Who: Brian Rhee; Steven M. Tommasini, PhD; Kenneth Milligan, MD; Julia Morton; Michael Leslie, DO, FAOA; Daniel H. Wiznia, MD

Overview: The frequency of hip fractures is the main cause of morbidity and death in elderly patients, and is expected to increase exponentially in the next few decades. The purpose of this study was to evaluate the ability of stainless steel hollow screws to reduce the risk of femoral neck fractures during preventive placement before a fall.

The author uses 3D image processing and model generation software to create a finite element model from a 3D model of an elderly patient based on a computed tomography (CT) scan. The researchers used linear finite element simulations to analyze the effects of the cannulated proximal femur screw on one-leg standing and lateral falls, and deal with peak von Mises stress and component failure.

Preventive placement of the hollow screw significantly reduced the failure of the proximal femur due to osteoporosis in a lateral fall. Three screws implanted in the form of an inverted triangle reduced proximal femoral trabecular failure by 21% and cortical failure by 5%. Femoral neck failure was reduced by 55%, and lateral cortex failure was reduced by 14%.

The results show that the hollow hip screw in the inverted triangle structure can strengthen the osteoporotic proximal femur in the event of a lateral fall. Mechanical tests on cadavers or composite models are required to verify these results.