Diagnostic Value of Distal Forearm Densitometry for Osteoporosis; Alone or Add to Hip and Spine Densitometry?

Background: In most centers of the world, for diagnosing osteoporosis is used densitometry in hip and spine, but due to the high prevalence of distal forearm fracture and osteoporosis as its main etiology and on the other hand, evaluation of the distal forearm densitometry as an predictor indicator for axial osteoporosis, evaluate the diagnostic value of distal forearm densitometry for osteoporosis; alone and with adding to hip and spine densitometry.

Materials and Methods: This cross-sectional descriptive-analytic study was carried out on 250 patients referring to Sanandaj densitometry center from September 2017 to September 2018. For the studied subjects, BMD was performed by DXA method in three regions of hip, spine and distal forearm. Data were analyzed using independent t-test, fisher exact test, chi-square test and logistic regression test using SPSS v. 23 software.

Results: In this study, 68 cases (27.2%) in the spine region, 38 cases (15.2%) in the hip and 85 cases (34%) in distal forearm were osteoporotic. Based on the results of this study, using the conventional method (hip and spine) in comparison with the studied method (hip, spine and distal forearm), 29 (11.6%) of those cases with osteoporosis are not diagnosed. Distal forearm densitometry alone in comparison with the conventional method has diagnostic sensitivity 74.66%, specificity 83.43%, positive predictive value (PPV) 65.88% and negative predictive value (NPV) 88.48%.

Conclusion: Adding distal forearm densitometry to conventional method significantly increasing diagnostic sensitivity of osteoporosis and would prevent misdiagnosis. Distal forearm densitometry can use as a predictor indicator of axial osteoporosis.