The role of the fiber ply configurations on the biomechanics of the hip prosthesis

Author(s):  
Kamran Hassani ◽  
Mohammad Nikkhoo ◽  
Alireza Karimi

The total hip replacement is the only approved procedure for restoring a degenerated hip joint through operation. The life span of a prosthesis could depend on the geometry and material properties of the implant. This study aims to analyze the biomechanics of the carbon/polyetheretherketone (PEEK) composite prosthesis having three different fiber ply configurations compared to traditional stainless steel (SS) ones. The implant-bone system was established and subjected to a load from the head of the femur and abductor muscle sides. The stresses and strains in the implant-bone systems were calculated and compared. The results revealed lower stresses and strains in composite prostheses compared to SS ones. The fiber ply orientation of the carbon/PEEK composite prosthesis is shown to be a key asset in stress and strain distribution of the 13 implant-bone systems. The fiber plies which orientated multidirectionally with −45 and +45 degrees exhibited uniform stress and strain distributions. The results suggested the advantage of using composite prostheses in implant designs as they not only invoke lower stresses and strains in the implant-bone system but also amplify the life span of implants in the body.

1986 ◽  
Vol 27 (6) ◽  
pp. 619-627 ◽  
Author(s):  
K. Herrlin ◽  
G. Selvik ◽  
H. Pettersson

A method for in vivo determination of orientation and relation in space of components of total hip prosthesis is described. The method allows for determination of the orientation of the prosthetic components in well defined anatomic planes of the body. Furthermore the range of free motion from neutral position to the point of contact between the edge of the acetabular opening and the neck of the femoral component can be determined in various directions. To assess the accuracy of the calculations a phantom prosthesis was studied in nine different positions and the measurements of the space oriented parameters according to the present method correlated to measurements of the same parameters according to Selvik's stereophotogrammetric method. Good correlation was found. The role of prosthetic malpositioning and component interaction evaluated with the present method in the development of prosthetic loosening and displacement is discussed.


2021 ◽  
Vol 9 (12) ◽  
pp. 3124-3132
Author(s):  
Anujaa D ◽  
Rashmi B.V ◽  
Rekha K.B.P ◽  
Kalpana Kalpana

Ayurveda emphasizes on maintenance of health in a healthy individual and treating the diseased ones. The human body comprises Tridosha, Saptadhatu, Trimala (structural and functional entities of the body). Sharira (body) is a mula for health as well as disease. Srotas (body channels) are those channels that transport and transform the sub- stances to respective tissues, cells of the human body required for life sustenance. As the Dhatu’s are classified as Sthayi and Asthayi dhatu, based on the Aahara (food) consumed the respective Dosha Utpatti (biotransformation) takes place leading to Saara Kitta Vibhajana (formation of metabolic nutrients and waste). Rasa dhatu is an Asthayi Dhatu which is predominant of Jala Mahabhuta. From the Aahara Rasa, Rasa Dhatu is formed which is the prime Dhatu resulting in the development of subsequent dhatus of the sharira. Rasa Saara Purusha is en- dowed with Aayushmanta (longer life span) and Aarogya (health). As Rasadhatu Dusti Janya Vikaras are abun- dant in our clinics, understanding of Rasavaha Srotodusti Nidana (causative factor) and Lakshana (signs and symptoms) in a patient with a relevant examination by means of Trividha Pariksha and prescribing appropriate Chikitsa (treatment) by understanding Guna -Karma principle is the need of the hour. Keywords: Rasavaha Srotas (lymph channels), Pariksha (examination), Chikitsa (treatment)


2021 ◽  
pp. 1-4
Author(s):  
Alagnide Hountondji Etienne ◽  
◽  
Chigblo Pascal ◽  

After a hip prosthesis, an increasingly targeted goal is hip forgetfulness. What about this result in Benin. Objective: To study hip forgetting after hip prosthesis in Benin. Methods: Prospective study with a descriptive and analytical aim carried out from February to October 2019. It focused on patients with prosthesis of a single hip for at least 3 months in hospitals in Cotonou and surroundings, without comprehension disorders or other pathologies causing locomotor system disability and who consented to participate in the study. The “Forgotten Joint Score -12” (FJS-12) and the “Hip disability and Osteoarthritis Outcome Score” (HOOS) were the tools to assess, respectively, the forgetfulness and functionality of the prosthetic hip of patients. Results: The mean age of patients was 52.90 ± 16.76 years. The sex ratio was 1.31. These were mainly cases of PTH (88.64%), first-line (86.36%). Only one patient between four had actually forgotten his hip. The latter was significantly associated mainly with the parameters of functional capacities of the hip. Conclusion: Hip forgetting still remains a major challenge in hip replacement patients in Benin. The role of functional rehabilitation in achieving this goal is legitimate, showing the need to collaborate between specialties in the care of these patients.


2020 ◽  
Vol 11 (4) ◽  
pp. 1223
Author(s):  
Raffaella Aversa ◽  
Relly Victoria Virgil Petrescu ◽  
Antonio Apicella ◽  
Florian Ion Tiberiu Petrescu

The complex biomechanics and morphology of the femur proximal epiphysis are presented. This specific region in the human femur is characterized by high flexibility compared to that of other primates, since evolved lighter and longer due to the human vertical position and more balanced loading. The nature and fine morphology of the femur head and its structural behavior have been investigated. Isotropic and orthotropic trabecular structures, which are not present in other primates, have been associated with compression and tension areas of the femur head. These isotropic/orthotropic trabecular morphologies and allocations govern the stress and strain distribution in the overall proximal femur region. Use of femur proper biofidel modeling while enabling the explanation of physiological stress distribution elucidates the critical mechanical role of the trabecular bone that should be accounted in the design of a new innovative more “biologic” prosthetic system.


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.


2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.


Somatechnics ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 288-303
Author(s):  
Michael Connors Jackman

This article investigates the ways in which the work of The Body Politic (TBP), the first major lesbian and gay newspaper in Canada, comes to be commemorated in queer publics and how it figures in the memories of those who were involved in producing the paper. In revisiting a critical point in the history of TBP from 1985 when controversy erupted over race and racism within the editorial collective, this discussion considers the role of memory in the reproduction of whiteness and in the rupture of standard narratives about the past. As the controversy continues to haunt contemporary queer activism in Canada, the productive work of memory must be considered an essential aspect of how, when and for what reasons the work of TBP comes to be commemorated. By revisiting the events of 1985 and by sifting through interviews with individuals who contributed to the work of TBP, this article complicates the narrative of TBP as a bluntly racist endeavour whilst questioning the white privilege and racially-charged demands that undergird its commemoration. The work of producing and preserving queer history is a vital means of challenging the intentional and strategic erasure of queer existence, but those who engage in such efforts must remain attentive to the unequal terrain of social relations within which remembering forms its objects.


2020 ◽  
Vol 32 (3) ◽  
pp. 138-144
Author(s):  
Brian A. Jacobs

In federal criminal cases, federal law requires that judges consider the sentences other courts have imposed in factually similar matters. Courts and parties, however, face significant challenges in finding applicable sentencing precedents because judges do not typically issue written sentencing opinions, and transcripts of sentencings are not readily available in advanced searchable databases. At the same time, particularly since the Supreme Court’s 2005 decision in United States v. Booker, sentencing precedent has come to play a significant role in federal sentencing proceedings. By way of example, this article discusses recent cases involving defendants with gambling addictions, and recent cases involving college admissions or testing fraud. The article explores the ways the parties in those cases have used sentencing precedent in their advocacy, as well as the ways the courts involved have used sentencing precedent to justify their decisions. Given the important role of sentencing precedent in federal criminal cases, the article finally looks at ways in which the body of sentencing law could be made more readily available to parties and courts alike.


2014 ◽  
Vol 31 (1) ◽  
pp. 91-124
Author(s):  
Michael Dorfman

In a series of works published over a period of twenty five years, C.W. Huntington, Jr. has developed a provocative and radical reading of Madhyamaka (particularly Early Indian Madhyamaka) inspired by ‘the insights of post- Wittgensteinian pragmatism and deconstruction’ (1993, 9). This article examines the body of Huntington’s work through the filter of his seminal 2007 publication, ‘The Nature of the M?dhyamika Trick’, a polemic aimed at a quartet of other recent commentators on Madhyamaka (Robinson, Hayes, Tillemans and Garfield) who attempt ‘to read N?g?rjuna through the lens of modern symbolic logic’ (2007, 103), a project which is the ‘end result of a long and complex scholastic enterprise … [which] can be traced backwards from contemporary academic discourse to fifteenth century Tibet, and from there into India’ (2007, 111) and which Huntington sees as distorting the Madhyamaka project which was not aimed at ‘command[ing] assent to a set of rationally grounded doctrines, tenets, or true conclusions’ (2007, 129). This article begins by explicating some disparate strands found in Huntington’s work, which I connect under a radicalized notion of ‘context’. These strands consist of a contextualist/pragmatic theory of truth (as opposed to a correspondence theory of truth), a contextualist epistemology (as opposed to one relying on foundationalist epistemic warrants), and a contextualist ontology where entities are viewed as necessarily relational (as opposed to possessing a context-independent essence.) I then use these linked theories to find fault with Huntington’s own readings of Candrak?rti and N?g?rjuna, arguing that Huntington misreads the semantic context of certain key terms (tarka, d???i, pak?a and pratijñ?) and fails to follow the implications of N?g?rjuna and Candrak?rti’s reliance on the role of the pram??as in constituting conventional reality. Thus, I find that Huntington’s imputation of a rejection of logic and rational argumentation to N?g?rjuna and Candrak?rti is unwarranted. Finally, I offer alternate readings of the four contemporary commentators selected by Huntington, using the conceptual apparatus developed earlier to dismiss Robinson’s and Hayes’s view of N?g?rjuna as a charlatan relying on logical fallacies, and to find common ground between Huntington’s project and the view of N?g?rjuna developed by Tillemans and Garfield as a thinker committed using reason to reach, through rational analysis, ‘the limits of thought.’


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