Cortical bone plate properties assessment using inversion of axially transmitted low frequency ultrasonic guided waves.

Over the past few decades, early osteoporosis detection using ultrasonic bone quality evaluation has gained prominence. Specifically, various studies focused on axial transmission using ultrasonic guided waves and have highlighted this technique's sensitivity to intrinsic properties of long cortical bones. This work aims to demonstrate the potential of low-frequency ultrasonic guided waves to infer the properties of the bone inside which they are propagating.

3-D finite element model of the impaction of a press-fitted femoral stem under various biomechanical environments.

Background: Uncemented femoral stem insertion into the bone is achieved by applying successive impacts on an inserter tool called "ancillary". Impact analysis has shown to be a promising technique to monitor the implant insertion and to improve its primary stability.

Method: This study aims to provide a better understanding of the dynamic phenomena occurring between the hammer, the ancillary, the implant and the bone during femoral stem insertion, to validate the use of impact analyses for implant insertion monitoring.

Characterization of the concentration of agar-based soft tissue mimicking phantoms by impact analysis.

In various medical fields, a change of soft tissue stiffness is associated with its physio-pathological evolution. While elastography is extensively employed to assess soft tissue stiffness in vivo, its application requires a complex and expensive technology. The aim of this study is to determine whether an easy-to-use method based on impact analysis can be employed to determine the concentration of agar-based soft tissue mimicking phantoms.

Detection of periprosthetic fractures around the femoral stem by resonance frequency analysis: An study.

Periprosthetic femoral bone fractures are frequent complications of Total Hip Arthroplasty (THA) and may occur during the insertion of uncemented Femoral Stems (FS), due to the nature of the press-fit fixation. Such fracture may lead to the surgical failure of the THA and require a revision surgery, which may have dramatic consequences. Therefore, an early detection of intra-operative fractures is important to avoid worsening the fracture and/or to enable a peroperative treatment.

Debonding of coin-shaped osseointegrated implants: Coupling of experimental and numerical approaches.

While cementless implants are now widely used clinically, implant debonding still occur and is difficult to anticipate. Assessing the biomechanical strength of the bone-implant interface can help improving the understanding of osseointegration phenomena and thus preventing surgical failures. A dedicated and standardized implant model was considered.

Ultrasonic Evaluation of the Bone-Implant Interface.

While implant surgical interventions are now routinely performed, failures still occur and may have dramatic consequences. The clinical outcome depends on the evolution of the biomechanical properties of the bone-implant interface (BII). This chapter reviews studies investigating the use of quantitative ultrasound (QUS) techniques for the characterization of the BII.

Modal Analysis of the Ancillary During Femoral Stem Insertion: A Study on Bone Mimicking Phantoms.

The femoral stem primary stability achieved by the impaction of an ancillary during its insertion is an important factor of success in cementless surgery. However, surgeons still rely on their proprioception, making the process highly subjective. The use of Experimental Modal Analysis (EMA) without sensor nor probe fixation on the implant or on the bone is a promising non destructive approach to determine the femoral stem stability.

Ultrasonic assessment of osseointegration phenomena at the bone-implant interface using convolutional neural network.

Although endosseous implants are widely used in the clinic, failures still occur and their clinical performance depends on the quality of osseointegration phenomena at the bone-implant interface (BII), which are given by bone ingrowth around the BII. The difficulties in ensuring clinical reliability come from the complex nature of this interphase related to the implant surface roughness and the presence of a soft tissue layer (non-mineralized bone tissue) at the BII. The aim of the present study is to develop a method to assess the soft tissue thickness at the BII based on the analysis of its ultrasonic response using a simulation based-convolution neural network (CNN).

Stress shielding at the bone-implant interface: Influence of surface roughness and of the bone-implant contact ratio.

Short and long-term stabilities of cementless implants are strongly determined by the interfacial load transfer between implants and bone tissue. Stress-shielding effects arise from shear stresses due to the difference of material properties between bone and the implant. It remains difficult to measure the stress field in periprosthetic bone tissue.

Analytical modeling of the interaction of an ultrasonic wave with a rough bone-implant interface.

Quantitative ultrasound can be used to characterize the evolution of the bone-implant interface (BII), which is a complex system due to the implant surface roughness and to partial contact between bone and the implant. The determination of the constitutive law of the BII would be of interest in the context of implant acoustical modeling in order to take into account the imperfect characteristics of the BII. The aim of the present study is to propose an analytical effective model describing the interaction between an ultrasonic wave and a rough BII.

Ultrasonic Propagation in a Dental Implant.

Ultrasound techniques can be used to characterize and stimulate dental implant osseointegration. However, the interaction between an ultrasonic wave and the implant-bone interface (IBI) remains unclear. This study-combining experimental and numerical approaches-investigates the propagation of an ultrasonic wave in a dental implant by assessing the amplitude of the displacements along the implant axis.

Interaction of ultrasound waves with bone remodelling: a multiscale computational study.

Ultrasound stimulation is thought to influence bone remodelling process. But recently, the efficiency of ultrasound therapy for bone healing has been questioned. Despite an extensive literature describing the positive effect of ultrasound on bone regeneration-cell cultures, animal models, clinical studies-there are more and more reviews denouncing the inefficiency of clinical devices based on low-intensity pulsed ultrasound stimulation (LIPUS) of the bone healing.

Reflection of an ultrasonic wave on the bone-implant interface: Comparison of two-dimensional and three-dimensional numerical models.

Quantitative ultrasound is used to characterize osseointegration at the bone-implant interface (BII). However, the interaction between an ultrasonic wave and the implant remains poorly understood. Hériveaux, Nguyen, and Haiat [(2018).

A modified Coulomb's law for the tangential debonding of osseointegrated implants.

Cementless implants are widely used in orthopedic and dental surgery. However, debonding-related failure still occurs at the bone-implant interface. It remains difficult to predict such implant failure since the underlying osseointegration phenomena are still poorly understood.

Micromechanical modeling of the contact stiffness of an osseointegrated bone-implant interface.

Background: The surgical success of cementless implants is determined by the evolution of the biomechanical properties of the bone-implant interface (BII). One difficulty to model the biomechanical behavior of the BII comes from the implant surface roughness and from the partial contact between bone tissue and the implant. The determination of the constitutive law of the BII would be of interest in the context of implant finite element (FE) modeling to take into account the imperfect characteristics of the BII.

Elastography of the bone-implant interface.

The stress distribution around endosseous implants is an important determinant of the surgical success. However, no method developed so far to determine the implant stability is sensitive to the loading conditions of the bone-implant interface (BII). The objective of this study is to investigate whether a quantitative ultrasound (QUS) technique may be used to retrieve information on compressive stresses applied to the BII.

Dependence of the primary stability of cementless acetabular cup implants on the biomechanical environment.

Biomechanical phenomena occurring at the bone-implant interface during the press-fit insertion of acetabular cup implants are still poorly understood. This article presents a nonlinear geometrical two-dimensional axisymmetric finite element model aiming at describing the biomechanical behavior of the acetabular cup implant as a function of the bone Young's modulus , the diametric interference fit (), and the friction coefficient . The numerical model was compared with experimental results obtained from an test, which allows to determine a reference configuration with the parameter set:   0.

Reflection of an ultrasonic wave on the bone-implant interface: Effect of the roughness parameters.

Quantitative ultrasound can be used to characterize the evolution of the bone-implant interface (BII), which is a complex system due to the implant surface roughness and to partial contact between bone and the implant. The aim of this study is to derive the main determinants of the ultrasonic response of the BII during osseointegration phenomena. The influence of (i) the surface roughness parameters and (ii) the thickness W of a soft tissue layer on the reflection coefficient r of the BII was investigated using a two-dimensional finite element model.

Nonlinear Inversion of Ultrasonic Dispersion Curves for Cortical Bone Thickness and Elastic Velocities.

In this study, a nonlinear grid-search inversion has been developed to estimate the thickness and elastic velocities of long cortical bones, which are important determinants of bone strength, from axially-transmitted ultrasonic data. The inversion scheme is formulated in the dispersive frequency-phase velocity domain to recover bone properties. The method uses ultrasonic guided waves to retrieve overlying soft tissue thickness, cortical thickness, compressional, and shear-wave velocities of the cortex.

Reflection of an ultrasonic wave on the bone-implant interface: A numerical study of the effect of the multiscale roughness.

Quantitative ultrasound is used to characterize and stimulate osseointegration processes at the bone-implant interface (BII). However, the interaction between an ultrasonic wave and the implant remains poorly understood. This study aims at investigating the sensitivity of the ultrasonic response to the microscopic and macroscopic properties of the BII and to osseointegration processes.

Sensitivity analysis of ultrasonic guided waves propagating in trilayered bone models: a numerical study.

The fundamental ultrasonic guided modes are consistently observed in long bones ex vivo and in vivo. However, the responses of ultrasonic guided waves to the changes of cortical thickness, cortical elastic parameters, and thickness of the overlying soft tissues are not comprehensively understood. This paper systematically presents a sensitivity analysis of leaky Lamb modes to the geometry and material characteristics of layered bone model by means of semi-analytical finite element modeling.