Probabilistic Fracture Research Articles

Predicting the probability of osteoporotic fracture risk in men versus women: do we need specific reference interventional thresholds for men?

BackgroundGender differences in the diagnosis and treatment of osteoporosis is a relatively common phenomenon, particularly amongst those patients under 80 years of age presenting with fragility fractures. The clinical implications of these findings are that strategies, which tend to focus on osteoporosis management in women, should also pay enough attention to osteoporosis in men. However, there have been questions whether there is a gender difference when setting intervention thresholds for osteoporosis management. This work was carried out aiming to determine the fracture probabilities calculated by FRAX at which therapeutic intervention in older men and women can be considered.ResultsAssessment of fracture risk probability thresholds in men revealed that for hip fractures, ROC was 0.754 (95% CI: 0.69–0.817). The sensitivity was 80.5% for threshold probabilities of 2.5%. For the major osteoporosis fracture, ROC was 0.828 (95% CI: 0.694–0.963). The sensitivity was 87.5% for threshold probabilities of 10%. Assessment of fracture risk probability threshold in women ROC was 0.760 (95% CI: 0.691–0.83). The sensitivity was 76.1% for threshold probabilities of 3%. For major osteoporosis fracture, ROC was 0.848 (95% CI: 0.784–0.912). The sensitivity was 87.3% for threshold probabilities of 15%.ConclusionOperational aspects of osteoporosis management should consider gender specific fracture thresholds. Interventional thresholds were found to be different in men compared to women. This helps to optimise fracture prevention in older men.

Correlation between bone mineral density and type 2 diabetes mellitus in elderly men and postmenopausal women

The relationship between bone mineral density and type 2 diabetes is still controversial. The aim of this study is to investigate the relationship between type 2 diabetes mellitus (T2DM) and bone mineral density (BMD) in elderly men and postmenopausal women. The participants in this study included 692 postmenopausal women and older men aged ≥ 50 years, who were divided into the T2DM group and non-T2DM control group according to whether or not they had T2DM. The data of participants in the two groups were collected from the inpatient medical record system and physical examination center systems, respectively, of the Tertiary Class A Hospital. All data analysis is performed in SPSS Software. Compared with all T2DM group, the BMD and T scores of lumbar spines 1–4 (L1–L4), left femoral neck (LFN) and all left hip joints (LHJ) in the non-T2DM group were significantly lower than those in the T2DM group (P < 0.05), and the probability of major osteoporotic fracture in the next 10 years (PMOF) was significantly higher than that in T2DM group (P < 0.001). However, with the prolongation of the course of T2DM, the BMD significantly decreased, while fracture risk and the prevalence of osteoporosis significantly increased (P < 0.05). We also found that the BMD of L1-4, LFN and LHJ were negatively correlated with homeostatic model assessment-insulin resistance (HOMA-IR) (P = 0.028, P = 0.01 and P = 0.047, respectively). The results also showed that the BMD of LHJ was positively correlated with indirect bilirubin (IBIL) (P = 0.018). Although the BMD was lower in the non-T2DM group than in the T2DM group, the prolongation of the course of T2DM associated with the lower BMD. And the higher prevalence of osteoporosis and fracture risk significantly associated with the prolongation of the course of T2DM. In addition, BMD was significantly associated with insulin resistance (IR) and bilirubin levels in T2DM patients.Registration number: China Clinical Trials Registry: MR-51-23-051741; https://www.medicalresearch.org.cn/search/research/researchView?id=c0e5f868-eca9-4c68-af58-d73460c34028.

Head injury mechanisms of the occupant under high-speed train rear-end collision

To improve the passive safety of high-speed trains, it is very important to understand the mechanism of head injury in high-speed train collisions. In this study, the head injury mechanisms of occupants in high-speed train rear-end collisions were investigated based on the occupant-seat coupling model, which included a dummy representing the Chinese 50th percentile adult male. The typical injury responses in terms of skull fractures, brain contusions, and diffuse axonal injury (DAI) were analyzed. Meanwhile, the influences of collision speed and seat parameters on head injury response were examined. The simulation results indicate that the skull fractures primarily occur at the skull base region due to excessive neck extension, while the brain contusions and DAI result from the relative displacement of different brain regions. The increase in collision speed will promote the probability of skull fracture, brain contusion, and DAI. Seat design modifications, such as reduced seat spacing, increased seat backrest angles, and selecting the appropriate cushion angle (76°) and friction coefficient (0.15), can effectively mitigate probably occupant's head injury.

Effects of a 10-week footstrike transition programme on tibial stress fracture probability; a randomized controlled intervention using finite element and probabilistic modelling

Introduction: The aim of this study was to undertake a randomized control trial examining the effects of a 10-week footstrike transition program on tibial stress fracture risk compared to control. Material and methods: Twenty habitual rearfoot strike runners were randomly assigned to either footstrike or control groups. The footstrike group undertook a graduated 10-week program which allowed them to convert their habitual rearfoot strike pattern, whereas the control group maintained their normal training regime without any alterations to their strike pattern. Running biomechanics were collected using an eight-camera motion capture system, and ground reaction forces using a force plate. Tibial strains were quantified using finite element modelling and stress fracture probability calculated via probabilistic modelling over 100 days of running. The primary outcome: tibial stress fracture probability, and secondary outcomes: running biomechanics, muscle forces, joint contact forces, and tibial strain indices were measured at baseline and after 10 weeks. Results: Intention-to-treat analyses revealed no significant alterations in the primary outcome (Footstrike: baseline = 12.82% &amp; 10-weeks = 10.82%, Control: baseline = 15.43% &amp; 10-weeks = 13.39%) between arms. However, alterations in the strike index (Footstrike: baseline = 21.79% &amp; 10-weeks = 65.74%, Control: baseline = 13.61% &amp; 10-weeks = 12.41%) and the loading rate (Footstrike: baseline = 165.85BW/s &amp; 10-weeks = 100.01 BW/s, Control: baseline = 170.13 BW/s &amp; 10-weeks = 197.87 BW/s) were significantly greater in the footstrike group compared to the control one. Conclusion: This trial concludes that the footstrike intervention adopted in this study was not effective in mediating improvements in tibial stress fracture risk, although future intervention trials could examine the efficacy of footstrike modification on other musculoskeletal injuries in runners.

Postoperative Medial Malleolar Fractures in Total Ankle Replacement Are Associated With Decreased Medial Malleolar Width and Varus Malalignment: A Case-Control Study.

There are limited data regarding risk factors associated with periprosthetic medial malleolar fractures in total ankle arthroplasty (TAA). This case-control study aimed to identify the risk factors and analyze the effect of prophylactic screw fixation in preventing a medial malleolar fracture after TAA. A case-control study was conducted on 149 patients who underwent primary TAA. Twenty patients with postoperative medial malleolar fractures >4 weeks postoperatively (cases) were identified. An additional 129 patients (controls) were randomly selected from the TAA database. Radiographic evaluation included tibial component coronal alignment and postoperative medial malleolar width. Demographics and radiographic variables were compared between cohorts. Logistic regression was used to investigate the association between medial malleolar fracture and postoperative coronal alignment, medial malleolar width, and prophylactic fixation of the medial malleolus. Mean (SD) medial malleolar width was significantly smaller in the fracture cohort (8.52 mm [1.6]) than in the control group (11.78 mm [1.74]) (P < .001). Mean (SD) tibial component coronal alignment was 92.17 degrees (2.77) in the fracture cohort and 90.21 degrees (1.66) in the control group (P = .002). Regression analysis identified a significant negative association between postoperative medial malleolar width and the probability of fracture (OR = 0.06, 95% CI 0.01, 0.26, P < .001). Varus malalignment of the tibial component was positively associated with the probability of fracture (OR = 1.90, 95% CI 1.27, 2.86, P = .002). Prophylactic screw fixation resulted in more than 90% reduction in the odds of a fracture (OR = 0.04, 95% CI 0.01, 0.45, P = .01). ROC curve analysis determined a medial malleolar width of 10.3 mm as a potential threshold for predicting fracture. Decreased medial malleolar width and postoperative varus malalignment were associated with an increased risk of postoperative medial malleolar fracture. Therefore, surgeons should consider prophylactic screw fixation in patients with a medial malleolar width <10.3 mm or at risk of postoperative varus deformity.

Influence of the CO2–brine–rock interaction on the plastic zone of sandstone

During the long-term CO2 storage process, the CO2–brine–rock interaction (CBRI) may change the elastic-plastic behaviors of sandstone reservoirs, potentially leading to rock damage and CO2 leakage. A good understanding of the influence of the CBRI on the plastic zone of sandstone is crucial for evaluating the rock fracturing processes. In this paper, three-point bending tests were conducted under both monotonic and cyclic loading conditions, and the digital image correlation technique was used to analyze the elastic and plastic characteristics of the samples. The experimental results showed that the CBRI decreases the yield strength and corresponding crack mouth opening displacement by 25 % and 65%, respectively, thus increasing the probability of fracturing. Additionally, it was found that the CBRI enlarges the plastic zone by about 20 %. The size of the theoretical plastic zone in the sandstone sample for different loads was determined, and the ratio of the plastic zone size in the samples with CO2–brine saturation to that without CO2–brine saturation was found to be about 1.18. Finally, the mesoscale factors affecting the plastic zone size after CO2–brine saturation were analyzed. This study helps to understand the effect of the elastic-plastic behavior of sandstone on reservoir stability during long-term CO2 storage.

Fracture risk prediction in postmenopausal women with traditional and machine learning models in a nationwide, prospective cohort study in Switzerland with validation in the UK Biobank.

Fracture prediction is essential in managing patients with osteoporosis and is an integral component of many fracture prevention guidelines. We aimed to identify the most relevant clinical fracture risk factors in contemporary populations by training and validating short- and long-term fracture risk prediction models in 2 cohorts. We used traditional and machine learning survival models to predict risks of vertebral, hip, and any fractures on the basis of clinical risk factors, T-scores, and treatment history among participants in a nationwide Swiss Osteoporosis Registry (N = 5944 postmenopausal women, median follow-up of 4.1yr between January 2015 and October 2022; a total of 1190 fractures during follow-up). The independent validation cohort comprised 5474 postmenopausal women from the UK Biobank with 290 incident fractures during follow-up. Uno's C-index and the time-dependent area under the receiver operating characteristics curve were calculated to evaluate the performance of different machine learning models (Random survival forest and eXtreme Gradient Boosting). In the independent validation set, the C-index was 0.74 [0.58, 0.86] for vertebral fractures, 0.83 [0.7, 0.94] for hip fractures, and 0.63 [0.58, 0.69] for any fractures at year 2, and these values further increased for longer estimations of up to 7yr. In comparison, the 10-yr fracture probability calculated with FRAX Switzerland was 0.60 [0.55, 0.64] for major osteoporotic fractures and 0.62 [0.49, 0.74] for hip fractures. The most important variables identified with Shapley additive explanations values were age, T-scores, and prior fractures, while number of falls was an important predictor of hip fractures. Performances of both traditional and machine learning models showed similar C-indices. We conclude that fracture risk can be improved by including the lumbar spine T-score, trabecular bone score, numbers of falls and recent fractures, and treatment information has a significant impact on fracture prediction.

Machine Learning in Assessing Canine Bone Fracture Risk: A Retrospective and Predictive Approach

In the ever-evolving world of veterinary care, the occurrence of bone fractures in canines poses a common and complex problem, especially in extra-small breeds and dogs that are less than 1 year old. The objective of this research is to fill a gap in predicting the risk of canine bone fractures. A machine learning method using a random forest classifier was constructed. The algorithm was trained on a dataset consisting of 2261 cases that included several factors, such as canine age, gender, breed, and weight. The performance of the algorithm was assessed by examining its capacity to forecast the probability of fractures occurring. The findings of our study indicate that the tool has the capability to provide dependable predictions of fracture risk, consistent with our extensive dataset on fractures in canines. However, these results should be considered preliminary due to the limited sample size. This discovery is a crucial tool for veterinary practitioners, allowing them to take preventive measures to manage and prevent fractures. In conclusion, the implementation of this prediction tool has the potential to significantly transform the quality of care in the field of veterinary medicine by enabling the detection of patients at high risk, hence enabling the implementation of timely and customized preventive measures.

Hip Fracture Risk Assessment Tools for Adults Aged 80 Years and Older

While adults aged 80 years and older account for 70% of hip fractures in the US, performance of fracture risk assessment tools in this population is uncertain. To compare performance of the Fracture Risk Assessment Tool (FRAX), Garvan Fracture Risk Calculator, and femoral neck bone mineral density (FNBMD) alone in 5-year hip fracture prediction. Prognostic analysis of 3 prospective cohort studies including participants attending an index examination (1997 to 2016) at age 80 years or older. Data were analyzed from March 2023 to April 2024. Participants contacted every 4 or 6 months after index examination to ascertain incident hip fractures and vital status. Predicted 5-year hip fracture probabilities calculated using FRAX and Garvan models incorporating FNBMD and FNBMD alone. Model discrimination assessed by area under receiver operating characteristic curve (AUC). Model calibration assessed by comparing observed vs predicted hip fracture probabilities within predicted risk quintiles. A total of 8890 participants were included, with a mean (SD) age at index examination of 82.6 (2.7) years; 4906 participants (55.2%) were women, 866 (9.7%) were Black, 7836 (88.1%) were White, and 188 (2.1%) were other races and ethnicities. During 5-year follow-up, 321 women (6.5%) and 123 men (3.1%) experienced a hip fracture; 818 women (16.7%) and 921 men (23.1%) died before hip fracture. Among women, AUC was 0.69 (95% CI, 0.67-0.72) for FRAX, 0.69 (95% CI, 0.66-0.72) for Garvan, and 0.72 (95% CI, 0.69-0.75) for FNBMD alone (FNBMD superior to FRAX, P = .01; and Garvan, P = .01). Among men, AUC was 0.71 (95% CI, 0.66-0.75) for FRAX, 0.76 (95% CI, 0.72-0.81) for Garvan, and 0.77 (95% CI, 0.72-0.81) for FNBMD alone (P < .001 Garvan and FNBMD alone superior to FRAX). Among both sexes, Garvan greatly overestimated hip fracture risk among individuals in upper quintiles of predicted risk, while FRAX modestly underestimated risk among those in intermediate quintiles of predicted risk. In this prognostic study of adults aged 80 years and older, FRAX and Garvan tools incorporating FNBMD compared with FNBMD alone did not improve 5-year hip fracture discrimination. FRAX modestly underpredicted observed hip fracture probability in intermediate-risk individuals. Garvan markedly overpredicted observed hip fracture probability in high-risk individuals. Until better prediction tools are available, clinicians should prioritize consideration of hip BMD, life expectancy, and patient preferences in decision-making regarding drug treatment initiation for hip fracture prevention in late-life adults.

Highly stretchable six-leaf hand structure electrodes prepared by sacrificial layer method, resistant to sweat erosion, for EMG and ECG signal detection

Recently, wearable flexible electronic devices have become more widely used in detecting human physiological signals, so higher demands have been placed on flexible stretchable electrodes directly attached to the human body, which need to have better mechanical tensile properties, anti-fatigue properties, and chemical stability. In this paper, the four-segment hand structure is optimized to obtain the four-leaf hand structure, which reduces the maximum stress value when the electrode is stretched and decreases the probability of electrode fracture. Further, the structure of the electrode is optimized by changing the number of nodes, the six-leaf hand structure electrode is obtained. The six-leaf hand structure electrode has lower tensile stress and stability. The substrate-free six-leaf hand structure electrode prepared by the sacrificial layer method has a much higher stretchability than the electrode with a substrate layer due to the bonding of the substrate-free layer, and there is no significant change in the resistance value during the stretching process. The screen-printed waterproof-coated six-leaf hand structure electrode has good sweat resistance and can be used for ECG and EMG detection.

Bone mineral density and osteoporosis related risk factors in type 2 diabetes mellitus

Diabetes mellitus negatively affects bone tissue and unfavourably impacts bone mineral density (BMD), therfore increasing the probability of fractures through pathological mechanisms. This study aimed to explore the factors associated with BMD and osteoporosis risk in individuals with a diagnosis of type 2 diabetes mellitus (T2DM). An investigation was undertaken involving 49 patients diagnosed with T2DM who fulfilled the specified criteria. These individuals underwent BMD assessment as part of a cross-sectional study. The analysis encompassed both univariate and bivariate approaches, utilizing the Chi-square test (X2) and binary logistic regression methods. A total of 30 participants (61%) have decreased BMD. Among the participants aged 60 years and above, 83.4% exhibited a decreased BMD status (osteopenia and osteoporosis), in contrast to the under 60 years age group, in which 40% displayed decreased BMD status. Older age (&amp;gt;60 years) is a risk factor for decreasing bone density onset of diabetes mellitus (DM) diagnosis, duration of DM, glycemic control, body mass index (BMI), use of thiazolidinediones (TZD) drugs, kidney function, were not associated with lower BMD in T2DM patients.

Predictive role of FRAX© for postoperative proximal junctional kyphosis with vertebral fracture after adult spinal deformity surgery.

To identify risk factors, including FRAX (a tool for assessing osteoporosis) scores, for development of proximal junctional kyphosis (PJK), defined as Type 2 in the Yagi-Boachie classification (bone failure), with vertebral fracture (VF) after surgery for symptomatic adult spinal deformity. This was a retrospective, single institution study of 127 adults who had undergone corrective long spinal fusion of six or more spinal segments for spinal deformity and been followed up for at least 2years. The main outcome was postoperative development of PJK with VF. Possible predictors of this outcome studied included age at surgery, BMI, selected radiographic measurements, bone mineral density, and 10-year probability of major osteoporotic fracture (MOF) as determined by FRAX. We also analyzed use of medications for osteoporosis. Associations between the selected variables and PJK with VF were assessed by the Mann-Whitney, Fishers exact, and Wilcoxon signed-rank tests, and Kaplan-Meier analysis, as indicated. Forty patients (31.5%) developed PJK with VF postoperatively,73% of them within 6months of surgery. Statistical analysis of the selected variables found that only a preoperative estimate by FRAX of a > 15% risk of MOF within 10years, pelvic tilt > 30° at first standing postoperatively and lower instrumented level (fusion terminating at the pelvis) were significantly associated with development of PJK with VF. Preoperative assessment of severity of osteoporosis using FRAX provides an accurate estimate of risk of postoperative PJK with VF after surgery for adult spinal deformity.

External validation of a model using health administrative data to predict acetabular fracture probability: Brief report.

Analyses using population-based health administrative data can return erroneous results if case identification is inaccurate ("misclassification bias"). An acetabular fracture (AF) prediction model using administrative data decreased misclassification bias compared to identifying AFs using diagnostic codes. This study measured the accuracy of this AF prediction model in another hospital. We calculated AF probability in all hospitalizations in the validation hospital between 2015 and 2020. A random sample of 1000 patients stratified by expected AF probability was selected. Patient imaging studies were reviewed to determine true AF status. The validation population included 1000 people. The AF prediction model was very discriminative (c-statistic 0.90, 95% CI: 0.87-0.92) and very well calibrated (integrated calibration index 0.056, 95% CI: 0.039-0.074). AF probability can be accurately determined using routinely collected health administrative data. This observation supports using the AF prediction model to minimize misclassification bias when studying AF using health administrative data.

Update on fracture risk assessment in osteoporosis.

The assessment of fracture risk is playing an ever-increasing role in osteoporosis clinical management and informing international guidelines for osteoporosis. FRAX, a fracture risk calculator that provides individualized 10-year probabilities of hip and major osteoporotic fracture, has been widely used since 2008. In this review, we recap the development and limitations of intervention thresholds and the role of absolute fracture risk. There is an increasing awareness of disparities and inequities in the setting of intervention thresholds in osteoporosis. The limitations of the simple use of prior fracture or the DXA-derived BMD T -score threshold are increasingly being discussed; one solution is to use fracture risk or probabilities in the setting of such thresholds. This approach also permits more objective assessment of high and very high fracture risk to enable physicians to make choices not just about the need to treat but what agents to use in individual patients. Like all clinical tools, FRAX has limitations that need to be considered, but the use of fracture risk in deciding who to treat, when to treat and what agent to use is a mechanism to target treatment equitably to those at an increased risk of fracture.

Correction: Vanneschi et al. Hazard Assessment of Rocky Slopes: An Integrated Photogrammetry–GIS Approach Including Fracture Density and Probability of Failure Data. Remote Sens. 2022, 14, 1438

In the published publication [...]

Guiding postmenopausal care for osteoporosis: First evidence-based clinical practice guidelines for Pakistan.

Madam, We would like to address the issue of postmenopausal osteoporosis (PMO) management in Pakistan and advocate for the country-wide dissemination of the recently published Pakistan-specific clinical practice guideline (CPG) "GRADE-Adolopment of Clinical Practice Guideline for Postmenopausal Osteoporosis Management - a Pakistani Context" (1). Osteoporosis poses a significant threat to the health of postmenopausal women. Although osteoporosis prevalence among postmenopausal women ranges from 20% to 49.3% in Pakistan, there is a lack of epidemiological data, diagnostic facilities, and public awareness about bone health. Healthcare providers in Pakistan have thus far struggled with managing osteoporosis effectively because of the absence of local CPGs. The Pakistani PMO guideline, developed by the Aga Khan University aligns the recommendations of the Asia Pacific Consortium on Osteoporosis (2) and the American Association of Clinical Endocrinologists (3). The GRADE-ADOLOPMENT methodology used in developing the guideline provides a systematic support for the recommendations that are evidence based and suitable for adoption in Pakistan's medical settings. The guideline recommends higher doses (2000-4000 IU) of vitamin D in patients with obesity, malabsorption, and old age, considering their increased requirements and suboptimal response to lower doses. It addresses food insecurity and malnutrition, which contribute to vitamin D deficiency and fracture risk. Moreover, the guideline incorporates the surrogate FRAX model created for Pakistan, recommended by the International Osteoporosis Foundation for countries lacking fracture incidence data (4). A management algorithm is proposed, based on intervention thresholds developed for Pakistan for accurate estimation of fracture probability, and to guide clinical practice(5). The primary goal of the guideline is to improve the quality of care by changing the daily practice of physicians in the desired direction. Disseminating and integrating osteoporosis care into the healthcare system is challenging but remains a top priority. The endorsement of the guideline by relevant national societies can play a crucial role in its dissemination. Implementation through their members can help in assessing effectiveness and in shaping clinical practice. The guideline is a critical step in addressing osteoporosis management challenges in Pakistan, but for full impact, widespread dissemination and implementation in clinical practice is required. We implore the medical community, policymakers, and stakeholders to collaborate in this endeavor and work towards improving the management of osteoporosis, to enhance the health outcomes of the Pakistani population. It is essential that healthcare policymakers and practitioners recognize PMO as a significant public health issue and implement the CPG for appropriate practice changes.

FRAX-derived intervention and assessment thresholds for osteoporosis in ten Middle Eastern countries.

Developing fracture risk assessment tools allows physicians to select patients for therapy based on their absolute fracture risk instead of relying solely on bone mineral density (BMD). The most widely used tool is FRAX, currently available in ten Middle Eastern countries. This study aimed to set FRAX-derived assessment and intervention thresholds for individuals aged 40 or above in ten Middle Eastern countries. The age-specific 10-year probabilities of a major osteoporotic fracture (MOF) for a woman with a BMI of 25.0kg/m2, without BMD and clinical risk factors except for prior fracture, were calculated as intervention Threshold (IT). The upper and lower assessment thresholds were set at 1.2 times the IT and an age-specific 10-year probability of a MOF in a woman with a BMI of 25.0kg/m2, without BMD, prior fracture, and other clinical risk factors, respectively. IT is utilized to determine treatment or reassurance when BMD facilities are unavailable. However, with BMD facilities, assessment thresholds can offer treatment, reassurance, or bone densitometry based on MOF probability. The age-specific IT varied from 0.9 to 11.0% in Abu Dhabi, 2.9 to 10% in Egypt, 2.7 to 14.0% in Iran, 1.0 to 28.0% in Jordan, 2.7 to 27.0% in Kuwait, 0.9 to 35.0% in Lebanon, 1.0 to 16.0% in Palestine, 4.1 to 14% in Qatar, 0.6 to 3.7% in Saudi Arabia, and 0.9 to 36.0% in Syria at the age of 40 and 90years, respectively. FRAX-based IT in Middle Eastern countries provides an opportunity to identify individuals with high fracture risk.

Fracture risk prediction in postmenopausal women from GO Study: the comparison between FRAX, Garvan, and POL-RISK algorithms.

The aim of the longitudinal, retrospective study was to compare three tools designed to assess fracture risk: FRAX, Garvan, and POL-RISK in their prediction of fracture incidence. The study group consisted of 457 postmenopausal women with a mean age of 64.21 ± 5.94years from the Gliwice Osteoporosis (GO) Study. Comprehensive data on clinical factors related to fractures were collected for all participants. Bone densitometry was performed at the proximal femur using the Prodigy device (GE, USA). Fracture risk was established using the FRAX, Garvan, and POL-RISK algorithms. Data on the incidence of osteoporotic fractures were collected over the last 10years. During the period of observation 72, osteoporotic fractures occurred in 63 subjects. For a preliminary comparison of the predictive value of analyzed diagnostic tools, the fracture risk threshold of 10% was used. For FRAX, the fracture probability exceeding 10% was observed only in 11 subjects who experienced fractures; thus, the fracture was properly predicted only in 22.9% of women. For Garvan, the respective value was 90.5%, and for POL-RISK, it was 98.4%. That gave a very low true positive value for FRAX and a very high false positive value for Garvan and POL-RISK. Based on ROC curves, new thresholds for high risk of fractures were established for each calculator separately: 6.3% for FRAX major fracture, 20.0% for Garvan any fracture, and 18.0% for POL-RISK any fracture. Such thresholds improve the diagnostic accuracy of all compared fracture prediction tools. The current study showed that different fracture risk assessment tools, although having similar clinical purposes, require different cut-off thresholds for making therapeutic decisions. Better identification of patients requiring therapy based on such an approach may help reduce the number of new fractures.

External validation of predictive models for new vertebral fractures following percutaneous vertebroplasty.

To investigate the external validation and scalability of fourpredictive models regarding new vertebral fractures following percutaneous vertebroplasty. Utilizing retrospective data acquired from two centers, compute the area under the curve (AUC), calibration curve, and Kaplan-Meier plot to assess the model's discrimination and calibration. In the external validation of Zhong et al.'s 2015 predictive model for the probability of new fractures post-vertebroplasty, the AUC for re-fracture at 1, 2, and 3years postoperatively was 0.570, 0.617, and 0.664, respectively. The AUC for Zhong et al.'s 2016 predictive model for the probability of new fractures in neighboring vertebrae was 0.738. Kaplan-Meier plot results for both models indicated a significantly lower incidence of re-fracture in low-risk patients compared to high-risk patients. Li et al.'s 2021 model had an AUC of 0.518, and its calibration curve suggested an overestimation of the probability of new fractures. Li et al.'s 2022 model had an AUC of 0.556, and its calibration curve suggested an underestimation of the probability of new fractures. The external validation of four models demonstrated that the predictive model proposed by Zhong et al. in 2016 exhibited superior external generalization capabilities.

Associations of accelerometer-estimated free-living daily activity impact intensities with 10-year probability of osteoporotic fractures in adults

PurposeAccelerometers are used to objectively measure physical activity; however, the relationship between accelerometer-based activity parameters and bone health is not well understood. This study examines the association between accelerometer-estimated daily activity impact intensities and future risk estimates of major osteoporotic fractures in a large population-based cohort. MethodsParticipants were 3165 adults 46 years of age from the Northern Finland Birth Cohort 1966 who agreed to wear a hip-worn accelerometer during all waking hours for 14 consecutive days. Raw accelerometer data were converted to resultant acceleration. Impact magnitude peaks were extracted and divided into 32 intensity bands, and the osteogenic index (OI) was calculated to assess the osteogenic effectiveness of various activities. Additionally, the impact peaks were categorized into three separate impact intensity categories (low, medium, and high). The 10-year probabilities of hip and all major osteoporotic fractures were estimated with FRAX-tool using clinical and questionnaire data in combination with body mass index collected at the age of 46 years. The associations of daily activity impact intensities with 10-year fracture probabilities were examined using three statistical approaches: multiple linear regression, partial correlation, and partial least squares (PLS) regression. ResultsOn average, participants’ various levels of impact were 8331 (SD = 3478) low; 2032 (1248) medium; and 1295 (1468) high impacts per day. All three statistical approaches found a significant positive association between the daily number of low-intensity impacts and 10-year probability of hip and all major osteoporotic fractures. In contrast, increased number of moderate to very high daily activity impacts was associated with a lower probability of future osteoporotic fractures. A higher OI was also associated with a lower probability of future major osteoporotic fractures. ConclusionLow-intensity impacts might not be sufficient for reducing fracture risk in middle-aged adults, while high-intensity impacts could be beneficial for preventing major osteoporotic fractures.