Bone Morphology Properties Research Articles

Cold physical plasma treatment optimization for improved bone allograft processing.

In musculoskeletal surgery, the treatment of large bone defects is challenging and can require the use of bone graft substitutes to restore mechanical stability and promote host-mediated regeneration. The use of bone allografts is well-established in many bone regenerative procedures, but is associated with low rates of ingrowth due to pre-therapeutic graft processing. Cold physical plasma (CPP), a partially ionized gas that simultaneously generates reactive oxygen (O2) and nitrogen (N2) species, is suggested to be advantageous in biomedical implant processing. CPP is a promising tool in allograft processing for improving surface characteristics of bone allografts towards enhanced cellularization and osteoconduction. However, a preclinical assessment regarding the feasibility of pre-therapeutic processing of allogeneic bone grafts with CPP has not yet been performed. Thus, this pilot study aimed to analyze the bone morphology of CPP processed allografts using synchrotron radiation-based microcomputed tomography (SR-µCT) and to analyze the effects of CPP processing on human bone cell viability and function. The analyzes, including co-registration of pre- and post-treatment SR-µCT scans, revealed that the main bone morphological properties (total volume, mineralized volume, surface area, and porosity) remained unaffected by CPP treatment if compared to allografts not treated with CPP. Varying effects on cellular metabolic activity and alkaline phosphatase activity were found in response to different gas mixtures and treatment durations employed for CPP application. It was found that 3min CPP treatment using a He + 0.1% N2 gas mixture led to the most favourable outcome regarding a significant increase in bone cell viability and alkaline phosphatase activity. This study highlights the promising potential of pre-therapeuthic bone allograft processing by CPP prior to intraoperative application and emphasizes the need for gas source and treatment time optimization for specific applications.

On the material dependency of peri-implant morphology and stability in healing bone

The microstructural architecture of remodeled bone in the peri-implant region of screw implants plays a vital role in the distribution of strain energy and implant stability. We present a study in which screw implants made from titanium, polyetheretherketone and biodegradable magnesium-gadolinium alloys were implanted into rat tibia and subjected to a push-out test four, eight and twelve weeks after implantation. Screws were 4 mm in length and with an M2 thread. The loading experiment was accompanied by simultaneous three-dimensional imaging using synchrotron-radiation microcomputed tomography at 5 μm resolution. Bone deformation and strains were tracked by applying optical flow-based digital volume correlation to the recorded image sequences. Implant stabilities measured for screws of biodegradable alloys were comparable to pins whereas non-degradable biomaterials experienced additional mechanical stabilization. Peri-implant bone morphology and strain transfer from the loaded implant site depended heavily on the biomaterial utilized. Titanium implants stimulated rapid callus formation displaying a consistent monomodal strain profile whereas the bone volume fraction in the vicinity of magnesium-gadolinium alloys exhibited a minimum close to the interface of the implant and less ordered strain transfer. Correlations in our data suggest that implant stability benefits from disparate bone morphological properties depending on the biomaterial utilized. This leaves the choice of biomaterial as situational depending on local tissue properties.

Análise do consumo de chá das folhas de amoreira-negra sobre a morfologia e biomecânica óssea em ratas ovariectomizadas

O objetivo principal do estudo foi avaliar os efeitos do chá das folhas de amoreira-negra nos parâmetros morfológicos e biomecânicos ósseos em ratas ovariectomizadas. Para tal foi realizado um estudo experimental conduzido com ratas da linhagem wistar, divididas em quatro grupos experimentais, com ou sem ovários (n=32), aos quais foram oferecidos água filtrada ad libitum ou chá (forma de infusão) das folhas de Morus Nigra L. Após 60 dias de experimentação, os fêmures direitos foram retirados e submetidos a análise das propriedades morfológicas e biomecânicas. Como metodologia, durante o experimento os animais ganharam peso através da dieta baseada em consumo de componente sólido (ração) e de líquidos (chá ou água), dentro dos escassos padrões para roedores. O consumo de chá de folhas de amora revelou efeitos nas propriedades morfológicas ósseas e diminuição da resistência óssea em ratas ooforectomizados. A oferta do chá de folhas de Morus Nigra L. teve efeitos positivos nas propriedades morfológicas e biomecânicas dos fêmures, sugerindo maior resistência óssea no grupo de ratas não ovariectomizadas.

PSO-FuzzyNN Techniques in Gender Classification Based on Bovine Bone Morphology Properties

This simulation project aims to solve forensic anthropology issues by using the computational method. The positive identification on gender is such a potential field to be explored. Basically, gender identification in forensic anthropology by comparative skeletal anatomy by atlas and crucially affect the identification accuracy. The simulation identification method was studied in order to determine the best model, which reduce the total costs of the post-mortem as an objective. The computational method on simulation run improves the identification accuracy as proven by many studies. Fuzzy K-nearest neighbours classifier (FuzzyNN) is such a computational intelligence method and always shows the best performance in many fields including forensic anthropology. Thus, this intelligent identification method was implemented within the determining for best accuracy. The result of this proposed model was compared with raw data collection and standard collections datasets; Goldman Osteometric dataset and Ryan and Shaw Dataset (RSD) as a benchmark for the identification policy. To improve the accuracy of FuzzyNN classifier, Particle Swarm Optimization (PSO) feature selection was used as the basis for choosing the best features to be used by the selected FuzzyNN classification model. The model is called PSO-FuzzyNN and has been developed by MATLAB and WEKA tools platform. Comparisons of the performance measurement namely the percentage of the classification accuracy of the model were performed. The result show potential the proposed PSO-FuzzyNN method demonstrates the capability to the obtained highest accuracy of identification.

Ceramic cement as a potential stand-alone treatment for bone fractures: An in vitro study of ceramic–bone composites

BackgroundA vertebral burst fracture (VBF) treated with vertebroplasty using a ceramic cement consists of four regions; native bone fragments, native ceramic cement, ceramic cement–trabecular bone (ceramic–bone) composite and ceramic–bone interface. Although the mechanical properties of native bone and native ceramic cements have been well investigated, the mechanical properties of ceramic–bone composite and ceramic–bone interface remain unknown. Therefore, the aim of this study was to determine the mechanical properties of ceramic–bone composites and ceramic–bone interfaces. Two types of ceramic cement, calcium aluminate (CAC) with (w/F) and without (wo/F) fiber reinforcement, were investigated. MethodsCeramic–bone composite (Full, wo/F and w/F) and ceramic–bone interface (Fract, wo/F and w/F) groups were tested to determine their compressive and tensile properties. While a continuous bone cylinder was used for samples in the Full groups, each bone cylinder for the samples in the Fract groups contained a 3mm geometrical discontinuity to mimic the fracture gaps in VBFs. Two Cement groups (wo/F and w/F) and a Bone group were included in the study as controls. Micro-CT images were used to determine the bone morphological parameters, as potential predictors of the mechanical properties of Full and Fract groups. ResultsThe compressive strengths of Full and Fract groups were substantially lower than native CAC, but higher than bone. The tensile strength of the Full group was equal to bone, while the tensile strength of the Fract group was equivalent to CAC. Variable relationships between the bone morphological parameters and mechanical properties of Full and Fract groups were observed. Fiber reinforcement at an injectable level had a minimal influence on the mechanical properties. ConclusionsCAC augmentation does not provide adequate stabilization of bone fragments. The interface between bone and cement represents a weak point. The effect of cement augmentation cannot be predicted by bone morphological properties.

Influence of bone morphological properties on a new expandable orthopaedic fastener

Previous studies have demonstrated that bone morphological properties are a significant determinant of orthopaedic fastener fixation strength. The authors previously tested a new design of unthreaded expandable fastener (UEF) prototype against screws and demonstrated a significant increase in pull-out strength. However the effect of bone morphology on the pull-out strength of the UEF and expandable fasteners in general is unknown. This study assessed the correlation between failure force and maximum force against five microstructural parameters. The failure force of the UEF was correlated to the trabecular bone volume fraction, as with screws. Unlike screws, however, the maximum force of the UEF has an inverse relationship with cortical volume. No correlation was found between failure force and the Structural Model Index (SMI). Additionally the critical volume of interest (VOI) for the UEF is around the bottom of the fastener where the expansion occurs, whereas for the screw a full height VOI is critical. Furthermore, we observed that screw mechanical performance may be affected more by bone morphological parameters that are associated with poorer quality bone. Therefore the UEF may perform better than screws in low quality osteoporotic bone.

Bone morphology in 46 BXD recombinant inbred strains and femur-tibia correlation.

We examined the bone properties of BXD recombinant inbred (RI) mice by analyzing femur and tibia and compared their phenotypes of different compartments. 46 BXD RI mouse strains were analyzed including progenitor C57BL/6J (n = 16) and DBA/2J (n = 15) and two first filial generations (D2B6F1 and B6D2F1). Strain differences were observed in bone quality and structural properties (P < 0.05) in each bone profile (whole bone, cortical bone, or trabecular bone). It is well known that skeletal phenotypes are largely affected by genetic determinants and genders, such as bone mineral density (BMD). While genetics and gender appear expectedly as the major determinants of bone mass and structure, significant correlations were also observed between femur and tibia. More importantly, positive and negative femur-tibia associations indicated that genetic makeup had an influence on skeletal integrity. We conclude that (a) femur-tibia association in bone morphological properties significantly varies from strain to strain, which may be caused by genetic differences among strains, and (b) strainwise variations were seen in bone mass, bone morphology, and bone microarchitecture along with bone structural property.

Genetic relationships between obesity and osteoporosis in LGXSM recombinant inbred mice

Obesity and osteoporosis affect millions of Americans. While phenotypically, obesity is negatively correlated with fracture risk, research on a genetic basis for this relationship is lacking. We used males and females from 16 LGXSM recombinant inbred (RI) mouse strains to investigate the genetically mediated relationship between obesity and osteoporosis-related traits. First, heritabilities were estimated for (1) bone morphology properties determined by microCT (femoral and radial diaphyseal bone cross-sectional area and moments of inertia, as well as proximal tibial trabecular bone volume, connectivity density, structure model index, trabecular number, trabecular thickness and trabecular separation), (2) mechanical properties determined by bending tests (femoral and radial rigidity, yield moment, ultimate moment, fracture displacement and post-yield displacement), and (3) effective material properties (femoral and radial modulus of elasticity and ultimate tensile strength). All femoral (H2=43-74%) and tibial traits (H2=31-56%) were heritable; as were 8 of 10 radial traits (H2=21-33%). Eighteen significant genetic correlations were discovered between obesity- and osteoporosis-related phenotypes. Genetic correlations indicate that gene effects associated with increased fat mass and leptin levels are also associated with larger, stronger femora. Gene effects associated with larger, stronger radii and with denser tibiae were also associated with increased fat mass but not with leptin levels. Furthermore, quantitative trait loci (QTLs) previously reported for obesity and leptin levels also had effects on bone morphology, mechanical and material properties. Our results support the use of the LG/J-by-SM/J mouse intercross populations as models for normal, complex genetic variation in obesity, bone properties and their interrelationship.