Reliability of Singh's index Checked by the Dual Photon X-ray Absorptiometry(LUNAR D.P.X)

Yoo, Myung Chul; Ahn, Jin Hwan; Lee, Yong Girl; Kum, Se Jin; Ahn, Jae Sung; Kim, Kyung Tae

Abstract

There are several methods available to check bone masses. One of them is Singhs index which is singlest way with grading trabecular pattern of the proximal femur on anteroposterior X-ray film and the other is recently developed Dual Photon X-ray Absorptiometry which measures bone mineral contents. Some authors proclaim that Singh's index has low accuracy, objectiveness and reproducibility. So we studied for reliability of Singh's index and correlation between Singh's index and bone mineral contents measured by Dual Photon X-ray Absorptiometry in 65 patients. There are significant differences between 3 orthopedic surgeons in interpreting Singh's index (interpersonal difference). There are significant differences between first and second interpretation out of same surgeons (intrapersonal difference). There are significant differences interpretating among interpreted Singh's indices from films of different radiological exposures in the same radiograph. There are fair correlations(0.60-0.66) between Singhs index and bone mineral density. The Singh's index was overestimated in low bone mineral density with under-exposed radiograph, but Singh's index was under-estimated in high bone mineral density with over-exposed radiograph. Singh's index can be useful in clinical application by some modification.