POS0163 INCIDENT FRACTURE RISK PREDICTION USING THE FRAGILITY SCORE CALCULATED BY LUMBAR SPINE RADIOFREQUENCY ECHOGRAPHIC MULTI SPECTROMETRY (REMS) SCANS

Abstract

Background:The main consequence of osteoporosis is the occurrence of fractures due to bone fragility, with important sequelae in terms of disability and mortality. It has been already demonstrated that the information about bone mass density (BMD) alone is not sufficient to predict the risk of fragility fractures, since several fractures occur in patients with normal BMD [1].The Fragility Score is a parameter that allows to estimate skeletal fragility thanks to a trans-abdominal ultrasound scan performed with Radiofrequency Echographic Multi Spectrometry (REMS) technology. It is calculated by comparing the results of the spectral analysis of the patient’s raw ultrasound signals with reference models representative of fragile and non-fragile bones [2]. It is a dimensionless parameter, which can vary from 0 to 100, in proportion to the degree of fragility, independently from BMD.Objectives:This study aims to evaluate the effectiveness of Fragility Score, measured during a bone densitometry exam performed with REMS technology at lumbar spine, in identifying patients at risk of incident osteoporotic fractures at a follow-up period of 5 years.Methods:Caucasian women with age between 30 and 90 were scanned with spinal REMS and DXA. The incidence of osteoporotic fractures was assessed during a follow-up period of 5 years. The ability of the Fragility Score to discriminate between patients with and without incident fragility fractures was subsequently evaluated and compared with the discriminatory ability of the T-score calculated with DXA and with REMS.Results:Overall, 533 women (median age: 60 years; interquartile range [IQR]: 54-66 years) completed the follow-up (median 42 months; IQR: 35-56 months), during which 73 patients had sustained an incident fracture.Both median REMS and DXA measured T-score values were significantly lower in fractured patients than for non-fractured ones, conversely, REMS Fragility Score was significantly higher (Table 1).Table 1.Analysis of T-score values calculated with REMS and DXA and Fragility Score calculated with REMS. Median values and interquartile ranges (IQR) are reported. The p-value is derived from the Mann-Whitney test.Patients without incident fragility fracturePatients with incident fragility fracturep-valueT-score DXA[median (IQR)]-1.9 (-2.7 to -1.0)-2.6 (-3.3 to -1.7)0.0001T-score REMS[median (IQR)]-2.0 (-2.8 to -1.1)-2.7 (-3.5 to -1.9)<0.0001Fragility Score[median (IQR)]29.9 (25.7 to 36.2)53.0 (34.2 to 62.5)<0.0001By evaluating the capability to discriminate patients with/without fragility fractures, the Fragility Score obtained a value of the ROC area under the curve (AUC) of 0.80, higher than the AUC of the REMS T-score (0.66) and of the T-score DXA (0.64), and the difference was statistically significant (Figure 1).Figure 1.ROC curve comparison of Fragility Score, REMS and DXA T-score values in the classification of patients with incident fragility fractures.Furthermore, the correlation between the Fragility Score and the T-score values was low, with Pearson correlation coefficient r=-0.19 between Fragility Score and DXA T-score and -0.18 between the Fragility Score and the REMS T-score.Conclusion:The Fragility Score was found to be an effective tool for the prediction of fracture risk in a population of Caucasian women, with performances superior to those of the T-score values. Therefore, this tool presents a high potential as an effective diagnostic tool for the early identification and subsequent early treatment of bone fragility.