Human Femoral Bone Research Articles

Effect of glucocorticoids on the function of microvascular endothelial cells in the human femoral head bone.

The pathogenesis of glucocorticoid (GC)-induced osteonecrosis (ON) of the femoral head remains unclear. Recent research has suggested that it is closely associated with injured bone microvascular endothelial cells (BMECs). However, few studies have used BMECs to perform research pertaining ON of the femoral head. The objective of this study was to investigate the functional changes of BMECs treated with a GC and to detect the changes in related genes using microarrays. Cells were isolated using an enzymatic method and identified with EC markers, such as von Willebrand factor (vWF), CD31 and vascular endothelial cadherin (VE-cadherin). Bone microvascular endothelial cells were treated with 0.1 mg/mL and 0.3 mg/mL of hydrocortisone to establish a GC-damaged model of BMECs. The mRNA microarrays were used to detect the differential expression profiles between BMECs with and without GC damage. Primary cells appeared as having a cobblestone-like morphology. Immunofluorescence staining revealed that the cells were 100% positive for vWF and CD31, and near 100% positive for VE-cadherin. It also confirmed that the cells were BMECs. Bone microvascular endothelial cells treated with 0.1 mg/mL of hydrocortisone showed shrinkage, and those treated with 0.3 mg/mL of hydrocortisone mostly showed apoptosis. The mRNA microarray showed that genes associated with endothelial cells, such as endothelin 1 (ET-1) receptor, angiotensin II (AII) receptor, intercellular adhesion molecule 1 (ICAM-1), and plasminogen activator inhibitor 1 (PAI-1), were upregulated, and genes associated with endothelial nitric oxide synthase (eNOS), endothelin 1 (ET-1), prostaglandin I2 (PGI2) synthase, PGI2 receptor, vascular endothelial growth factor (VEGF), prostaglandin E (PGE) synthase, and PGE receptor were downregulated. The results of quantitative polymerase chain reaction (qPCR) validation were consistent with the findings of mRNA microarrays. Glucocorticoids promoted BMECs to express vasoconstrictors and procoagulant factors and related receptors, and decreased the expression of vasodilators and their receptors.

Assessment of the human bone lacuno-canalicular network at the nanoscale and impact of spatial resolution

Recently, increasing attention has been given to the study of osteocytes, the cells that are thought to play an important role in bone remodeling and in the mechanisms of bone fragility. The interconnected osteocyte system is deeply embedded inside the mineralized bone matrix and lies within a closely fitted porosity known as the lacuno-canalicular network. However, quantitative data on human samples remain scarce, mostly measured in 2D, and there are gaps to be filled in terms of spatial resolution. In this work, we present data on femoral samples from female donors imaged with isotropic 3D spatial resolution by magnified X-ray phase nano computerized-tomography. We report quantitative results on the 3D structure of canaliculi in human femoral bone imaged with a voxel size of 30 nm. We found that the lacuno-canalicular porosity occupies on average 1.45% of the total tissue volume, the ratio of the canalicular versus lacunar porosity is about 37.7%, and the primary number of canaliculi stemming from each lacuna is 79 on average. The examination of this number at different distances from the surface of the lacunae demonstrates branching in the canaliculi network. We analyzed the impact of spatial resolution on quantification by comparing parameters extracted from the same samples imaged with 120 nm and 30 nm voxel sizes. To avoid any bias related to the analysis region, the volumes at 120 nm and 30 nm were registered and cropped to the same field of view. Our results show that the measurements at 120 and 30 nm are strongly correlated in our data set but that the highest spatial resolution provides more accurate information on the canaliculi network and its branching properties.

Finite Element Analysis of Existing and Modified Intramedullary Rod for Orthopedic Applications

Finite Element Analysis (FEA) has been used in the field of biomedical engineering and especially in biomechanics, which helps to predict and validate feasible designs for complex cases. The role of biomechanics has grown steadily in the field of orthopedic surgery. For example, fixation was performed to stabilize a large femoral bone fragment. Femoral injury is analyzed in real time, and the experiment provides a three-dimensional visualization of finite elements designed to explain the mechanical properties of the femur. Modified trapezoidal nail shape is used in the modified intramedullary rod setup in order to obtain additional strength and stability. It also provides resistance to femoral head rotation. Potentially it improves patient mobility and recovery since the modified design is in par with the anatomy of the human femur bone.

A FEA on Assembled fractured human femur bone with and without HA coated prosthetic plate material

Femur, also called thighbone or hind leg in human body supports the maximum weight of the body under loading conditions. In this present work, the fractured femur bone is reconstructed using DICOM files obtained from Computed Tomography scan images using software’s 3D slicer and blender. In accordance with the crack, prosthetic plate was modelled in Unigraphics NX 11.0 version. The plate is then assembled with the fractured femur bone using Assembly module of the Unigraphics NX 11.0 version. Then Static structure Finite element Analysis was performed on the Assembly for different prosthetic plate materials like SS316L, Alumina, Nylon, Titanium, PMMA and PEEK with and without Hydroxyapatite (HA) coating on the prosthetic plate. It was proved in this work that best results are obtained with HA coated prosthetic plate material that means the bone healing will be much faster when prosthetic plated are coated with Hydroxyapetite

Changes in the mechanical properties of femoral cartilage tissue in advanced osteoarthritis

The main goal of this article was the analysis of the changes of mechanical properties, thickness and histology of the cartilage in different regions of the femur head in advanced stage of the osteoarthritis. The study material consisted of cylindrical specimens (9.7 mm) prepared form proximal epiphysis of the human femur bone after hip arthroplasty. The thickness was determined from the reconstruction of the specimen from microtomography (SkyScan 1172, Bruker®) images. Mechanical properties of the cartilage tissue were identified in static indentation test conducted the use of MTS® Synergie 100 testing machine. Histological study enabled us to determine cartilage total thickness as well as location and orientation of the collagen fibers. Depending on the region of the head, the cartilage tissue thickness was in the range (0.74-2.23 mm). The lowest thickness values were obtained for the R5 region and the lowest for R4. Samples from R1-R4 regions differ by 24%. Measurements of cartilage tissue indentation, determined with the help of Hayes' formula, showed that the values of mechanical parameters in regions R1, R2, R3 and R5 have similar values (the difference between them is about 5.5%). Region R4, which had the smallest thickness, also had the lowest values of mechanical parameters. Using κ coefficients, proposed by Hayes, enabled us to obtain similar values of mechanical parameters in the regions R1, R2, R3 and R5, despite differences in cartilage tissue thickness. The R4 region, which had the weakest mechanical parameters, was characterized by the strongest reduction of the articular cartilage tissue, which was accompanied by an unformed mass of cartilage residue originating from the abraded surface and bursa fluid.

Structural analysis of femur bone to predict the suitable alternative material

This study is based on the biomechanical analysis of femur bone using Finite Element technique. Real life activities are taken as boundary conditions and the weight of a person is considered as load for walking, standing and jumping. For biomechanical analysis, three-dimensional CAD model of human femur bone is modelled from MRI/CT Scan data using ITK-Snap software. Pre-processing and post-processing operations are done using HYPERWORKS whereas the solver is NASTRAN 10.0. Analysis is done using three materials- natural bone material, AZ31 (magnesium alloy), CP Ti (Commercially Pure Titanium Alloy). Comparative study shows that CP-Ti material generates minimum stresses for jumping, standing and walking, which are 5.69, 5.34 and 5.71 MPa respectively. And also minimum displacements for jumping, standing and walking are 0.146, 0.0583 and 0.0623 mm respectively. It is found that AZ31 is the best suited material for Bone implants and as its weight is approximately same as natural bone.

Classification of diaphysis based on the mechanical response of femur bone

This work deal with the biomechanical analysis of the Captum Collum Diaphysis (CCD) femur bone. The femur is the largest bone in the upper leg. The angle between femur neck and femur shaft of the femora is a parameter in determining the CCD or FSA angle. 126 ° is the usual angle for a healthy adult and variation in this angle leads to the CCD. This angle in the femur bone helps in determining the knock knee and bow leggedness orthopaedic disease. This angle impacts on the distribution of stress and deflection in the femur bone during the daily activities. Computational Multi-Scale analysis has been done for homogenized properties of femur bone. A Numerical simulation has been made for the biomechanical analysis of CCD femur bone using Finite Element Method. There is significant impact of stress distribution and deflection over the femur bone in case of change in optimum CCD angle (coxa norma) and also leads to change the natural frequency of the bone. Predicted results shows the above mentioned disease behaviour over the healthy bone. The study of these deformity and their results are of clinical importance in musculoseketal behaviour of the human femur bone.

Evaluation of Nutrient Foramina of the Dry Adult Human Femur Bone of North Indian Population

Evaluation of Nutrient Foramina of the Dry Adult Human Femur Bone of North Indian Population

Bone mineral health is sensitively related to environmental cadmium exposure- experimental and human data

Exposure to cadmium (Cd) is recognised as one of the risk factors for osteoporosis, although critical exposure levels and exact mechanisms are still unknown.Here, we first confirmed that in male Wistar rats challenged orally with 6 different levels of Cd (0.3–10 mg/kg b.w.), over 28 days, there was a direct dose relationship to bone Cd concentration. Moreover, bone mineral content was significantly diminished by ∼15% (p < 0.0001) plateauing already at the lowest exposure level. For the other essential bone elements zinc (Zn) loss was most marked. Having established the sensitive metrics (measures of Cd exposure), we then applied them to 20 randomly selected human femoral head bone samples from 16 independent subjects. Bone Cd concentration was inversely proportional to trabecular bone mineral density and mineral (calcium) content and Zn content of bone, but not the donor's age.Our findings, through direct bone analyses, support the emerging epidemiological view that bone health, adjudged by mineral density, is extremely sensitive to even background levels of environmental Cd. Importantly, however, our data also suggest that Cd may play an even greater role in compromised bone health than prior indirect estimates of exposure could reveal. Environmental Cd may be a substantially determining factor in osteoporosis and large cohort studies with direct bone analyses are now merited.

Effects of loading rate on the of mechanical behavior of the femur in falling condition

The Surgeon General estimates that by 2020, half of all Americans could have weak bones due to bone loss. Osteoporosis causes more than 1.5 million fractures every year. Identifying effective interventions based on individual patient characteristics remains a major challenge. Proximal femur fractures are common and devastating events for individuals with osteoporosis. Since fracture is primarily a mechanical event, noninvasive predictions of fracture strength and location would be useful both for identifying at-risk individuals and evaluating treatment effects. However, bone fracture prediction is complicated due to the complex microstructure and nanostructure of bone. Bone is a highly heterogeneous material with rate-dependent mechanical behavior and large inter-individual variation. In this study, we designed two mechanical test procedures to understand the mechanical response of bone under impact and quasi-static load tests. The boundary conditions of the tests were designed in a way to simulate a fall to the side. The present study consists of three main parts: cadaver testing, quantitative image analysis, and finite element (FE) modeling. We obtained ten human femur bones and used high-resolution CT to quantify the microstructure and density of each sample. Specimen-specific FE models were created to evaluate the ability of various failure criteria to predict experimental fracture. Afterward, the samples were tested and their failure patterns were recorded. The fractured samples were rescanned to analyze the fractured surfaces. Our experimental results show that the loading necessary to fracture the femur samples is much higher in the impact tests. However, the toughening mechanisms are more pronounced in quasi-static tests. We found that FE model formulations were able to accurately predict femur stiffness and strength for quasi-static and impact conditions separately, but that no single formulation could account for the rate-dependent outcomes.

Determination of Sex from Epicondylar Breadth of Femur

Introduction: Sex determination from skeletal remains allows one to narrow the search in individual identification. As the femur shows 75% Variation between individuals, it has been useful for sex determination. There are many possible femoral measurements, but the Epicondylar breadth is routinely considered to be useful for sexing individuals. To date, nothing has been published on other measurements of distal femur, which may be useful if the bone is fragmented, and only lower part of bone is available. This study is an attempt to evaluate sex determination from distal femora of Indian origin. Subjects and Methods: For this study total 208 normal dry human femur bones of known sex were studied, which were collected from various medical colleges of Gujarat. For measurement of Epicondylar breadth of femur, Digital sliding vernier caliper was used. Results: The discriminant function equation for sex determination from Epicondylar Breadth (EB) of femur is:-Y = 0.143 * EB + (-8.334) If Y is &lt; 0 then the sex of the bone is Female and if Y is &gt; 0 then the sex of the bone is Male. Conclusion: With the use of discriminant function score, 87% of femur samples are correctly predicted about sex. The results of this study is particularly useful in a case for sex determination in which the skeletal remains of an individual are incomplete or damaged and thus more accurate bones such as the pelvis or cranium are absent.

Trabecular Bone Structure in the Distal Femur of Humans, Apes, and Baboons.

Trabecular bone structure has been used to investigate the relationship between skeletal form and locomotor behavior on the premise that trabecular bone remodels in response to loading during an animal's lifetime. The aim of this study is to characterize human distal femoral trabecular bone structure in comparison to three non-human primate taxa and relate the patterns of trabecular structural variation in the distal femur to knee posture during habitual locomotor behavior. A whole-epiphysis approach was applied using microCT scans of the distal femora of extant Homo sapiens, Pan troglodytes, Pongo pygmaeus, and Papio spp. (N = 48). Bone volume fraction (BV/TV) was quantified in the epiphysis and analyzed with both whole-condyle and a novel sector analysis. The results indicate high trabecular bone structural variation within and between species. The sector analysis reveals the most distinctive patterns in the stereotypically loaded human knee, with a pattern of high BV/TV distally. In general, Pan, Pongo, and Papio show evidence of flexed knee postures, typical of their locomotor behaviors, with regions of high BV/TV posteriorly within the condyles. The pairwise comparisons confirm the unique pattern in Homo and reveal a shared high BV/TV region in the patellar groove of both Homo and Papio. The distinct pattern found in Homo relative to the other primate taxa suggests a plastic response to unique loading patterns during bipedal locomotion. Results may facilitate resolving the antiquity of habitual bipedality in the hominin fossil record. This analysis also presents new approaches for statistical analysis of whole-epiphysis trabecular bone structure. Anat Rec, 2018. © 2018 American Association for Anatomy.

Optimization of the configuration of porous bone scaffolds made of Polyamide/Hydroxyapatite composites using Selective Laser Sintering for tissue engineering applications

Numerous biomaterials are used to fabricate bone scaffolds to repair the bones subjected to trauma. The scaffolds are fabricated with interconnected pores with 40-70% porosity to facilitate the entry of the cells that ensures rapid bone formation. In addition, the interconnected pores also serve as a channel for the exchange of nutrients and waste materials. Rapid prototyping techniques use the CAD model of the scaffold to be fabricated which facilitates fabrication of components with complex architecture easily. This research deals with the design, fabrication and analysis of porous scaffold models with different configurations. Apart from the conventional pore geometry like cubical, spherical shaped pores, their shifted arrangements were also considered for this study. The minimum pore size used for the study is 400μm and the porosity ranges from 40-70%. Based on the results of finite element analysis, the best scaffold configuration is identified and was fabricated with different build orientation using Selective Laser Sintering (SLS) process with different mix of Polyamide and Hydroxyapatite. The fabricated test specimens were evaluated based on mechanical tests for its strength and in vitro studies with human osteosarcoma cell line for cell growth studies. The mechanical tests witnesses good physical properties than the earlier reported research. The suitability of the porous scaffolds for bone repair is also ensured using finite element analysis of a human femur bone under various physical activities.

Urban and rural area differences in the interaction between oxidative process elements in human femoral bone

Elements in the human body come from contaminated food, water, and air from the living area. Bones are a marker of long-term exposure to elements and show a relationship between them. The aim of the study was to analyze the correlation between the contents of Zn, Cu, Fe, Mo, Cr, Ni, Ba, Sr, and Pb in the proximal femoral head (cancellous bone) and femoral neck (cortical bone) in rural and urban populations. The study included 96 patients who were operated on for total hip replacement (THR), acquired in a surgical procedure with atomic absorption spectrometry, and the content of Zn, Cu, Fe, Mo, Cr, Ni, Ba, Sr, and Pb was evaluated. In rural areas, significant negative correlations were observed for Mo/Cr, Mo/Cu, and Ni/Fe, and positive correlations were observed for Fe/Zn and Pb/Zn. In urban areas, a negative correlation was found for Pb/Mo. Pb and Ni increased with age only in villagers, and Zn and Sr decreased with age in urban citizens. Ba decreased with age in people from rural areas. The correlation showed variances mainly in molybdenum, nickel, and oxidative elements between rural and urban populations.

Diversity in intracortical remodeling in the human femoral bone: A novel view point with the morphological analysis of secondary osteons

IntroductionIn humans, intracortical bone remodeling is performed by a basic multicellular unit (BMU) composed of osteoclasts and osteoblasts penetrating through cortical bones. As a result, secondary osteons and their boundaries, cement lines, can be observed on the transverse section. There have been few reports mention whether there is diversity within a single individual and on the relevance to bone remodeling. The purpose of this study is to investigate the morphological diversity of secondary osteons in human femoral bone and to examine the relationship with bone remodeling. Material and methodsFirst of all, we developed an original method to get the cross-sectional images of the cortical bones around the whole circumference for the purpose of evaluating the morphology of the secondary osteon exhaustively. Then, a total of ten cross-sectional slices from one right human femoral bone of male were prepared and stained with this method. The osteon population density and complexity of cement lines in osteons were evaluated in detail. ResultsWithin this femoral bone, the osteon population density was significantly higher in the periosteal side and in the posterior area. Conversely, the cement line density and the osteon complexity were higher in the endosteal side; the proportion of complexed osteon significantly increased from the periosteal side toward the endosteal side. DiscussionThe results suggested that there were diversities in osteon population densities and osteon morphological pattern within one human femoral bone. It seemed that the BMUs ran to avoid the existing regions of osteon in the periosteal sides and to overlap the existing osteon in the endosteal sides. This seemed to be one of the novel viewpoints in the morphological analysis of secondary osteons. It might be better for the orthopedic surgeons to be aware that the osteon distribution in the cortical bone is not uniform.

Perfluoroalkyl substances in human bone: concentrations in bones and effects on bone cell differentiation

Perfluoroalkyl substances (PFAS), including two most commonly studied compounds perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are widely distributed environmental pollutants, used extensively earlier. Due to their toxicological effects the use of PFAS is now regulated. Based on earlier studies on PFOA’s distribution in bone and bone marrow in mice, we investigated PFAS levels and their possible link to bone microarchitecture of human femoral bone samples (n = 18). Soft tissue and bone biopsies were also taken from a 49-year old female cadaver for PFAS analyses. We also studied how PFOA exposure affects differentiation of human osteoblasts and osteoclasts. PFAS were detectable from all dry bone and bone marrow samples, PFOS and PFOA being the most prominent. In cadaver biopsies, lungs and liver contained the highest concentrations of PFAS, whereas PFAS were absent in bone marrow. Perfluorononanoic acid (PFNA) was present in the bones, PFOA and PFOS were absent. In vitro results showed no disturbance in osteogenic differentiation after PFOA exposure, but in osteoclasts, lower concentrations led to increased resorption, which eventually dropped to zero after increase in PFOA concentration. In conclusion, PFAS are present in bone and have the potential to affect human bone cells partly at environmentally relevant concentrations.

Vibrational characterization of a human femur bone and its significance in the designing of artificial implants

PurposeBeing an interdisciplinary research area, biomechanics has gained interest among researchers. Biomechanics deals with integration of mechanical phenomenon with the structural and functional aspects of biological systems. Biological systems being very much complex provide a very intricate platform for their analysis. In case of damages created by accidents or sport malfunctions, artificial implants are used for the replacement of bones. These implants may cause incompatibility with the human body, depending on their design and characterization. So, this research aims to analyze the vibrational characteristics of a human femur bone and to predict the safe ranges of frequencies of operation.Design/methodology/approachThe current research is aimed at vibrational characterization of a human femur bone. The model of the femur bone is prepared using SOLIDWORKS software. The material properties of the femur are collected from the available literature and provided with the CAD model. The model is imported to the ANSYS software. Loading patterns as applied on the human body are also applied to the prepared model. Suitable boundary conditions are chosen for normal sitting and standing positions. The natural frequencies of the femur bone and other vibrational parameters are found out.FindingsThe first data obtained from the ANSYS software are the natural frequencies and mode shapes of vibration. Other data include the stress distributions, strain distributions, deformation patterns and potential zones of damage. The frequencies and mode shapes enable the safe ranges of human operation and the frequency range to be followed in the designing of implants. The stress distributions enable to know the potential zones of damage so that those areas can be given focus during strength considerations.Research limitations/implicationsThe current investigations take into account only normal sitting and walking conditions. This work can be included under static loadings. This can also be extended toward dynamic loading conditions. In the dynamic loading, walking and running conditions can be taken into account. This work focuses on the safe designing of the artificial implants and their compatibility with the human body. This can also be extended toward role of dynamic forces in the damaged bone formation and the role of implant’s characteristics for healing of bones.Practical implicationsBone damage and ligament fracture are common nowadays due to increasing number of accidents, which may be vehicular or sports. In case of any damage to the skeletal parts, some artificial implant is used to support the damaged part and to help in the process of healing. The designing of the implants must be compatible with the human body. The natural frequencies and mode shapes give an idea that the vibrational parameters of the implant material must fall in the same range as the actual bone. The stress distribution and potential zone damage emphasize on strength considerations.Originality/valueThe current method is a novel approach toward implant designing. Here an analysis of vibrational parameters of the human femur bone is performed. Those parameters include natural frequencies, mode shapes, principal normal stress distributions, principal shear stress distributions, maximum shear elastic strains and total deformation. These parameters reflect an idea about behavior of the femur bone under actual loading conditions. This analysis enables an implant designer to focus on material properties and strength considerations of the implants which are to be used in case of bone damage.

Characterization of human cancellous and subchondral bone with respect to electro physical properties and bone mineral density by means of impedance spectroscopy

Computational simulation of electrical bone stimulation of the electrical and dielectric parameters of osteoarthritic bone tissue is useful for an exact patient-individual adaptation of the bone models. Therefore, we investigated electrical and dielectric parameters at a frequency of 20Hz of cancellous and subchondral human femoral head bone samples. Furthermore, the mechanical properties and the bone mineral density (BMD) were determined. Finally, these data were compared with the electrical and dielectric parameters. The bone samples were taken from patients with hip osteoarthritis. Electrical conductivity and dielectric permittivity of cancellous bone amounted to 0.043S/m and 8.1⋅106. BMD of the bone samples determined by dual-x-ray-absorptiometry (DXA) and ashing resulted in 193 ± 70mg/cm² and 286 ± 59mg/cm³ respectively. Structural modulus (ES) and ultimate compression strength (σmax) were measured with 227 ± 94N/mm² and 6.5 ± 3.4N/mm². No linear correlation of the electrical and dielectric parameters compared with BMD and mechanical properties of cancellous bone samples was found. Electrical conductivity and dielectric permittivity of subchondral bone resulted in 0.029S/m and 8.97×106.

Bone Mineral Density Measurements Around Osseointegrated Implants: A Precision Study and Validation of Scan Protocol for Transfemoral Amputees

Visual evaluation of bone changes around an osseointegration (OI) implant in femoral amputees examined on plain radiographs shows that periprosthetic bone resorption takes place during the first years after OI surgery, but the bone mineral density (BMD) change has not been previously quantified by dual-energy X-ray absorptiometry (DXA). Precision is vital when monitoring BMD changes around implants, and thus the aim of this study was to evaluate the precision and feasibility of a scan protocol for BMD measurements in proximity of OI implants. The proximal part of 2 human cadaveric femoral bones (specimens A and B) with OI implants were mounted in a positioning jig and DXA scans were repeated 5 times in increments of 5° from neutral (0°) to 20° flexion and rotation. BMD changes as a result of change in leg position were evaluated. Repeated patient examinations (n = 20) were conducted in a clinical setting and the precision error was calculated for each of 7 periprosthetic custom-made regions of interest (ROIs). The precision of cadaveric BMD measurements in neutral position was <3.3%. Even 5° flexion or rotation in femur position caused significant changes in average BMD (p < 0.04). Depending on ROI, the percentage of coefficient of variation (%CV) and average BMD was <6% at 10° flexion and rotation. At 20° flexion, %CV increased up to 12.7% and average BMD increased up to 9.9%. The clinical short-term precision root mean square standard deviation ranged from 0.031 g/cm2 to 0.047 g/cm2 and %CV ranged from 3.12% to 6.57% depending on ROI. Simulated hip flexion or rotation of the femur affected periprosthetic BMD measurements around OI implants in cadaveric femoral bones, which stresses the importance of a reproducible set-up during DXA scans to reduce measurement errors caused by variation in leg position. Adherence to the scan protocol with a relaxed position of the residual limb resulted in an acceptable short-term precision below 6.6%.

Influences of osteoarthritis and osteoporosis on the electrical properties of human bones as in vivo electrets produced due to Wolff's law.

We characterized the electrical properties of living bone obtained from patients who had undergone total hip arthroplasty (THA) or hemiarthroplasty by means of analysis of the electrically polarized and nonpolarized bone specimens, and we discussed the role of an organic and inorganic matrix of human bone in bone piezoelectricity.We used human femoral neck bone that was harvested during THA for advanced osteoarthritis of the hip joint (OA group) and hemiarthroplasty for femoral neck fracture (FNF group). The specimens were scanned to evaluate the cancellous bone structures using micro-computed tomography, and we quantified the carbonic acid by attenuated total reflection (ATR) spectra to estimate carbonate apatite. The stored electrical charge in the electrically polarized and nonpolarized bone specimens were calculated using thermally stimulated depolarized current (TSDC) measurements.Each TSDC curve in the groups had peaks at 100°C, 300°C and 500°C, which may be attributed to collagen, carbonate apatite and hydroxyapatite, respectively. It is suggested that organic substances are more effectively electrically polarized than apatite minerals by the polarization at room temperature and that the stored charge in living bone may be affected not only by total bone mass but also by bone quality, including 3-dimensional structure and structural component.