Maria Daniela Renna

Major osteoporotic fragility fractures: Risk factor updates and societal impact

Osteoporosis is a silent disease without any evidence of disease until a fracture occurs. Approximately 200 million people in the world are affected by osteoporosis and 8.9 million fractures occur each year worldwide. Fractures of the hip are a major public health burden, by means of both social cost and health condition of the elderly because these fractures are one of the main causes of morbidity, impairment, decreased quality of life and mortality in women and men. The aim of this review is to analyze the most important factors related to the enormous impact of osteoporotic fractures on population. Among the most common risk factors, low body mass index; history of fragility fracture, environmental risk, early menopause, smoking, lack of vitamin D, endocrine disorders (for example insulin-dependent diabetes mellitus), use of glucocorticoids, excessive alcohol intake, immobility and others represented the main clinical risk factors associated with augmented risk of fragility fracture. The increasing trend of osteoporosis is accompanied by an underutilization of the available preventive strategies and only a small number of patients at high fracture risk are recognized and successively referred for therapy. This report provides analytic evidences to assess the best practices in osteoporosis management and indications for the adoption of a correct healthcare strategy to significantly reduce the osteoporosis burden. Early diagnosis is the key to resize the impact of osteoporosis on healthcare system. In this context, attention must be focused on the identification of high fracture risk among osteoporotic patients. It is necessary to increase national awareness campaigns across countries in order to reduce the osteoporotic fractures incidence.

A novel ultrasound methodology for estimating spine mineral density.

We investigated the possible clinical feasibility and accuracy of an innovative ultrasound (US) method for diagnosis of osteoporosis of the spine. A total of 342 female patients (aged 51-60 y) underwent spinal dual X-ray absorptiometry and abdominal echographic scanning of the lumbar spine. Recruited patients were subdivided into a reference database used for US spectral model construction and a study population for repeatability and accuracy evaluation. US images and radiofrequency signals were analyzed via a new fully automatic algorithm that performed a series of spectral and statistical analyses, providing a novel diagnostic parameter called the osteoporosis score (O.S.). If dual X-ray absorptiometry is assumed to be the gold standard reference, the accuracy of O.S.-based diagnoses was 91.1%, with k = 0.859 (p < 0.0001). Significant correlations were also found between O.S.-estimated bone mineral densities and corresponding dual X-ray absorptiometry values, with r(2) values up to 0.73 and a root mean square error of 6.3%-9.3%. The results obtained suggest that the proposed method has the potential for future routine application in US-based diagnosis of osteoporosis.

OP0003 Fracture Risk Prediction: Comparative Evaluation of Ultrasound-Based Fragility Score and DXA-Measured BMD Against Frax®

Background A high percentage of fragility fractures occur in subjects showing low bone strength in presence of a normal bone mineral density (BMD). Consequently, the approach to bone health assessment and fracture prevention is gradually changing, moving the focus from the identification of osteoporotic patients (based on BMD thresholds) towards the detection of individuals at high risk of fracture. Currently, the only validated tool that provides a precise quantification of the osteoporotic fracture risk is FRAX®, which is based on age, sex, body mass index (BMI) and a series of clinical risk factors, taking into account epidemiological data that are specific for patient country. FRAX® calculation can also include femoral neck BMD measured by dual X-ray absorptiometry (DXA), since it has been shown that integration of BMD and clinical risk factors provides improved fracture predictions. Nevertheless, DXA availability is limited by the typical issues related to ionizing radiation employment (high costs, need of dedicated structures with certified operators, long-term safety risks). Objectives Aim of this work was to compare the performance of DXA-measured BMD and a novel ultrasound (US) parameter measured on lumbar spine in the estimation of osteoporotic fracture risk as calculated by FRAX®. Methods 80 female patients [40-80 years; BMI (body mass index) ≤30 kg/m2] were enrolled for the study. Each of them answered the FRAX® questionnaire and underwent the following diagnostic examinations: a conventional DXA investigation of lumbar spine and proximal femur (Hologic Discovery) and an abdominal US scan of lumbar spine. US data were analyzed by an innovative algorithm that processed both echographic images and “raw” radiofrequency (RF) signals, providing as final output a new parameter named Fragility Score (F.S.), which quantifies bone strength. For each patient, FRAX®10-year probability of a major osteoporotic fracture was calculated both with and without femoral neck BMD inclusion. Pearson coefficient (r) was used to compare the performance of F.S. and BMD values in the estimation of fracture risk provided by FRAX®. Results Fracture risk provided by FRAX® with femoral BMD included in the calculation showed a good correlation with F.S. (r =0.70, p<0.001) and, as expected, with femoral neck BMD (r = -0.72, p<0.001), while the correlation was weaker for lumbar BMD (r = -0.44, p<0.001). Furthermore, F.S. was the only considered diagnostic parameter that kept an appreciable correlation with FRAX® predictions even when their calculation did not include femoral BMD (r =0.52 for F.S., r = -0.21 for femoral BMD, r = -0.07 for lumbar BMD; p<0.001 for all). Conclusions The proposed US-based F.S. alone showed a good correlation with osteoporotic fracture risk calculated by FRAX® integrated with femoral neck BMD, which represents the most reliable value. The performance of F.S. in fracture risk estimation was significantly better than lumbar BMD and comparable with femoral BMD. Therefore, F.S. is a suitable candidate to be employed for fracture risk prediction in primary healthcare settings. Acknowledgements This work was partially funded by FESR P.O. Apulia Region 2007-2013 – Action 1.2.4, grant n. 3Q5AX31 (ECHOLIGHT Project) Disclosure of Interest None declared

SAT0491 Accuracy of A New Ultrasonic Method for Osteoporosis Diagnosis on Lumbar Spine

Background Osteoporosis is a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility and susceptibility to fracture. Fractures associated with osteoporosis represent a major cause of public health burden in terms of mortality, disability and health care costs emphasizing the need of more effective diagnostic methods. Currently, osteoporosis is mainly diagnosed through dual-energy X-ray absorptiometry (DXA) which provides quantitative measurements of bone mineral density (BMD). Spinal DXA, in particular, is the preferred technique for temporal monitoring of BMD variations, since it has been demonstrated that BMD measurement on this site is the most reliable to predict the global fracture risk. However, DXA cannot be used for early diagnoses through population mass screenings because of issues related to ionizing radiation employment. Objectives Aim of this work is to test the diagnostic accuracy of a novel ultrasound (US)-based method to perform spinal densitometry without employing X-rays. Methods A cohort of 358 female patients was recruited according to the following criteria: 45-65 years, body mass index (BMI) <25 kg/m2, absence of significant severe deambulation impairments, medical prescription for a spinal DXA, signed informed consent. All the enrolled patients underwent two examinations: a conventional spinal DXA (Hologic Discovery) and an US scan of lumbar spine. US data were analyzed by a novel algorithm that processed both echographic images and “raw” radiofrequency signals and, performing a series of spectral and statistical analyses, calculated the same diagnostic parameters provided by DXA (bone mineral density (BMD), T-score, Z-score). Diagnostic accuracy of obtained results was evaluated through a direct comparison with DXA output as a function of patient age. Results For 83.0% of the patients US diagnosis (osteoporotic, osteopenic, healthy) was the same of the corresponding DXA one. In particular, diagnostic accuracy showed the following trend as a function of patient age range: accuracy was 86.4% in 45-50 y, 85.6% in 50-55 y, 87.1% in 55-60 y and 72.4% in 60-65 y. For patients in the same age range, Pearson correlation coefficient (r) between DXA and US measurements was also evaluated for each diagnostic parameter (BMD, T-score, Z-score): all the obtained values of r were within the interval 0.52-0.78 (p<0.001) and their trends against age qualitatively resembled the observed diagnostic accuracy profile. The lower diagnostic agreement and correlation values found in correspondence of the oldest analyzed patients can be at least partially due to spinal degenerations affecting the accuracy of DXA measurements. Conclusions The proposed method for US evaluation of BMD directly on the spine showed a very good and significant agreement with DXA diagnoses. This innovative non-ionizing approach has the potential to anticipate osteoporosis diagnosis by several years through extended screenings in younger populations and to become a useful tool for therapeutic outcome monitoring. Acknowledgements This work was partially funded by FESR P.O. Apulia Region 2007-2013 – Action 1.2.4, grant n. 3Q5AX31. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.5446