Inverse relation between osteoporosis and spondylosis in postmenopausal women as evaluated by bone mineral density and semiquantitative scoring of spinal degeneration

Study Design. The relation between bone mineral density and severity of spondylosis was evaluated in post-menopausal women. Objective. To examine the possible inverse relation between osteoporosis and spondylosis by evaluating the association between bone mineral density and osteophyte formation or intervertebral disc narrowing using a semiquantitative scoring system. Summary of Background Data. The literature contains studies demonstrating an inverse relation between osteoporosis and spondylosis as well as those documenting insufficient support for such a relation. However, in these studies, only limited-range grading systems (e.g., Grades 1-4) were used to evaluate the severity of spondylosis. Methods. In this study, 104 postmenopausal women older than 60 years underwent bone mineral density measurement of the lumbar spine (anteroposterior, lateral and midlateral) and proximal femur (femoral neck, trochanter, and Ward's triangle) using dual-energy x-ray absorptiometry. Raw data representing the semiquantitative osteophyte score and disc score as well as the number of vertebral fractures were obtained using spinal radiograph. Correlations between bone mineral density and the radiographic variable were then analyzed. Results. Significant negative correlations were found between all bone mineral density data and the number of vertebral fractures (-0.524 less than or equal to r less than or equal to -0.347; P < 0.05). Marginal/moderate positive correlations were observed between the osteophyte score and the bone mineral density data (0.263 ≤ r ≤ 0.580, P < 0.05), and between the disc score and the bone mineral density data (0.233 less than or equal to r less than or equal to 0.570, P < 0.05). Conclusions. On the basis of the finding that spondylotic changes in postmenopausal women exhibit positive correlations not only with the lumbar bone mineral density, but also with the remote-site bone mineral density, this study supports the view that osteoporosis has an inverse relation with spondylosis.