Jose Antonio Simões

• PhD
• Professor (Associate) at University of Aveiro

Num livro que abrange muitos e diferentes trabalhos, os agradecimentos também assumem destaque especial. A “Artroplastia total da anca: aspetos biomecânicos, biológicos e clínicos” é o resultado do trabalho que cada um de nós foi desenvolvendo no âmbito da sua investigação e atividade profissional, mas também teve o contributo, direto ou indireto,...

Bone loss is often encountered in revision total knee arthroplasty. In particular, when the cortex of distal femur is breached, the surgical decision on the reconstructive options to be taken is challenging due to the variety of defects and the lack of data from clinical or experimental studies that can support it. The aim of the present work was t...

Interferometric fiber optic based sensors, namely those based on the Fabry-Perot (F-P) configuration seem very attractive for biomechanical and biomedical applications. The present study is focused on the proof of concept of two developed FP based sensors, for high and low pressure measurements of fluids. For low pressure sensor, it was used a poly...

Background Aseptic loosing is one of the most important failure scenarios in orthopedics and cement damage accumulation is an indicator of potential mechanical failure of cement. The aim of this study was to assess, comparatively, the influence of the stem position and other design factors of four different commercial femoral stems. Methods Stem p...

Experimental studies have been made to study and validate the biomechanics of the pair femur/acetabulum considering both structures without the presence of cartilage. The main goal of this study was to validate a numerical model of the intact hip. Numerical and experimental models of the hip joint were developed with respect to the anatomical restr...

Instrumented hip implants were proposed as a method to monitor and predict the biomechanical and thermal environment surrounding such implants. Nowadays, they are being developed as active implants with the ability to prevent failures by loosening. The generation of electric energy to power active mechanisms of instrumented hip implants remains a q...

Charnley and Stanmore cemented femoral stems are of the most studied stems and in vivo long-term results up to 15 and 20 years, respectively, have been published. The in vitro study hereby described correlates biomechanical factors such as stem position in the femoral canal, cement thickness and fatigue cracks with in vivo published results. Four o...

The press-fit hip acetabular prosthesis implantation can cause crack formation in the thin regions surrounding the acetabular. As a consequence the presence of cracks in this region can lead to poor fixation and fibrous tissue formation. Numerical and experimental models of commercial press-fit hip replacements were developed to compare the behavio...

A 3D finite element model of an in vitro implanted mandible was analysed. The load point was placed on the condyle in three positions (inside the mouth, centred and outside) to simulate different contact points between the mandible condyle and the temporal bone. The strain fields in the condyle were assessed and detailed around the surgical screws....

Virtual design gives flexibility to explore constructive solutions or structures. It enables analysis that would often be impossible even if expensive real prototypes were available. Simulations using finite element models allow access to the stress and strain tensor or to the deformation tensor within an implant or a tissue which is impossible exp...

As optical fibers revolutionize the way data is carried in telecommunications, the same is happening in the world of sensing. Fiber-optic sensors (FOS) rely on the principle of changing the properties of light that propagate in the fiber due to the effect of a specific physical or chemical parameter. We demonstrate the potentialities of this sensin...

Background: Bone loss and subsequent defects are often encountered in revision total knee arthroplasty. In particular, when the cortical rim of proximal tibia is breached, the surgical decision on the reconstructive options to be taken is challenging due to the variety of defects and the lack of data from clinical or experimental studies that can...

Fiber optic sensors have a set of properties that make them very attractive in biomechanics. However, they remain unknown to many who work in the field. Some possible causes are scarce information, few research groups using them in a routine basis, and even fewer companies offering turnkey and affordable solutions. Nevertheless, as optical fibers r...

Experimental pre-clinical tests associated with numeric models of cemented implants are important for screening of new implants in the market. The aim of this study was to measure strain profiles and maximum temperature polymerization inside a cement mantle of an in vitro cemented hip reconstruction using optical fiber Bragg grating (FBG) sensors....

Aseptic loosening of cemented hip implants frequently indicates failure by shear or tension of the cement–bone interface. An element-failure algorithm is proposed for the simulation of the mechanical behavior of the cement–bone interface until failure, under tensile and shear loading. To validate the model proposed, analysis on the cement–bone inte...

This book focuses on the recent advances in natural polymers, biopolymers, biomaterials, and their composites, blends, and IPNs. Biobased polymer blends and composites occupy a unique position in the dynamic world of new biomaterials. The growing need for lubricious coatings and surfaces in medical devices—an outcome of the move from invasive to no...

This in vivo study presents the preliminary results of the use of a novel piezoelectric actuator for orthopedic application. The innovative use of the converse piezoelectric effect to mechanically stimulate bone was achieved with polyvinylidene fluoride actuators implanted in osteotomy cuts in sheep femur and tibia. The biological response around t...

At present, most of the orthopaedic implants used in articular reconstruction are fixed to host bone using acrylic bone-cement. Bone-cement polymerization leads to an exothermic reaction with heat release and consequent temperature rise. The increase of temperature in the bone beyond the tolerated limits can develop osteocyte thermal necrosis and u...

Revision total knee arthroplasty presents numerous technical challenges, with lower patient outcomes compared with those obtained in primary surgery. Extended stems have been used in revision total knee arthroplasty to improve component alignment and fixation. Hybrid fixation with cemented tibial tray and press-fit stem has shown good results. One...

1. Abstract Topology optimization is presently used in most diverse scientific, technologic and industrial areas, including biomechanics. Bone remodelling models and structural optimization have mutually provided inspiration for new developments in both areas. Considering that bone has the ability to adapt its internal structure to mechanical loadi...

Ever since the first studies about biomedical implantable devices, the problem of how to energize them has stood out as both important and notoriously difficult to solve. In order to extend the lifetime of implants, it is imperative to develop power generators that are autonomous, safe and maintenance-free. Energy harvesting is a natural way of mee...

CAD systems have greatly affected the way which engineers perform their function. Computers have simplified and eliminated many of repetitious tasks and the gap between computer models and physical products has significantly shortened. These tools have stimulated the impetus for product development but the manufacturing processes still depends on h...

Advances using optical fibres as sensors may represent an important contribution for development of minimally invasive techniques in biomedical and biomechanical applications. Concerning spine injuries, intervertebral disc (IVD) degeneration is a major clinical issue since it represents gross structural disruption and it is irreversible. Measuring...

This study aimed to validate a numerical model of an intact mandible for further development of a new TMJ implant. Numerical and experimental models of the biomechanics of the mandible were elaborated to characterize the human temporomandibular joint and to approach the development of a condyle implant. The model of the mandible was obtained throug...

Numerous models of elbow prostheses are being used and can be divided into two categories: one being a semi-constrained, linked type; and the other being non-constrained, unlinked type. Recent reports of National Elbow Arthroplasty Registers reveal no significant differences in the survival rates between linked and unlinked prosthesis brands, and t...

A 3D finite element model of in vitro intact and implanted mandibles with different temporomandibular joints (TMJ) was analyzed. Three TMJ implant geometries were assessed. The displacements, stress and strain fields on the condyle were obtained for both simulated cases. Strains were also assessed near the screws that fixate the implant to the mand...

It has been hypothesized that femoral notching in total knee arthroplasties weakens the cortex of the femur, which can predispose to femoral fractures in the postoperative period. Some authors suggest that patients who sustain inadvertent notching should have additional protection in the postoperative period, and consideration should be given to th...

Taguchi technique is a powerful method of solving engineering problems in order to improve the performance of a process and to enhance the productivity. The methodology for the design of the experiment is proposed in order to find the best parameters for better experimental results with less number of experiments as possible. In this study, Taguchi...

Fiber Bragg gratings were used to measure stress caused by the orthodontic appliance in an experimental model reproducing the maxilla and dentition. This study brings light to the understanding of the way forces are dissipated on the dentition and propagate to the adjacent bone. Results show deformations on the order of 4 muε and a linear relations...

In this work, nanocomposites of ultrahigh molecular weight polyethylene (UHMWPE) reinforced with multiwalled carbon nanotubes (MWCNTs) were evaluated for their ability to produce nanocomposites with superior mechanical properties. As homogeneity of the nanocomposite plays an important role into final mechanical properties, mechanical ball-milling i...

Ultrahigh molecular weight polyethylene (UHMWPE) is a unique polymer with outstanding physical and mechanical properties that makes it particularly attractive to fabricate the bearing surface for artificial joints. Despite the requirement of visco-elastic properties of the UHWMPE and its composites, the characterization of them has received relativ...

Prosthetic materials and bone present quite different mechanical properties. Consequently, mandible reconstruction with metallic materials (or a mandible condyle implant) modifies the physiologic behavior of the mandible (stress, strain patterns, and condyle displacements). The changing of bone strain distribution results in an adaptation of the te...

Using the new trend of energy harvesting, an envisioned electromagnetic power transducer that uses human gait to produce electrical energy is presented as a solution to energize biomedical devices. Regardless of the walking speed, starting at 0.7 Hz, it is possible to store a total energy of 2.2 mJ, using two 1000 μF capacitors as energy storage el...

In this work, nanocomposites of ultrahigh molecular weight polyethylene (UHMWPE) reinforced with multiwalled carbon nanotubes (MWCNTs) were evaluated for their ability to produce nanocomposites with superior mechanical properties. As homogeneity of the nanocomposite plays an important role into final mechanical properties, mechanical ball-milling i...

Ultrahigh molecular weight polyethylene (UHMWPE) is a unique polymer with outstanding physical and mechanical properties that makes it particularly attractive to fabricate the bearing surface for artificial joints. The growing demand for UHMWPE as a bearing material for joint replacement has lead to active research in the development and understand...

Bone is a composite with piezoelectric properties. Bone mass and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels, but the role piezoelectricity plays in bone physiology is yet to be understood. Physical activity enhances bone density, through mechanical stimulation. Osteocytes and osteoblasts are ess...

Computer-aided technologies have allowed new 3D modelling capabilities and engineering analyses based on experimental and numerical simulation. It has enormous potential for product development, such as biomedical instrumentation and implants. However, due to the complex shapes of anatomical structures, the accuracy of these technologies plays an i...

There are several diseases that can affect the human temporomandibular joint (TMJ), among which we highlight cancer, trauma or fracture, congenital malformation and osteochondritis. TMJ reconstruction was developed to improve mandibular function, reduce disability. Total replacement of the TMJ involves the removal of the “non functional” joint and...

Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwalled carbon nanotubes in biomaterials contacting with bone. However, carbon nanotubes are also controversial in regards to effects exerted on living organisms. Carbon nanot...

Bone mass distribution and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels. Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. A wide variety of devices have been tested for mechanical stimulation of ce...

A Doença Degenerativa do Disco refere-se, em geral, à instabilidade e à degenerescência estrutural do disco intervertebral. Essa degenerescência ocorre como parte do processo normal de envelhecimento e é muito frequentemente causa de dor. Se a dor se torna crónica e não responde aos tratamentos não-cirúrgicos, a substituição total do disco é uma al...

Strain shielding, a mechanical effect occurring in structures combining stiff with more flexible materials, is considered to lead to a reduction of density in bone surrounding the implant. This effect can be related to the weakness of the implant fixation, which can promote implant loosening. Several studies describe a significant decrease in posto...

Biomedical implantable devices in real-time telemetry applications offer many advantages to study and monitor physiologic parameters in human and animal bodies. As in power-constrained implantable devices, batteries and wires are two key issues that usually compromise their application. Inductive coupling is a well-established technology because it...

Recognized failure mechanisms after revision total knee arthroplasty include failure of fixation, instability and loosening. Thus, extended stems have been used to improve fixation and stability. In clinical cases where the stem is only applied in the femur, a question concerning the structural aspect of tibia may arise: Does a stemmed femur change...

In this work it is reported the measurement of the differential strain between the dental and bone tissues under effect of an applied load. Slices of swine mandible, containing the premolar tooth, are cut and measured in fresh condition. The strain is measured using fibre Bragg grating sensors glued to both tissues. In the measured range the result...

Este trabajo tuvo como principal objetivo evaluar la eficacia de la aplicación de dos tratamientos hormonales distintos en la anticipación de la estación reproductiva – progestágenos + eCG vs. melatonina + progestágenos + eCG –, en ovejas de la raza Churra Galega Bragançana. Adicionalmente, por primera vez en esta raza portuguesa, se valoró el uso...

Experimental models can be used for pre-clinical testing of cemented and other type of hip replacements. Total hip replacement (THR) failure scenarios include, among others, cement damage accumulation and the assessment of accurate stress and strain magnitudes at the cement mantle interfaces (stem-cement and cement-bone) can be used to predict mech...

Bone mass distribution and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels. Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. The aim of this work was to experimentally validate the possibility of u...

The genesis, evolving and spontaneous regression of a single luteinised ovarian cyst in a nulliparous goat and the ultrasonograhic characterisation of a follicular cyst in a primiparous goat were described, after oestrus induction with cloprostenol or male effect with progestagen treatment, respectively. Daily ovarian and uterine transrectal ultras...

Fatigue damage of cement mantle of cemented hip replacements has been extensively studied. Different conclusions concerning the micro-cracking mechanism has been reported. An in vitro study on commercial cemented synthetic femurs was conducted to determine if micro-cracking formation of the cement mantle would preferentially be at the cement–stem i...

This study, aimed the development of a methodology for rapid manufacture of orthopedic implants simultaneously with the surgical intervention, considering two potential applications in the fields of orthopedics: the manufacture of anatomically adapted implants and implants for bone loss replacement. This work innovation consists on the capitation o...

Purpose The purpose of this paper is to present the development of a technical procedure for the manufacturing of medical implant prototypes. Design/methodology/approach The paper was performed on a new hip implant design and manufactured with different metallic alloys F75 (ASTM) commonly used in biomedical applications. Dimensional parameters bet...

The aim of this work was the study and understanding of the behavior and linearity of an optical fiber Bragg grating (FBG) sensor embedded in bone cement. Test its ability to monitor strains inside bone cement during different mechanical tests, at real-time. Bone cement is a biomaterials based on polymethacrylate used as fixation method in artifici...

Materials and design are important issues within general product development and even more in biomedical product. Knee prosthesis is a product that still lacks of adequate design solutions. Stress shielding and stress concentrations related to the end-of-stem pain are frequent clinical evidences that are intimately related to the design of the pros...

Restoration of lost bone support and joint stability are the primary challenges in revision total knee arthroplasty (TKA). Normally, the defects type 2B and type 3 are associated with several damaged metaphyseal bone and loss of cortical bone. Structural allografts have been used for the treatment of large, contained, or uncontained osseous defect...