To see whether different types of DEXA and levels of lumbar vertebrae show any differences in making standard values of lumbar bone mineral density (BMD) in osteoporotic vertebral fracture.

Four hundred and sixty-two postmenopausal women who visited our center due to back pain were screened. Sixty osteoporotic vertebral fracture out of 462 patients were subdivided into QDR group and DPX group, according to densitometers (QDR 39 patients, DPX 21 patients). The BMD was compared between the two groups. The difference between BMD measured in L3 and that measured in L2-4 was analyzed by student t-test. Fracture threshold was defined.

There was no difference between BMD of L3 and L2-4 standard level (P>0.05). The mean BMD measured by QDR and DPX, using L2-4 standard, were 0.667±0.127 g/cm² and 0.756±0.123 g/cm², respectively, and showed statistically significant difference (P=0.012). Fracture threshold was 0.831 g/cm² in QDR and 0.896 g/cm² in DPX.

The type of bone mineral densitometer should be taken into consideration in follow-up of osteoprosis patients, and the L3 standard level might not be superior over the conventional L2-4 standard level in measuring BMD in osteoporotic vertebral fracture patients.