Evaluation of Heel-Based Quantitative Ultrasound Bone Densitometry as a Screening Tool for Post-Menopausal Osteoporosis

Osteoporosis is the major cause of fragility fractures in postmenopausal women. It has been aptly termed as the ‘silent disease’, as most women are asymptomatic, and a fragility fracture is often the first presentation. Fragility fractures have significant implications in terms of decreased quality of life, and increased morbidity, mortality, and healthcare cost. This study has showed that a multivariable logistic regression model based on clinic-demographic parameters and speed of sound that can be used to predict osteoporosis using quantitative ultrasonography. The Cross-sectional study done for a period of one year in Departments of Orthopaedics and Radiodiagnosis, PGIMER, Chandigarh with a Sample Size of N=100 subjects. By itself, estimation of osteoporosis using speed of sound, may not be very reliable or accurate, however, a multivariable model taking into account age, body mass index along with speed of sound, can improve the diagnostic accuracy of such estimates. However, these results need to be validated in a larger cohort of patients. The speed of sound measured at the heel by quantitative ultrasonography was found to be significantly lower (mean difference of approximately 20 m/s) in subjects who had a DEXA proven osteoporosis verses who did not have osteoporosis. Using the normative data of speed of sound of the Japanese population as the reference (Strategy 1), QUS was found to have a poor accuracy for diagnosis of osteoporosis. A cut-off value of speed of sound of less than 1536 m/s at the heel was found to have sensitivity of 91.7% for diagnosis of DEXA proven osteoporosis. On the other hand, a cut-off value of speed of sound of less than 1467 m/s at the heel was found to have specificity of 91.5%. For determining the optimal cut-off for diagnosing osteoporosis based on speed of sound, cut-offs obtained from receiver operating curve analysis (strategy 2b) were found to have a lower percentage of misclassification, as compared to cut-offs obtained from normative data of young Indian females (strategy 2b). In the univariate analysis age, body mass index, hip circumference and time since menopause were significantly associated with DEXA proven osteoporosis.