Correlation between Saville's index and Bone Mineral Density Measured by the Lateral Dual x-ray Absorptiometry & Clinical Usefulness of Saville's index

Kang, Chung Nam; Kim, Jong Ho; Yoo, Yong Whan

Abstract

For measurement of the degree of osteoporosis, various methods have been used. The Saville's index of the lumbar spine is very simple method. With the object of studying the reliability and clinical usefulness of Saville's index, authors compared the Saville's index with anteroposterior(A.P.) and lateral Dual x-ray absorptiometry, and the Singh's index with the anteroposterior D.X.A. We took the D.X.A. and simple lumbar spine lateral view in 124 patients in same time and also performed D.X.A. and both hips anteroposterior views in 112 patients, then analyzed the correlation between the A.P. and lateral D.X.A., Saville's index and D.X.A., Singh's index and D.X.A. The results were as follows. 1. The correlation coefficient of the A.P. and lateral D.X.A. was 0.46 and appeared the low degree of correlation. 2. The correlation coefficient of the A.P. and lateral D.X.A. compared with Saville's index were 0.68 and 0.83, respectively. Saville's index appeared the higher correlation in lateral D.X.A. than A.P. D.X.A. 3. The correlation coefficient of Singh's index and D.X.A. was 0.84, appeared nearly the same results of Saville's index with lateral D.X.A. 4. Intrapersonal differences were 36% in Saville's index, 28% in Singh's index. Saville's index appeared higher intrapersonal error than Singh's index. The lateral D.X.A. is more accurate and precise method than A.P. D.X.A. because lateral D.X.A. reduces the influence of soft tissue calcification and degenerative changes of spine. As Saville's index is a grading method based on lateral view of lumbar spine, we think that it should be compared with the lateral D.X.A. Regarding this results, authors suggest that Saville's index is not any accurate measurement of bone quantity, but has clinical usefulness for evaluation of osteroporosis.