Bone Biomechanical Properties Research Articles

Metformin treatment prevents experimental metabolic syndrome-induced femoral bone marrow adiposity in rats.

Motivation for the study. Most research supports a negative association between metabolic syndrome and bone health, although there is an overall lack of consensus. Therefore, there is a need for research in this area to develop a better understanding. Main findings. Metabolic syndrome induced by a fructose-rich diet increases the adipogenic predisposition of bone marrow progenitor cells and femoral medullary adiposity in rats. Furthermore, this can be partially prevented by co-treatment with metformin. Implications. Experimental metabolic syndrome has negative effects on bone tissue and can be prevented by oral treatment with metformin as a normoglycemic drug. To determine the effect of metformin (MET) treatment on adipogenic predisposition of bone marrow progenitor cells (BMPC), bone marrow adiposity and bone biomechanical properties. 20 young adult male Wistar rats were sorted into four groups. Each of the groups received the following in drinking water: 100% water (C); 20% fructose (F); metformin 100 mg/kg wt/day (M); or fructose plus metformin (FM). After five weeks the animals were sacrificed. Both humeri were dissected to obtain BMPC, and both femurs were dissected to evaluate medullary adiposity (histomorphometry) and biomechanical properties (3-point bending). BMPC were cultured in vitro in adipogenic medium to evaluate RUNX2, PPAR-γ and RAGE expression by RT-PCR, lipase activity and triglyceride accumulation. The fructose-rich diet (group F) caused an increase in both triglycerides in vitro, and medullary adiposity in vivo; being partially or totally prevented by co-treatment with metformin (group FM). No differences were found in femoral biomechanical tests in vivo, nor in lipase activity and RUNX2/PPAR-γ ratio in vitro. DRF increased RAGE expression in BMPC, being prevented by co-treatment with MET. Metabolic syndrome induced by a fructose-rich diet increases femoral medullary adiposity and, in part, the adipogenic predisposition of BMPC. In turn, this can be totally or partially prevented by oral co-treatment with MET.

Dietary supplementation with mushroom powder (Agaricus bisporus) on performance, carcass traits, meat quality, and bone biomechanical properties of quail (Coturnix coturnix japonica)

This study was performed to determine the effect of mushroom powder (MP) (Agaricus bisporus) supplementation on growing Japanese quail (Coturnix coturnix japonica). A total of 300 unsexed 1-day-old Japanese quails with similar body weights (8.38 ± 0.2 g) were randomly assigned to five treatment groups with six replications. Additions of 0, 0.25, 0.50, 0.75, or 1.00% of MP to the basal diet were used to develop the treatment groups. Quails were fed ad libitum for 42 days. At the end of the experiment, 12 quails from each experimental unit were euthanised to determine performance, carcass traits, meat quality, and bone biochemical properties. Results showed that all dietary MP did not negatively affect any performance parameters (P > 0.05), while by the third week of life, there was an increase (P < 0.05) in body weight and body weight gain in the quails of the 0.75% MP group compared to the control group. Nevertheless, these differences disappeared at the end of the trial (P > 0.05). No differences were observed (P > 0.05) for any of the studied carcass traits, except for the pancreas weight which decreased (P < 0.05) with the addition of high MP (1.00%). Regarding meat quality, all color parameters were affected on the fifth day of sampling (P < 0.05) but not on the first day (P > 0.05). It was detected that the breast of the quails in group 0.75% MP had the highest L* value and the lowest a* value. While the breast of the 1.00% MP group had the highest b value and the lowest pH value. Dietary MP enhanced oxidative stability, reducing malondialdehyde (MDA) value in the breast compared to the control at both sampling points (P < 0.01), being more noted on the fifth day of sampling. Bone biomechanical properties (in terms of shear force or shear stress) were improved (P < 0.01) with the dietary addition of MP at 0.75% compared to the control. It can be suggested that MP is a secure ingredient in animal feed without negatively affecting performance parameters, carcass traits, or meat quality. Therefore, including an interval of 0.50–0.75% of MP in the diet of growing quails could be a suitable strategy to improve certain parameters such as the meat’s oxidative stability and the bone’s biomechanical parameters. Moreover, the efficacy of MP on performance development would be greater during the first weeks of the quails’ life due to their intestinal conditions at this stage.

Effects of manganese and boron levels in breeder Japanese quails ration on performance, eggshell quality, and bone biomechanical properties

BackgroundImproved understanding of the impact of (Mn) and boron (B) levels in the dietary regimen of Japanese quails on their performance, eggshell quality, and bone properties might facilitate the optimization of their nutritional intake and improving health and productivity. MethodsThe effects of Mn and B added to the rations of breeder Japanese quail alone or together were investigated on performance, eggshell quality, and bone biomechanical characteristics. ResultsEgg production, egg mass, feed consumption, and feed conversion ratio values related to the performance of breeding quail were not affected by the single or combined addition of Mn and B. Average live weight gain and egg weight values were significantly affected by Mn and B additions. The highest average body weight gain (47.917 g) and egg weight (13.805 g) values were reached at 120 × 20 (120 mg Mn/kg + 20 mg B/kg) interaction. The interaction of 120 × 20 was appropriate considering the eggshell ratio and eggshell fracture strength values. The ultimate shear force and shear stress parameters were significantly affected by 60 mg/kg Mn or 20–80 mg/kg B additions compared to the control. The addition of 40–80 mg/kg B significantly increased the shear fracture energy. The femur bone Iron (Fe) content significantly increased with the combined additions of Mn and B. The combined Mn and B additions had no significant effect on bone calcium (Ca), phosphorus (P), and magnesium (Mg) contents, while the 0Mn × 20B interaction resulted in significantly higher bone Ca and P content than the control. The increase in Fe, Ca, P, and Mg accumulation in the bones could be associated with B addition in the Mn × B interaction. ConclusionIn the production of breeding Japanese quail, the addition of 120 mg Mn/kg to the diet would be appropriate, considering the performance characteristics of the quails, when Mn is used alone. The results revealed that the addition of 60 × 120 (Mn × B) interaction can be recommended for successful Japanese quail production. Nevertheless, more detailed studies assessing the effect of combined Mn and B additions to Japanese quail diets are needed to elucidate the action mechanism and to draw more precise conclusions.

Deleterious effect of chronic high-dose ethanol intake on biomechanical bone properties and periodontal status.

To evaluate the effect of high-graduation chronic ethanol (EtOH) intake on bone and periodontal tissues of rats. Male Wistar rats (250g) were divided into two groups of n = 12 each one. EtOH (5ml of 3g/kg) was administered to the experimental group by gastric gavage twice a day for 20days and the control group received water under the same conditions. The rats were euthanized and used to perform biochemical determination in plasma and gingival tissue, and histological and biomechanical studies in the femur and mandibular tissues. Alcohol increased both TNFα (p < 0.01) and PGE2 (p < 0.05) in plasma and gingiva (p < 0.05) as compared to controls. In addition, EtOH increased the alveolar bone loss as evidenced by the increased distance between the cement enamel junction and the alveolar crest (p < 0.01), the lower % of interradicular bone expressed as bone area/total area (B.Ar/T.Ar, p < 0.05) and the larger periodontal space (p < 0.05), as compared to controls. Likewise, the mandibular microtomographic analysis in alcoholized rats revealed a lower % of interradicular bone volume/total volume (BV/TV, p < 0.05), greater trabecular separation (p < 0.05) and greater % trabecular porosity (p < 0.05) than controls. No biomechanical alteration was observed in lower jaws, while the femur of alcoholized rats presented a decrease in the structural bone properties (p < 0.001), as a systemic consequence of deterioration of the diaphyseal architecture (p < 0.01) without changes in material properties. The consumption of high doses of alcohol produces deleterious effects on periodontal tissues that could be due not only to local but also systemic effects.

Analyzing entheseal changes in commingled human remains from Mesolithic and Neolithic periods in Portugal

AbstractThe analysis of entheseal changes requires knowing the biological profile of the sample analyzed, given that, mainly, the sex and age of the individuals influence the prevalence and degrees of the entheseal features. However, the bioarcheological record of several past populations presents isolated and commingled human bone remains, which constrains the estimation of such data. In this work, we propose to analyze the entheseal changes with the Coimbra method in a sample composed mainly of commingled human bone remains and, to a lesser extent, of semi‐complete individuals. For this purpose, we analyzed 312 bone elements from the upper and lower limbs of Late Mesolithic (Muge complex) and Late Neolithic/Chalcolithic archeological sites from Portugal. The results support previous information that individuals older than 40 present higher entheseal changes. In addition, body size has a low effect on entheseal changes and bone's biomechanical properties are positively correlated with some entheseal features. Some entheseal traits show higher prevalence during the Mesolithic, but there is mainly an increase in entheseal changes during the Neolithic. Although these differences could be due to different biological profiles between both samples, differences in lifestyle may also have contributed to the results.

In Vivo Assessment of Skin Surface Pattern: Exploring Its Potential as an Indicator of Bone Biomechanical Properties.

The mechanical properties of bone tissue are the result of a complex process involving collagen-crystal interactions. The mineral density of the bone tissue is correlated with bone strength, whereas the characteristics of collagen are often associated with the ductility and toughness of the bone. From a clinical perspective, bone mineral density alone does not satisfactorily explain skeletal fragility. However, reliable in vivo markers of collagen quality that can be easily used in clinical practice are not available. Hence, the objective of the present study is to examine the relationship between skin surface morphology and changes in the mechanical properties of the bone. An experimental study was conducted on healthy children (n = 11), children with osteogenesis imperfecta (n = 13), and women over 60 years of age (n = 22). For each patient, the skin characteristic length (SCL) of the forearm skin surface was measured. The SCL quantifies the geometric patterns formed by wrinkles on the skin's surface, both in terms of size and elongation. The greater the SCL, the more deficient was the organic collagen matrix. In addition, the bone volume fraction and mechanical properties of the explanted femoral head were determined for the elderly female group. The mean SCL values of the healthy children group were significantly lower than those of the elderly women and osteogenesis imperfecta groups. For the aged women group, no significant differences were indicated in the elastic mechanical parameters, whereas bone toughness and ductility decreased significantly as the SCL increased. In conclusion, in bone collagen pathology or bone aging, the SCL is significantly impaired. This in vivo skin surface parameter can be a non-invasive tool to improve the estimation of bone matrix quality and to identify subjects at high risk of bone fracture.

Pharmacologic Inhibition of Myostatin With a Myostatin Antibody Improves the Skeletal Muscle and Bone Phenotype of Male Insulin-Deficient Diabetic Mice.

Type 1 diabetes (T1D) is associated with low bone and muscle mass, increased fracture risk, and impaired skeletal muscle function. Myostatin, a myokine that is systemically elevated in humans with T1D, negatively regulates muscle mass and bone formation. We investigated whether pharmacologic myostatin inhibition in a mouse model of insulin-deficient, streptozotocin (STZ)-induced diabetes is protective for bone and skeletal muscle. DBA/2J male mice were injected with low-dose STZ (diabetic) or vehicle (non-diabetic). Subsequently, insulin or palmitate Linbits were implanted and myostatin (REGN647-MyoAb) or control (REGN1945-ConAb) antibody was administered for 8 weeks. Body composition and contractile muscle function were assessed in vivo. Systemic myostatin, P1NP, CTX-I, and glycated hemoglobin (HbA1c) were quantified, and gastrocnemii were weighed and analyzed for muscle fiber composition and gene expression of selected genes. Cortical and trabecular parameters were analyzed (micro-computed tomography evaluations of femur) and cortical bone strength was assessed (three-point bending test of femur diaphysis). In diabetic mice, the combination of insulin/MyoAb treatment resulted in significantly higher lean mass and gastrocnemius weight compared with MyoAb or insulin treatment alone. Similarly, higher raw torque was observed in skeletal muscle of insulin/MyoAb-treated diabetic mice compared with MyoAb or insulin treatment. Additionally, muscle fiber cross-sectional area (CSA) was lower with diabetes and the combination treatment with insulin/MyoAb significantly improved CSA in type II fibers. Insulin, MyoAb, or insulin/MyoAb treatment improved several parameters of trabecular architecture (eg, bone volume fraction [BV/TV], trabecular connectivity density [Conn.D]) and cortical structure (eg, cortical bone area [Ct. Ar.], minimum moment of inertia [Imin]) in diabetic mice. Lastly, cortical bone biomechanical properties (stiffness and yield force) were also improved with insulin or MyoAb treatment. In conclusion, pharmacologic myostatin inhibition is beneficial for muscle mass, muscle function, and bone properties in this mouse model of T1D and its effects are both independent and additive to the positive effects of insulin. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The combined treatment of insulin and naringin improves bone properties in rats with type 1 diabetes mellitus.

We have studied the effects of individual and combined treatment of insulin (I) and naringin (NAR) on the bone structure and biomechanical properties of femurs from streptozotocin (STZ)-induced diabetic rats. Male Wistar rats were divided into five groups: (1) controls, (2) STZ-induced diabetic rats, (3) STZ-induced diabetic rats treated with I, (4) STZ-induced diabetic rats treated with NAR, and (5) STZ-induced diabetic rats treated with I+NAR. Bone mineral density (BMD), bone histomorphometry, biomechanical testing, and bone biomarker expressions were accomplished in femur of all animals, as well as serum biochemical analyses. The combined treatment of I+NAR increased the body weight and the femur BMD from STZ-induced diabetic rats. The bone biomechanical properties and the bone morphology of the femurs from STZ-induced diabetic rats were also improved by the combined treatment. The increased number of osteoclasts in STZ-induced diabetic rats was partially prevented by I, NAR, or I+NAR. NAR or I+NAR completely blocked the decrease in the number of osteocalcin (+) cells in the femur from STZ-induced diabetic rats. RUNX family transcription factor 2 immunostaining was much lower in STZ-induced diabetic rats than in control animals; the combination of I+NAR totally blocked this effect. The combined treatment not only ameliorated bone quality and function, but also normalized the variables related to glucose metabolism. Therefore, the combination of I+NAR might be a better therapeutic strategy than the individual I or NAR administration to reduce bone complications in diabetic patients.

Effect of Distal Tibiofibular Syndesmosis Overcompression on the Biomechanical Properties of the Ankle Bones: An In Vitro Cadaveric Model

Category: Trauma; Ankle Introduction/Purpose: Overtightening of the distal tibiofibular syndesmosis during open reduction and internal fixation (ORIF) of ankle fractures remains a clinical concern, and there are limited data delineating the effect of syndesmosis overcompression on subsequent range of motion of the ankle joint bones. The primary objective of the current study was to determine the effect of syndesmotic overcompression on the relative range of motion (ROM) of the tibia, fibula, and talus, and to determine the syndesmotic fixation construct that most accurately restores native motion. Methods: Ten cadaveric lower limbs were utilized (78.3±13.0 yrs, 4F; 6M). A musculoskeletal simulator at ±7.5 Nm was used to test flexibility in dorsiflexion-plantarflexion, inversion-eversion, and internal-external rotation. After intact testing, syndesmotic probes were used to arthroscopically measure the intact position of the distal tibiofibular syndesmosis. The force needed to compress the syndesmosis just beyond the intact position represented the intact force (100%), and overcompression was defined as 150% of the intact force. The anterior inferior tibiofibular ligament (AITFL), interosseus membrane (IOM), and posterior inferior tibiofibular ligament (PITFL) were then sectioned. Testing was repeated for destabilized, IOM reconstruction at 100% compression and 150% overcompression, IOM reconstruction plus AITFL fixation at 100% compression and 150% overcompression, and AITFL fixation alone. ROM data was reported as a percentage of the intact condition. Repeated measures ANOVA and Bonferroni post hoc test were performed to assess differences between conditions with p&lt; 0.05. Results: Average force needed to compress the syndesmosis was 71.0 ± 22.2 N. There was a significant increase in distal tibiofibular ROM in internal and external rotation for all conditions compared to intact (Figure 1) (p &lt; 0.05). In the axial plane, reconstruction of the IOM membrane did not restore the intact condition and was similar to the destabilized treatment, regardless of compression force. The addition of AITFL fixation significantly reduced distal tibiofibular motion compared to IOM reconstructions alone, but still did not approach the intact condition. Overcompression of the syndesmosis did not significantly affect relative ROM of the ankle bones in any plane (p&gt;0.05). Changes in the proximal tibiofibular ROM were similar in magnitude and direction as the distal tibiofibular ROM for all conditions. Conclusion: In the current study, overcompression of the distal tibiofibular syndesmosis did not restrict relative ROM of the tibia, fibula, or talus. Reconstructing the AITFL in addition to the IOM decreased tibiofibular ROM, particularly in the axial plane. In the clinical setting, surgical reconstruction with dynamic fixation of the distal tibiofibular syndesmosis may result in increased ROM and mechanical stress at the proximal tibiofibular articulation.

Strontium chloride improves bone mass by affecting the gut microbiota in young male rats.

Bone mass accumulated in early adulthood is an important determinant of bone mass throughout the lifespan, and inadequate bone deposition may lead to associated skeletal diseases. Recent studies suggest that gut bacteria may be potential factors in boosting bone mass. Strontium (Sr) as a key bioactive element has been shown to improve bone quality, but the precise way that maintains the equilibrium of the gut microbiome and bone health is still not well understood. We explored the capacity of SrCl2 solutions of varying concentrations (0, 100, 200 and 400 mg/kg BW) on bone quality in 7-week-old male Wistar rats and attempted to elucidate the mechanism through gut microbes. The results showed that in a Wistar rat model under normal growth conditions, serum Ca levels increased after Sr-treatment and showed a dose-dependent increase with Sr concentration. Three-point mechanics and Micro-CT results showed that Sr exposure enhanced bone biomechanical properties and improved bone microarchitecture. In addition, the osteoblast gene markers BMP, BGP, RUNX2, OPG and ALP mRNA levels were significantly increased to varying degrees after Sr treatment, and the osteoclast markers RANKL and TRAP were accompanied by varying degrees of reduction. These experimental results show that Sr improves bones from multiple angles. Further investigation of the microbial population revealed that the composition of the gut microbiome was changed due to Sr, with the abundance of 6 of the bacteria showing a different dose dependence with Sr concentration than the control group. To investigate whether alterations in bacterial flora were responsible for the effects of Sr on bone remodeling, a further pearson correlation analysis was done, 4 types of bacteria (Ruminococcaceae_UCG-014, Lachnospiraceae_NK4A136_group, Alistipes and Weissella) were deduced to be the primary contributors to Sr-relieved bone loss. Of these, we focused our analysis on the most firmly associated Ruminococcaceae_UCG-014. To summarize, our current research explores changes in bone mass following Sr intervention in young individuals, and the connection between Sr-altered intestinal flora and potentially beneficial bacteria in the attenuation of bone loss. These discoveries underscore the importance of the "gut-bone" axis, contributing to an understanding of how Sr affects bone quality, and providing a fresh idea for bone mass accumulation in young individuals and thereby preventing disease due to acquired bone mass deficiency.

Effects of blood flow restriction training on bone turnover markers, microstructure, and biomechanics in rats.

The present study aimed to investigate the effects of blood flow restriction training on muscle strength, bone tissue structure material, and biomechanical properties in rats applying various exercise interventions and to analyze the process by identifying the bone turnover markers, it provides a theoretical basis for the application of BFRT in clinical rehabilitation. A total of 24, 3-month-old male SD (Sprague Dawley) rats were randomly divided into pressurized control group (CON, n=6), low-intensity training group (LIRT, n=6), high-intensity training group (HIRT, n=6), and blood flow restriction training group (LIBFR, n=6) for 8-week ladder-climbing exercises. The pressured control group were given only ischemia treatments and did not undertake any burden. The low-intensity training group was allowed to climb the ladder with 30% of the maximum voluntary carrying capacity (MVCC). The rats in the high-intensity training group were allowed to climb the ladder with 70% MVCC. The blood flow restriction training group climbed the ladder with 30% MVCC while imposing blood flow restriction. Before sampling, the final MVCC was measured using a ladder-climbing protocol with progressively increasing weight loading. The serum, muscle, and bone were removed for sampling. The concentrations of the bone turnover markers PINP, BGP, and CTX in the serum were measured using ELISA. The bone mineral density and microstructure of femur bones were measured using micro-CT. Three-point bending and torsion tests were performed by a universal testing machine to measure the material mechanics and structural mechanics indexes of the femur bone. The results of maximum strength test showed that the MVCC in LIRT, HIRT, and LIBFR groups was significantly greater than in the CON group, while the MVCC in the HIRT group was significantly higher than that in the LIRT group (P<0.05). According to the results of the bone turnover marker test, the concentrations of bone formation indexes PINP (amino-terminal extension peptide of type I procollagen) and BGP (bone gla protein) were significantly lower in the CON group than in the HIRT group (P<0.01), while those were significantly higher in the LIRT group compared to the HIRT group (P<0.01). In terms of bone resorption indexes, significant differences were identified only between the HIRT and other groups (P<0.05). The micro-CT examination revealed that the HIRT group had significantly greater bone density index values than the CON and LIRT groups (P<0.05). The results of three-point bending and torsion test by the universal material testing machine showed that the elastic modulus and maximum load indexes of the HIRT group were significantly smaller than those of the LIBFR group (P<0.05). The fracture load indexes in the HIRT group were significantly smaller than in the LIBFR group (P<0.05). 1. LIRT, HIRT, LIBFR, and CON all have significant differences, and this training helps to improve maximum strength, with HIRT being the most effective. 2. Blood flow restriction training can improve the expression of bone turnover markers, such as PINP and BGP, which promote bone tissue formation. 3. Blood flow restriction training can improve muscle strength and increase the positive development of bone turnover markers, thereby improving bone biomechanical properties such as bone elastic modulus and maximum load.

Bavachinin selectively modulates PPAR γ and maintains bone homeostasis in Type 2 Diabetes.

Full peroxisome proliferator-activated receptor (PPAR) γ agonists, Thiazolidinediones (TZDs), effectively prevent the process of Type 2 Diabetes Mellitus (T2DM), but their side effects have curtailed use in the clinic, including weight gain and bone loss. Here, we identified that a selective PPAR γ modulator, Bavachinin (BVC), isolated from the seeds of Psoralea Corylifolia L., could potently regulate bone homeostasis. MC3T3-E1 pre-osteoblast cells and C3H10T1/2 mesenchymal stem cells were assessed for osteogenic differentiation activities, and receptor activator of NF-κB ligand (RANKL)-induced RAW 264.7 cells were assessed osteoclasts formation. Leptin receptor-deficient mice and diet-induced obesity mice were applied to evaluate the effect of BVC on bone homeostasis in vivo. Compared to full PPAR γ agonist rosiglitazone, BVC significantly increased the osteogenesis differentiation activities under normal and high glucose conditions in MC3T3-E1 cells. Moreover, BVC could alleviate osteoclast differentiation in RANKL-induced RAW 264.7 cells. In vivo, synthesized BVC prodrug (BN) has been applied to improve water solubility, increase the extent of oral absorption of BVC and prolong its residence time in blood circulation. BN could prevent weight gain, ameliorate lipid metabolism disorders, improve insulin sensitivity, and maintain bone mass and bone biomechanical properties. BVC, a unique PPAR γ selective modulator, could maintain bone homeostasis, and its prodrug (BN) exhibits insulin sensitizer activity while circumventing the side effects of the TZDs, including bone loss and undesirable weight gain.

A vitamin D deficient diet increases weight gain and compromises bone biomechanical properties without a reduction in BMD in adult female mice

Vitamin D contributes to the development and maintenance of bone. Evidence suggests vitamin D status can also alter energy balance and gut health. In young animals, vitamin D deficiency (VDD) negatively affects bone mineral density (BMD) and bone microarchitecture, and these effects may also occur due to chronic ethanol intake. However, evidence is limited in mature models, and addressing this was a goal of the current study. Seven-month-old female C57BL/6 mice (n = 40) were weight-matched and randomized to one of four ad libitum diets: control, alcohol (Alc), vitamin D deficient (0 IU/d), or Alc+VDD for 8 weeks. A purified (AIN-93) diet was provided with water or alcohol (10 %) ad libitum. Body weight and food intake were recorded weekly, and feces were collected at 0, 4, and 8 weeks. At the age of 9 months, intestinal permeability was assessed by oral gavage of fluorescein isothiocyanate–dextran. Thereafter, bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. The microarchitecture of the distal femur was assessed by micro-computed tomography and biomechanical properties were evaluated by cyclic reference point indentation. VDD did not affect BMD or most bone microarchitecture parameters, however, the polar moment of inertia (p < 0.05) was higher in the VDD groups compared to vitamin D sufficient groups. VDD mice also had lower whole bone water content (p < 0.05) and a greater average unloading slope (p < 0.01), and energy dissipated (p < 0.01), indicating the femur displayed a brittle phenotype. In addition, VDD caused a greater increase in energy intake (p < 0.05), weight gain (p < 0.05), and a trend for higher intestinal permeability (p = 0.08). The gut microbiota of the VDD group had a reduction in alpha diversity (p < 0.05) and a lower abundance of ASVs from Rikenellaceae, Clostridia_UCG-014, Oscillospiraceae, and Lachnospiraceae (p < 0.01). There was little to no effect of alcohol supplementation on outcomes. Overall, these findings suggest that vitamin D deficiency causes excess weight gain and reduces the biomechanical strength of the femur as indicated by the higher average unloading slope and energy dissipated without an effect on BMD in a mature murine model.

Fabricating Stiffness-Matched Three Dimensional -Printed Metal Implants for Total Wrist Arthroplasty.

Total wrist arthroplasty (TWA) is a motion-sparing treatment for pancarpal arthritis; however, complication rates up to 50% have limited widespread use. Implant micromotion, stress shielding, and periprosthetic osteolysis result in implant failure and revision to arthrodesis. Metal 3-dimensional (3D) printing allows for more accurate matching of surrounding bone biomechanical properties, theoretically reducing periprosthetic osteolysis. Herein, we use computed tomography to characterize the relationship of relative stiffness along the length of the distal radius with patient demographic factors. After institutional review, wrist computed tomography scans at a single institution between 2013 and 2021 were identified. Exclusion criteria were history of radius or carpal trauma or fracture. Collected demographics included age, sex, and comorbidities (including osteoporosis/osteopenia). Scans were analyzed using Materialize Mimics Innovation Suite 24.0 (Leuven, Belgium). Distal radius cortical density (in Hounsfield units) and medullary volume (in cubic millimeters) with relation to distance from the radiocarpal joint were recorded. Average values for each variable were used to 3D-printed distal radius trial components with stiffness matched to bone density by length. Thirty-two patients met inclusion criteria. Distal radius cortical bone density progressively increased proximal to the radiocarpal joint, whereas medullary volume decreased; changes in both plateaued 20 mm proximal to the joint. Distal radius material properties differed by age, sex, and comorbidities. Total wrist arthroplasty implants were fabricated to match these variables as proof of concept. Distal radius material properties vary along the bone length; conventional implants do not account for this variance. This study showed 3D-printed implants can be created to match bone properties along the length of the implant.

Study of Image-Based Finite Element Model for Predicting the Biomechanical Properties of Femur Bone: A Review

Study of Image-Based Finite Element Model for Predicting the Biomechanical Properties of Femur Bone: A Review

Validation of a novel testing machine for the investigation of the biomechanical properties of lumbar vertebrae in an osteoporotic rat model

BackgroundFor the investigation of the biomechanical properties of bone, various testing devices have been described. However, only a limited number have been developed to test the vertebral body of small animals. The aim of this study was to develop and validate a new bone testing device, which investigates the different biomechanical properties in small-animal vertebrae as a whole, three-dimensional unit, respecting its anatomical structure.MethodsThirty-five twelve-week-old female Sprague Dawley rats were utilized. Group 1 was composed of 17 rats with a normal bone metabolism without osteoporosis, while Group 2 consisted of 18 rats with manifest osteoporosis, 8 weeks after ovariectomy. The 5th lumbar vertebra of each animal was tested using the new bone testing device. This device has the ability to be adjusted to the slanted nature of each individual vertebral body and fix the vertebra in a natural position to allow for a non-dislocating axial force application. The device is designed to respect the anatomical three-dimensional shape of the vertebral body, thus avoiding the application of non-anatomic, non-physiological forces and thus preventing a distortion of the biomechanical testing results. The parameters investigated were stiffness, yield load, maximum load and failure load, and the results were compared to current literature values.ResultsThe conduction of the biomechanical bone testing of the vertebral bodies with the new device was conductible without any instances of dislocation of the vertebrae or machine malfunctions. Significant differences were found for stiffness, maximum load and failure load between groups, with a lower value in the osteoporotic rats in each parameter tested. The yield load was also lower in the osteoporotic group, however not significantly. The values achieved correlate with those in current literature.ConclusionsThis study demonstrates that the newly developed testing machine is easy to handle and produces valid data sets for testing biomechanical bone parameters of whole vertebral bodies in an established small animal model. Therefore, it can be utilized, also as reference data, to test different structural properties and changes in vertebral bone, for example, in different metabolic settings or under the influence of different pharmaceutical entities in further studies.

Photoacoustic Imaging and Characterization of Bone in Medicine: Overview, Applications, and Outlook.

Photoacoustic techniques have shown promise in identifying molecular changes in bone tissue and visualizing tissue microstructure. This capability represents significant advantages over gold standards (i.e., dual-energy X-ray absorptiometry) for bone evaluation without requiring ionizing radiation. Instead, photoacoustic imaging uses light to penetrate through bone, followed by acoustic pressure generation, resulting in highly sensitive optical absorption contrast in deep biological tissues. This review covers multiple bone-related photoacoustic imaging contributions to clinical applications, spanning bone cancer, joint pathologies, spinal disorders, osteoporosis, bone-related surgical guidance, consolidation monitoring, and transsphenoidal and transcranial imaging. We also present a summary of photoacoustic-based techniques for characterizing biomechanical properties of bone, including temperature, guided waves, spectral parameters, and spectroscopy. We conclude with a future outlook based on the current state of technological developments, recent achievements, and possible new directions.

This is the way: The effect of artificial cues on early life ramp use behaviour of laying hen chicks

Providing laying hen chicks with ramps during the rearing phase has been shown to increase inter-tiers transitions and use of elevated surfaces within aviaries. To maximize these benefits, we aimed to investigate if artificial cues that utilize the behavioural predispositions of domestic chicks would increase ramp use during the rearing phase and whether this increase would benefit the birds by improving their spatial cognition and skeletal strength. For this, we conducted two experiments: E1 compared two light cues (Dotter and Flicker) and E2 three moving cues (Beak, Hen, and LED) with respective control groups. Identical pens with two vertically stacked tiers connected by two ramps that housed 22 LSL chicks each were used for both experiments (N = 4/treatment). Cues were applied in intermittent bouts spread throughout the day until 60 days of age (DoA). We counted the number of inter-tier transitions using ramps, as well as the active use of ramps (e.g., walk/run, jump) that did not result in a transition by scan sampling recorded videos both when the cues were on and off. In E1, 47 birds (N = ∼12/treatment) underwent a spatial cognition test during 64 – 75 DoA and biomechanical properties of the tibiae and humeri were assessed for 20 birds per treatment by performing a three-point bending test at 87 DoA. Generalized linear mixed model analysis for E1, revealed that birds from both light cue groups performed more transitions when the cues were on compared to when the cues were off (χ2 = 6.18, p = 0.03). A three-way interaction between treatment, cue status, and DoA was found for active use of ramps (χ2 = 5.19, p = 0.02) with birds performing more active behaviours on ramps when cues were on compared to when cues were off until 38 and 24 DoA for Dotter and Flicker treatments, respectively. No differences between light cues and control groups were found in bone biomechanical properties and spatial cognition. In E2, birds from the Beak treatment performed 1.5 times fewer transitions than the Control birds (χ2 = 10.16, p = 0.02). Active use of ramps was affected by an interaction between treatment and DoA (χ2 = 13.33, p < 0.01) with birds from LED groups performing more active behaviours with increasing age while it decreased in the Hen and Control group groups. Overall, birds were more responsive to the cues that utilized predispositions based on the foraging aspects than the cues based on predispositions that aided in social interactions.

Effect of photobiomodulation therapy with different wavelengths on bone mineral density in osteoporotic rats.

Osteoporosis is associated with severe pain, bone deformity, fracture, and bone loss. It is important to find strategies to prevent bone resorption and treat osteoporosis. This study sought to assess the effect of photobiomodulation therapy (PBMT) with different wavelengths on bone mineral density (BMD) in osteoporotic rats. This animal study evaluated 63 adult female rats. The rats underwent ovariectomy to induce osteoporosis. Ovariectomized rats were randomly divided into 9 groups of control (OC), treatment with zoledronic acid alone (0.02mg/kg), and treatment with 660nm, 810nm, and 940nm PBMT alone (3 times a week for 6weeks, energy density of 4J/cm2), and combined with zoledronic acid. The healthy control group (HC) only underwent sham surgery. The rats underwent cone-beam computed tomography (CBCT) 52days after the first treatment session to measure their BMD according to the gray value (GV) of images. To assess the biomechanical properties of bone, the resected bones were subjected to 3-point bending test (3-PBT). The experimental groups had significant differences with the OC group regarding radiographic and biomechanical properties of bone (P < 0.05), indicating a healing course. No significant difference was noted between the experimental groups treated with different laser wavelengths and those treated with zoledronic acid (P > 0.05). In the condition of this study, it was found that PBMT at a constant energy density of 4J/cm2 with 660-, 810-, and 940-nm wavelengths is effective for enhancement of bone mineral density and biomechanical properties. No significant difference was noted between different wavelengths of diode laser regarding radiographic and biomechanical properties of bone.

Retraction notice to "The Effects of Clockwise and Counterclockwise Conventional and Osseodensification Drilling on the Dimensions, Density, and Biomechanical Properties of Bone" [Int J Oral Maxillofac Implants 2023;38:77-83

Purpose: To compare the effects of regular implant drills to osseodensifying drills used in clockwise and counterclockwise motions on bone dimension change and primary implant stability. Materials and Methods: A total of 40 bone models were made (20 × 15 × 4 mm) from porcine tibia to represent implants placed in soft bone. Implant osteotomies were prepared in the bone models using one of the following techniques: (1) regular implant drills in a clockwise direction (group A), (2) regular implant drills in a counterclockwise direction (group B), (3) osseodensifying drills in a clockwise direction (group C), and (4) osseodensifying drills in a counterclockwise direction (group D). Bone-level tapered titanium alloy implants (4.1 × 10 mm) were placed following osteotomy creation. The implant stability quotient (ISQ) was measured after implant placement. Each bone model was scanned with an optical scanner to convert to Standard Tessellation Language (STL) files before and after the osteotomy creation. Presurgical and postsurgical STL files were superimposed, and the dimensional changes were measured at 1, 3, and 7 mm from the crestal bone. Histomorphometric analysis was done, and bone-to-implant contact percentage (BIC%) was calculated. Results: There were no significant differences in ISQ values (P = .239) between any of the groups. Histomorphometric analysis showed implants in group D had significantly higher BIC% than groups A (P = .020) and B (P = .009). The amount of bone expansion decreased with distance from the crest (P < .001). Groups B (P = .039) and D (P = .001) showed significant expansions at all levels compared with group A. No other statistically significant differences in dimensional change were found between groups. Conclusion: Both regular and osseodensification burs used in a counterclockwise motion contribute to expansion of bone dimension compared to conventional drilling methods.