Biomechanical Performance of an Injectable Screw for Fixation in Severely Osteoporotic Bone: an Experimental Study

INTRODUCTION Pedicle screw fixation in a severely osteoporotic spine remains a challenge for orthopaedic surgeons. Previous studies have demonstrated that pedicle screw fixation is highly correlated to the bone mineral density [1], and increasing the screw’s pullout strength can be achieved using a variety of methods, these include the use of pedicle screws with various designs [2,3]. However, the literature on the effects of radial holes for cannulated screws with cement injection and pilot-hole tapping on the bone/screw interfacial strength is lacking. To increase the effectiveness of securing a pedicle screw on severe osteoporosis patient, this work examines how a self-designed cannulated pedicle screw with various numbers of radial holes injected with bone cement can increase the interfacial strength. The effect of pilot-hole tapping prior to screw insertion was also examined.