Trabecular Parameters Research Articles

Characterization of age- and gender-specific trabecular bone structural parameters and mesenchymal stromal cells of osteoarthritic facet joints in lumbar spinal stenosis

Purpose: Facet joint osteoarthritis may be a cause of low back pain in degenerative spine diseases such as lumbar spinal stenosis. While increased bone remodeling is a clinical hallmark of osteoarthritis, the trabecular bone structural parameters of osteoarthritic lumbar facet joints have not been characterized thus far. Interestingly, an age- and gender-specific decrease of trabecular number, thickness and volume fraction has been previously described for lumbar 4/5 facet joints of healthy individuals. Here, we sought to characterize trabecular bone structural parameters and subchondral bone-resident mesenchymal stromal cells (MSC) of osteoarthritic facet joints and compare these with regard to age, gender and healthy controls. Methods: Twenty-one patients scheduled for decompression and stabilization surgery for degenerative spinal stenosis were recruited for this study. Facet joint specimens were harvested during surgery and either fixed in formalin for microcomputed tomography (n = 15) or isolation of MSC by collagenase digestion (n = 6). MicroCT was performed spatial resolution of 20.5 μm. Bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) and trabecular number (Tb.N) were evaluated using CT Analyser. Trabecular bone structural parameters of healthy subjects were taken from Wilke and co-workers (J. Anat. 2012). Statistical analysis of differences between gender and age groups (40–60 and 60–80 years) were performed using two-way analysis of variance (ANOVA). Early passage MSC were subjected to adipogenic and osteogenic differentiation for three weeks and evaluated using alkaline phosphatase assay, Alizarin red and Oil red O staining and RT-PCR. Results: Trabecular BV/TV was 0.36 ± 0.14 and 0.35 ± 0.17 for osteoarthritic lumbar facet joints of male and female individuals, respectively. Contrastingly, mean BV/TV in age-matched healthy controls was 0.32 (male) and 0.25 (female). Tb.Th was in the same range for both genders and age-groups (overall mean 0.20 ± 0.07 mm) and did not differ from healthy controls. The overall Tb.Sp averaged 0.52 ± 0.16 mm, which was lower than averages observed for age-matched healthy females (0.60) and males (0.71). Accordingly, Tb.N in osteoarthritic facet joints of male (1.9 ± 1.3/mm) and female (1.7 ± 0.8/mm) patients with lumbar spinal stenosis was higher than reported for healthy controls (1.5–1.0/mm). Statistical analysis did not reveal any age- or gender-specific differences in trabecular bone structural parameters of osteoarthritic lumbar facet joints. Facet joint MSC showed a strongly upregulated alkaline phosphatase activity upon adipogenic (8.1-fold) and osteogenic (4.6-fold) differentiation. Only a low number of lipid vacuoles were detected after adipogenesis. Alizarin red staining revealed varying degrees of in vitro matrix mineralization in MSC, which ranged from blunted to strong mineralization. Conclusions: Subchondral trabecular bone remodeling in lumbar facet joint osteoarthritis is characterized by an increase in bone volume fraction due to a higher trabecular number, but not an increase of trabecular thickness. MSC from osteoarthritic facet joints display impaired adipogenesis and abnormal mineralization during osteogenesis. These data provide a strong rationale for targeting increased bone remodeling in lumbar facet joint osteoarthritis.

Trabecular Bone Morphological Analysis for Preclinical Osteoporosis Application Using Micro Computed Tomography Scanner

Trabecular bone morphological parameter (TMP) analysis with micro computed tomography (micro-CT) has been used to evaluate the risk of fracture of osteoporosis in small animals. Many researchers have pointed out the drawback of making decisions based on bone mineral density only due to the lack of morphological information. Our study describes the application of a laboratory micro-CT system and a self-designed TMP algorithm combined with two statistical methodological tools for the evaluation of the artificially induced animal model by the ovariectomy (OVX) surgery process. The results show that the percentage bone volume (BV/TV), the trabecular properties thickness (TbTh), number (TbN), and separation (TbSp) have significant differences between the normal and OVX groups. TbTh and TbSp had very low p-values and are associated with bone loss caused by osteoporosis. The method can be used to early detect osteoporosis to prevent the risk of fracture in aging small animals.

Analysis of trabecular bone microstructure in osteoporotic femoral heads in human patients: in vivo study using multidetector row computed tomography.

BackgroundLag screw position is very important in the treatment of intertrochanteric femoral fracture to prevent complications such as screw cut-out. Current studies recommend central or inferior placement of the lag screw on the anteroposterior radiograph, and central placement on the lateral radiographs. These reports are based on radiographic evaluation, but few studies have investigated the importance of bone quality at the site of lag screw placement. In this study, we used multidetector row computed tomography (MDCT) to perform in vivo evaluation of the bone microstructure of the femoral head in patients with intertrochanteric femoral fractures.MethodsThis study was approved by the Ethics Committee of Okanami General Hospital. MDCT images were obtained in our hospital from ten patients who had sustained intertrochanteric femoral fracture. Patients who needed computed tomography to confirm fracture morphology were included. We defined six areas as regions of interest (ROI): ROI 1–3 were defined as the femoral head apex area, and ROI 4–6 were defined as the femoral neck area. Trabecular microstructure parameters, including mean bone volume to total volume (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), and structure model index (SMI), were evaluated with bone analysis software (TRI/3D-BON). Statistical analyses were performed using EZR software; each parameter among the ROIs was statistically evaluated by analysis of variance (ANOVA) and Tukey’s test. Statistical significance was established at p < 0.05.ResultsIn the apical area, all parameters indicated that ROI 1 (superior) had the highest bone quality and ROI 2 (central) was higher in bone quality than ROI 3 (inferior). In the femoral neck, all parameters indicated that bone quality was significantly greater in ROI 6 (inferior) than ROI 5 (central).Discussion and ConclusionsWe could evaluate bone quality with clinical MDCT in vivo. Bone quality in the central area of the femoral head apical was greater than in the inferior area, and bone quality in the inferior area of the femoral neck was greater than in the central area. Recognizing which area of femoral head has greater bone quality may lead to a better clinical result in treating intertrochanteric femoral fracture.

Use of MR-based trabecular bone microstructure analysis at the distal radius for osteoporosis diagnostics: a study in post-menopausal women with breast cancer and treated with aromatase inhibitor.

Treatment with aromatase inhibitor (AI) is recommended for post-menopausal women with hormone-receptor positive breast cancer. However, AI therapy is known to induce bone loss leading to osteoporosis with an increased risk for fragility fractures. The purpose of this study was to investigate whether changes of magnetic resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarker can already be detected in subjects with AI intake but still without evidence for osteoporosis according to dual energy X-ray absorptiometry (DXA)-based bone mineral density (BMD) measurements as current clinical gold standard. Twenty-one postmenopausal women (62±6 years of age) with hormone-receptor positive breast cancer, ongoing treatment with aromatase inhibitor for 23±15 months, and no evidence for osteoporosis (current DXA T-score greater than -2.5) were recruited for this study. Eight young, healthy women (24±2 years of age) were included as controls. All subjects underwent 3 Tesla magnetic resonance imaging (MRI) of the distal radius to assess the trabecular bone microstructure. Trabecular bone microstructure parameters were not significantly (p>0.05) different between subjects with AI intake and controls, including apparent bone fraction (0.42±0.03 vs. 0.42±0.05), trabecular number (1.95±0.10 mm(-1) vs 1.89±0.15 mm(-1)), trabecular separation (0.30±0.03 mm vs 0.31±0.06 mm), trabecular thickness (0.21±0.01 mm vs 0.22±0.02 mm), and fractal dimension (1.70±0.02 vs. 1.70±0.03). These findings suggest that the initial deterioration of trabecular bone microstructure as measured by MRI and BMD loss as measured by DXA occur not sequentially but rather simultaneously. Thus, the use of MR-based trabecular bone microstructure assessment is limited as early diagnostic biomarker in this clinical setting.

The relationship between dental implant stability and trabecular bone structure using cone-beam computed tomography.

PurposeThe objective of this study was to investigate the relationships between primary implant stability as measured by impact response frequency and the structural parameters of trabecular bone using cone-beam computed tomography(CBCT), excluding the effect of cortical bone thickness.MethodsWe measured the impact response of a dental implant placed into swine bone specimens composed of only trabecular bone without the cortical bone layer using an inductive sensor. The peak frequency of the impact response spectrum was determined as an implant stability criterion (SPF). The 3D microstructural parameters were calculated from CT images of the bone specimens obtained using both micro-CT and CBCT.ResultsSPF had significant positive correlations with trabecular bone structural parameters (BV/TV, BV, BS, BSD, Tb.Th, Tb.N, FD, and BS/BV) (P<0.01) while SPF demonstrated significant negative correlations with other microstructural parameters (Tb.Sp, Tb.Pf, and SMI) using micro-CT and CBCT (P<0.01).ConclusionsThere was an increase in implant stability prediction by combining BV/TV and SMI in the stepwise forward regression analysis. Bone with high volume density and low surface density shows high implant stability. Well-connected thick bone with small marrow spaces also shows high implant stability. The combination of bone density and architectural parameters measured using CBCT can predict the implant stability more accurately than the density alone in clinical diagnoses.

Collaborative cross mice in a genetic association study reveal new candidate genes for bone microarchitecture

BackgroundThe microstructure of trabecular bone is a composite trait governed by a complex interaction of multiple genetic determinants. Identifying these genetic factors should significantly improve our ability to predict of osteoporosis and its associated risks. Genetic mapping using collaborative cross mice (CC), a genetically diverse recombinant inbred mouse reference panel, offers a powerful tool to identify causal loci at a resolution under one mega base-pairs, with a relatively small cohort size.Here, we utilized 31 CC lines (160 mice of both sexes in total) to perform genome-wide haplotype mapping across 77,808 single-nucleotide polymorphisms (SNPs). Haplotype scans were refined by imputation with the catalogue of sequence variation segregating in the CC to suggest potential candidate genes. Trabecular traits were obtained following microtomographic analysis, performed on 10-μm resolution scans of the femoral distal metaphysis. We measured the trabecular bone volume fraction (BV/TV), number (Tb.N), thickness (Tb.Th), and connectivity density (Conn.D).ResultsHeritability of these traits ranged from 0.6 to 0.7. In addition there was a significant (P < 0.01) sex effect in all traits except Tb.Th. Our haplotype scans yielded six quantitative trait loci (QTL) at 1 % false discovery rate; BV/TV and Tb.Th produced two proximal loci each, on chromosome 2 and 7, respectively, and Tb.N and Conn.D yielded one locus on chromosomes 8 and 14, respectively. We identified candidate genes with previously-reported functions in bone biology, and implicated unexpected genes whose function in bone biology has yet to be assigned. Based on the literature, among the genes that ranked particularly high in our analyses (P < 10-6) and which have a validated causal role in skeletal biology, are Avp, Oxt, B2m (associated with BV/TV), Cnot7 (with Tb.N), Pcsk6, Rgma (with Tb.Th), Rb1, and Cpb2 (with Conn.D). Other candidate genes strongly suggested by our analyses are Sgcz, Fgf20 (associated with Tb.N), and Chd2 (with Tb.Th).ConclusionWe have demonstrated for the first time genome-wide significant association between several genetic loci and trabecular microstructural parameters for genes with previously reported experimental observations, as well as proposing a role for new candidate genes with no previously characterized skeletal function.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2213-x) contains supplementary material, which is available to authorized users.

Chitosan nanofiber scaffold improves bone healing via stimulating trabecular bone production due to upregulation of the Runx2/osteocalcin/alkaline phosphatase signaling pathway.

Osteoblasts play critical roles in bone formation. Our previous study showed that chitosan nanofibers can stimulate osteoblast proliferation and maturation. This translational study used an animal model of bone defects to evaluate the effects of chitosan nanofiber scaffolds on bone healing and the possible mechanisms. In this study, we produced uniform chitosan nanofibers with fiber diameters of approximately 200 nm. A bone defect was surgically created in the proximal femurs of male C57LB/6 mice, and then the left femur was implanted with chitosan nanofiber scaffolds for 21 days and compared with the right femur, which served as a control. Histological analyses revealed that implantation of chitosan nanofiber scaffolds did not lead to hepatotoxicity or nephrotoxicity. Instead, imaging analyses by X-ray transmission and microcomputed tomography showed that implantation of chitosan nanofiber scaffolds improved bone healing compared with the control group. In parallel, microcomputed tomography and bone histomorphometric assays further demonstrated augmentation of the production of new trabecular bone in the chitosan nanofiber-treated group. Furthermore, implantation of chitosan nanofiber scaffolds led to a significant increase in the trabecular bone thickness but a reduction in the trabecular parameter factor. As to the mechanisms, analysis by confocal microscopy showed that implantation of chitosan nanofiber scaffolds increased levels of Runt-related transcription factor 2 (Runx2), a key transcription factor that regulates osteogenesis, in the bone defect sites. Successively, amounts of alkaline phosphatase and osteocalcin, two typical biomarkers that can simulate bone maturation, were augmented following implantation of chitosan nanofiber scaffolds. Taken together, this translational study showed a beneficial effect of chitosan nanofiber scaffolds on bone healing through stimulating trabecular bone production due to upregulation of Runx2-mediated alkaline phosphatase and osteocalcin gene expressions. Our results suggest the potential of chitosan nanofiber scaffolds for therapy of bone diseases, including bone defects and bone fractures.

Chronic administration of Glucagon-like peptide-1 receptor agonists improves trabecular bone mass and architecture in ovariectomised mice

Some anti-diabetic therapies can have adverse effects on bone health and increase fracture risk. In this study, we tested the skeletal effects of chronic administration of two Glucagon-like peptide-1 receptor agonists (GLP-1RA), increasingly used for type 2 diabetes treatment, in a model of osteoporosis associated bone loss and examined the expression and activation of GLP-1R in bone cells. Mice were ovariectomised (OVX) to induce bone loss and four weeks later they were treated with Liraglutide (LIR) 0.3mg/kg/day, Exenatide (Ex-4) 10μg/kg/day or saline for four weeks. Mice were injected with calcein and alizarin red prior to euthanasia, to label bone-mineralising surfaces. Tibial micro-architecture was determined by micro-CT and bone formation and resorption parameters measured by histomorphometric analysis. Serum was collected to measure calcitonin and sclerostin levels, inhibitors of bone resorption and formation, respectively. GLP-1R mRNA and protein expression were evaluated in the bone, bone marrow and bone cells using RT-PCR and immunohistochemistry. Primary osteoclasts and osteoblasts were cultured to evaluate the effect of GLP-1RA on bone resorption and formation in vitro. GLP-1RA significantly increased trabecular bone mass, connectivity and structure parameters but had no effect on cortical bone. There was no effect of GLP-1RA on bone formation in vivo but an increase in osteoclast number and osteoclast surfaces was observed with Ex-4. GLP-1R was expressed in bone marrow cells, primary osteoclasts and osteoblasts and in late osteocytic cell line. Both Ex-4 and LIR stimulated osteoclastic differentiation in vitro but slightly reduced the area resorbed per osteoclast. They had no effect on bone nodule formation in vitro. Serum calcitonin levels were increased and sclerostin levels decreased by Ex-4 but not by LIR. Thus, GLP-1RA can have beneficial effects on bone and the expression of GLP-1R in bone cells may imply that these effects are exerted directly on the tissue.

Knee joint subchondral bone structure alterations in active athletes: a cross-sectional case–control study

It has been shown that trabecular bone structure parameters extracted from radiographs known as fractal signature analysis (FSA) are able to predict structural outcomes such as radiographic osteoarthritis (OA) progression. Little is known about their involvement in early disease or about differences between subjects exposed to increased joint loading such as young active athletes compared to non-athletes. Aim was to compare horizontal and vertical dimensions of bone texture considering athlete status, gender, previous anterior cruciate ligament (ACL) surgery and age. Included were 685 patients of which 135 consecutive athletes (82% soccer players) 18-36 years old and 550 non-athletes controls in the same age range had knee radiography for assessment of subacute or chronic knee complaints. Regions of interest (ROI) were placed in the subchondral medial and lateral tibial plateaus. Fractal signatures were calculated in the horizontal and vertical dimensions. Curve fitting algorithms were applied taking into account all four risk factors in the same model adjusting for each other. For the horizontal dimensions significant differences were observed for gender (estimate (E) 0.098 (95% confidence interval(CI)) (-0.009, 0.008), P<.0001), previous ACL surgery (E-0.031, 95% CI (-0.043,-0.019), P<.0001) and highest age group (E-0.039, 95% CI (-0.048,-0.029), P<.0001). For vertical dimensions, significant differences were shown for athletes (E-0.012, 95% CI (-0.020,-0.004), P<.0001), gender (E 0.056, 95% CI (0.049, 0.062), P<.0001), and age range from 28 to 32 years (E-0.028, 95% CI (-0.037,-0.019), P<.0001). Trabecular bone structure differs between athletes and non-athletes, in regard to previous ACL surgery, gender and higher age.

Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation.

Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hibernation. The mechanisms that prevent disuse osteoporosis in bears are unclear as previous studies using histological and serum markers of bone remodeling show conflicting results. However, previous studies used serum markers of bone remodeling that are known to accumulate with decreased renal function, which bears have during hibernation. Therefore, we measured serum bone remodeling markers (BSALP and TRACP) that do not accumulate with decreased renal function, in addition to the concentrations of serum calcium and hormones involved in regulating bone remodeling in hibernating and active bears. Bone resorption and formation markers were decreased during hibernation compared with when bears were physically active, and these findings were supported by histomorphometric analyses of bone biopsies. The serum concentration of cocaine and amphetamine regulated transcript (CART), a hormone known to reduce bone resorption, was 15-fold higher during hibernation. Serum calcium concentration was unchanged between hibernation and non-hibernation seasons. Suppressed and balanced bone resorption and formation in hibernating bears contributes to energy conservation, eucalcemia and the preservation of bone mass and strength, allowing bears to survive prolonged periods of extreme environmental conditions, nutritional deprivation and anuria.

Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models.

BackgroundOsteoporosis is defined as a skeletal disorder characterized by compromised bone strength due to a reduction of bone mass and deterioration of bone microstructure predisposing an individual to an increased risk of fracture. Trabecular bone microstructure analysis and finite element models (FEM) have shown to improve the prediction of bone strength beyond bone mineral density (BMD) measurements. These computational methods have been developed and validated in specimens preserved in formalin solution or by freezing. However, little is known about the effects of preservation on trabecular bone microstructure and FEM. The purpose of this observational study was to investigate the effects of preservation on trabecular bone microstructure and FEM in human vertebrae.MethodsFour thoracic vertebrae were harvested from each of three fresh human cadavers (n = 12). Multi-detector computed tomography (MDCT) images were obtained at baseline, 3 and 6 month follow-up. In the intervals between MDCT imaging, two vertebrae from each donor were formalin-fixed and frozen, respectively. BMD, trabecular bone microstructure parameters (histomorphometry and fractal dimension), and FEM-based apparent compressive modulus (ACM) were determined in the MDCT images and validated by mechanical testing to failure of the vertebrae after 6 months.ResultsChanges of BMD, trabecular bone microstructure parameters, and FEM-based ACM in formalin-fixed and frozen vertebrae over 6 months ranged between 1.0–5.6 % and 1.3–6.1 %, respectively, and were not statistically significant (p > 0.05). BMD, trabecular bone microstructure parameters, and FEM-based ACM as assessed at baseline, 3 and 6 month follow-up correlated significantly with mechanically determined failure load (r = 0.89–0.99; p < 0.05). The correlation coefficients r were not significantly different for the two preservation methods (p > 0.05).ConclusionsFormalin fixation and freezing up to six months showed no significant effects on trabecular bone microstructure and FEM-based ACM in human vertebrae and may both be used in corresponding in-vitro experiments in the context of osteoporosis.

TBS reflects trabecular microarchitecture in premenopausal women and men with idiopathic osteoporosis and low-traumatic fractures

Transiliac bone biopsies, while widely considered to be the standard for the analysis of bone microstructure, are typically restricted to specialized centers. The benefit of Trabecular Bone Score (TBS) in addition to areal bone mineral density (aBMD) for fracture risk assessment has been documented in cross-sectional and prospective studies. The aim of this study was to test if TBS may be useful as a surrogate to histomorphometric trabecular parameters of transiliac bone biopsies. Transiliac bone biopsies from 80 female patients (median age 39.9years—interquartile range, IQR 34.7; 44.3) and 43 male patients (median age 42.7years—IQR 38.9; 49.0) with idiopathic osteoporosis and low traumatic fractures were included. Micro-computed tomography values of bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), structural model index (SMI) as well as serum bone turnover markers (BTMs) sclerostin, intact N-terminal type 1 procollagen propeptide (P1NP) and cross-linked C-telopeptide (CTX) were investigated. TBS values were higher in females (1.282 vs 1.169, p< 0.0001) with no differences in spine aBMD, whereas sclerostin levels (45.5 vs 33.4pmol/L) and aBMD values at the total hip (0.989 vs 0.971g/cm2, p<0.001 for all) were higher in males. Multiple regression models including: gender, aBMD and BTMs revealed TBS as an independent, discriminative variable with adjusted multiple R2 values of 69.1% for SMI, 79.5% for Tb.N, 68.4% for Tb.Sp, and 83.3% for BV/TV. In univariate regression models, BTMs showed statistically significant results, whereas in the multiple models only P1NP and CTX were significant for Tb.N. TBS is a practical, non-invasive, surrogate technique for the assessment of cancellous bone microarchitecture and should be implemented as an additional tool for the determination of trabecular bone properties.

Bone structure assessed by HR-pQCT, TBS and DXL in adult patients with different types of osteogenesis imperfecta.

Bone microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT) was assessed in adult patients with mild, moderate, and severe osteogenesis imperfecta (OI). The trabecular bone score (TBS), bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), and dual X-ray and laser (DXL) at the calcaneus were likewise assessed in patients with OI. Trabecular microstructure and BMD in particular were severely altered in patients with OI. OI is characterized by high fracture risk but not necessarily by low BMD. The main purpose of this study was to assess bone microarchitecture and BMD at different skeletal sites in different types of OI. HR-pQCT was performed in 30 patients with OI (mild OI-I, n = 18 (41.8 [34.7, 55.7] years) and moderate to severe OI-III-IV, n = 12 (47.6 [35.3, 58.4] years)) and 30 healthy age-matched controls. TBS, BMD by DXA at the lumbar spine and hip, as well as BMD by DXL at the calcaneus were likewise assessed in patients with OI only. At the radius, significantly lower trabecular parameters including BV/TV (p = 0.01 and p < 0.0001, respectively) and trabecular number (p < 0.0001 and p < 0.0001, respectively) as well as an increased inhomogeneity of the trabecular network (p < 0.0001 and p < 0.0001, respectively) were observed in OI-I and OI-III-IV in comparison to the control group. Similar results for trabecular parameters were found at the tibia. Microstructural parameters were worse in OI-III-IV than in OI-I. No significant differences were found in cortical thickness and cortical porosity between the three subgroups at the radius. The cortical thickness of the tibia was thinner in OI-I (p < 0.001), but not OI-III-IV, when compared to controls. Trabecular BMD and trabecular bone microstructure in particular are severely altered in patients with clinical OI-I and OI-III-IV. Low TBS and DXL and their significant associations to HR-pQCT parameters of trabecular bone support this conclusion.

Trabecular Bone Score: Where are we now?

The Trabecular Bone Score is a rather new index obtained at the lumbar spine at the same time as a real bone mineral density. It was developed to reflect bone microarchitecture. It was proposed to be easily used in everyday practice as a surrogate of bone strength. Our aim was to review 1. technical points such as correlations between Trabecular Bone Score and bone microarchitectural parameters, Trabecular Bone Score and bone strength, the effects of dual-energy X-ray absorptiometry image spatial resolution, age, macroarchitecture, body mass index, and osteoarthritis, on Trabecular Bone Score, and 2. evidences to use Trabecular Bone Score for separating individuals with fragility fractures from controls, predicting fragility fractures, and for longitudinally monitoring changes related to treatments. Correlations between Trabecular Bone Score and bone microarchitectural parameters vary widely across bone sites, microarchitectural parameters, and study designs. In vivo, the Trabecular Bone Score explains little of the variance in trabecular microarchitectural parameters. We emphasize that it is a texture parameter. The Trabecular Bone Score is reduced in patients with fragility fracture. Several retrospective and prospective studies have shown its discriminative ability regarding the fracture risk. When combining the areal Bone mineral Density and Trabecular Bone Score, the Trabecular Bone Score remains a predictor of fracture but not the areal Bone Mineral Density. However in prospective studies, the best predictor of fracture remains hip areal bone mineral density. Due to the lack of evidence, we recommend not to use Trabecular Bone Score for following patients treated by anti-osteoporotic drugs.

Ischemic heart disease is associated with lower cortical volumetric bone mineral density of distal radius.

In this study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was used to investigate geometric, volumetric and microstructural parameters at the distal radius and at the distal tibia in participants with ischaemic heart disease. We found that, compared with participants without ischaemic heart disease, they had substantially lower cortical volumetric bone mineral density (BMD) at the distal radius. HR-pQCT captures novel aspects of bone geometry and volumetric bone mineral density (vBMD) and offers the ability to measure bone microarchitecture, but data relating measures obtained from this technique in patients with ischemic heart disease (IHD) are lacking. Here, we report an analysis from the Hertfordshire Cohort Study, where we were able to study associations between measures obtained from HR-pQCT of distal radius and distal tibia in 350 participants (184 men and 166 women) aged 71.5-80.5years with or without IHD (e.g. heart attack, angina or heart failure; n = 75 and n = 275, respectively). Analyses for all participants (men and women together) revealed that cortical vBMD (Ct.vBMD) was lower (p < 0.001) and cortical thickness (Ct.th) was not different (p = 0.519), whereas cortical porosity (Ct.Po) was higher (p = 0.016) in participants with IHD at the distal radius. Moreover, trabecular microarchitectural parameters were not significantly different in patients with IHD (p > 0.05 for all). Adjustment for a priori confounders (age, gender, body mass index, smoking status, alcohol consumption, high blood pressure and diabetes mellitus) did not materially affect the relationship described for Ct.vBMD (p = 0.002), but differences in Ct.Po were attenuated. Analyses in men alone revealed that only Ct.vBMD was lower at the distal radius in participants with IHD with and without adjustment for a priori confounders (p = 0.0002 and p = 0.004, respectively), whereas no statistical differences were found in women, although patterns of differences were similar in both sexes. Moreover, no association was found between IHD and bone parameters at the distal tibia either in men or women. We have demonstrated that IHD is associated with lower Ct.vBMD of the distal radius.

Regional Variations in Trabecular Morphological Features of Femoral Head of Patients with Proximal Femoral Fractures

The regional microstructural variations in femoral head from proximal femoral fracture patients were investigated. Micro-CT scanning was performed on seven femoral heads from proximal femoral fracture patients. Each femoral head was divided into three regions according to the trabecular orientation from the fovea of femoral head to the femoral neck. Eight three-dimensional trabecular cube models were reconstructed from each region. A total of 154 trabecular cubic models were reconstructed because the corresponding areas for 14 cubic models were damaged during the surgeries. Eight trabecular morphological parameters were measured and analyzed, namely, trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), specific bone surface (BS/BV), bone volume fraction (BV/TV), structural model index (SMI), degree of anisotropy (DA), trabecular pattern factor (Tb.Pf), and trabecular number (Tb.N). Bivariate correlation analyses were performed for all morphological parameters. One-way ANOVA tests were performed to analyze the differences of each parameter among three regions. Post-hoc multiple comparisons (Student-Newman-Keuls method) were performed to analyze the morphological difference between two regions. Trabecular bone of proximal femoral fracture patients significantly degenerated in all regions of femoral heads. BV/TV was statistically correlated with Tb.Th, Tb.Sp, BS/BV, Tb.Pf, and Tb.N (p < 0.05). Statistical differences in morphological parameters were observed between regions (p < 0.05). The trabecular strength in the middle regions was significantly higher than that in other regions because of the relationships between morphological parameters and mechanical parameters. Trabeculae in the medial region were more uniform and stable along each direction than those in the lateral region. Most trabeculae in the lateral region only grew along the weight-bearing direction, and those along the other directions degenerated significantly. This study provides detailed trabecular morphological information on fractured femoral heads, as well as references for the prevention of high fracture risk in the elderly.

MicroCT-based evaluation of the trabecular bone quality of different implant anchorage sites for masticatory rehabilitation of the maxilla

In the severely atrophied maxilla, implant anchorage in the zygomatic bone is considered a viable alternative to conventional dental implants with preceding bone augmentation procedures. The present microCT-based study compared the trabecular bone quality of the maxilla and zygomatic bone. MicroCT scanning was conducted in 12 halves of cadaver heads (5 male, 7 female) with edentulous, atrophied maxillae. Relevant trabecular bone quality parameters were determined in the anterior and posterior maxilla and in the zygomatic bone and compared by region and sex. Any difference in mean values between the anterior maxilla and the zygomatic bone was insignificant. Comparison of both with the posterior maxilla presented significantly higher values for bone volume fraction, surface density, and trabecular thickness and number, and significantly lower values for specific bone surface, structure model index, and trabecular separation. A significant sex-specific difference was not detected. The present microCT-based analysis is, to the best of our knowledge, the first intra-individual comparison of different implant anchorage sites for masticatory rehabilitation of the maxilla. The trabecular compartment of the zygomatic bone offered bone quality and, thus, an implant bed comparable with those of the anterior maxilla, and both were superior to the posterior maxilla.

Tissue level microstructure and mechanical properties of the femoral head in the proximal femur of fracture patients

This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head, as well as to determine the relationship between trabecular morphological and mechanical parameters. Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system. Each femoral head was divided into 12 sub-regions according to the trabecular orientation. One $$125\,\hbox {mm}^{3}$$ trabecular cubic model was reconstructed from each sub-region. A total of 81 trabecular models were reconstructed, except three destroyed sub-regions from two femoral heads during the surgery. Trabecular morphological parameters, i.e. trabecular separation (Tb.Sp), trabecular thickness (Tb.Th), specific bone surface (BS/BV), bone volume fraction (BV/TV), structural model index (SMI), and degree of anisotropy (DA) were measured. Micro-finite element analyses were performed for each cube to obtain the apparent Young’s modulus and tissue level von Mises stress distribution under 1 % compressive strain along three orthogonal directions, respectively. Results revealed significant regional variations in the morphological parameters ( $$P < 0.05$$ ). Young’s moduli along the trabecular orientation were significantly higher than those along the other two directions. In general, trabecular mechanical properties in the medial region were lower than those in the lateral region. Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV, BV/TV, Tb.Th, and DA. In this study, regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level. The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly. Bone blocks were reconstructed from micro-CT images of proximal femoral fracture patients. Apparent Young’s modulus and average stress of cancellous bone along three orthogonal directions were calculated by FEA. There were significant differences in mechanical properties between different regions and between different directions.

Hemoglobin is Positively Associated with Bone Strength in Young Adults Entering the Military

Stress fracture incidence is high during initial military training (IMT) with 2-6% of male and 8-21% of female recruits sustaining fractures. Identification and mitigation of risk factors is critical in efforts to preserve the health of military trainees and decrease injury costs. Prior reports indicate that iron deficiency anemia (IDA) is a risk factor for stress fracture in military recruits. The current study aimed to determine whether hemoglobin (Hgb), the iron-containing oxygen transport protein, was associated with bone strength in young adults entering the military. Bone density, geometry, and strength were measured using peripheral quantitative computed tomography at the 4, 14, and 66% tibia sites , and fasted blood samples collected in 165 (n=90 female [Age = 21.4 ± 2.6 y; BMI=23.9 ± 2.7], n=75 male [Age=20.0 ± 2.6 y, BMI=25.1 ± 3.3]) recruits prior to IMT. Hgb was not associated with any trabecular bone parameter including bone strength at the 4% site (r=0.11, p=0.19). However, Hgb was positively correlated with cortical content (r=0.17, p=0.04) at the 14% site and polar stress-strain index, a surrogate measure of bone strength, at the 66% site (r=0.17, p=0.05) even when controlling for sex and body weight. These findings support a potential role of iron status in cortical bone health suggesting it may be involved in suppression of bone resorption or promotion of bone formation, and provides the basis for future research exploring the effects of iron on bone metabolism in young adults. Research supported by: ORISE and USAMRMC.

Thymoquinone Attenuates Ovariectomy Induced Alteration in Bone Architecture and Metabolism in Rats

Thymoquinone (THQ) reported to have beneficial effects on bone disorders. Thus the present study was designed to investigate its protective effects on experimentally-induced osteoporosisin ovariectomized (OVX) rats. The OVX rats were treated with different doses (2.5, 5 and 10 mg/kg/day) of THQ for ten weeks. Bone turnover biomarkers and inflammatory cytokines were determined using ELISA techniques. Changes in bones cortical and trabecular morphometric parameters were determined using micro-CT scan. Body weights and abdominal fats were significantly increased in OVX rats while the uterus and femoral bone weights were markedly inhibited in OVX rats. Estrogen deficiency elevated the level of bone turnover biomarkers as well as inflammatory cytokines in serum. Moreover, cortical and trabecular morphometric parameters of the femoral bones were severely altered by ovariectomy operation.THQ treatments inhibited the increased bone turnover biomarkers and inflammatory cytokines in dose dependent manner. The altered morphometric parameters of the femoral bones were also markedly attenuated by THQ. Present data revealed that THQ has osteoprotective properties may be due to its ability to inhibit osteoclastogenesis inducing factors and inflammation, which stabilize the osteoclasts and decreased their bone matrix's degradation or resorption. We believe that this effect may be through its both the anti-inflammatory and antioxidant properties.