The spine deformity index in osteoporosis is not related to bone mineral and ultrasound measurements

Abstract

In 34 female patients suffering from osteoporotic vertebral compression fractures, the spine deformity index (SDIM) was determined, according to the method of Minne et al (1988), to reflect the radiological severity of established osteoporosis. Peripheral (single-photon absorptiometry (SPA) of the non-dominant distal forearm) and axial (quantitative computed tomography (QCT) of the lumbar spine) bone mineral measurements, as well as the broadband ultrasound attenuation of the os calcis, were performed in the osteoporotic patients and in a control group of 20 age-matched women. No correlation could be found between bone mineral measurements and radiological severity of osteoporosis, expressed as SDIM. All three densitometry methods showed clearly reduced values in patients with vertebral crush fractures. Correlations established in the control group between peripheral and axial bone mass (SPA versus QCT) could no longer be found in the osteoporotic group, thus indicating changes in bone mineral density of the spine after the occurrence of osteoporotic fractures. Our data show that SDIM is an additional parameter of osteoporotic change in the spine, independent from bone mass measurements. In the management of osteoporotic patients, quantitative radiological methods (i.e. SDIM) in addition to densitometry might be of value for grading and monitoring the progress of disease.