Fracture discrimination by combined bone mineral density (BMD) and microarchitectural texture analysis

Preoperative Prediction of New Vertebral Fractures after Vertebral Augmentation with a Radiomics Nomogram

The occurrence of new vertebral fractures (NVFs) after vertebral augmentation (VA) procedures is common in patients with osteoporotic vertebral compression fractures (OVCFs), leading to painful experiences and financial burdens. We aim to develop a radiomics nomogram for the preoperative prediction of NVFs after VA. Data from center 1 (training set: n = 153; internal validation set: n = 66) and center 2 (external validation set: n = 44) were retrospectively collected. Radiomics features were extracted from MRI images and radiomics scores (radscores) were constructed for each level-specific vertebra based on least absolute shrinkage and selection operator (LASSO). The radiomics nomogram, integrating radiomics signature with presence of intravertebral cleft and number of previous vertebral fractures, was developed by multivariable logistic regression analysis. The predictive performance of the vertebrae was level-specific based on radscores and was generally superior to clinical variables. RadscoreL2 had the optimal discrimination (AUC ≥ 0.751). The nomogram provided good predictive performance (AUC ≥ 0.834), favorable calibration, and large clinical net benefits in each set. It was used successfully to categorize patients into high- or low-risk subgroups. As a noninvasive preoperative prediction tool, the MRI-based radiomics nomogram holds great promise for individualized prediction of NVFs following VA.

Spine Fragility Fracture Prediction Using TBS and BMD in Postmenopausal Women: A Bayesian Approach

The trabecular bone score (TBS) estimates bone microarchitecture and can be used to evaluate the risk of osteoporotic fractures independently of bone mineral density (BMD). In this retrospective case-control study, we tested and compared the ability of TBS and lumbar spine BMD (LS-BMD) to predict vertebral fragility fractures. The inclusion criteria were female sex, age range 50-90 years, menopause, and clinical risk factors for osteoporosis. Patients with secondary osteoporosis were excluded. LS-BMD and TBS were measured at the L1-L4 vertebral level. The ability of the two diagnostic systems in predicting vertebral fragility fractures was assessed by combining LS-BMD and TBS according to the Bayesian "OR rule" (the diagnosis is negative only for those negative for both tests, and it is positive for those who were positive for at least one test) or to the "AND rule" (the diagnosis is positive only for those positive to both tests and is negative for those negative for at least one test). Of the 992 postmenopausal women included, 86 had a documented vertebral fragility fracture. At the cutoff value used in the present study, the TBS and LS-BMD showed a similar diagnostic ability to predict vertebral fragility fractures, having positive predictive values (PPV) of, respectively, 13.19% and 13.24%. Negative predictive values (NPV) were, respectively, 95.40% and 94.95%. Compared to that of each single diagnostic system, the "OR-rule" significantly increased the NPV to 97.89%, while no statistically significant differences were found by using the "AND-rule". In conclusion, the present study highlights the possibility that combining LS-BMD and TBS could improve their predictive ability in diagnosing vertebral fragility fractures, and that there is a significant probability of absence of fractures in women who test negative to both diagnostic systems.

Effect of Romosozumab on Trabecular Bone Score Compared to Anti-Resorptive Agents in Postmenopausal Women with Osteoporosis

BACKGROUND

Romosozumab has shown significant improvement in bone mineral density (BMD) in previously reported trials. However, BMD reflects only bone strength and does not offer insight into the bone microarchitecture. The trabecular bone score (TBS) is a non-invasive tool used to assess bone microarchitecture. Several previous studies have evaluated the efficacy of anti-osteoporotic agents using the TBS. However, data regarding the potency of romosozumab based on the TBS is lacking. This retrospective observational cohort study demonstrated the impact of romosozumab use on the TBS.

METHODS

The primary outcome was the percentage change in the TBS from baseline to post-treatment. Postmenopausal osteoporosis patients were followed up for 6 and 12 months after romosozumab (210 mg monthly, N =10) and denosumab (60 mg every 6 months, N=21) or ibandronate (150 mg monthly, N=24) treatments, respectively. Patients who had previously used osteoporosis medications were included, if any the washout period was sufficient.

RESULTS

The percentage change in TBS from baseline to post-treatment was 2.53±2.98% (6 months, N=10; P=0.04), 0.59%±3.26% (12 months, N=21; P=0.48), and -0.45±3.66% (12 months, N=24; P=0.51) in the romosozumab, denosumab, and ibandronate groups, respectively. Romosozumab demonstrated a noticeable increase in TBS, although it did not reach the least significant change (5.8%) in TBS.

CONCLUSIONS

Romosozumab improved the TBS in postmenopausal women with osteoporosis. TBS may be potentially useful for monitoring romosozumab treatment.

Automated bone mineral density prediction and fracture risk assessment using plain radiographs via deep learning

Dual-energy X-ray absorptiometry (DXA) is underutilized to measure bone mineral density (BMD) and evaluate fracture risk. We present an automated tool to identify fractures, predict BMD, and evaluate fracture risk using plain radiographs. The tool performance is evaluated on 5164 and 18175 patients with pelvis/lumbar spine radiographs and Hologic DXA. The model is well calibrated with minimal bias in the hip (slope = 0.982, calibration-in-the-large = -0.003) and the lumbar spine BMD (slope = 0.978, calibration-in-the-large = 0.003). The area under the precision-recall curve and accuracy are 0.89 and 91.7% for hip osteoporosis, 0.89 and 86.2% for spine osteoporosis, 0.83 and 95.0% for high 10-year major fracture risk, and 0.96 and 90.0% for high hip fracture risk. The tool classifies 5206 (84.8%) patients with 95% positive or negative predictive value for osteoporosis, compared to 3008 DXA conducted at the same study period. This automated tool may help identify high-risk patients for osteoporosis.

Discriminative ability of trabecular bone score over bone mineral density for vertebral and fragility fracture in patients treated with long-term and low-dose glucocorticoid

AIM

To evaluate the ability of the trabecular bone score (TBS) to discriminate vertebral fracture (VF) and fragility fracture (FF) in patients with chronic inflammatory rheumatic diseases on long-term and low-dose glucocorticoid (GC) treatment and those without exposure to GC.

METHODS

This study assessed TBS and bone mineral density (BMD) in chronic GC users, defined as ≥2.5 mg/d of prednisone for >3 months (n = 89, mean age: 62.5 ± 11 years), and in controls (n = 59, mean age: 60.3 ± 9.6 years). Osteoporosis risk factors, radiographs of the thoracolumbar spine, non-VF history, osteoporosis drugs, and current/cumulative GC doses were collected. Patients were classified as high (TBS <1.23), intermediate (1.23-1.31), or low risk (>1.31), according to the fracture risk based on a recent meta-analysis.

RESULTS

The mean current dose and duration of GC treatment were 3.9 ± 1.9 mg/d and 3.9 ± 4.2 years, respectively. The prevalence of VF was significantly higher in chronic GC users than in controls (20.2% vs 5.1%, P = .010), although the prevalence of non-VF was similar (11.2% vs 5.1%). The GC group had significantly lower L1-L4 TBS and femur total BMD than did the controls (all with P < .01) without significantly different lumbar BMD. TBS (<1.31) showed a higher sensitivity for patients with VF and FF (83.3% and 81.8%, respectively) than with densitometric osteoporosis in the GC group (61.1% and 59.1%, respectively). Using the receiver operating characteristic curve, TBS <1.31 showed better diagnostic accuracy than TBS <1.23 and BMD in chronic GC users.

CONCLUSION

TBS is more sensitive than BMD in detecting VF and FF in chronic GC users, even at a lower dose.

Giant cells and osteoclasts present in bone grafted with nacre differ by nuclear cytometry evaluated by texture analysis

Nacre (mother of pearl) is a natural biomaterial used to prepare orthopedic devices. We have implanted screws and plates made with nacre in five sheeps. Bone were harvested after two months and embedded in poly(methyl methacrylate). Blocks were saws and the thick slabs were grinded, polished and surface stained. Sections were photographed at an ×1000 magnification. Giant cells were found in contact with nacre in eroded areas and true osteoclasts were found at distance in the neighboring bone in Howship lacunae. A texture analysis of the nuclei of giant cells and osteoclasts was done using the run-length method of the MaZda freeware. The size of the nuclei was reduced in osteoclast and their mean gray level appeared reduced. Texture analysis revealed that chromatin had a completely different pattern in giant cells when compared to osteoclasts. Giant cells had a fine repartition of the chromatin with large clear areas around prominent nucleoli. On the contrary, osteoclast nuclei had chromatin blocks evenly dispersed in the nuclei. This reflects the different origin of these cells expressing different functions.

Current and Emerging Diagnostic Imaging-Based Techniques for Assessment of Osteoporosis and Fracture Risk

Osteoporosis is a metabolic bone disorder characterized by low bone mass, degradation of bone microarchitecture, and susceptibility to fracture. It is a growing major health concern across the world, especially in the elderly population. Osteoporosis can cause hip or spinal fractures that may lead to high morbidity and socio-economic burden. Therefore, there is a need for early diagnosis of osteoporosis and prediction of fragility fracture risk. In this review, state of the art and recent advances in imaging techniques for diagnosis of osteoporosis and fracture risk assessment have been explored. Segmentation methods used to segment the regions of interest and texture analysis methods used for classification of healthy and osteoporotic subjects are also presented. Furthermore, challenges posed by the current diagnostic tools have been studied and feasible solutions to circumvent the limitations are discussed. Early diagnosis of osteoporosis and prediction of fracture risk require the development of highly precise and accurate low-cost diagnostic techniques that would help the elderly population in low economies.

The QUALYOR (QUalité Osseuse LYon Orléans) study: a new cohort for non invasive evaluation of bone quality in postmenopausal osteoporosis. Rationale and study design

The diagnostic performance of densitometry is inadequate. New techniques of non-invasive evaluation of bone quality may improve fracture risk prediction. Testing the value of these techniques is the goal of the QUALYOR cohort.

INTRODUCTION

The bone mineral density (BMD) of postmenopausal women who sustain osteoporotic fracture is generally above the World Health Organization definition for osteoporosis. Therefore, new approaches to improve the detection of women at high risk for fracture are warranted.

METHODS

We have designed and recruited a new cohort to assess the predictive value of several techniques to assess bone quality, including high-resolution peripheral quantitative computerized tomography (HRpQCT), hip QCT, calcaneus texture analysis, and biochemical markers. We have enrolled 1575 postmenopausal women, aged at least 50, with an areal BMD femoral neck or lumbar spine T-score between - 1.0 and - 3.0. Clinical risk factors for fracture have been collected along with serum and blood samples.

RESULTS

We describe the design of the QUALYOR study. Among these 1575 women, 80% were aged at least 60. The mean femoral neck T-score was - 1.6 and the mean lumbar spine T-score was -1.2. This cohort is currently being followed up.

CONCLUSIONS

QUALYOR will provide important information on the relationship between bone quality variables and fracture risk in women with moderately decreased BMD.

Comparisons of TBS and lumbar spine BMD in the associations with vertebral fractures according to the T-scores: A cross-sectional observation

Trabecular bone score (TBS) is a parameter of bone quality that has been shown to be related to vertebral fractures. This study aimed to analyze the difference in discriminatory power of TBS for vertebral fractures according to the bone mineral density (BMD) T-score. Areal BMD at the lumbar spine (LS, L1-L4), femur neck (FN) and total hip were assessed using dual x-ray absorptiometry (Discovery W, Hologic, Bedford, MA) in 929 women aged 50years or older. TBS was analyzed using iNsight software (Med-Imaps, Pessac, France). Vertebral fractures were identified on lateral X-ray films of the thoracic and lumbar spine using a semi-quantitative method. The study subjects consisted of 158 subjects (17.0%) with normal BMD, 461 (49.6%) with osteopenia and 310 (33.4%) with osteoporosis. The incident vertebral fractures were observed in 92 (9.9%) subjects, including 59 fractures in osteoporosis, 29 fractures in osteopenia, and only 4 fractures in normal BMD. We stratified study subjects into two groups according to their BMD T-scores, osteoporosis or osteopenia/normal BMD. The logistic regression model showed that LS BMD values per each 1 standard deviation (SD) decrease were significantly associated with increased risk of vertebral fracture in both osteoporosis and osteopenia/normal BMD group with stronger association in osteoporosis group. However, a TBS value that was lower by 1SD was significantly associated with vertebral fracture risk only in the osteopenia/normal BMD group. The TBS use in addition to FN BMD and age also showed significantly better discriminatory power for vertebral fracture only in the osteopenia/normal BMD group, but not osteoporosis group. In conclusion, TBS is significantly associated with vertebral fractures in subjects with osteopenia/normal BMD levels. Additional assessment of bone microarchitecture using TBS is better able to identify women at risk of fracture, in particular, those with relatively higher BMD.

Utility of trabecular bone score in the evaluation of osteoporosis

PURPOSE OF REVIEW

Trabecular bone score (TBS) is a lumbar spine dual-energy absorptiometry texture index which provides information on skeletal quality partially independent of bone mineral density (BMD). A body of work has emerged demonstrating the relationship between TBS and fracture risk, with lower TBS values associated with increased risk for osteoporotic fracture in postmenopausal women and older men. TBS is derived from standard DXA images; however, the information provided by TBS is complementary to that provided by BMD. In this article, we review the current state of TBS and its evolving role in the assessment and management of osteoporosis, with particular emphasis on the literature of the previous year.

RECENT FINDINGS

TBS-adjusted The Fracture Risk Assessment tool (FRAX) probabilities enhance fracture risk prediction compared with conventional FRAX predictions. TBS has been found to better categorize fracture risk and assists in FRAX-based treatment decisions, particularly for patients close to an intervention threshold. However, change in lumbar spine TBS while undergoing antiresorptive treatment is not a useful indicator of antifracture effect.

SUMMARY

Lumbar spine TBS is a recently developed image-based software technique for skeletal assessment, complementary to conventional BMD, which has been shown to be clinically useful as a fracture risk prediction tool.

Effects of Teriparatide, Denosumab, or Both on Spine Trabecular Microarchitecture in DATA-Switch: a Randomized Controlled Trial

In postmenopausal women, 2 yr of combined teriparatide and denosumab increases bone mineral density more than either drug alone, and switching from either combination or teriparatide to denosumab for an additional 2 yr further increases bone mineral density. Conversely, switching from denosumab to teriparatide results in transient bone loss. The effects of these interventions on spine microarchitecture are unknown. In the DATA and DATA-Switch studies, 94 postmenopausal osteoporotic women were randomized to receive 24 mo of teriparatide (20 µg daily), denosumab (60 mg every 6 mo), or both. Then, women originally assigned to 24 mo of teriparatide received 24 mo of denosumab, whereas subjects originally randomized to 24 mo of denosumab received 24 mo of teriparatide. Subjects who received both drugs received an additional 24 mo of denosumab alone. Spine trabecular bone score (TBS, a gray-level textural assessment of bone microarchitecture) was measured blinded from treatment groups using images from 2-dimensional dual-energy X-ray absorptiometry spine scans at 0, 12, 24, 30, 36, and 48 mo in 65 women who had posterior-anterior spine dual-energy X-ray absorptiometry images suitable for TBS analysis. After 24 mo, TBS increased by 2.7 ± 4.7% in the teriparatide group (p = 0.009 vs baseline), by 1.8 ± 5.0% in the denosumab group (p = 0.118 vs baseline), and by 4.5 ± 6.7% in the combination group (p = 0.017 vs baseline), with no significant between-group differences. In the 6 mo after the treatments were switched (months 24-30), TBS continued to increase in the combination-to-denosumab and teriparatide-to-denosumab groups but decreased by -1.1 ± 4.0% in the denosumab-to-teriparatide group (p < 0.05 vs other groups). After 48 mo, compared to month 0, TBS increased by 5.1 ± 5.8% in the teriparatide-to-denosumab group, by 3.6 ± 4.2% in the denosumab-to-teriparatide group, and by 6.1 ± 4.7% in the combination-to-denosumab group (p < 0.001 vs baseline for all groups, p = not significant for between-group differences). Switching from teriparatide to denosumab also increased spine TBS. Conversely, switching from denosumab to teriparatide transiently degraded spine trabecular microarchitecture, the clinical consequences of which require further study.

Effect of denosumab on trabecular bone score in postmenopausal women with osteoporosis

Trabecular bone score (TBS) assesses bone quality in the lumbar spine using dual-energy X-ray absorptiometry (DXA) scans. In postmenopausal women with osteoporosis, denosumab significantly improved TBS independently of bone mineral density (BMD). This practical technique may have a role in managing patients with osteoporosis.

INTRODUCTION

TBS, a gray-level texture index determined from lumbar spine DXA scans, correlates with bone microarchitecture and enhances assessment of vertebral fracture risk independently of BMD. In the FREEDOM study, denosumab increased BMD and reduced new vertebral fractures in postmenopausal women with osteoporosis. This retrospective analysis explored the effect of denosumab on TBS and the association between TBS and BMD in FREEDOM.

METHODS

Postmenopausal women with lumbar spine or total hip BMD T-score <-2.5 and -4.0 or higher at both sites received placebo or denosumab 60 mg subcutaneously every 6 months. TBS indices were determined from DXA scans at baseline and months 12, 24, and 36 in a subset of 285 women (128 placebo, 157 denosumab) who had TBS values at baseline and ≥1 postbaseline visit.

RESULTS

Baseline characteristics were comparable between treatment groups; mean (SD) lumbar spine BMD T-score was -2.79 (0.64), and mean (standard deviation [SD]) TBS was 1.200 (0.101) overall. In the placebo group, BMD and TBS increased by ≤0.2% or decreased from baseline at each visit. In the denosumab group, progressive increases from baseline at 12, 24, and 36 months were observed for BMD (5.7, 7.8, and 9.8%) and TBS (1.4, 1.9, and 2.4%). Percentage changes in TBS were statistically significant compared with baseline (p < 0.001) and placebo (p ≤ 0.014). TBS was largely unrelated to BMD, regardless of treatment, either at baseline or for annual changes from baseline (all r ² ≤ 0.06).

CONCLUSIONS

In postmenopausal women with osteoporosis, denosumab significantly improved TBS independently of BMD.

Glycemic control protects against trabecular bone microarchitectural damage in a juvenile male rat model of streptozotocin-induced diabetes

PURPOSE

To determine which features of the bone microarchitecture are affected by established diabetes mellitus (DM) and the effectiveness of glycemic control in the protection of bone tissue.

MATERIAL AND METHODS

Sixty juvenile Wistar male rats were divided into three groups of 20 animals: a control group (C) that included healthy animals, a diabetic group (D) that included animals with induced diabetes, and a controlled diabetic group (CD) that included animals with induced diabetes that were treated with insulin. The animals were euthanized at the periods of 6 and 8 weeks after the induction of diabetes (10 animals per group/period). Vertebral L4 specimens were submitted to μCT analysis to assess the following parameters of the bone microarchitecture: bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular spacing (Tb.Sp).

RESULTS

The D group exhibited lower values of BV/TV (%) and numbers of trabeculae compared with the C group at 6 and 8 weeks and compared with the CD group at 8 weeks. The CD group exhibited higher trabecular thickness values compared with the D group at 8 weeks. There were no differences between the groups regarding the spaces between the trabeculae.

CONCLUSION

Induced diabetes affected the microarchitecture of the trabecular bone of the vertebrae by reducing the values of the majority of the parameters in relation to those of the control group. Glycemic control with insulin appears to protect bones from the effects of the hyperglycemia.

Clinical Utility of Using Lumbar Spine Trabecular Bone Score to Adjust Fracture Probability: The Manitoba BMD Cohort

Decreased lumbar spine trabecular bone score (TBS), a dual-energy X-ray absorptiometry (DXA)-derived image texture measurement, is a risk factor for major osteoporotic fracture (MOF) and hip fracture (HF) independent of 10-year fracture probability estimated using FRAX. We determined how often applying the TBS adjustment to fracture probability altered treatment qualification. Using a population-based registry containing all clinical DXA results for Manitoba, Canada, we identified 34,316 women with baseline spine and hip DXA, FRAX-based fracture probability measurements (computed with femoral neck bone mineral density), lumbar spine TBS, and minimum 5 years of observation (mean 8.7 years). Population-based health services data were used to identify incident non-traumatic MOF and HF in 3503 and 945 women, respectively. Baseline MOF and HF probabilities were estimated using FRAX before and after applying the TBS adjustment. Risk recategorization was assessed using net reclassification improvement (NRI) for individual FRAX-based intervention criteria and three national clinical practice guidelines (CPGs) (US National Osteoporosis Foundation, Osteoporosis Canada, and UK National Osteoporosis Guideline Group). Overall, proportions of women reclassified with the TBS adjustment to FRAX were small (less than 5%) with more than 90% of the reclassification occurring close to the intervention threshold. For women close to an intervention cut-off reclassification, rates ranged from 9.0% to 17.9% and were <1% otherwise. There was a small but significant improvement in overall NRI for all individual FRAX-based intervention criteria (range 0.007 to 0.018) and all three national CPGs (range 0.008 to 0.011). NRI was larger in women below age 65 years (up to 0.056 for hip fracture). In summary, a small but significant improvement in MOF and HF risk assessment was found by using lumbar spine TBS to adjust FRAX probability. An improvement in risk reclassification was observed for CPGs from three different countries, with almost all of the benefit found in individuals close to an intervention threshold. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

Trabecular Bone Score: A New DXA-Derived Measurement for Fracture Risk Assessment

Trabecular bone score (TBS) is a novel method that assesses skeletal texture from spine dual-energy X-ray absorptiometry (DXA) images. TBS improves fracture-risk prediction beyond that provided by DXA bone mineral density (BMD) and clinical risk factors, and can be incorporated to the Word Health Organization Fracture Risk Assessment tool (FRAX®) to enhance fracture prediction. There is insufficient evidence that TBS can be used to monitor treatment with bisphosphonates. TBS may be particularly helpful to assess fracture risk in diabetes. This article reviews technical and clinical aspects of TBS and its potential utility as a clinical tool to predict fracture risk.

Assessment of trabecular bone score (TBS) in overweight/obese men: effect of metabolic and anthropometric factors

The "trabecular bone score" (TBS) indirectly explores bone quality, independently of bone mineral density (BMD). We investigated the effects of anthropometric and metabolic parameters on TBS in 87 overweight/obese men. We assessed BMD and TBS by DXA, and some parameters of glucose metabolism, sex-and calciotropic hormone levels. Regression models were adjusted for either age and BMI, or age and waist circumference, or age and waist/hip ratio, also considering BMI >35 (y/n) and metabolic syndrome (MS) (y/n). Correlations between TBS and parameters studied were higher when correcting for waist circumference, although not significant in subjects with BMI >35. The analysis of covariance showed that the same model always had a higher adjusted r-square index. BMD at lumbar spine and total hip, fasting glucose, bioavailable testosterone, and sex hormone-binding globulin are the only covariates having a significant effect (p < 0.05) on the variations of TBS. The presence of MS negatively affected only the association between TBS and BMD at total hip. We did not find any significant effect of BMI >35 on TBS values or significant interaction terms between each covariate and either BMI >35 or the presence of MS. Obesity negatively affected TBS, despite unchanged BMD. Alterations of glucose homeostasis and sex hormone levels seem to influence this relationship, while calciotropic hormones have no role. The effect of waist circumference on TBS is more pronounced than that of BMI.

Fractional Brownian Motion and Rao Geodesic Distance for Bone X-Ray Image Characterization

Osteoporosis diagnosis has attracted particular attention in recent decades. Textured images from the microarchitecture of osteoporotic and healthy subjects show a high degree of similarity, increasing the difficulty of classifying such textures. Thus, the evaluation of osteoporosis from the bone X-ray images presents a major challenge for pattern recognition and medical applications. The purpose of this paper is to use the fractional Brownian motion (fBm) model and the probability density function of its increments to compute a similarity measure with the Rao geodesic distance to classify trabecular bone X-ray images. When evaluated on synthetic fBm images (test vectors) with the well-known Hurst parameter H, the proposed method met our expectations in which a good classification of the synthetic images was achieved. A clinical study was conducted on textured bone X-ray images from two different female populations of osteoporotic patients (fracture cases) and control subjects. Using the proposed method, an area under curve rate of 97% was achieved.

Densitometric evaluation of bone remodelling around Trabecular Metal Primary stem: a 24-month follow-up

BACKGROUND

Today, an increasing number of total hip arthroplasty (THA) procedures are being performed. Osseointegration is a physiological phenomenon that leads to the direct anchorage of an implant by the formation of bony tissue around the implant without the growth of fibrous tissue at the bone-implant interface. Several factors may affect this phenomenon: some of these depend on the patient and others may depend on implant design and materials. Variations in periprosthetic bone mineral density (BMD) can be studied through several scans by dual energy X-ray absorptiometry (DEXA) around the femoral stem.

AIMS

The purpose of this study is to investigate correlations between periprosthetic BMD and the factors affecting osseointegration.

METHODS

We retrospectively analysed patients who underwent primary THA. In all the patients, Trabecular Metal Primary (TMP), a standard uncemented tapered stem with a proximal porous tantalum coating, was implanted. Preoperatively, postoperatively, 3 and 6 months, 1 year and 2 years after implantation, DEXA scans were performed around the femoral stem. The patients were matched for diagnosis, sex, BMD of the lumbar spine and contralateral femur, Body Mass Index and age.

RESULTS

One hundred and eight patients (51 males and 57 females) with a mean age of 73 years were studied. Different BMD changing patterns were observed and a greater bone resorption was noted in all the conditions associated with poor bone quality.

DISCUSSION

The proximal coating of Trabecular Metal Primary (TMP) seemed to be effective in promoting new bone formation in the proximal femur also in the conditions associated with poor bone quality.

CONCLUSIONS

At the present time, DEXA is considered the most reliable tool for evaluating bone remodelling after THA.

Trabecular bone score (TBS) as a new complementary approach for osteoporosis evaluation in clinical practice

Trabecular bone score (TBS) is a recently-developed analytical tool that performs novel grey-level texture measurements on lumbar spine dual X-ray absorptiometry (DXA) images, and thereby captures information relating to trabecular microarchitecture. In order for TBS to usefully add to bone mineral density (BMD) and clinical risk factors in osteoporosis risk stratification, it must be independently associated with fracture risk, readily obtainable, and ideally, present a risk which is amenable to osteoporosis treatment. This paper summarizes a review of the scientific literature performed by a Working Group of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis. Low TBS is consistently associated with an increase in both prevalent and incident fractures that is partly independent of both clinical risk factors and areal BMD (aBMD) at the lumbar spine and proximal femur. More recently, TBS has been shown to have predictive value for fracture independent of fracture probabilities using the FRAX® algorithm. Although TBS changes with osteoporosis treatment, the magnitude is less than that of aBMD of the spine, and it is not clear how change in TBS relates to fracture risk reduction. TBS may also have a role in the assessment of fracture risk in some causes of secondary osteoporosis (e.g., diabetes, hyperparathyroidism and glucocorticoid-induced osteoporosis). In conclusion, there is a role for TBS in fracture risk assessment in combination with both aBMD and FRAX.

B vitamins, homocysteine and bone health

Nutrition is one of the most important modifiable factors involved in the development and maintenance of good bone health. Calcium and Vitamin D have confirmed and established roles in the maintenance of proper bone health. However, other nutritional factors could also be implicated. This review will explore the emerging evidence of the supporting role of certain B Vitamins as modifiable factors associated with bone health. Individuals with high levels of homocysteine (hcy) exhibit reduced bone mineral density (BMD), alteration in microarchitecture and increased bone fragility. The pathophysiology caused by high serum homocysteine is not completely clear regarding fractures, but it may involve factors, such as bone mineral density, bone turnover, bone blood flow and collagen cross-linking. It is uncertain whether supplementation with B Vitamins, such as folate, Vitamin B1, and Vitamin B6, could decrease hip fracture incidence, but the results of further clinical trials should be awaited before a conclusion is drawn.