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). . Methods. We developed a subject-specific computational model of a trochanteric
fracture (31-A2 in the AO classification) with lack of medial support
and varied the bone density to account for variability in bone properties
among hip fracture patients. Results. We show that for a bone density corresponding to 100% of the
bone density of the cadaveric femur, there does not seem to be any
advantage in using a PFNA with respect to the risk of blade cut-out.
On the other hand, in a more osteoporotic femoral head characterised
by a density corresponding to 75% of the initial bone density, local
bone compaction around the helical blade provides additional bone
purchase, thereby decreasing the risk of cut-out, as quantified
by the volume of bone susceptible to yielding. Conclusions. Our findings indicate benefits of using a PFNA over an intramedullary
nail with a conventional lag screw and suggest that any clinical
trial reporting
