Pedicle screw insertion torque positively correlated with bone mineral density in osteoporotic patients

Lee J. J Bone Joint Surg. 2012. doi:10.1302/0301-620X.94B1.27032.

Bone mineral density is positively correlated with the maximum torque required to insert a pedicle screw during posterior lumbar screw fixation in patients with osteoporosis and osteopenia, according to recently published research.

In 181 patients with degenerative disease of the lumbar spine, researchers found positive correlations between bone mineral density (BMD) and T-values in the instrumented lumbar vertebrae, between mean BMD and T-values in the lumbar vertebrae and between mean BMD and T-values in the proximal femur, according to the abstract. Patients were analyzed by dual-energy X-ray absorptiometry and were measured during surgery for screw placement.

“The positive correlation between BMD and the maximum torque required to insert a pedicle screw suggests that preoperative assessment of BMD may be useful in determining the ultimate strength of fixation of a device, as well as the number of levels that need to be fixed with pedicle screws in patients who are suspected of having osteoporosis,” the authors wrote