Amir Putra

Universiti Teknologi Malaysia | UTM · Department of Applied Mechanics and Design

Humans carry out various activities in everyday life, where the most frequently performed are normal walking activities. Loading under this human activity has been adopted by several studies for developing hip joint replacement in vivo or in vitro. The presented research performs a von Mises stress investigation on CoCrMo-on-CoCrMo bearing in norma...

In daily human activity, normal walking becomes the most common performed activity. For this reason, many researchers have been adopted normal walking condition to giving actual loading on many hip implants studies. Our recent article intends to conducting deformation study in hip joint bearing during normal walking activity using numerical analysi...

Various studies of total hip arthroplasty from many existing researchers have examined implant user external factors from implant user. Unfortunately, internal factor of implant user is not profoundly discussed. Our current study aims to understand von mises stress in CoCrMo-on-CoCrMo of total hip arthroplasty based on body mass index of implant us...

The dynamic characteristic of bone is its ability to remodel itself through mechanobiological responses. Bone regeneration is triggered by mechanical cues from physiological activities that generate structural strain and cause bone marrow movement. This phenomenon is crucial for bone scaffold when implanted in the cancellous bone as host tissue. Of...

Bone processing and radiation were reported to influence mechanical properties of cortical bones due in part to structural changes and denaturation of collagen composition. This comparative study was to determine effects of bone processing on mechanical properties and organic composition, and to what extent the radiation damaging after each process...

The paper available of total hip arthroplasty is still concerned with the external factors of implant user, but the internal factor that is the user’s body weight has not deeply understood. Our research presents deformation analysis of total hip arthroplasty with different loading conditions based on the patient’s body mass index category. 2D model...

This investigation aims to wear analyze of acetabular cup on metal-on-metal total hip arthroplasty with and without dimple addition. Our contribution that present in this paper is to explore the effect of surface texturing application to reduce wear that important for implant's survival. Finite element method is using with 3D human's hip joint load...

While doing daily physiological activities, the trabecular bone will experience a certain amount of deformation which leads to the bone marrow movement. The movement can affect the bone remodelling process and the properties of the bone itself. The bone marrow plays a role as a hydraulic stiffening of the trabecular structure. However, previous stu...

Introduction: Total hip prosthesis has become one of the important aspects of hip joint replacement surgery. The study about this implant to extent its lifetime is still limited on external factors of the patient that undergo replacement surgery. Besides, evaluating internal aspects also needs to be studied, there is users body weight. Methods: Rec...

Wear and wear-induced debris is a significant factor in causing failure in implants. Reducing contact pressure by using a textured surface between the femoral head and acetabular cup is crucial to improving the implant’s life. This study presented the effect of surface texturing as dimples on the wear evolution of total hip arthroplasty. It was imp...

The present study has sought to investigate the fluid characteristic and mechanical properties of trabecular bone using fluid–structure interaction (FSI) approach under different trabecular bone orientations. This method imposed on trabecular bone structure at both longitudinal and transverse orientations to identify effects on shear stress, permea...

Glenoid conformity is one of the important aspects that could contribute to implant stability. However, the optimal conformity is still being debated among the researchers. Therefore, this study aims to analyze the stress distribution of the implant and cement in three types of conformity (conform, non-conform, and hybrid) in three load conditions...

This research aims to analyze the contact pressure on acetabular cup surface with dimple addition and without dimple addition. The main contribution in this research is to explore the influence of dimple addition to contact pressure that affects implant lifetime. The simulation is carried out by giving fully 3D physiological loading of the hip join...

Porosity plays a vital role in the development of tissue engineering scaffolds. It influences the biocompatibility performance of the scaffolds by increasing cell proliferation and allowing the transportation of the nutrients, oxygen, and metabolites in the blood rapidly to generate new tissue structure. However, a high amount of porosity can reduc...

Kajian ini bertujuan untuk menganalisa tekanan kontak pada permukaan acetabular cup dengan dan tanpa paplikasi permukaan bertekstur. Kontribusi utama dari studi ini adalah mempelajari efek penambahan dimple terhadap tekanan kontak yang berkorelasi terhadap keausan yang terjadi. Pendekatan dengan menggunakan perangkat lunak dilakukan dengan melakuka...

This paper proposes a simple degradation model that estimates morphological changes in pure iron scaffolding due to surface erosion. The main contribution of this work is to estimate the degradation of porous pure iron scaffolding and analyze the impact of morphological changes on mechanical properties. In this study, the pure iron scaffolding mode...

This paper proposes the replacement of artificial hip joints which is one of the successful methods used to restore the movement of damaged hip bones. The main contribution of this work is to reduce wear caused by contact pressure between the femoral head and acetabular cup surfaces, where the average wear rate is very high. This can be achieved th...

Higher strength and lower degradation rate of Fe compared to magnesium and zinc have made it the most reliable for orthopaedic reconstruction. Hence, this paper studies the morphological and mechanical characteristics of porous Fe fabricated using subtractive manufacturing for load bearing bone replacement. Three types of porous Fe (19%, 39% and 59...

Glenoid perforation is not the intended consequence of the surgery and must be avoided. The analysis on biomechanical aspect of glenoid vault perforation remains unknown. The purpose of this study is to determine the impact of glenoid perforation towards stress distribution and micromotion at the interfaces. Eight glenoid implant models had been co...

INTRODUCTION High impact polystyrene (HIPS) is a commodity plastic with good impact strength compared to other commodity plastics but it has low thermal stability and flammability resistance. Incorporation of nanofiller not only can improve mechanical strength, but also improved thermal stability and flammability resistance [1,2]. Graphene is a mul...

A new generation of bone scaffolds incorporates features like biodegradability and biocompatibility. A combination of these attributes will result in having a temporary bone scaffold for tissue regeneration that mimics the natural cancellous bone. Under normal conditions, scaffolds will be gradually eroded. This surface erosion occurs due to the im...

This study employs a computational approach to analyse the impact of morphological changes on the structural properties of biodegradable porous Mg subjected to a dynamic immersion test for its application as a bone scaffold. Porous Mg was immersed in a dynamic immersion test for 24, 48, and 72 h. Twelve specimens were prepared and scanned using mic...

Intact glenoid labrum is one of passive stabilizer for glenohumeral joint, which have various stiffness at different region. The aim of this study is to develop new artificial glenoid labrum from Polyvinyl Alcohol (PVA) hydrogel, which known as good biomaterial due to its biocompatibility and ability to tailor its modulus. PVA hydrogel was formed u...

Nanobioceramics with enhanced mechanical and degradable properties are demanding for bone tissue engineering purposes. We report the influence of partial replacement of ZnO by tricalcium phosphate (TCP) on the improved structure, degradation and mechanical properties of sol-gel grown MgO-ZnO-TCP nanobioceramics. Sample containing 40 mol% of TCP rev...

This paper proposes a modeling approach for biodegradation of implant-bone scaffolds. A Computer simulation was performed to determine the wall shear stress (WSS) and permeability of simulated body fluid (SBF) with a constant flow rate of 0.025 ml/min. In this study, four morphological samples were used to immersion time from 0 to 72 hours. Each sp...

The purpose of this study is to analyze the influence of morphology on the degrading behavior of porous magnesium bone scaffold by using computer simulation. Based on the experimental work, the three bone scaffold prepared with 30%, 41%, and 55% of porosity, respectively. The bone scaffold made of pure magnesium that immersed in simulated body flui...

This paper proposes an improved modeling approach for bone scaffolds biodegradation. In this study, the numerical analysis procedure and computer-based simulation were performed for the bone scaffolds with varying porosities in determining the wall shear stresses and the permeabilities along with their influences on the scaffolds biodegradation pro...

The aim of this research is to validate the behavior of degradation rate within porous magnesium scaffolds in terms of morphological which includes weight loss after degradation by way of micro-computed tomography (µCT) based on image processing. The main contribution of this work is finding another method to determine morphology based on computer...

This study analyse the effect of integrating of physiological environment of human cancellous bone as shown by different level of cyclic compressive on the degradation behaviour of porous magnesium under dynamic immersion for bone scaffold applications. The porous magnesium (30%, 41% and 55% of porosity) were immersed in simulated body fluid (SBF)...

This study shows the effect of dynamic flow on the degradation behaviour and mechanical integrity of porous magnesium. A test rig that mimics the environment surrounding a cancellous bone was developed and a dynamic immersion test was performed to assess the degradation rate of the material for bone scaffold application. Three different percentages...

Wear performance was affected by several factors to contribute towards wear generation. Prospect of minimize wear is needed further study by using optimize design parameter. Inevitability to optimize the design is to improve the understanding of reducing wear in human ankle joint. Change in implant dimension has been suggested, may result in better...

Three-dimensional (3D) models of a right ankle TAR have been created to represent Bologna-Oxford (BOX) TAR model. Finite element analysis of ankle stance phase of gait cycle was developed to simulate the static response behaviour and extract the data in determining the contact pressure on contact surface of the bearing and talar components. Sliding...

Interest in cancellous bone analogous materials is driven by the development of tissue engineering and biomaterials. For the past decade, the research focus has been centered on biodegradable materials, in which the ability of the material to safely degrade in the human body while retaining sufficient qualities during service is conveniently cost-e...

This book develops and analyses computational wear simulations of the total ankle replacement for the stance phase of gait cycle. The emphasis is put on the relevant design parameters. The book presents a model consisting of three components; tibial, bearing and talar representing their physiological functions.

Pre-clinical experimental wear testing is very effective to evaluate new ankle replacement in the aspect of design and material used. However, both cost and time can be one of the constraints factors, particularly in the early stage of design or analysis. Numerical method has been addressed as an alternative to predict wear on ankle replacement. Th...

The trapezium shape of the talar dome limits the use of 2-dimensional plain radiography for morphometric assessment because only 2 of the 4 required parameters can be measured. We used computed tomography data to measure the 4 morphologic parameters of the trochlea tali: anterior width, posterior width, trochlea tali length, and angle of trapezium...

The trapezium shape of the talar dome limits the use of 2-dimensional plain radiography for morphometric assessment because only 2 of the 4 required parameters can be measured. We used computed tomography data to measure the 4 morphologic parameters of the trochlea tali: anterior width, posterior width, trochlea tali length, and angle of trapezium...