Objectives. The use of two implants to manage concomitant ipsilateral femoral shaft and proximal femoral fractures has been indicated, but no studies address the relationship of dynamic hip screw (DHS) side plate screws and the intramedullary nail where failure might occur after union. This study compares different implant configurations in order to investigate bridging the gap between the distal DHS and tip of the intramedullary nail. Methods. A total of 29 left synthetic femora were tested in three groups: 1) gapped short nail (GSN); 2) unicortical short nail (USN), differing from GSN by the use of two unicortical bridging screws; and 3) bicortical long nail (BLN), with two angled bicortical and one unicortical bridging screws. With these findings, five matched-pairs of cadaveric femora were tested in two groups: 1) unicortical long nail (ULN), with a longer nail than USN and three bridging unicortical screws; and 2) BLN. Specimens were axially loaded to 22.7 kg (50 lb), and internally rotated 90°/sec until failure. Results. For synthetic femora, a difference was detected between GSN and BLN in energy to failure (p = 0.04) and torque at failure (p = 0.02), but not between USN and other groups for energy to failure (vs GSN, p = 0.71; vs BLN, p = 0.19) and torque at failure (vs GSN, p = 0.55; vs BLN, p = 0.15). For cadaveric femora, ULN and BLN performed similarly because of the improvement provided by the bridging screws. Conclusions. Our study shows that bicortical angled screws in the DHS side plate are superior to no screws at all in this model and loading scenario, and suggests that adding unicortical screws to a gapped construct is probably beneficial

Objectives

Because of the contradictory body of evidence related to the potential benefits of helical blades in trochanteric fracture fixation, we studied the effect of bone compaction resulting from the insertion of a proximal femoral nail anti-rotation (PFNA).

Introduction

The objective of this study was to determine if a synthetic bone substitute would provide results similar to bone from osteoporotic femoral heads during in vitro testing with orthopaedic implants. If the synthetic material could produce results similar to those of the osteoporotic bone, it could reduce or eliminate the need for testing of implants on bone.