mice
#8
Shunsuke Yamada, Mary C Wallingford, Suhaib Borgeia, Timothy C Cox, Cecilia M Giachelli
Normal bone mineralization requires phosphate oversaturation in bone matrix vesicles, as well as normal regulation of phosphate metabolism via the interplay among bone, intestine, and kidney. In turn, derangement of phosphate metabolism greatly affects bone function and structure. The type III sodium-dependent phosphate transporters, PiT-1 and PiT-2, are believed to be important in tissue phosphate metabolism and physiological bone formation, but their requirement and molecular roles in bone remain poorly investigated...
November 10, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/29133001/effects-of-low-bone-mineral-status-on-biomechanical-characteristics-in-idiopathic-scoliotic-spinal-deformity
#9
Xiao-Xing Song, Lin-Yu Jin, Xin-Feng Li, Lie Qian, Hong-Xing Shen, Zu-De Liu, Bu-Wei Yu
BACKGROUND: Low bone mass in adolescent idiopathic scoliosis patients has been well reported. Poor bone quality was regarded as a new and unique prognostic factor in aggravating the curve progression. However, the potential biomechanical correlation between them remains unclear. METHODS: Three-dimensional finite element models of idiopathic scoliotic spine with different bone mineral status were created for axial loading simulation. Axial load of three different body weights were applied on different bone mineral mass models...
November 10, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/29129406/neuropeptide-y-y2-antagonist-treated-ovariectomized-mice-exhibit-greater-bone-mineral-density
#10
K L Seldeen, P G Halley, C H Volmar, M A Rodríguez, M Hernandez, M Pang, S K Carlsson, L J Suva, C Wahlestedt, B R Troen, S P Brothers
Osteoporosis, a disease characterized by progressive bone loss and increased risk of fracture, often results from menopausal loss of estrogen in women. Neuropeptide Y has been shown to negatively regulate bone formation, with amygdala specific deletion of the Y2 receptor resulting in increased bone mass in mice. In this study, ovariectomized (OVX) mice were injected once daily with JNJ-31020028, a brain penetrant Y2 receptor small molecule antagonist to determine the effects on bone formation. Antagonist treated mice had reduced weight and showed increased whole-body bone mineral density compared to vehicle-injected mice...
November 7, 2017: Neuropeptides
https://www.readbyqxmd.com/read/29128580/reduction-of-protein-phosphatase-2a-c%C3%AE-promotes-in-vivo-bone-formation-and-adipocyte-differentiation
#11
Kaya Yoshida, Jumpei Teramachi, Kenta Uchibe, Mika Ikegame, Lihong Qiu, Di Yang, Hirohiko Okamura
Serine/threonine protein phosphatase 2A (PP2A) regulates diverse physiological processes such as cell cycle, growth, apoptosis, and signal transduction. Previously, we demonstrated that silencing of the α-isoform of PP2A catalytic subunit (PP2A Cα) in osteoblasts accelerated osteoblast differentiation, whereas its overexpression suppressed differentiation. In this study, we examined the role of PP2A Cα in in vivo bone formation by generating transgenic mice (PP2A-Tg), in which the dominant negative form of PP2A Cα was specifically expressed in osteoblasts...
November 8, 2017: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/29128112/predicting-pathological-fracture-in-femoral-metastases-using-a-clinical-ct-scan-based-algorithm-a-case-control-study
#12
Stein J Janssen, Nuno Rui Paulino Pereira, Timion A Meijs, Miriam A Bredella, Marco L Ferrone, C Niek van Dijk, Jos A M Bramer, Santiago A Lozano-Calderón, Joseph H Schwab
BACKGROUND: We assessed whether there was a difference in attenuation measurements (in Hounsfield units - HU) and geometric distribution of HU between femora with metastatic lesions that fracture, and metastatic lesions that did not fracture nor underwent prophylactic fixation. METHODS: Nine patients with femoral metastases who underwent CT and developed a pathological fracture were matched to controls. All femora were delineated in axial CT slices using a region of interest (ROI) tool; the HU within these ROIs were used to calculate: (1) the cumulative HU of the affected over the nonaffected side per slice and presented as a percentage, and (2) the cumulative HU accounting for geometric distribution (polar moment of HU)...
November 8, 2017: Journal of Orthopaedic Science: Official Journal of the Japanese Orthopaedic Association
https://www.readbyqxmd.com/read/29127605/er-yag-laser-piezosurgery-and-surgical-drill-for-bone-decortication-during-orthodontic-mini-implant-insertion-primary-stability-analysis-an-animal-study
#13
Jacek Matys, Rafał Flieger, Gianluca Tenore, Kinga Grzech-Leśniak, Umberto Romeo, Marzena Dominiak
It is important to identify factors that affect primary stability of orthodontic mini-implants because it determines the success of treatment. We assessed mini-implant primary stability (initial mechanical engagement with the bone) placed in pig jaws. We also assessed mini-implant insertion failure rate (mini-implant fracture, mini-implants to root contact). A total of 80 taper-shaped mini-implants (Absoanchor® Model SH1312-6; Dentos Inc., Daegu, Korea) 6 mm long with a diameter of 1.1 mm were used. Bone decortication was made before mini-implant insertion by means of three different methods: Group G1: Er:YAG laser (LiteTouch®, Light Instruments, Yokneam, Israel) at energy of 300 mJ, frequency 25 Hz, fluence 38...
November 10, 2017: Lasers in Medical Science
https://www.readbyqxmd.com/read/29127344/catabolic-effects-of-human-pth-1-34-on-bone-requirement-of-monocyte-chemoattractant-protein-1-in-murine-model-of-hyperparathyroidism
#14
Jawed A Siddiqui, Joshua Johnson, Carole Le Henaff, Claudine L Bitel, Joseph A Tamasi, Nicola C Partridge
The bone catabolic actions of parathyroid hormone (PTH) are seen in patients with hyperparathyroidism, or with infusion of PTH in rodents. We have previously shown that the chemokine, monocyte chemoattractant protein-1 (MCP-1), is a mediator of PTH's anabolic effects on bone. To determine its role in PTH's catabolic effects, we continuously infused female wild-type (WT) and MCP-1(-/-) mice with hPTH or vehicle. Microcomputed tomography (µCT) analysis of cortical bone showed that hPTH-infusion induced significant bone loss in WT mice...
November 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29126603/effect-of-integration-time-on-the-morphometric-densitometric-and-mechanical-properties-of-the-mouse-tibia
#15
S Oliviero, Y Lu, M Viceconti, E Dall'Ara
Micro-Computed Tomography (microCT) images are used to measure morphometric and densitometric properties of bone, and to develop finite element (FE) models to estimate mechanical properties. However, there are concerns about the invasiveness of microCT imaging due to the X-rays ionising radiation induced by the repeated scans on the same animal. Therefore, the best compromise between radiation dose and image quality should be chosen for each preclinical application. In this study, we investigated the effect of integration time (time the bone is exposed to radiation at each rotation step during microCT imaging) on measurements performed on the mouse tibia...
November 7, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/29126229/osteoblast-amp-activated-protein-kinase-regulates-postnatal-skeletal-development-in-male-mice
#16
Ippei Kanazawa, Ayumu Takeno, Ken-Ichiro Tanaka, Masakazu Notsu, Toshitsugu Sugimoto
Studies have shown that AMP-activated protein kinase (AMPK), a crucial regulator of energy homeostasis, plays important roles in osteoblast differentiation and mineralization. However, little is known about in vivo roles of osteoblastic AMPK in bone development. Thus, to investigate in vivo roles of osteoblast AMPK, we conditionally inactivated Ampk in osterix (Osx)-expressing cells by crossing Osx-Cre mice with floxed AMPKα1 to generate mice lacking AMPKα1 in osteoblasts (Ampk-/- mice). Compared with wild-type and Ampk+/- mice, Ampk-/- mice displayed retardation of postnatal bone development, although bone deformity was not observed at birth...
November 3, 2017: Endocrinology
https://www.readbyqxmd.com/read/29125988/quantification-of-nitrogenous-bases-dna-and-collagen-type-i-for-the-estimation-of-the-postmortem-interval-in-bone-remains
#17
Cristina Pérez-Martínez, María D Pérez-Cárceles, Isabel Legaz, Gemma Prieto-Bonete, Aurelio Luna
Estimating the postmortem interval (PMI) is an important goal in forensic medicine and continues to be one of the most difficult tasks of the forensic investigator. Few accurate methods exist to determine the time since death of skeletonized human remains due to the great number of intrinsic and external factors that may alter the normal course of postmortem change. The purpose of this research was to assess the usefulness of various biochemical parameters, such as nitrogenous bases (adenine, guanine, purines, cytosine, thymine, pyrimidines, hypoxanthine and xanthine), DNA and Collagen Type I peptides to estimate PMI...
November 4, 2017: Forensic Science International
https://www.readbyqxmd.com/read/29125931/outcome-analysis-and-unexpected-scenario-prediction-in-2-stage-orthodontic-lower-third-molar-extraction
#18
Tze-Ta Huang, Chen-Jung Chang, Ken-Chung Chen, Jen-Bang Lo, Meng-Yen Chen, Jehn-Shyun Huang
PURPOSE: We propose a 2-stage orthodontic lower third molar extraction procedure to reduce iatrogenic inferior alveolar nerve injury. We tested our hypothesis that there are factors that can predict both dislodgement of the root portion and limited traction distances. PATIENTS AND METHODS: Fifteen patients (mean age, 25.7 years; age range, 17 to 65 years) with 20 lower third molars were enrolled. Panoramic films and cone beam computed tomography were analyzed...
October 16, 2017: Journal of Oral and Maxillofacial Surgery
https://www.readbyqxmd.com/read/29125430/cortical-bone-trajectory-screw-fixation-versus-traditional-pedicle-screw-fixation-for-2-level-posterior-lumbar-interbody-fusion-comparison-of-surgical-outcomes-for-2-level-degenerative-lumbar-spondylolisthesis
#19
Hironobu Sakaura, Toshitada Miwa, Tomoya Yamashita, Yusuke Kuroda, Tetsuo Ohwada
OBJECTIVE The cortical bone trajectory (CBT) screw technique is a new nontraditional pedicle screw (PS) insertion method. However, the biomechanical behavior of multilevel CBT screw/rod fixation remains unclear, and surgical outcomes in patients after 2-level posterior lumbar interbody fusion (PLIF) using CBT screw fixation have not been reported. Thus, the purposes of this study were to examine the clinical and radiological outcomes after 2-level PLIF using CBT screw fixation for 2-level degenerative lumbar spondylolisthesis (DS) and to compare these outcomes with those after 2-level PLIF using traditional PS fixation...
November 10, 2017: Journal of Neurosurgery. Spine
https://www.readbyqxmd.com/read/29124339/accuracy-of-screw-fixation-using-the-o-arm-%C3%A2-and-stealthstation-%C3%A2-navigation-system-for-unstable-pelvic-ring-fractures
#20
Jun Takeba, Kensuke Umakoshi, Satoshi Kikuchi, Hironori Matsumoto, Suguru Annen, Naoki Moriyama, Yuki Nakabayashi, Norio Sato, Mayuki Aibiki
PURPOSE: Screw fixation for unstable pelvic ring fractures is generally performed using the C-arm. However, some studies reported erroneous piercing with screws, nerve injuries, and vessel injuries. Recent studies have reported the efficacy of screw fixations using navigation systems. The purpose of this retrospective study was to investigate the accuracy of screw fixation using the O-arm(®) imaging system and StealthStation(®) navigation system for unstable pelvic ring fractures. METHODS: The participants were 10 patients with unstable pelvic ring fractures, who underwent screw fixations using the O-arm StealthStation navigation system (nine cases with iliosacral screw and one case with lateral compression screw)...
November 9, 2017: European Journal of Orthopaedic Surgery & Traumatology: Orthopédie Traumatologie
keyword
keyword
100010
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"