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https://www.readbyqxmd.com/read/28819592/insufficiency-fractures-of-the-distal-tibia-and-fibula-following-total-hip-arthroplasty-a-case-report
#1
Ryu Kojima, Toshiki Miura, Eisei Fukatani
INTRODUCTION: Although periprosthetic fractures of the femur have been well documented, insufficiency fractures following total hip arthroplasty (THA) have been rarely described. We report a case of an insufficiency fracture in the distal tibia and fibula that occurred after THA. CASE REPORT: A 54-year-old woman presented with severe pain in the bilateral hip joints and was diagnosed with end-stage osteoarthritis. She underwent THA on the right side. Although the postoperative course was uneventful, she suddenly experienced severe pain and swelling in the right leg without any history of trauma 22 weeks after the surgery...
March 2017: Journal of Orthopaedic Case Reports
https://www.readbyqxmd.com/read/28817701/effect-of-exoskeletal-joint-constraint-and-passive-resistance-on-metabolic-energy-expenditure-implications-for-walking-in-paraplegia
#2
Sarah R Chang, Rudi Kobetic, Ronald J Triolo
An important consideration in the design of a practical system to restore walking in individuals with spinal cord injury is to minimize metabolic energy demand on the user. In this study, the effects of exoskeletal constraints on metabolic energy expenditure were evaluated in able-bodied volunteers to gain insight into the demands of walking with a hybrid neuroprosthesis after paralysis. The exoskeleton had a hydraulic mechanism to reciprocally couple hip flexion and extension, unlocked hydraulic stance controlled knee mechanisms, and ankles fixed at neutral by ankle-foot orthoses...
2017: PloS One
https://www.readbyqxmd.com/read/28815099/enabling-comprehension-of-patient-subgroups-and-characteristics-in-large-bipartite-networks-implications-for-precision-medicine
#3
Suresh K Bhavnani, Tianlong Chen, Archana Ayyaswamy, Shyam Visweswaran, Gowtham Bellala, Divekar Rohit, Bassler Kevin E
A primary goal of precision medicine is to identify patient subgroups based on their characteristics (e.g., comorbidities or genes) with the goal of designing more targeted interventions. While network visualization methods such as Fruchterman-Reingold have been used to successfully identify such patient subgroups in small to medium sized data sets, they often fail to reveal comprehensible visual patterns in large and dense networks despite having significant clustering. We therefore developed an algorithm called ExplodeLayout, which exploits the existence of significant clusters in bipartite networks to automatically "explode" a traditional network layout with the goal of separating overlapping clusters, while at the same time preserving key network topological properties that are critical for the comprehension of patient subgroups...
2017: AMIA Summits on Translational Science Proceedings
https://www.readbyqxmd.com/read/28814020/piecewise-and-unified-phase-variables-in-the-control-of-a-powered-prosthetic-leg
#4
Dario J Villarreal, David Quintero, Robert D Gregg
Many control methods have been proposed for powered prosthetic legs, ranging from finite state machines that switch between discrete phases of gait to unified controllers that have a continuous sense of phase. In particular, recent work has shown that a mechanical phase variable can parameterize the entire gait cycle for controlling a prosthetic leg during steady rhythmic locomotion. However, the unified approach does not provide voluntary control over non-rhythmic motions like stepping forward and back. In this paper we present a phasing algorithm that uses the amputee's hip angle to control both rhythmic and non-rhythmic motion through two modes: 1) a piecewise (PW) function that provides users voluntary control over stance and swing in a piecewise manner, and 2) a unified function that continuously synchronizes the motion of the prosthetic leg with the amputee user at different walking speeds...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813861/exoskeleton-for-gait-rehabilitation-of-children-conceptual-design
#5
Jorge L Cornejo, Jesus F Santana, Sergio A Salinas
This paper presents the conceptual design of an exoskeleton for gait rehabilitation of children. This system has electronics, mechanicals and software sections, which are implemented and tested using a mannequin of a child. The prototype uses servomotors to move robotic joints that are attached to simulated patient's legs. The design has 4 DOF (degrees of freedom) two for hip joints and other two for knee joints, in the sagittal plane. A microcontroller measures sensor signals, controls motors and exchanges data with a computer...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813857/kinematic-effects-of-inertia-and-friction-added-by-a-robotic-knee-exoskeleton-after-prolonged-walking
#6
C Shirota, M R Tucker, O Lambercy, R Gassert
The capabilities of robotic gait assistive devices are ever increasing; however, their adoption outside of the lab is still limited. A critical barrier for the functionality of these devices are the still unknown mechanical properties of the human leg during dynamic conditions such as walking. We built a robotic knee exoskeleton to address this problem. Here, we present the effects of our device on the walking pattern of four subjects. We assessed the effects after a short period of acclimation as well as after a 1...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813829/development-of-an-automatic-rotational-orthosis-for-walking-with-arm-swing
#7
Juan Fang, Guo-Yuan Yang, Le Xie
Interlimb neural coupling is often observed during normal gait and is postulated to be important for gait restoration. In order to provide a testbed for investigation of interlimb neural coupling, we previously developed a rotational orthosis for walking with arm swing (ROWAS). The present study aimed to develop and evaluate the feasibility of a new system, viz. an automatic ROWAS (aROWAS). We developed the mechanical structures of aROWAS in SolidWorks, and implemented the concept in a prototype. Normal gait data from walking at various speeds were used as reference trajectories of the shoulder, hip, knee and ankle joints...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28813828/active-lower-limb-orthosis-with-one-degree-of-freedom-for-people-with-paraplegia
#8
Michal Gloger, Goro Obinata, Eiichi Genda, Jan Babjak, Yanling Pei
The main challenges of designing devices for paraplegic walking can be summarized into three groups, stability and comfort, high efficiency or low energy consumption, dimensions and weight. A new economical device for people with paraplegia which tackles all problems of the three groups is introduced in this paper. The main idea of this device is based on HALO mechanism. HALO is compact passive medial hip joint orthosis with contralateral hip and ankle linkage, which keeps the feet always parallel to the ground and assists swinging the leg...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28809634/-wear-and-roughness-of-bearing-surface-in-retrieved-polyethylene-bicon-plus-cups
#9
M Ranuša, J Gallo, M Hobza, M Vrbka, D Nečas, M Hartl
PURPOSE OF THE STUDY By 7th December 2016, 4,755 Bicon-Plus cups in total were implanted in the Czech Republic. Some of them have been continuously re-operated, while the most frequent reason of failure is polyethylene wear and aseptic loosening. The present study is focused on surface analysis of retrieved polyethylene Bicon-Plus cups and the determination of the roughness of their bearing surfaces. MATERIAL AND METHODS In this study, we had 13 high molecular weight polyethylene cups with the average time in situ of 8...
2017: Acta Chirurgiae Orthopaedicae et Traumatologiae Cechoslovaca
https://www.readbyqxmd.com/read/28808674/in-situ-generated-tribomaterial-in-metal-metal-contacts-current-understanding-and-future-implications-for-implants
#10
N Espallargas, A Fischer, A Igual Muñoz, S Mischler, M A Wimmer
Artificial hip joints operate in aqueous biofluids that are highly reactive towards metallic surfaces. The reactivity at the metal interface is enhanced by mechanical interaction due to friction, which can change the near-surface structure of the metal and surface chemistry. There are now several reports in the literature about the in-situ generation of reaction films and tribo-metallurgical transformations on metal-on-metal hip joints. This paper summarizes current knowledge and provides a mechanistic interpretation of the surface chemical and metallurgical phenomena...
June 2017: Biotribology (Oxf)
https://www.readbyqxmd.com/read/28806708/predictive-simulation-of-diabetic-gait-individual-contribution-of-ankle-stiffness-and-muscle-weakening
#11
Gilmar F Santos, Aline A Gomes, Isabel C N Sacco, Marko Ackermann
Diabetic neuropathic individuals present massive muscle strength reduction at the ankle plantar- and dorsiflexors and increased joint stiffness. Our aim is to investigate the adaptation strategies to these musculoskeletal alterations during walking by means of predictive simulations. We used a seven segment planar musculoskeletal model actuated by eight Hill-type muscles in each leg. The effect of all passive tissue in muscles and other joint structures was modeled by net passive joint moment curves. The predictive simulations were generated by solving an optimal control problem that minimized a cost function, including effort and tracking terms, using direct collocation and a commercial optimal control package...
August 1, 2017: Gait & Posture
https://www.readbyqxmd.com/read/28803114/the-inferomedial-femoral-neck-is-compromised-by-age-but-not-disease-fracture-toughness-and-the-multifactorial-mechanisms-comprising-reference-point-microindentation
#12
T Jenkins, O L Katsamenis, O G Andriotis, L V Coutts, B Carter, D G Dunlop, R O C Oreffo, C Cooper, N C Harvey, P J Thurner, The OStEO Group
The influence of ageing on the fracture mechanics of cortical bone tissue is well documented, though little is known about if and how related material properties are further affected in two of the most prominent musculoskeletal diseases, osteoporosis and osteoarthritis (OA). The femoral neck, in close proximity to the most pertinent osteoporotic fracture site and near the hip joint affected by osteoarthritis, is a site of particular interest for investigation. We have recently shown that Reference Point micro-Indentation (RPI) detects differences between cortical bone from the femoral neck of healthy, osteoporotic fractured and osteoarthritic hip replacement patients...
June 30, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28799491/exercise-programmes-for-osteoarthritis-with-different-localization
#13
Sevdalina Lambova
Therapeutic exercises in osteoarthritis (OA) are therapeutic approach with proven efficacy. On the other hand, the different disease form, the lack of established consensus and system for patient education limit the widespread use of therapeutic exercises in clinical practice. The mechanisms of action of therapeutic exercise in OA include the following components e. g., neuromuscular (improvement of proprioception, muscle strength and joint stability), intra-articular (prevention of cartilage degeneration, antiinflammatory effect, improvement of the quality of the joint fluid), periarticular, general health with reduction of cardiovascular risk and psychological components...
August 10, 2017: Current Rheumatology Reviews
https://www.readbyqxmd.com/read/28797104/increased-microrna-93-5p-inhibits-osteogenic-differentiation-by-targeting-bone-morphogenetic-protein-2
#14
Ying Zhang, Qiu-Shi Wei, Wei-Bin Ding, Lei-Lei Zhang, Hui-Chao Wang, Ying-Jie Zhu, Wei He, Yu-Na Chai, You-Wen Liu
BACKGROUND AND PURPOSE: Trauma-induced osteonecrosis of the femoral head (TIONFH) is a major complication of femoral neck fractures. Degeneration and necrosis of subchondral bone can cause collapse, which results in hip joint dysfunction in patients. The destruction of bone metabolism homeostasis is an important factor for osteonecrosis. MicroRNAs (miRNAs) have an important role in regulating osteogenic differentiation, but the mechanisms underlying abnormal bone metabolism of TIONFH are poorly understood...
2017: PloS One
https://www.readbyqxmd.com/read/28792710/effects-of-passive-smoking-on-glycemic-parameters-and-lipid-profiles-in-a-chinese-female-population
#15
Lijuan Gu, Jing Li, Gui Pan, Xiaojun Zhou, Jianmin Zhang, Xiaoyang Lai, Jianping Liu
BACKGROUND: The adverse effects of exposure to second-hand cigarette smoke on glucose and lipid parameters in women and the underlying mechanisms are not well understood. In this prospective community-based study, we examined the effects of passive smoking on glycemic parameters and lipid profiles in a Chinese female population. METHODS: Of 3197 healthy women enrolled (30 - 75 years), 2082 self-reported passive exposure to smoke (≥ 15 minutes/day, 3 days/week, > 1 year) and 1115 had no smoke exposure (control group)...
July 1, 2017: Clinical Laboratory
https://www.readbyqxmd.com/read/28790799/bilateral-misalignment-compensating-full-dof-hip-exoskeleton-design-and-kinematic-validation
#16
Karen Junius, Marc Degelaen, Nina Lefeber, Eva Swinnen, Bram Vanderborght, Dirk Lefeber
A shared design goal for most robotic lower limb exoskeletons is to reduce the metabolic cost of locomotion for the user. Despite this, only a limited amount of devices was able to actually reduce user metabolic consumption. Preservation of the natural motion kinematics was defined as an important requirement for a device to be metabolically beneficial. This requires the inclusion of all human degrees of freedom (DOF) in a design, as well as perfect alignment of the rotation axes. As perfect alignment is impossible, compensation for misalignment effects should be provided...
2017: Applied Bionics and Biomechanics
https://www.readbyqxmd.com/read/28790464/the-history-of-biomechanics-in-total-hip-arthroplasty
#17
Jan Van Houcke, Vikas Khanduja, Christophe Pattyn, Emmanuel Audenaert
Biomechanics of the hip joint describes how the complex combination of osseous, ligamentous, and muscular structures transfers the weight of the body from the axial skeleton into the appendicular skeleton of the lower limbs. Throughout history, several biomechanical studies based on theoretical mathematics, in vitro, in vivo as well as in silico models have been successfully performed. The insights gained from these studies have improved our understanding of the development of mechanical hip pathologies such as osteoarthritis, hip fractures, and developmental dysplasia of the hip...
July 2017: Indian Journal of Orthopaedics
https://www.readbyqxmd.com/read/28781018/high-early-major-complication-rate-after-revision-for-mechanically-assisted-crevice-corrosion-in-metal-on-polyethylene-total-hip-arthroplasty
#18
Brian J McGrory, Anna H Jorgensen
BACKGROUND: Failed total hip arthroplasty caused by mechanically assisted crevice corrosion (MACC) has serious consequences such as adverse local tissue reaction. Revision is currently indicated for significant hip pain, stiffness, and dysfunction; hip instability; progressive bone loss; and soft tissue destruction. Outcomes of this revision surgery are not yet completely understood. METHODS: We examined the surgical outcomes at a minimum of 6 months (average, 25; range, 7-68 months) in a cohort of 27 consecutive patients who underwent revision total hip arthroplasty for MACC associated with a single implant vendor and taper type...
July 14, 2017: Journal of Arthroplasty
https://www.readbyqxmd.com/read/28780593/the-mechanical-effects-of-cup-inclination-and-anteversion-angle-on-the-bearing-surface
#19
Nobuhiro Kaku, Tomonori Tabata, Hiroaki Tagomori, Tetsutaro Abe, Hiroshi Tsumura
BACKGROUND: Regarding the cup setting in total hip arthroplasty, range of motion and prevention of dislocation are important. From past reports, the wear of the bearing surface may affect long-term results. This study evaluated the stress applied to the bearing surface by the combined use of the three-dimensional rigid spring model and the finite-element analysis. METHODS: For contact pressure distribution of the bearing surface, interference analysis was performed using a three-dimensional rigid body spring model...
August 5, 2017: European Journal of Orthopaedic Surgery & Traumatology: Orthopédie Traumatologie
https://www.readbyqxmd.com/read/28777383/3rd-generation-ceramic-on-ceramic-cementless-total-hip-arthroplasty-a-minimum-10-year-follow-up-study
#20
Yeong J Lau, Shashank Sarmah, Johan D Witt
INTRODUCTION: 3rd generation ceramic bearings were introduced in total hip arthroplasty (THA) with the potential to have better mechanical strength and wear properties than their predecessors. At present, there are few studies looking at the long-term results of this latest generation of ceramic bearings.The purpose of our study was to investigate the long-term clinical and radiographic results of 3rd generation ceramic-on-ceramic THA and the incidence of ceramic specific complications such as squeaking and bearing surface fracture...
July 29, 2017: Hip International: the Journal of Clinical and Experimental Research on Hip Pathology and Therapy
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