Aging societies have an increased incidence of fractures caused by osteoporosis.Vertebral compression fractures occur most frequently in the thoracolumbar vertebrae of elderly individuals. The severe pain caused by this type of fracture causes many patients to become bedridden. However, the initial pain generally diminishes after around 1 month and is replaced by dull pain in the lumbar and lumbosacral regions. We carried out a cross-sectional and longitudinal study of these fractures in 328 female outpatients with osteoporosis. All subjects initially presented at our hospital with back pain and bone mineral density measurements were taken using both dual energy X-ray absorptiometry and quantitative computed tomography. Our main findings were as follows. Decreased BMD appears to be one cause of vertebral body deformities. However, we found it difficult to predict whether deformities will progress or cause additional deformities of adjacent vertebral bodies, because the key contributing factors include not only BMD and age but also lifestyle and activity patterns. In addition, none of the drug administration methods investigated here resulted in a notable increase in BMD.