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1

Using X-ray diffraction in characterization of bone remodeling and nanocomposites in ovariectomized rats osteopenia model

Kostyshyn Nazar, Gzhegotskyi Mechyslav, Kostyshyn Liubov, Yarova Oksana, Kulyk Yuriy, Mudry Stepan

Polish Journal of Medical Physics and Engineering

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2021

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Vol. 27, Iss. 2

157--163

EN

Sedentary lifestyle and physiological menopause are among the risk factors of osteopenia, especially in elderly people. However, bone mineral density decrease can also be observed in young individuals, for instance, due to deficiency of female sex hormones after surgical interventions, particularly ovariectomy. Our research enabled us to assess the efficacy of whole-body vibration in preventing the loss of bone mineral density in the ovariectomy rat osteopenia model. Thus, whole-body vibration with acceleration level 0.3 g and frequency 50 Hz was used on young female rats, which had been subjected to ovariectomy (n = 18). It had been conducted for 24 weeks, exposure time – 30 minutes per day, 5 times a week. Assessment of mineral component loss of the tibia was performed by means of X-ray diffraction. Bone remodeling was assessed by determining hormones: parathyroid hormone and calcitonin, Ca and P in the blood. X-ray diffraction is an effective method, which enables the evaluation a nanocomposites structure of the bone tissue in the experiment. In the article, we applied this method to determine the loss of bone mineral mass after ovariectomy and the impact of wholebody vibration under such conditions. In the ovariectomy group, the volume of a mineral component significantly decreased starting already from the 16th week (р<0.05) versus control. However, in the group with ovariectomy + wholebody vibration, the loss of a mineral component was insignificant during 8-16 weeks of the investigation, compared with the control group. On the 24th day, the spectrums almost did not differ from ovariectomized rats group. Meanwhile, hormone levels changed in ovariectomized rats group. It should be emphasized that the aforementioned whole-body vibration parameters do not cause severe bone damage or further negative consequences.

2

The influence of osteoporotic bone structures of the pelvic-hip complex on stress distribution under impact load

Arkusz K., Klekiel T., Niezgoda T. M., Będziński R.

Acta of Bioengineering and Biomechanics

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2018

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Vol. 20, no. 1

29--38

EN

Purpose: The aim of this study was to determine the effect of bone mineral density (BMD) on the stress distribution in pelvic-hip complex (PHC) model which included bone structures and soft tissues. Bone mass changes in osteoporosis and osteopenia were considered in this analysis. In addition, the relations between force direction and stress distribution causing PHC fractures were determined. Methods: This paper presents the development and validation of a detailed 3D finite element model with high anatomical fidelity of the PHC and BMD changes in trabecular and cortical bones, modelled based on CT scans. 10 kN loading was induced on a model consisting of 8 ligaments, the pelvis, sacrum, femur in front and side directions. Results: For validation, the results of this model were compared to physiological stress in standing position and previous results with high-energy crashes under side impact load. Analysis of side-impact indicated the influence of BMD on femoral neck fractures, acetabular cartilage and sacroiliac joint delaminations. Front-impact analysis revealed the inferior pubic ramus, femoral neck fractures and soft tissue injuries, i.e., acetabular cartilage and symphysis pubis in osteoporosis and osteopenia. Conclusions: The elaborated PHC model enables effective prediction of pelvis injuries in high-energy trauma, according to Young-Burgess classification, and the determination of the influence of BMD reduction on pelvis trauma depending on force direction. The correlation between BMD and stress distribution causing varying injuries was determined.

3

Relationship between the mineral content of human trabecular bone and selected parameters determined from fatigue test at stepwise-increasing amplitude

Mazurkiewicz A. J., Topoliński T.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 3

19--26

EN

Purpose: The study aimed to investigate a relationship between the mineral content of the human trabecular bone and parameters determined from compression fatigue tests at stepwiseincreasing amplitude. Methods: Mineral content of the trabecular bone was estimated as ash density and bone mineral density values. The relationship between the ash density, bone mineral density and factors obtained from fatigue test: fatigue life, cumulative elastic energy and cumulative energy of dissipation was determined. Results: The results from the measurements of ash density and bone mineral density show good correlation with the fatigue test results. The relationship was estimated based on the correlation coefficient R within 0.74-0.79 for the particular pairs of factors. Conclusions: The study shows that the ash density and the bone mineral density are good predictors to estimate the fatigue life of trabecular bone. The study also validates the applicability of the tests at stepwise-increasing amplitude in determining the mechanical properties of trabecular bone.

4

Drilling resistance : A method to investigate bone quality

Lughmani W. A., Farukh F., Bouazza-Marouf K., Ali H.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 1

55--62

EN

Purpose: Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill-bit penetration and drill-bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. Methods: This study demonstrates that bone drilling force data if recorded in-vivo, during the repair of bone fractures, can provide information about the quality of the bone. To understand the variability and anisotropic behaviour of cortical bone tissue, specimens cut from three anatomic positions of pig and bovine were investigated at the same drilling speed and feed rate. Results: The experimental results showed that the drilling force does not only vary from one animal bone to another, but also vary within the same bone due to its changing microstructure. Drilling force does not give a direct indication of bone quality; therefore it has been correlated with screw pull-out force to provide a realistic estimation of the bone quality. A significantly high value of correlation (r 2 = 0.93 for pig bones and r 2 = 0.88 for bovine bones) between maximum drilling force and normalised screw pull-out strength was found. Conclusions: The results show that drilling data can be used to indicate bone quality during orthopaedic surgery.

5

Investigation of microstructure of bone tissue in mandibles of newborn rats after maternal treatment with antiretroviral drugs

Filipek J., Binkowski M., Maciejewska K., Drzazga Z., Wróbel Z.

Biocybernetics and Biomedical Engineering

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2015

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Vol. 35, no. 1

54--63

EN

High-resolution imaging has become a powerful tool for measurements in clinics, laboratory and animal studies, etc. In the present study, we aimed to investigate age related changes in bone development, and the effect of two antiretroviral agents (zidovudine and indinavir), which were administered during pregnancy, on the microstructure and bone mineral density (BMD) in newborn rats (7-, 14- and 28-day-old), with the use of X-ray microcomputed tomography (XMT). Fifty-four mandible bones were collected and divided into 3 groups: group 1 and 2: newborns after maternal treatment of zidovudine and indinavir respectively, group 3: control animals. The specimens were XMT scanned with the resolution of 7 μm and with a density phantom. Histomorphometric parameters and BMD were calculated to assess bone development depending on the administered drug. A statistical analysis was carried out to compare the differences among the control, zidovudine and indinavir groups. The analysis of the microstructure revealed disturbances in the development of the bone tissue in newborn rats. Indinavir seems to have a greater impact on bone microstructure than zidovudine.

6

Comparison of two interpolation methods for empirical mode decomposition based evaluation of radiographic femur bone images

Udhayakumar G., Sujatha C. M., Ramakrishnan S.

Acta of Bioengineering and Biomechanics

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2013

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Vol. 15, no. 2

73--80

EN

Analysis of bone strength in radiographic images is an important component of estimation of bone quality in diseases such as osteoporosis. Conventional radiographic femur bone images are used to analyze its architecture using bi-dimensional empirical mode decomposition method. Surface interpolation of local maxima and minima points of an image is a crucial part of bi-dimensional empirical mode decomposition method and the choice of appropriate interpolation depends on specific structure of the problem. In this work, two interpolation methods of bi-dimensional empirical mode decomposition are analyzed to characterize the trabecular femur bone architecture of radiographic images. The trabecular bone regions of normal and osteoporotic femur bone images (N = 40) recorded under standard condition are used for this study. The compressive and tensile strength regions of the images are delineated using pre-processing procedures. The delineated images are decomposed into their corresponding intrinsic mode functions using interpolation methods such as Radial basis function multiquadratic and hierarchical b-spline techniques. Results show that bi-dimensional empirical mode decomposition analyses using both interpolations are able to represent architectural variations of femur bone radiographic images. As the strength of the bone depends on architectural variation in addition to bone mass, this study seems to be clinically useful.

7

Differences in trabecular bone mechanical strength measured by the x-ray microcomputed tomography and compressive test

Binkowski M., John A., Nowak R., Bożek M., Bielecki M.

Journal of Medical Informatics & Technologies

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2010

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Vol. 15

163--168

EN

The article describes the concept of measurement of the mechanical strength of trabecular bone dissected from human femoral head. When the studies are performed based on the human trabecular bone, there is a risk that correlation can be not achieved due to high discrepancy in the distribution of the bone density and mechanical properties. The compressive tests and X-ray microcomputed tomography with associated density phantom were used to deliver quantitative data. There is a conclusion that the selection of the region in the femoral head has to be performed very carefully. The region where cylinder is dissected can influence the results and produce fake data, which could not be correlated in the density of bone.

8

Thyroid hormone and thyreotropin (TSH) association with densitometric parameters in children

Porwik E., Matusik P., Drzyzdzyk K.

Journal of Medical Informatics & Technologies

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2009

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Vol. 13

141--144

EN

The influence of TSH on bones is still vastly unknown and the information that is known is considered controversial. This important relationship has not been studied in detail. The aim of our research was to assess the correlation between TSH, thyroid hormone and bone mineral density in children measured by DXA scanning. Our study group included 36 children (16 girls and 20 boys) mean age 12.9 š 3.3 years. Basic anthropometrical measurements were performed (height, weight, body mass index-BMI), in all subjects. Blood was collected and measured for TSH and FT4. Bone mineral density of lumbar spine (L2-L4 BMD) and total body (Total Body BMD) were measured by DXA and expressed as bone mineral content (BMC [g]) and bone mineral density (BMD [g/cm2]). BMD Z-Score was also calculated. Correlation between the parameters obtained by DXA and anthropometrical data, TSH and thyroid hormone concentration were calculated. A statistically significant positive correlation was observed between height, weight and BMI and BMD which was calculated. Weight and BMI also had a statically significant correlation with Z-Score and total bone mineral content (BMC – expressed in grams). There was a statistically significant positive correlation between TSH level and Z-Score for both L2-L4 lumbar spine and for total body. TSH did not correlate significantly with BMD [g/cm2] and BMC [g]. FT4 was negatively and significantly correlated with Z-Score for both L2-L4 lumbar spine and for total body. There was also no significant correlation between FT4 and BMD [g/cm2] and BMC [g]. Conclusion: 1. Thyroid stimulating-hormone (TSH) appears to be associated with maintenance of bone mineral density in children. 2. BMD Z-Score especially from L2-L4 lumbar spine assessed by DXA scanning is correlated best with hormonal and biochemical factors potentially influencing bone mineralization in children.

9

The influence of bone tissue microstructure' parameters on bone mineral density parameter computed within the computer simulation process

Binkowski M., Dyszkiewicz A., Wróbel Z.

Journal of Medical Informatics & Technologies

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2005

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Vol. 9

49--55

EN

The given article was created with reference to lack of correlation between results from densitometry test of bone tissue and its mechanical strength. The changes of bone mechanical strength cannot be solely connected with changes of bone mineral density with micro structural construction of bone tissue. The article describes the research using a computer simulation where changes of physical density and parameters of bone microstructure were modelled. The influences of those parameters for changing the bone mineral density have been computed. It has been calculated during simulation process similar to the way it has been provided from densitometry test. The computation process has been carried out on the basis of computer method of simulation of x-ray radiation propagating through the object and had been was created and tested in the previous research. The model of tested object was defined by spatial high resolution distribution of density. The simulation was executed on a sample of bone tissue. The input data to the model of sample were series of cross-sections obtained previously from micro CT of an animal sample. The changes of parameters were simulated in the model based on a method of 2D image processing. The procedure was used to reduce the trabecular surface for all cross-sections. The results of the algorithm were measured during algorithm process. Images were also analyzed by software to measure parameters of microstructure. It gave a chance to estimate the correlation between measured parameter and parameters of microstructure. The applied method of simulation of attenuation of x-ray radiation allowed to produce densitometry image and to compute parameter similar to bone mineral density. The analysis of obtained results shows how the bone mineral density computed from simulation depends on changes of parameters of microstructure.

10

Simulation of the reaction of X-ray radiation with an object while densitometry tests

Binkowski M., Dyszkiewicz A., Wróbel Z.

Journal of Medical Informatics & Technologies

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2004

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Vol. 8

MM95--104

EN

The computer modelling of absorption effect of X-ray radiation in the bone tissue was analysed. An image, which is produced as a result of X-ray absorption was computed based on the absorption law. The simulation enables to define dimensions and resolution of space where the experiment will be realised. A model of a sample contains information about its geometry and distribution of density. It can be made as simple solids or loaded from external source, like files. This method may be useful to load information about bone microstructure into the simulation space. A source of X-ray radiation was defined as a plate, which has initial radiation intensity. Rules of radiation propagation were simplified to straight model where radiation propagates in the direction perpendicular to the surface of detector which records an image. The image is generated by computation of partial absorption for each space elements. The results of simulation of model of micro-structure of bone tissue are presented. They can be useful to show when densitometry test does not contain accurate and full information about bone tissue. It may by helpful in the future while searching for reasons of incomplete correlation between mineral density and mechanical strength.

11

Ocena wpływu redystrybucji naprężeń na właściwości biologiczne i materiałowe tkanki kostnej po implantacji panewki endoprotezy stawu biodrowego.

Żmudzki J., Kusz D., Okrajni J.

Inżynieria Materiałowa

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1999

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R. XX, nr 2

62-66

PL

W pracy poddano analizie współzależność pomiędzy czynnikami o charakterze mechanicznym, materiałowym i biologicznym w organiźmie człowieka po zabiegu implantacji endoprotezy stawu biodrowego. Do wyznaczenia pól naprężeń zastosowano modelowanie numeryczne metodą elementów skończonych. Opracowano modele fizyczne stawu biodrowego prawidłowego i sztucznego z panewką typu PM, kotwiczoną w miednicy za pomocą połączenia z użyciem gwintu. Modele obciążono wg schematu Pauwelsa. Porównano rozkłady naprężeń w modelu części miedniczej stawu prawidłowego i po implantacji komponenty panewkowej endoprotezy. Określono wpływ implantu na redystrybucję naprężeń w kości miedniczej po endoprotezoplastyce. Redystrybucja ta polega na lokalnych zmianach pól naprężeń oraz związanego z nimi wytężenia w poszczególnych punktach biomechanicznego układu. Za miarę wytężenia przyjęto naprężenia zastępcze wyznaczone zgodnie z hipotezą Hubera. Równolegle przeprowadzono badania densytometrem rentgenowskim podwójnej energii LUNAR DPX u 53 chorych z jednostronną koksartozą przeciętnie w 10 dobie pooperacyjnej oraz po dalszych 6, 12 i 18 miesiącach. Pomiarom podlegały zawartość wapnia w gramach - BMC (bone mineral content) oraz jego gęstość w gramach na centymetr kwadratowy - BMD (bone mineral density). Zmiany mineralne prześledzono w najbliższym sąsiedztwie gwintowanej panewki PM w strefach DeLee i Charnleya. Wprowadzono wielkość względnej zmiany naprężeń średnich (alfa) i względnej zmiany średniej gęstości BMD (beta), odnoszące stan stawu w 18 miesięcy po alloplastyce do stanu przed operacją. Podjęto próbę znalezienia korelacji pomiędzy względną zmianą naprężeń średnich (alfa) oraz względną zmianą średniej gęstości BMD (beta). Dokonano na tej podstawie oceny możliwości prognozowania wpływu czynników mechanicznych na materiałowe i biologiczne właściwości tkanki kostnej.

EN

The correlation between mechanical, material and biological features in the human organism after total hip arthoplasty has been discussed in the paper. FEM has been used to stress fields determination. Physical models of regular and artificial (Parhofer-Monch) hip joint have been made. Models were loaded according to Pauwels scheme. Stress patern in regular and artificial hip joint have been compared. An implant influence on stress redistribution in bone tissue after total hip arthoplasty has been determined. The points of redistribution are changes in local stress according to Hubert law in different points of biomechanical structure. In the same time, densitometer double energy LUNAR DPX has been applied to measurements bone mineral content - BMC and bone mineral density - BMD in 53 cases by one-side artificial hip joint. Mineral changes in the DeLee and Charnley zones after 10 days and sequel 6, 12, and 18 month have been inspected. Relative changes of average stress (alpha) and average bone material density-BMD (beta), which describe hip condition 18 month after surgery and before it, have been defined. An attempt to find correlation between average stress (alpha) and average bone material density - BMD (beta) has been taken up. On this basis possibility of calculation of mechanical features influence on material and biological properties has been estimated.

12

Analiza tekstur obrazów radiologicznych dla detekcji zmian gęstości mineralnej tkanki kostnej

Cichy P., Materka A., Tuliszkiewicz J.

Elektronika : prace naukowe

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1998

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nr 3

51-63

PL

W artykule przedstawiono zastosowanie cyfrowych technik obróbki i analizy obrazów rentgenowskich do oceny zmian w gęstości mineralnej kości. Rezultaty analizy odniesiono do pomiarów densytometrycznych, wykonanych metodą DXA. Obrazy rentgenograficzne, przedstawiające dalszą część przedramienia, były zarejestrowane z zachowaniem jednakowych warunków technicznych. Dodatkowo w celu ujednolicenia jasności radiogramów zastosowano fantom kalibracyjny. Analizie poddano zarówno obrazy z wyrównaną jasnością fantomu, jak i bez standaryzacji. Zdjęcia rentgenowskie przetworzono na postać cyfrową przy użyciu systemu obrazowego wyposażonego w kamerę CCD. W artykule przedstawiono algorytmy wyznaczania poszczególnych parametrów statystycznych oraz wymiaru fraktainego obrazów cyfrowych. Rozważano wartość oczekiwaną jasności, odchylenie standardowe jasności, skośność histogramu, współczynnik skupienia-kurtozę, energię i entropię oraz wymiary fraktalne estymowane w dziedzinie częstotliwości i metodą wariancyjną. Dlu poszczególnych parametrów wyznaczono ich wartość średnią, odchylenie standardowe oraz współczynnik korelacji liniowej z gęstością tkanki kostnej dystalnego odcinka kości promieniowej. Celem badań byio określenie związków korelacyjnych między parametrami obrazu a wynikami pomiarów densytometrycznych.

EN

Digital image processing and analysis techniques for detection of changes in bone mineral density (BMD) are examined m this paper Analysis results are compared with BMD measured using DXA method. A further part of forearm (Radius UD) is examined. Roentgenogram patterns were registered in the same conditions of exposure and chemical development. Additionally a calibration phantom was used to standardize the results. Radiogram patterns were digitized with a CCD camera. Algorithms for computation of statistical parameters of roentgenogram textures and their fractal dimension are presented. The following texture parameters were computed the mean of intensity, standard deviation of intensity, skewness, kurtosis, energy, entropy and fractal dimension. Fifty radiograms were analyzed. The mean value, standard deviation and coefficient of linear correlation with BMD were estimated for every parameter. Occurrence probability of intensity level is highly correlated with densitometry results. It seems that analysis of fractal dimension can additionally enrich diagnostic knowledge about bone microarchitecture.