Read by QxMD icon Read

Tibia geometry

Yunzhu Meng, Wansoo Pak, Berkan Guleyupoglu, Bharath Koya, F Scott Gayzik, Costin D Untaroiu
Child pedestrian protection deserves more attention in vehicle safety design since they are the most vulnerable road users who face the highest mortality rate. Pediatric Finite Element (FE) models could be used to simulate and understand the pedestrian injury mechanisms during crashes in order to mitigate them. Thus, the objective of the study was to develop a computationally efficient (simplified) six-year-old (6YO-PS) pedestrian FE model and validate it based on the latest published pediatric data. The 6YO-PS FE model was developed by morphing the existing GHBMC adult pedestrian model...
October 16, 2016: Accident; Analysis and Prevention
Qing-Hang Zhang, Andrew Cossey, Jie Tong
Periprosthetic bone strain distributions in some of the typical cases of total knee replacement (TKR) were studied with regard to the selection of material, design and the alignments of tibial components to examine which conditions are more forgiving than the others to stress shielding post a TKR. Four tibial components with two implant designs (cruciate sacrificing and cruciate retaining) and material properties (metal-backed (MB) and all-polyethylene (AP)) were considered in a specimen-specific finite element tibia bone model loaded in a neutral position...
October 10, 2016: Medical Engineering & Physics
A Ireland, R F Capozza, G R Cointry, L Nocciolino, J L Ferretti, J Rittweger
: Fibula response to disuse is unknown; we assessed fibula bone in spinal cord injury (SCI) patients and able-bodied counterparts. Group differences were smaller than in the neighbouring tibia which could not be explained by bone geometry. Differential adaptation of the shank bones may indicate previously unknown mechanoadaptive behaviours of bone. INTRODUCTION: The fibula supports only a small and highly variable proportion of shank compressive load (-8 to +19 %), and little is known about other kinds of stresses...
October 12, 2016: Osteoporosis International
Kristin L Popp, William McDermott, Julie M Hughes, Stephanie A Baxter, Steven D Stovitz, Moira A Petit
PURPOSE: To determine differences in bone geometry, estimates of bone strength, muscle size and bone strength relative to load, in women runners with and without a history of stress fracture. METHODS: We recruited 32 competitive distance runners aged 18-35, with (SFX, n=16) or without (NSFX, n=16) a history of stress fracture for this case-control study. Peripheral quantitative computed tomography (pQCT) was used to assess volumetric bone mineral density (vBMD, mg/mm(3)), total (ToA) and cortical (CtA) bone areas (mm(2)), and estimated compressive bone strength (bone strength index; BSI, mg/mm(4)) at the distal tibia...
October 10, 2016: Bone
Oui Sik Yoo, Yong Seuk Lee, Myung Chul Lee, Jae Hong Park, Jae Won Kim, Doo Hoon Sun
BACKGROUND: After open wedge high tibial osteotomy (OWHTO), the proximal fragment resembles the anatomy of the proximal tibia that is aligned in the anterior-posterior direction and the distal fragment resembles the anatomy of the mid shaft that is aligned in the proximal-distal direction. In addition, the medial portion of the proximal fragment becomes aligned medially and the medial portion of the distal fragment, laterally, depending on the magnitude of the posterior opening gap. Therefore, there would be a mismatch between the post-correction bony surface and the previous pre-contoured plate geometry...
October 10, 2016: BMC Musculoskeletal Disorders
Anna Petryk, Lynda E Polgreen, Molly Grames, Dawn A Lowe, James S Hodges, Peter Karachunski
INTRODUCTION: Dystrophinopathies are X-linked muscle degenerative disorders that result in progressive muscle weakness complicated by bone loss. This study's goal was to evaluate feasibility and tolerability of whole body low intensity vibration (WBLIV) and its potential effects on muscle and bone in patients with Duchenne or Becker muscular dystrophy. METHODS: This 12-month pilot study included 5 patients (age 5.9-21.7 years) who used a low-intensity Marodyne LivMD plate vibrating at 30-90 Hz for 10 minutes/day for the first 6 months...
October 8, 2016: Muscle & Nerve
T Shimizu, M Takahata, H Kimura-Suda, Y Kameda, K Endo, H Hamano, S Hiratsuka, M Ota, D Sato, T Ito, M Todoh, S Tadano, N Iwasaki
: This study showed that autoimmune arthritis induces especially severe osteoporosis in the periarticular region adjacent to inflamed joints, suggesting that arthritis increases the fragility fracture risk near inflamed joints, which is frequently observed in patients with RA. INTRODUCTION: Periarticular osteoporosis near inflamed joints is a hallmark of early rheumatoid arthritis (RA). Here we show that rheumatic inflammation deteriorates the bone quality and bone quantity of periarticular bone, thereby decreasing bone strength and toughness in a mouse model of RA...
October 4, 2016: Osteoporosis International
Young Gon Na, Moon Jong Chang, Sang Hwa Eom, Seok Jin Kim, Seong Cheol Park, Tae Kyun Kim
BACKGROUND: We aimed to determine whether coronal alignment measured on the single-limb stance (SLS) radiographs differs from those on the double-limb stance (DLS) images. We also investigated whether the size of such differences was affected by the knee pathology, lower limb alignment, and geometry of the tibia or femur. METHODS: We measured coronal alignment with mechanical tibiofemoral angle (MTFA) on the DLS and SLS radiographs in patients with posterolateral rotatory instability (PLRI, 30 knees), osteoarthritis (OA) with varus deformity who were scheduled for high tibial osteotomy (HTO) (60 knees), and in normal control (60 knees)...
September 28, 2016: Knee
Martin Nilsson, Daniel Sundh, Dan Mellström, Mattias Lorentzon
Physical activity is believed to have the greatest effect on the skeleton if exerted early in life, but whether or not possible benefits of physical activity on bone microstructure or geometry remain at old age has not been investigated in women. The aim of this study was to investigate if physical activity during skeletal growth and young adulthood or at old age was associated with cortical geometry and trabecular microarchitecture in weight-bearing and non-weight bearing bone, and areal bone mineral density (aBMD) in elderly women...
September 27, 2016: Journal of Bone and Mineral Research: the Official Journal of the American Society for Bone and Mineral Research
A L Kepley, K K Nishiyama, B Zhou, J Wang, C Zhang, D J McMahon, K F Foley, M D Walker, X Edward Guo, E Shane, T L Nickolas
: This is a cross-sectional study to assess differences in bone quality in young Asian and Caucasian (n = 30/group) men between 25 and 35 years. We found that Asians had smaller bones, thicker and denser cortices, and more plate-like trabeculae, but stiffness did not differ between groups. INTRODUCTION: We conducted a cross-sectional study to assess differences in bone quality in young Asian and Caucasian (n = 30/group) men between 25 and 35 years. METHODS: We measured bone mineral density (BMD) at the spine, total hip (TH), femoral neck (FN), and forearm by dual energy X-ray absorptiometry (DXA), and bone geometry, density, microarchitecture, and mechanical competence at the radius and tibia by high-resolution peripheral quantitative computed tomography (HR-pQCT) with application of individual trabecula segmentation (ITS) and trabecular and whole bone finite element analysis (FEA)...
September 16, 2016: Osteoporosis International
N Garijo, N Verdonschot, K Engelborghs, J M García-Aznar, M A Pérez
The systematic development of subject-specific computer models for the analysis of personalized treatments is currently a reality. In fact, many advances have recently been developed for creating virtual finite element-based models. These models accurately recreate subject-specific geometries and material properties from recent techniques based on quantitative image analysis. However, to determine the subject-specific forces, we need a full gait analysis, typically in combination with an inverse dynamics simulation study...
August 26, 2016: Journal of the Mechanical Behavior of Biomedical Materials
C E Kawalilak, S A Kontulainen, M A Amini, J L Lanovaz, W P Olszynski, J D Johnston
BACKGROUND: The distal radius is the most common osteoporotic fracture site occurring in postmenopausal women. Finite element (FE) modeling is a non-invasive mathematical technique that can estimate bone strength using inputted geometry/micro-architecture and tissue material properties from computed tomographic images. Our first objective was to define and compare in vivo precision errors for three high-resolution peripheral quantitative computed tomography (HR-pQCT, XtremeCT; Scanco) based FE models of the distal radius and tibia in postmenopausal women...
2016: BMC Musculoskeletal Disorders
Donlaporn Kittivanichhkul, Narattaphol Charoenphandhu, Phisit Khemawoot, Suchinda Malaivijitnond
Since the in vitro and in vivo anti-osteoporotic effects of Pueraria mirifica (PM) in rodents have been verified, its activity in menopausal monkeys was evaluated as required before it can be applicable for human use. In this study, postmenopausal osteoporotic monkeys were divided into two groups (five per group), and fed daily with standard diet alone (PMP0 group) or diet mixed with 1,000 mg/kg BW of PM powder (PMP1000 group) for 16 months. Every two months, the bone mineral density (BMD), bone mineral content (BMC) and bone geometry parameters (cortical area and thickness, and periosteal and endosteal circumference) at the distal radius and proximal tibia were determined using peripheral quantitative computed tomography together with plasma and urinary bone markers...
September 6, 2016: Journal of Endocrinology
Leigh Gabel, Heather M Macdonald, Heather A McKay
Sex differences in bone strength and fracture risk are well-documented. However, we know little about bone strength accrual during growth and adaptations in bone microstructure, density and geometry that accompany gains in bone strength. Thus, our objectives are to 1) describe growth related adaptations in bone microarchitecture, geometry, density and strength at the distal tibia and radius in boys and girls; 2) compare differences in adaptations in bone microarchitecture, geometry, density and strength between boys and girls...
August 24, 2016: Journal of Bone and Mineral Research: the Official Journal of the American Society for Bone and Mineral Research
L C Pop, D Sukumar, S H Schneider, Y Schlussel, T Stahl, C Gordon, X Wang, T V Papathomas, S A Shapses
: The effects of higher than recommended vitamin D doses on bone mineral density (BMD) and quality are not known. In this study, higher intakes, in postmenopausal women undergoing weight control over 1 year, had no effect on areal or volumetric BMD but prevented the deterioration in cortical bone geometry. INTRODUCTION: Studies examining how bone responds to a standard dose of vitamin D supplementation have been inconsistent. In addition, the effects of higher doses on BMD and quality are not known...
August 17, 2016: Osteoporosis International
N Tümer, L Blankevoort, M van de Giessen, M P Terra, P A de Jong, H Weinans, G J M Tuijthof, A A Zadpoor
OBJECTIVE: The etiology of osteochondral defects (OCDs), for which the ankle (talocrural) joint is one of the common sites, is not yet fully understood. In this study, we hypothesized that bone shape plays a role in development of OCDs. Therefore, we quantitatively compared the morphology of the talus and the distal tibia between an OCD group and a control group. METHODS: The shape variations of the talus and distal tibia were described separately by constructing two statistical shape models (SSMs) based on the segmentation of the bones from ankle computed tomography (CT) scans obtained from control (i...
August 3, 2016: Osteoarthritis and Cartilage
Eoin Parle, Hannah Larmon, David Taylor
Insects are among the most diverse groups of animals on Earth. Their cuticle exoskeletons vary greatly in terms of size and shape, and are subjected to different applied forces during daily activities. We investigated the biomechanics of the tibiae of three different insect species: the desert locust (Schistocerca gregaria), American cockroach (Periplaneta americana) and Death's Head cockroach (Blaberus discoidalis). In a previous work, we showed that these tibiae vary not only in geometry (length, radius and thickness) but also in material quality (Young's modulus) and in the applied stress required to cause failure when loaded in bending...
2016: PloS One
M Pereira, S Gohin, N Lund, A Hvid, P J Smitham, M J Oddy, I Reichert, D Farlay, J P Roux, M E Cleasby, C Chenu
: In contrast to previously reported elevations in serum sclerostin levels in diabetic patients, the present study shows that the impaired bone microarchitecture and cellular turnover associated with type 2 diabetes mellitus (T2DM)-like conditions in ZDF rats are not correlated with changes in serum and bone sclerostin expression. INTRODUCTION: T2DM is associated with impaired skeletal structure and a higher prevalence of bone fractures. Sclerostin, a negative regulator of bone formation, is elevated in serum of diabetic patients...
July 28, 2016: Osteoporosis International
A Zengin, S R Pye, M J Cook, J E Adams, F C W Wu, T W O'Neill, K A Ward
Relatively little is known about the bone health of ethnic groups within the UK and data are largely restricted to women. The aim of this study was to investigate ethnic differences in areal bone mineral density (aBMD), volumetric bone mineral density (vBMD), bone geometry and strength in UK men. White European, Black Afro-Caribbean and South Asian men aged over 40years were recruited from Greater Manchester, UK. aBMD at the spine, hip, femoral neck and whole body were measured by DXA. Bone geometry, strength and vBMD were measured at the radius and tibia using pQCT at the metaphysis (4%) and diaphysis (50% radius; 38% tibia) sites...
October 2016: Bone
Guenther Maderbacher, Armin Keshmiri, Hans R Springorum, Felix Greimel, Joachim Grifka, Clemens Baier
BACKGROUND: In comparison to coronal, sagittal, and rotational alignment, translational alignment parameters have been widely neglected in total knee arthroplasty (TKA) so far. As there is a certain variable range of possible component placement in mediolateral, ventrodorsal, and proximodistal direction, we hypothesized that relative positions between the femoral and tibial bones are changed after TKA, resulting in a subluxation of knees. METHODS: In 10 knees of Thiel-embalmed whole body cadavers, the relative position between the femur and the tibia during passive flexion was measured before and after TKA by means of a navigational device...
June 11, 2016: Journal of Arthroplasty
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"