• Structural Engineering and Mechanics
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• v.87 no.6
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• pp.575-583
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• 2023

The postoperative period for a carrier of total hip prosthesis (THP), especially in the first months, remains the most difficult period for a patient after each operation, even if traumatologist surgeons want the relief and success of their operations. In this investigation, selected three of the daily activities for a wearer of total hip replacement (THR), such as sitting in a chair, lifting a chair, and going downstairs, and was performed a numerical simulation by finite elements based on experimental data by Bergmann (Bergmann 2001) in terms of effort for each activity. Different stresses have been extracted, and a detailed comparison between two activities with different induced stresses such as normal, tensile, and compressive shear stresses.

• Structural Engineering and Mechanics
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• v.86 no.5
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• pp.635-645
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• 2023

This study aims to simulate the mechanical behavior of the total prosthesis model of Charnley (CMK3) by the 3D finite element method and to determine the state of the stresses in the femoral components (prosthesis, cement, and bone). The components are subjected to a dynamic load due to three activities (normal walking, climbing stairs, and standing up a chair). Static loading is by selecting the maximum load for the same activities mentioned. The results show that the maximum stresses in the proximal part of the cement are very important. Moreover, new results obtained for different parameters were discussed in detail. It is understood that current research provides important lessons for the surgeon to contribute to the clinical diagnosis of durable implantations and a better understanding of the process of bone remodeling and bone prosthesis.

• Journal of Biomedical Engineering Research
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• v.23 no.2
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• pp.119-130
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• 2002

The nonlinear finite element program has been developed to analyze the design performance of an artificial hip prosthesis and long term behavior of a treated femur with stems made of composite material after cementless total hip arthroplasty(THA). The authors developed the three dimentional FEM models of femoral bone with designed composite stem which was taken with elliptic cross section of 816 brick elements under hip contact load and muscle farce in simulating single leg stand. Using the program, density changes, stress distributions and micromotions of the material femoral bone were evaluated by changing fiber orientation of stems for selected manufacturing method such as plate cut and bend mold. The results showed that the composite materials such as AS4/PEEK and T300/976 gave less bone resorption than the metallic material such as cobalt chrome alloy, titanium alloy and stainless steal. It was found that increasing the long term stability of the prosthesis in the femur could be obtained by selecting the appropriate ply orientation and stacking sequence of composite.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1183-1184
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• 2012

• Structural Engineering and Mechanics
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• v.88 no.6
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• pp.583-588
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• 2023

Total hip replacement is a crucial intervention for patients with fractured hips who face challenges in natural recovery. The design of durable prostheses requires a comprehensive understanding of the natural processes occurring in bone. This article focuses on static loading analysis, specifically during stumbling activity, aiming to enhance the longevity of prosthetic implants. Three distinct implants, Charnley, Osteal, and Thompson, were selected for a detailed study to determine the most appropriate model. The results revealed critical insights into the distribution of Von Mises stresses on the components of femoral arthroplasty, including the cement, implant, and cortical bone. Furthermore, the examination of shear stress within the cement emerged as a pivotal aspect for all three implants, playing a crucial role in evaluating the performance and durability of hip prostheses. The conclusions drawn from this study strongly suggest that the Thompson model stands out as the most suitable choice for hip joint implants.

• Biomaterials and Biomechanics in Bioengineering
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• v.5 no.1
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• pp.11-23
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• 2020

Total hip prosthesis is used for the patients who have hip fracture and are unable to recover naturally. To de-sign highly durable prostheses one has to take into account the natural processes occurring in the bone. Finite element analysis is a computer based numerical analysis method which can be used to calculate the response of a model to a set of well-defined boundary conditions. In this paper, the static load analysis is based, by se-lecting the peak load during the stumbling activity. Two different implant materials have been selected to study appropriate material. The results showed the difference of maximum von Misses stress and detected the frac-ture of the femur shaft for different model (Charnley and Osteal) implant with the extended finite element method (XFEM), and after the results of the numerical simulation of XFEM for different was used in deter-mining the stress intensity factors (SIF) to identify the crack behavior implant materials for different crack length. It has been shown that the maximum stress intensity factors were observed in the model of Charnley.

• Structural Engineering and Mechanics
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• v.57 no.4
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• pp.717-731
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• 2016

In orthopedic surgery and more especially in total arthroplastie of hip, the fixing of the implants generally takes place essentially by means of constituted surgical polymer cement. The damage of this materiel led to the fatal rupture and thus loosening of the prosthesis in total hip, the effect of over loading as the case of tripping of the patient during walking is one of the parameters that led to the damage of this binder. From this phenomenon we supposed that a remain of bone is included in the cement implantation. The object of this work is to study the effect of this bony inclusion in the zones where the outside conditions (loads and geometric shapes) can provoke the fracture of the cement and therefore the aseptic lousing of the prosthesis. In this study it was assumed the presence of two bones -type inclusions in this material, one after we analyzed the effect of interaction between these two inclusions damage of damage to this material. One have modeled the damage in the cement around this bone inclusion and estimate the crack length from the damaged cement zone in the acetabulum using the finite element method, for every position of the implant under the extreme effort undergone by the prosthesis. We noted that the most intense stress position is around the sharp corner of the bone fragment and the higher level of damage leads directly the fracture of the total prosthesis of the hip.

• Korean Journal of Computational Design and Engineering
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• v.13 no.3
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• pp.200-208
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• 2008

Total Hip Replacement(THR) is a surgical procedure that replaces a diseased hip joint with a prosthesis. A plastic or metal cup forms the socket, and the head of the femur is replaced by a metal ball on a stem placed inside the femur. Due to the various types and shapes of human hip joint of every individual, a selected commercial implant sometimes may not be the best-fit to a patient, or it cannot be applied because of its discrepancy. Hence extracting geometry parameters of hip joint is one of the most crucial processes in designing custom-made implants. This paper describes the framework of a methodology to extract the geometric parameters of the hip joint. The parameters include anatomical axis, femoral head, head offset length, femoral neck, neck shaft angle, anteversion, acetabulum, and canal flare index. The proposed system automatically recommends the size and shape of a custom-made hip implant with respect to the patient's individual anatomy from 3D models of hip structures. The proposed procedure creating these custom-made implants with some typical examples is precisely presented and discussed in this paper.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.390-394
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• 2022

A 6-year-old, 36.5 kg castrated male Golden Retriever presented for revision surgery for left total hip replacement. The patient underwent removal of the cup and head implants due to unmanageable prosthetic hip dislocation, despite revision surgery. On physical examination, the dog showed persistent weight-bearing lameness after exercise of the left hindlimb with mild muscle atrophy. Radiographic examination revealed dorsolateral displacement of the femur with a remnant stem and bony proliferation around the cranial and caudal acetabulum rims. The surgical plan was to apply the dual mobility cup to increase the range of motion and jump distance to correct soft tissue elongation and laxity caused by a prolonged period of craniodorsal dislocation of the femur. The preparation of the acetabulum for cup fixation was performed with a 29-mm reamer, and the 29.5-mm outer shell was fixed with five 2.4-mm cortical screws. The head and medium neck of the dual-mobility system were placed on the cup, and the hip joint was reduced between the neck and stem. The dog exhibited slight weight bearing on a controlled leash walk the day after surgery. The patient was discharged 2 weeks postoperatively without any complications. Six months postoperatively, osseointegration and a well-positioned cup implant were observed, and the dog showed excellent limb function without hip dislocation until 18 months of phone call follow-up.

• Biomaterials Research
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• v.22 no.4
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• pp.259-270
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• 2018

Background: Total hip arthroplasty (THA) is probably one of the most successful surgical interventions performed in medicine. Through the revolution of hip arthroplasty by principles of low friction arthroplasty was introduced by Sir John Charnley in 1960s. Thereafter, new bearing materials, fixation methods, and new designs has been improved. The main concern regarding failure of THA has been the biological response to particulate polyethylene debris generated by conventional metal on polyethylene bearing surfaces leading to osteolysis and aseptic loosening of the prosthesis. To resolve these problems, the materials of the modern THA were developed since then. Methods: A literature search strategy was conducted using various search terms in PUBMED. The highest quality articles that met the inclusion criteria and best answered the topics of focus of this review were selected. Key search terms included 'total hip arthroplasty', 'biomaterials', 'stainless steel', 'cobalt-chromium', 'titanium', 'polyethylene', and 'ceramic'. Results: The initial search retrieved 6921 articles. Thirty-two articles were selected and used in the review. Conclusion: This article introduces biomaterials used in THA and discusses various bearing materials in currentclinical use in THA as well as the newer biomaterials which may even further decrease wear and improve THA survivorship.