The Relationship between the Pedicle Screw Loosening and Bone Mineral Density after Transpedicular Spinal Instrumentation / 대한골다공증학회지

OBJECTIVES: We have analyzed relationship between pedicle screw loosening and bone mineral densitiy (BMD) after spinal arthrodesis with pedicle screw. MATERIALS AND METHODS: We have chosen 31 cases that had screw loosening radiologically on the follow up X-ray among the patients who underwent spinal arthrodesis with pedicle screws, and compared Saville's index that was measured by lateral view of preoperative X-ray with Dual energy X-ray absortiometry (DEXA) score.

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

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.

Comparison Between Reliavilty and Clinical Usefulness of Saville's Spine Index and those of Singh's Index in Osteoporosis / 대한정형외과학회잡지

The Saville's index of the lumbar spine and the Singh's index of the femoral neck is very simple method to measure degree of osteoporosis. Authors compared Singh's index and Savilles index with Dual Photon Absorptiometry(D.P.X.) and studied the reliability and clinical usefulness of two indices. We took the D.P.X. and simple L-spine lateral view in 103 patients in same time and also performed D.P.X. and both hips A-P view in 70 patients, then analyzed and compared each two indices with D.P.X. The Singh's index had less interpersonal difference and intrapersonal difference compared with Saville's spine index. There was some confidence of Singh's index and Saville's spine index compared with the D.P.X., but the relationship between Saville's spine index and D.P.X. was less promising than that of Singh's index. Authors suggest that the Saville's spine index has less clinical usefulness than Singh's index in measurement of osteoporosis.