Wear analysis of explanted conventional metal back polyethylene glenoid liners
Glenoid component wear and loosening is the Achilles heel of total shoulder replacement [1]. Analysis of failed, revised implants may give an insight into the causes of component failure. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 3, 2018 Category: Biomedical Engineering Authors: Gyorgy Kocsis, Charlie J. Payne, Angus Wallace, Donal McNally Source Type: research
A compliant aortic model for in vitro simulations: Design and manufacturing process
The pathophysiological behavior of the vascular system can be analyzed by means of different approaches, e.g., mathematical and numerical methods, in vivo analyses and in vitro tests. Among them, in vitro investigations of physiological/pathological fluid dynamic conditions help physiologists and clinicians in understanding the behavior of the vascular system and the impact of specific pathologies. Moreover, in vitro analyses support the design of prostheses and devices, and the pre-operative planning. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 1, 2018 Category: Biomedical Engineering Authors: Stefania Marconi, Ettore Lanzarone, Guido H.W. van Bogerijen, Michele Conti, Francesco Secchi, Santi Trimarchi, Ferdinando Auricchio Source Type: research
Correlations between core muscle geometry, pain intensity, functional disability and postural balance in patients with nonspecific mechanical low back pain
Chronic low back pain (CLBP) is a highly prevalent musculoskeletal problem worldwide. In the Iranian population, the lifetime prevalence of LBP has been estimated between 14.4% and 84.1%, and it is considered the third leading cause of disability and work absenteeism [1]. Many people with LBP are labeled as having nonspecific LBP because no known pathological or anatomical cause can be identified [2]. It has been proposed that weakened or insufficient motor control in the deep trunk musculature can contribute to chronic nonspecific low back pain (CNLBP) [3]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 1, 2018 Category: Biomedical Engineering Authors: Farahnaz Emami, Amin Kordi Yoosefinejad, Mohsen Razeghi Source Type: research
On a “Columbus’ Egg”: Modeling the shape of asymptomatic, dysplastic and impinged hip joints
Morphological variations of the hip joint anatomy, such as femoroacetabular impingement (FAI) and dysplasia, have been suggested to be linked to the lesion mechanism of articular cartilage and progress towards osteoarthritis (OA) [1 –9]. It has been estimated that FAI morphology affects between 10% and 15% of the general adult population [10] and approximately 55% among young athletes [11]. Regarding hip dysplasia prevalence in adults, it exhibits high variability amongst different racial groups, going from approximately 6– 21% [12]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 28, 2018 Category: Biomedical Engineering Authors: Daniel Sim ões Lopes, Sara M. Pires, Vasco V. Mascarenhas, Miguel T. Silva, Joaquim A. Jorge Source Type: research
Simple implantable wireless sensor platform to measure pressure and force
The use of patient-specific data to drive personal care regimens has significant potential for optimizing medical treatments [1]. One approach to collecting patient-specific data is through the use of “smart implants”. Smart implants serve not only a therapeutic capacity, but also are instrumented with sensing technology to provide diagnostic data. In orthopaedic surgery, the relatively large size of the implants provides an ideal vehicle for introducing diagnostic technology into the body. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 28, 2018 Category: Biomedical Engineering Authors: John F. Drazan, Omar T. Abdoun, Michael T. Wassick, Reena Dahle, Luke Beardslee, George A. Marcus, Nathaniel C. Cady, Eric H. Ledet Tags: Technical note Source Type: research
On a “Columbus’ Egg” for the shape of asymptomatic, dysplastic and impinged hip joints
Morphological variations of the hip joint anatomy, such as femoroacetabular impingement (FAI) and dysplasia, have been suggested to be linked to the lesion mechanism of articular cartilage and progress towards osteoarthritis (OA) [1 –9]. It has been estimated that FAI morphology affects between 10% and 15% of the general adult population [10] and approximately 55% among young athletes [11]. Regarding hip dysplasia prevalence in adults, it exhibits high variability amongst different racial groups, going from approximately 6– 21% [12]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 28, 2018 Category: Biomedical Engineering Authors: Daniel Sim ões Lopes, Sara M. Pires, Vasco V. Mascarenhas, Miguel T. Silva, Joaquim A. Jorge Source Type: research
How a pilot hole size affects osteosynthesis at the screw –bone interface under immediate loading
Plates and screws are widely used as an internal fixation for the various bone fractures [1]. The success of this conventional internal fixation depends usually on the implant primary stability that occurs immediately after the implant insertion [2]. Among several factors, the primary stability is affected by the micromovement of a screw as a result of the low stiffness of screw –bone interface [3]. Other researchers have reported that the holding power of the screw depends on the changes induced in the bone by the insertion trauma as well as the bone reaction around the implant [4]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 28, 2018 Category: Biomedical Engineering Authors: F. Affes, H. Ketata, M. Kharrat, M. Dammak Source Type: research
Modal frequency and shape curvature as a measure of implant fixation: A computer study on the acetabular cup
It is generally known that insufficient initial fixation of press-fitted acetabular implants leads to an excessive implant movement and consequent fibrous layer formation [44], which can cause aseptic loosening of the implant [15,16]. On the other hand, excessive mechanical press-fit fixation leads to an inadequate stress load in the peripheral bone. This may result in damage to the surrounding bone and subsequent implant failure [7]. Achieving the optimal fixation level is a fundamental factor for the long term outcome of the implant longevity. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 27, 2018 Category: Biomedical Engineering Authors: Petr Heny š, Steven Leuridan, Quentin Goossens, Michiel Mulier, Leonard Pastrav, Wim Desmet, Jos Vander Sloten, Kathleen Denis, Lukáš Čapek Source Type: research
A novel method to measure rim deformation in UHMWPE acetabular liners
Fluoroscopy studies of total hip replacement (THR) have shown that the femoral head and acetabular cup can separate in vivo, causing edge loading on the rim of the cup [1 –3]. It is thought that this may be caused by sub-optimal component positioning, such as a steeply inclined cup or unmatched centres of rotation of the head and cup, or by joint laxity or lever-out following femoral neck impingement [4–8]. Pre-clinical testing of THR involves ISO standard motion and loading parameters that are representative of a standard walking gait [9]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 27, 2018 Category: Biomedical Engineering Authors: Susan Partridge, Paige Buckley, Greg de Boer, Sophie Williams Tags: Technical note Source Type: research
A compression system for studying depth-dependent mechanical properties of articular cartilage under dynamic loading conditions
Articular cartilage is composed of a solid phase, a fluid phase, chondrocytes and a small amount of charged anions (carboxyl or sulfate groups) and cations (e.g., Na + , K + , Ca + + ) [1], which are dissolved in the interstitial fluid. Using advanced microscopy techniques, it has been possible to elucidate some of the biological processes inside chondrocytes and selected mechanical interaction of chondrocytes with their environment. For instance, the deformation of the extracellular matrix (ECM) was found to be a stimulus regulating chondrocyte function [2–4]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 27, 2018 Category: Biomedical Engineering Authors: Amin Komeili, Ziad Abusara, Salvatore Federico, Walter Herzog Tags: Technical note Source Type: research
Patellar tendon buckling is altered with age
Tendon injuries remain poorly understood, making them difficult to both prevent and treat. Some risk factors, like age and sex, have been identified, but these factors seem to affect different tendons disparately. For example, although the Achilles and patellar tendons have similar functional behavior, the influence of age and sex on injury incidence varies; whereas Achilles tendon rupture and tendinopathy occur most commonly in middle-age [1,2], ruptures in the patellar tendon occur much later in life [1], and no clear link has been found between age and patellar tendinopathy [3 –6]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 27, 2018 Category: Biomedical Engineering Authors: Laura Chernak Slane, F élix Dandois, Stijn Bogaerts, Hilde Vandenneucker, Lennart Scheys Source Type: research
Biomechanical characteristics of immediately loaded and osseointegration dental implants inserted into Sika deer antler
With the worldwide growing of aging population, there has been considerable increase in the demand for the replacement of lost teeth by means of implant-retained restorations over the last few decades. The clinical success of implant therapy is based on osseointegration, defined as the direct contact between living bone and the implant without the interposition of fibrous tissue [1 –3]. Conventionally, loading on implant-retained restoration should be avoided before osseointegration. However, immediately loaded (IL) implants which allow for shorter rehabilitation times have shown similar implant stability and success rat...
Source: Medical Engineering and Physics - July 15, 2018 Category: Biomedical Engineering Authors: Yun He, Istabrak Hasan, Ludger Keilig, Dominik Fischer, Luisa Ziegler, Markus Abboud, Gerhard Wahl, Christoph Bourauel Source Type: research
Geometric surrogates of abdominal aortic aneurysm wall mechanics
An abdominal aortic aneurysm is a dilatation of the infrarenal aorta which, if left untreated, can rupture. When this occurs, there is a 50% mortality rate before reaching the operating room and an additional 25% intra-operative mortality rate [1]. AAA disease is ranked as the 13th cause of death in the U.S. [2] and is most common in patients 65 years of age and older [3]. This high rate of mortality is due to most AAAs remaining asymptomatic until they rupture. Risk factors associated with AAA rupture include smoking, obesity, high blood pressure, and high cholesterol, but timely diagnosis of asymptomatic AAA is still a d...
Source: Medical Engineering and Physics - July 10, 2018 Category: Biomedical Engineering Authors: Jes ús Urrutia, Anuradha Roy, Samarth S. Raut, Raúl Antón, Satish C. Muluk, Ender A. Finol Source Type: research
Intraoperative bone defect measurement in the acetabulum using a navigation system: The influence of bone porosity on the digitalization process
The demand of revision total hip arthroplasty is expected to increase due to the higher demand of primary total hip arthroplasties [1]. Revision total hip arthroplasties are expected to increase by 137% by 2030 based on a prediction made by Kurtz et al in the United States [2]. Acetabular bone loss caused by osteolysis, stress-shielding and/or component migration pose a difficult challenge in the operative management in revision total hip arthroplasty [1]. In revision hip arthroplasty the patient's bone stock is frequently of a poorer quality than at the primary operation and substantial patient bone defects are created du...
Source: Medical Engineering and Physics - July 9, 2018 Category: Biomedical Engineering Authors: David Putzer, Florian Scholl, Lukas Dankl, Dietmar Dammerer, Martin Thaler, Michael Nogler Tags: Technical note Source Type: research
Accuracy of a novel marker tracking approach based on the low-cost Microsoft Kinect v2 sensor
Marker-based optical motion capture systems and wearable inertial sensors have been employed widely in clinical gait analysis [1]. In the most favourable conditions, optical marker-based tracking can provide an overall accuracy of 63 ± 5 μm [2]. However, these systems are not always practical in the clinical setting, given the substantial setup costs and space requirements [3]. Wearable devices based on inertial sensors are low-cost, but are subject to position measurement errors as a consequence of acceleration integra tion [1]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 6, 2018 Category: Biomedical Engineering Authors: Alessandro Timmi, Gino Coates, Karine Fortin, David Ackland, Adam L. Bryant, Ian Gordon, Peter Pivonka Tags: Technical note Source Type: research
