scholarly journals AE Monitoring of Microdamages in Bioceramics for Artificial Joints under Simulated Body Environment

2006 ◽  
Vol 49 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Shuichi WAKAYAMA ◽  
Yasuhiro SUZUKI ◽  
Toyokatsu OSHIMA ◽  
Satoshi KOBAYASHI
Keyword(s):  
Artificial Joints

Assessment of Amorphous Carbon Coating for Artificial Joints Application

2005 ◽  
Vol 48 (2) ◽  
pp. 190-198 ◽  
Author(s):  
O. O. Ajayi ◽  
B. Shi ◽  
M. J. Soppet ◽  
A. Erdemir ◽  
H. Liang ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Carbon Coating ◽  
Artificial Joints

The Role of Macrophages in the Biological Reaction to Wear Debris from Artificial Joints

2016 ◽  
Vol 26 (4) ◽  
pp. 303-309 ◽  
Author(s):  
Christophe Nich ◽  
Yuya Takakubo ◽  
Jukka Pajarinen ◽  
Jiri Gallo ◽  
Yrjo T. Konttinen ◽  
...  
Keyword(s):  
Wear Debris ◽  
Artificial Joints ◽  
Biological Reaction

scholarly journals A review of the bio-tribology of medical devices

Friction ◽  
2021 ◽  
Author(s):  
Xiaogang Zhang ◽  
Yali Zhang ◽  
Zhongmin Jin
Keyword(s):  
Service Life ◽  
Medical Devices ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Dental Restoration ◽  
Surgical Instruments ◽  
Cardiovascular Devices ◽  
Artificial Joints ◽  
Future Developments ◽  
Fixation Devices

AbstractNumerous medical devices have been applied for the treatment or alleviation of various diseases. Tribological issues widely exist in those medical devices and play vital roles in determining their performance and service life. In this review, the bio-tribological issues involved in commonly used medical devices are identified, including artificial joints, fracture fixation devices, skin-related devices, dental restoration devices, cardiovascular devices, and surgical instruments. The current understanding of the bio-tribological behavior and mechanism involved in those devices is summarized. Recent advances in the improvement of tribological properties are examined. Challenges and future developments for the prospective of bio-tribological performance are highlighted.

scholarly journals Morphological residual convolutional neural network (M-RCNN) for intelligent recognition of wear particles from artificial joints

Friction ◽  
2021 ◽  
Author(s):  
Xiaobin Hu ◽  
Jian Song ◽  
Zhenhua Liao ◽  
Yuhong Liu ◽  
Jian Gao ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Data Augmentation ◽  
Support Vector ◽  
Wear Particles ◽  
Artificial Joints ◽  
Performance Deterioration ◽  
Overall Performance ◽  
Correct Category ◽  
Intelligent Recognition

AbstractFinding the correct category of wear particles is important to understand the tribological behavior. However, manual identification is tedious and time-consuming. We here propose an automatic morphological residual convolutional neural network (M-RCNN), exploiting the residual knowledge and morphological priors between various particle types. We also employ data augmentation to prevent performance deterioration caused by the extremely imbalanced problem of class distribution. Experimental results indicate that our morphological priors are distinguishable and beneficial to largely boosting overall performance. M-RCNN demonstrates a much higher accuracy (0.940) than the deep residual network (0.845) and support vector machine (0.821). This work provides an effective solution for automatically identifying wear particles and can be a powerful tool to further analyze the failure mechanisms of artificial joints.

Implant Infections Due to Enterococci: Role of Capsular Polysaccharides and Biofilm

2005 ◽  
Vol 28 (11) ◽  
pp. 1079-1090 ◽  
Author(s):  
F. Fabretti ◽  
J. Huebner
Keyword(s):  
Antimicrobial Agents ◽  
Capsular Polysaccharide ◽  
Female Genital Tract ◽  
Teichoic Acid ◽  
Capsular Polysaccharides ◽  
Human Pathogens ◽  
Artificial Joints ◽  
Artificial Hearts ◽  
Intravascular Catheters ◽  
Enterococcal Infections

Enterococci are natural inhabitants of the gastrointestinal tract and of the female genital tract of humans and many animals. In recent years, enterococci have been increasingly recognized as important human pathogens causing infections associated with medical devices. Their resistance to most antimicrobial agents and their ability to form biofilm has contributed to the increasing incidence of nosocomial enterococcal infections. Enterococci possess a capsular polysaccharide composed of a glycerol-teichoic acid-like molecule consisting of repeating units of 6-α-D-glucose-1-2-glycerol-3-PO4, substituted on carbon 2 with a α-2,1-linked molecule of glucose. Using both immunologic and genetic data E. faecalis can be assigned to specific serotypes based on capsular polysaccharides. Clinical examples of foreign-body infections due to enterococci are described, comprising infections of artificial joints, implanted intravascular catheters, artificial hearts and artificial valves, stents, liquor shunt devices, and intraocular infections. Methods to prevent and/or treat enterococcal infections are presented.

scholarly journals System for intraoperative evaluation of soft-tissue-generated forces during total hip arthroplasty by measurement of the pressure distribution in artificial joints

2007 ◽  
Vol 12 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Yoshito Otake ◽  
Naoki Suzuki ◽  
Asaki Hattori ◽  
Hidenobu Miki ◽  
Mitsuyoshi Yamamura ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Total Hip Arthroplasty ◽  
Pressure Distribution ◽  
Hip Arthroplasty ◽  
Artificial Joints ◽  
Total Hip ◽  
Intraoperative Evaluation

Recommendations with Respect to the Improvement of Lubricating Qualities of Synovial Fluid in Artificial Joints

1993 ◽  
Vol 207 (2) ◽  
pp. 111-114 ◽  
Author(s):  
N S Gavrjushenko
Keyword(s):  
Synovial Fluid ◽  
Short Description ◽  
Plate Model ◽  
Red Bone Marrow ◽  
Artificial Joints ◽  
Hip Endoprosthesis ◽  
New Approach ◽  
Red Marrow ◽  
Ultra High Molecular Weight ◽  
Lubricating Properties

This paper gives a short description of the lubricating properties of yellow and red bone marrow taken from a femur of a cadaver. The experiments have been conducted on a ‘ball-on-plate’ model. The balls were made from steel 100 CR6 (German) and the plates were made from the same steel and ultra-high molecular weight polyethylene (UHMWPE, German ‘Herulen’). The friction coefficients under loads of 50 and 300 N were determined with different combinations of friction components. It has been found that the lubricating properties of yellow and red marrow have advantages over synovial fluid. In the light of these results the author develops a new approach to the design of a new hip endoprosthesis.

Long-Term Reliability Assessment of Bioceramics for Artificial Joints Using Microdamage Monitoring by AE

2006 ◽  
Vol 309-311 ◽  
pp. 1191-1194
Author(s):  
Shuichi Wakayama ◽  
Teppei Kawakami ◽  
Junji Ikeda
Keyword(s):  
Critical Stress ◽  
Reliability Assessment ◽  
Physiological Saline ◽  
Bending Test ◽  
Unstable Fracture ◽  
Artificial Joints ◽  
Bending Tests ◽  
Four Point Bending

Microfracture process during bending tests of alumina ceramics used for artificial joints was evaluated by acoustic emission (AE) technique. Four-point bending tests were carried out in air, refined water, physiological saline and simulated body fluid. AE behavior during bending test inhibited the rapid increasing point of AE events and energy prior to the final unstable fracture. It was understood that the bending stress at the increasing point corresponds to the critical stress for maincrack formation. The critical stress was affected by water in environments more strongly than fracture strength. Consequently, it was suggested that the characterization of maincrack formation is essential for the long-term reliability assessment of load-bearing bioceramics.

scholarly journals Mechanical Failure of Artificial Joint Materials: Wear and Fatigue

2000 ◽  
Author(s):  
L. D. Timmie Topoleski
Keyword(s):  
Cyclic Loading ◽  
Bone Cement ◽  
Fatigue Failure ◽  
Relative Motion ◽  
Wear Mechanisms ◽  
Bone Cements ◽  
Artificial Joint ◽  
Artificial Joints ◽  
Cocrmo Alloy ◽  
Pmma Bone Cement

Abstract Total artificial joint replacements are one of the most effective treatments for arthritis. Artificial joints are used to replace damaged cartilage and act as low-friction articulating materials in joints. During normal human walking, some of the materials used for artificial knee and hip replacements are subjected to both sliding articulation (relative motion) and cyclic loading. A common example is the CoCrMo alloy femoral surface of an artificial knee that articulates against an ultra-high-molecular-weight-polyethylene (UHMWPE) component. Other materials do not experience relative motion (at least not intentionally) and are subjected to only cyclic loading. An example is the poly(methyl methacrylate) or PMMA bone cement used to fix components of artificial joints into bones. In the case of articulating materials, both surfaces are susceptible to wear, from both second-body and third body (in the presence of abrasive particles) mechanisms. Wear of the UHMWPE has received considerable attention recently, since the polymer wear is far more obvious than the metal wear. The Biomaterials field is developing an understanding of the wear mechanisms and how to enhance the wear resistance of UHMWPE. The wear of the metal components has not received as much attention, yet materials wear as a couple; both surfaces play a role in the overall wear. In the UMBC Laboratory for Implantable Materials, we are investigating the mechanisms of CoCrMo alloy wear, and the effect of worn metal components on the wear of UHMWPE. Understanding the wear mechanisms of metal components may help to extend the life of artificial joints by allowing new articulating material combinations and joint designs. For non-articulating materials, fatigue failure is a primary concern. Fatigue of metal components is relatively rare. In the distal portion of an artificial hip, the metal hip stem is fixed into the bone by a layer of PMMA bone cement. The PMMA bone cement is far weaker and less resistant to fracture and fatigue than either the bone or the metal, and thus may be considered the mechanical “weak link” in cemented total joints. We are investigating the fatigue properties of PMMA bone cements, and studying the mechanisms of fatigue crack initiation. If we can determine how fatigue cracks start in bone cement, we may be able to develop, for example, new surgical procedures (e.g., bone preparation) that will reduce the likelihood of fatigue failure. New formulations of bone cement have been developed for both joint fixation, and also for bone repair or replacement. Understanding the failure mechanisms of bone cements may enable safe and effective new uses for new bone cements, and extend the lives of cemented artificial joints.

Sign in / Sign up

Export Citation Format

Share Document