Trabecular mineral contents of lumbar vertebra in patients with osteoporosis.

The trabecular mineral contents (TMCs) of the third lumbar vertebra in normal subjects and patients with spinal osteoporosis and with femoral neck fracture were measured by quantitative computed tomography (QCT) using a reference phantom. The present paper describes these results. The TMCs in patients with spinal osteoporosis and with femoral neck fracture were significantly lower than those in normal subjects. When evaluated in terms of the ratio to the mean trabecular mineral content (mTMC) in normal subjects of the same decade groups, it was assumed that there should be a threshold value of vertebral compression fracture, and that value was approximately 50% of the mTMC in normal subjects. A correlation was noted between the data of the QCT method and those of the microdensitometric method in the groups with vertebral compression fracture and with femoral neck fracture, but not in the group without vertebral fracture.