Apparent Bone Density Research Articles

Effect of baseplate positioning on fixation of reverse total shoulder arthroplasty

BackgroundThe glenoid component in reverse total shoulder arthroplasty is recommended to be positioned inferiorly or with a downward tilt with the intention of reducing scapular notching. However, it is still unclear whether modifying the position of the glenoid prosthesis affects implant stability. The aim of this study was to determine the association between implant positioning and glenoid prosthesis fixation using Grammont reverse total shoulder arthroplasty. MethodsFour positions for the glenoid prosthesis were studied using the finite element method. The glenosphere was positioned as follows: 1) in the middle of the glenoid fossa, 2) flush with the inferior glenoid rim, 3) with an inferior overhang, 4) with a 15° inferior inclination. Bone-prosthesis micromotions and strain-induced bone adaptations were quantified during five daily activities. FindingsWhen the glenoid component was tilted inferiorly, the activities producing anterior-posterior shear forces (e.g. standing up from an armchair) caused an increase in peak micromotions. In the lateral-middle glenoid, inferior positioning caused a 64.6% reduction in bone apparent density. In the lateral-inferior glenoid, central positioning led to the most severe bone resorption, reaching 43.9%. InterpretationReducing activities which generate anterior-posterior shear forces on the shoulder joint will increase bone formation and may improve the primary stability of the implant when fixed in the position with an inferior tilt. Postoperative bone resorption is highly dependent on implant positioning. Understanding the relationship between bone resorption and implant positioning will help surgeons improve the long-term stability of reverse total shoulder arthroplasty.

Feasibility of a Nonlinear Acoustic Method for the Assessment of Bone Status and Osteoporosis in Trabecular Bone

The present study aims to investigate the feasibility of using a simple nonlinear acoustic method for the assessment of bone status and osteoporosis in trabecular bone. Correlations of linear and nonlinear ultrasound parameters with the apparent bone density were obtained in 32 bovine femoral trabecular bone samples. Highly significant positive correlations were observed between the apparent bone density and the two linear ultrasound parameters, the speed of sound (SOS) and the normalized broadband ultrasound attenuation (nBUA), with Spearman’s correlation coefficients of r = 0.85 and 0.77. In contrast, the apparent bone density was found to be negatively correlated with the nonlinear ultrasound parameter introduced in the present study, the logarithmic difference between the power spectrum levels of the fundamental frequency and the second harmonic (PSL1-PSL2), with the highest correlation coefficient of r = −0.92. These results suggest that the PSL1-PSL2, in addition to the SOS and the nBUA, may be useful for the assessment of bone status and osteoporosis.

Relationships of Ultrasonic Backscatter With Bone Densities and Microstructure in Bovine Cancellous Bone.

This study was designed to investigate the associations among ultrasonic backscatter, bone densities, and microstructure in bovine cancellous bone. Ultrasonic backscatter measurements were performed on 33 bovine cancellous bone specimens with a 2.25-MHz transducer. Ultrasonic apparent backscatter parameters ("apparent" means not compensating for ultrasonic attenuation and diffraction) were calculated with optimal signals of interest. The results showed that ultrasonic backscatter was significantly related to bone densities and microstructure ( R2 = 0.17 -0.88 and ). After adjusting the correlations by bone mineral density (BMD), the bone apparent density (BAD) and some trabecular structural features still contributed significantly to the adjusted correlations, with moderate additional variance explained ( ∆R2 = 9.7 % at best). Multiple linear regressions revealed that both BAD and trabecular structure contributed significantly and independently to the prediction of ultrasound backscatter (adjusted R2 = 0.75 -0.89 and ), explaining an additional 14% of the variance at most, compared with that of BMD measurements alone. The results proved that ultrasonic backscatter was primarily determined by BAD, not BMD, but the combination of bone structure and densities could achieve encouragingly better performances (89% of the variance explained at best) in predicting backscatter properties. This study demonstrated that ultrasonic apparent backscatter might provide additional density and structural features unrelated to current BMD measurement. Therefore, we suggest that ultrasonic backscatter measurement could play a more important role in cancellous bone evaluation.

‘Pre-launch’ finite element analysis of a short-stem total hip arthroplasty system consisting of two implant types

BackgroundWe applied a previously established and validated numerical model to a novel short-stemmed implant for a ‘pre-launch’ investigation. MethodsThe implant system consists of two different implant geometries for valgus/varus-positioned proximal femurs with differences in volume distribution, head/neck angle, and calcar alignment. The aim of the design was to achieve a better adaption to the anatomic conditions, resulting in a favourable load transfer. The implant type G showed the best fit to our model, but both stem geometries were implanted; the implant type B was used to compute an ‘imperfection scenario’. FindingsApparent bone density decreased by 4.3% in the entire femur with the implant type G, and by 12.3% with the implant type B. Bone mass loss was pronounced in the proximal calcar region. Apparent bone density increased at the lateral cortical ring and in the minor trochanter. The apparent bone density in the imperfection scenario was very similar to that of a straight stem, indicating a distal load transfer. InterpretationNo adverse effects of the A2 short-stemmed implant system on bone remodeling could be detected. The overall bone density reduction was acceptable, and wedge fixation was not observed, indicating that there was no distal load transfer. The simulation of an incongruous implant indicates the sensitivity of our model in response to modifications of implant positioning. Correct implant selection and positioning is crucial when using the A2 system.

Cancellous bone characterization using ultrasonic backscatter parametric imaging

The ultrasonic imaging of the highly attenuated porous media (like spongy bone) is of great interest to the researchers. In this study, we used a 7.5 MHz focal transducer (V321, Panametrics, USA) to scan a total of 35 bovine cancellous bone samples. The −-6dB lateral resolution of the transducer was 0.157 mm which is comparable to the trabecular bone thickness (0.1–0.2mm). Apparent integrated backscatter (AIB) was calculated using different signal of interest (SOI) to reconstruct the ultrasonic backscatter parametric images. The trabecular bone structure can be clearly seen from the images. AIB was positively correlated with bone mineral density (BMD) (R = 0.61, p<0.05), bone volume fraction (BV/TV) (R = 0.53, p<0.05), and apparent bone density (ABD) (R = 0.58, p<0.05) when SOI was chosen around the surface of the bone sample, but negatively correlated with BMD (R=-0.77, p<0.05), BV/TV (R=-0.81, p<0.05), and ABD (R=-0.82, p<0.05) when SOI was chosen below the surface of the bone sample. We suppose that single scattering (SS) and multiple scattering (MS) may lead to this opposite correlation phenomena. When wavelength is comparable to the scatterer diameter, diffractive scattering is complex as predicted by Faran cylinder model. We suggest that MS may play an important role in cancellous bone characterization.The ultrasonic imaging of the highly attenuated porous media (like spongy bone) is of great interest to the researchers. In this study, we used a 7.5 MHz focal transducer (V321, Panametrics, USA) to scan a total of 35 bovine cancellous bone samples. The −-6dB lateral resolution of the transducer was 0.157 mm which is comparable to the trabecular bone thickness (0.1–0.2mm). Apparent integrated backscatter (AIB) was calculated using different signal of interest (SOI) to reconstruct the ultrasonic backscatter parametric images. The trabecular bone structure can be clearly seen from the images. AIB was positively correlated with bone mineral density (BMD) (R = 0.61, p<0.05), bone volume fraction (BV/TV) (R = 0.53, p<0.05), and apparent bone density (ABD) (R = 0.58, p<0.05) when SOI was chosen around the surface of the bone sample, but negatively correlated with BMD (R=-0.77, p<0.05), BV/TV (R=-0.81, p<0.05), and ABD (R=-0.82, p<0.05) when SOI was chosen below the surface of the bone sample. We suppose that si...

Modeling of anisotropic remodeling of trabecular bone coupled to fracture

As a living tissue, bone is subjected to internal evolutions of its trabecular architecture under normal everyday mechanical loadings leading to damage. The repeating bone remodeling cycle aims at repairing the damaged zones in order to maintain bone structural integrity; this activity of sensing the peak stress at locations where damage or microcracks have occurred, removing old bone and apposing new bone is achieved thanks to a complicated machinery at the cellular level involving specialized cells (osteocytes, osteoclasts, and osteoblasts). This work aims at developing an integrated remodeling-to-fracture model to simulate the bone remodeling process, considering trabecular bone anisotropy. The effective anisotropic continuum mechanical properties of the trabecular bone are derived from an initially discrete planar hexagonal structure representative of femur bone microstructure, relying on the asymptotic homogenization technique. This leads to scaling laws of the effective elastic properties of bone versus effective density at an intermediate mesoscopic scale. An evolution law for the local bone apparent density is formulated in the framework of the thermodynamics of irreversible processes, whereby the driving force for density evolutions is identified as the local strain energy density weighted by the locally accumulated microdamage. We adopt a classical nonlinear damage model for high cycle fatigue under purely elastic strains, where the assumed homogeneous damage is related to the number of cycles bone experiences. Based on this model, we simulate bone remodeling for the chosen initial microstructure, showing the influence of the external mechanical stimuli on the evolution of the density of bone and the incidence of this evolution on trabecular bone effective mechanical properties.

Mechanical bone remodelling: Comparative study of distinct numerical approaches

Bone is a complex living structure. Induced by its biomechanical environment, bone constantly adapts its internal and external structure, altering its mass and morphology. In this work, three distinct discretization techniques are combined with a mechanologic bone tissue remodelling algorithm, which describes the remodelling process by minimizing the strain energy density (SED) field. During an iterative remodelling process, bone tissue's mechanical properties are recurrently correlated with bone apparent density through a phenomenological law. The purpose of this study is to compare bone tissue remodelling solutions obtained with the Finite Element Method (FEM), the Radial Point Interpolation Method (RPIM) and the Natural Neighbour RPIM (NNRPIM). Thus, two numerical examples were analysed, namely a benchmark bone patch and a femur. On both examples, regardless the discretization technique, it was possible to accurately reproduce the trabecular bone architecture. Additionally, a comparison between each numerical method was performed. The model shown high adaptability, since, for every method, successful performances were obtained. Nevertheless, meshless solutions produced smoother and more accurate results, closer to real X-ray images.

Micro-CT and micro-FE analysis of pedicle screw fixation under different loading conditions

Anchorage of pedicle screw instrumentation in the elderly spine with poor bone quality remains challenging. In this study, micro finite element (µFE) models were used to assess the specific influence of screw design and the relative contribution of local bone density to fixation mechanics. These were created from micro computer tomography (µCT) scans of vertebras implanted with two types of pedicle screws, including a full region-or-interest of 10 mm radius around each screw, as well as submodels for the pedicle and inner trabecular bone of the vertebral body. The local bone volume fraction (BV/TV) calculated from the µCT scans around different regions of the screw (pedicle, inner trabecular region of the vertebral body) were then related to the predicted stiffness in simulated pull-out tests as well as to the experimental pull-out and torsional fixation properties mechanically measured on the corresponding specimens. Results show that predicted stiffness correlated excellently with experimental pull-out strength (R2 > 0.92, p < .043), better than regional BV/TV alone (R2 = 0.79, p = .003). They also show that correlations between fixation properties and BV/TV were increased when accounting only for the pedicle zone (R2 = 0.66–0.94, p ≤ .032), but with weaker correlations for torsional loads (R2 < 0.10). Our analyses highlight the role of local density in the pedicle zone on the fixation stiffness and strength of pedicle screws when pull-out loads are involved, but that local apparent bone density alone may not be sufficient to explain resistance in torsion.

The Finite Element Analysis of Osteoporotic Lumbar Vertebral Body by Influence of Trabecular Bone Apparent Density and Thickness of Cortical Shell

Abstract Osteoporosis causes the bone mass loss and increased fracture risk. This paper presents the modelling of osteoporotic human lumbar vertebrae L1 by employing finite elements method (FEM). The isolated inhomogeneous vertebral body is composed by cortical out-er shell and cancellous bone. The level of osteoporotic contribution is characterised by reducing the thickness of cortical shell and elasticity modulus of cancellous bone using power-law dependence with apparent density. The strength parameters are evaluated on the basis of von Mises-Hencky yield criterion. Parametric study of osteoporotic degradation contains the static and nonlinear dynamic analysis of stresses that occur due to physiological load. Results of our investigation are presented in terms of nonlinear interdependence between stress and external load.

Associations between ultrasonic backscatter, bone density, and microstructure in cancellous bone characterization

Ultrasonic backscatter is related to the microstructure of cancellous bone. However, whether backscatter measurement can provide additional information independently of BMD remains speculative. In this study, we analyzed the independent contribution of cancellous bone densities and microstructure to apparent backscatter signals in vitro. The results showed that ultrasonic backscatter and the statistics of backscatter envelope were significantly correlated with bone densities and microstructure. After adjustment for BMD, some trabecular structures still contributed significantly to the adjusted correlations, with moderate additional variance explained. Multiple linear regressions revealed that both bone density and structure contributed significantly to the prediction of ultrasonic backscatter (adjusted R2 = 0.75–0.93, p&amp;lt;0.05), explaining an additional 14.0% of the variance at most, compared with that of BMD measurements alone. We also demonstrated that the Nakagami model had great potential in trabecular microstructure characterization. The results proved that ultrasonic backscatter was primarily determined by bone apparent density, but bone densities plus microstructure structure could achieve encouragingly better predictive performance than BMD alone. This study implied that ultrasonic apparent backscatter might provide additional density and structural features unrelated to current BMD measurement. Thus, we suggest that ultrasonic backscatter measurement could play a more important role in cancellous bone evaluation.

Effect of gate choice on backscatter difference measurements of cancellous bone.

A variety of ultrasonic techniques have been developed to detect changes in bone caused by osteoporosis. One approach, called the backscatter difference technique, analyzes the power difference between two different portions of a backscatter signal. Analysis gates with a certain delay τd, width τw, and separation τs are used to define portions of the backscatter signal for analysis. The goal of the present study was to investigate how different choices of τd, τw, and τs affect four backscatter difference parameters: the normalized mean of the backscatter difference (nMBD), the normalized slope of the backscatter difference (nSBD), the normalized intercept of the backscatter difference (nIBD), and the normalized backscatter amplitude ratio (nBAR). Backscatter measurements were performed on 54 cube shaped specimens of human cancellous bone. nMBD, nSBD, nIBD, and nBAR were determined for 34 different combinations of τd, τw, and τs for each specimen. nMBD and nBAR demonstrated the strongest correlations with apparent bone density (0.48 ≤ Rs ≤ 0.90). Generally, the correlations were found to improve as τw + τs was increased and as τd was decreased. Among the four backscatter difference parameters, the measured values of nMBD were least sensitive to gate choice (<16%).

Spatial mapping of humeral head bone density

BackgroundShort-stem humeral replacements achieve fixation by anchoring to the metaphyseal trabecular bone. Fixing the implant in high-density bone can provide strong fixation and reduce the risk of loosening. However, there is a lack of data mapping the bone density distribution in the proximal humerus. The aim of the study was to investigate the bone density in proximal humerus.MethodsEight computed tomography scans of healthy cadaveric humeri were used to map bone density distribution in the humeral head. The proximal humeral head was divided into 12 slices parallel to the humeral anatomic neck. Each slice was then divided into 4 concentric circles. The slices below the anatomic neck, where short-stem implants have their fixation features, were further divided into radial sectors. The average bone density for each of these regions was calculated, and regions of interest were compared using a repeated-measures analysis of variance with significance set at P < .05.ResultsAverage apparent bone density was found to decrease from proximal to distal regions, with the majority of higher bone density proximal to the anatomic neck of the humerus (P < .05). Below the anatomic neck, bone density increases from central to peripheral regions, where cortical bone eventually occupies the space (P < .05). In distal slices below the anatomic neck, a higher bone density distribution in the medial calcar region was also observed.ConclusionThis study indicates that it is advantageous with respect to implant fixation to preserve some bone above the anatomic neck and epiphyseal plate and to use the denser bone at the periphery.

Zoledronic acid improves bone histomorphometry in a murine model of Rett syndrome

Rett syndrome (RTT) is a neurodevelopmental disorder predominately affecting young females, caused by deficiency of the global transcriptional protein methyl CpG binding protein 2 (MeCP2). Osteoblasts express MeCP2 and girls with RTT experience early onset osteoporosis, decreased bone mass and an increased fracture risk. There is no defined treatment for osteoporosis associated with RTT. The present study evaluated the effects of zoledronic acid (ZA), a third generation nitrogen-containing bisphosphonate with primarily anti-osteoclastic activity, in a mouse model of MeCP2 deficiency. Mice received weekly injections of 20μg/kg ZA for six weeks. Due to the shortened lifespan of hemizygous male (Mecp2-null) mice, treatment began at 3weeks of age for this group and corresponding wildtype (WT) male mice. Treatment for heterozygous (HET) and WT female mice began at 8weeks of age. Micro-computed tomography (micro-CT) and dynamic analyses of bone turnover were performed. ZA treatment led to significant increases in bone volume fraction, number, connectivity density and apparent density of trabecular bone in all genotypes of mice. In contrast, cortical bone generally was unaffected by ZA injections. Parameters of bone turnover, including mineral apposition rate, labeled bone surface and bone formation rate decreased after treatment with ZA. Mecp2-null mice had reduced labeled bone surface and bone formation rate compared to WT male mice. The results indicate that ZA treatment significantly improved trabecular bone mass in a murine model of RTT with little effect on cortical bone.

Material model of pelvic bone based on modal analysis: a study on the composite bone.

Digital models based on finite element (FE) analysis are widely used in orthopaedics to predict the stress or strain in the bone due to bone-implant interaction. The usability of the model depends strongly on the bone material description. The material model that is most commonly used is based on a constant Young's modulus or on the apparent density of bone obtained from computer tomography (CT) data. The Young's modulus of bone is described in many experimental works with large variations in the results. The concept of measuring and validating the material model of the pelvic bone based on modal analysis is introduced in this pilot study. The modal frequencies, damping, and shapes of the composite bone were measured precisely by an impact hammer at 239 points. An FE model was built using the data pertaining to the geometry and apparent density obtained from the CT of the composite bone. The isotropic homogeneous Young's modulus and Poisson's ratio of the cortical and trabecular bone were estimated from the optimisation procedure including Gaussian statistical properties. The performance of the updated model was investigated through the sensitivity analysis of the natural frequencies with respect to the material parameters. The maximal error between the numerical and experimental natural frequencies of the bone reached 1.74% in the first modal shape. Finally, the optimised parameters were matched with the data sheets of the composite bone. The maximal difference between the calibrated material properties and that obtained from the data sheet was 34%. The optimisation scheme of the FE model based on the modal analysis data provides extremely useful calibration of the FE models with the uncertainty bounds and without the influence of the boundary conditions.

An investigation into the effects of osteocytes density and mechanosensitivity on trabecular bone loss in aging and osteoporotic individuals

Purpose Optimal bone remodeling is responsible for bone health and strength, and an imbalance in this process may cause diseases such as osteoporosis. Both osteocyte density and mechanosensitivity are effective parameters in changing bone apparent density. This study aimed at investigating the effects of osteocyte density in healthy adults, and osteocyte mechanosensitivity in osteoporotic bones, on bone loss using a semi-mechanistic bone remodeling theory.

Stabilité primaire de la cupule acétabulaire dans les prothèses totales de hanche sur perte de substance cotyloïdienne. Une étude comparative sur os normal et os porotique

Background contextReconstruction of acetabular defect has been advocated as standard procedure in total hip arthroplasty. The presence of bony defects at the acetabulum is viewed as a cause of instability and acetabular wall augmentation is often used without proper consideration of surrounding bone density. The initial cup-bone stability is, however, a challenge and a number of studies supported by clinical follow-ups of patients suggested that if the structural graft needs supporting more than 50% of the acetabular component, a reconstruction cage device spanning ilium to ischium should be preferred to protect the graft and provide structural stability. This study aims to (1) investigate the relationship between cup motion and bone density and (2) quantify the re-distribution of stress at the defect site after augmentation. HyphotesisPaprosky type I or II, acetabular defects, when reconstructed with bone screws supported by bioabsorbable calcified triglyceride bone cement are significantly less effective for osteoporotic bone than healthy bone. Materials and methodsAcetabular wall defects were reconstructed on six cadaveric subjects with bioabsorbable calcified triglyceride bone cement using a re-bar technique. Data of the specimen with higher bone density was used to validate a Finite Element Model. Values of bone apparent density ranging from healthy to osteoporotic were simulated to evaluate (1) the cup motion, through both displacement and rotation, (2) and the von Mises stress distribution. ResultsDefect reconstruction with bone screws and bioabsorbable calcified triglyceride bone cement results in a re-distribution of stress at the defect site. For a reduction of 65% in bone density, the cup displacement was similar to a healthy bone for loads not exceeding 300N, as load progressed up to 1500N, the reconstructed defect showed increase of 99μm (128%) in displacement and of 0.08° in rotation angle. ConclusionsBased on the results, we suggest that an alternative solution to wall defect augmentation with bone screws supported by bioabsorbable calcified triglyceride bone cement, be used for osteoporotic bone. Level of evidenceLevel IV, experimental and cadaveric study.

The analysis of the bone remodelling around femoral stems: A meshless approach

In this work the bone tissue remodelling analysis of the femur bone due to the insertion of a stem is analysed. The innovation of this numerical application lies on the use of an efficient advanced discretization meshless technique to obtain the variable fields required by the remodelling process.The remodelling algorithm used in this work allows to update locally and gradually the bone tissue density of the model. Based on the minimization of the strain energy density (SED), the remodelling algorithm uses a phenomenological bone tissue mathematical law, which permits to correlate the bone apparent density with its own mechanical properties. Comparing with other numerical approaches, the advanced discretization meshless technique used in this work allows to obtain smoother and more accurate SED fields, leading to more reliable remodelling predictions.The numerical remodelling results obtained for the femoral diaphysis after the insertion of the stem are in accordance with the clinical observation and with other numerical approaches results available in the literature.

Primary cup stability in THA with augmentation of acetabular defect. A comparison of healthy and osteoporotic bone

Background contextReconstruction of acetabular defect has been advocated as standard procedure in total hip arthroplasty. The presence of bony defects at the acetabulum is viewed as a cause of instability and acetabular wall augmentation is often used without proper consideration of surrounding bone density. The initial cup-bone stability is, however, a challenge and a number of studies supported by clinical follow-ups of patients suggested that if the structural graft needs supporting more than 50% of the acetabular component, a reconstruction cage device spanning ilium to ischium should be preferred to protect the graft and provide structural stability. This study aims to (1) investigate the relationship between cup motion and bone density and (2) quantify the re-distribution of stress at the defect site after augmentation. HyphotesisPaprosky type I or II, acetabular defects, when reconstructed with bone screws supported by bioabsorbable calcified triglyceride bone cement are significantly less effective for osteoporotic bone than healthy bone. Materials and methodsAcetabular wall defects were reconstructed on six cadaveric subjects with bioabsorbable calcified triglyceride bone cement using a re-bar technique. Data of the specimen with higher bone density was used to validate a Finite Element Model. Values of bone apparent density ranging from healthy to osteoporotic were simulated to evaluate (1) the cup motion, through both displacement and rotation, (2) and the von Mises stress distribution. ResultsDefect reconstruction with bone screws and bioabsorbable calcified triglyceride bone cement results in a re-distribution of stress at the defect site. For a reduction of 65% in bone density, the cup displacement was similar to a healthy bone for loads not exceeding 300N, as load progressed up to 1500N, the reconstructed defect showed increase of 99μm (128%) in displacement and of 0.08° in rotation angle. ConclusionsBased on the results, we suggest that an alternative solution to wall defect augmentation with bone screws supported by bioabsorbable calcified triglyceride bone cement, be used for osteoporotic bone. Level of evidenceLevel IV, experimental and cadaveric study.

THE MANDIBLE REMODELING INDUCED BY DENTAL IMPLANTS: A MESHLESS APPROACH

This work aims to evaluate the prediction efficiency of a recently developed numerical approach in the mandible bone tissue remodeling process. The remodeling algorithm, seeking the minimization of the strain energy density, includes a phenomenological anisotropic material law capable of predicting the bone tissue mechanical properties based on the bone apparent density. The key factor of the proposed numerical approach is the inclusion of a flexible and efficient meshless method, which is used to obtain the strain energy density field. The inclusion of this advance discretization technique in the process is an asset since meshless methods produce smoother and more accurate strain energy density fields when compared with other numerical approaches. The bone tissue remodeling process of the molar region of the mandible, due to the inclusion of an implant system, is studied. The obtained results are in accordance with other numerical approach results available in the literature.

Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices.

Bone quality is one of the reported factors influencing the success of bone anchors in arthroscopic repairs of torn rotator cuffs at the shoulder. This work was aimed at developing refined numerical methods to investigate how bone quality can influence the fixation stiffness of bone anchors. To do that bone biopsies were scanned at 26-μm resolution with a high-resolution microcomputer tomography (micro-CT) scanner and their images were processed for virtual implantation of a typical design of bone anchor. These were converted to microfinite element (μFE) and homogenized classical FE models, and analyses were performed to simulate pulling on the bone anchor with and without cement augmentation. Quantification of structural stiffness for each implanted specimen was then computed, as well as stress distributions within the bone structures, and related to the bone volume fraction of the specimens. Results show that the classical method is excellently correlated to structural predictions of the more refined μFE method, despite the qualitative differences in local stresses in the bone surrounding the implant. Predictions from additional loading cases suggest that structural fixation stiffness in various directions is related to apparent bone density of the surrounding bone. Augmentation of anchoring with bone cement stiffens the fixation and alters these relations. This work showed the usability of homogenized FE (hFE) in the evaluation of bone anchor fixation and will be used to develop new methodologies for virtual investigations leading to optimized repairs of rotator cuff and glenoid Bankart lesions.