Interest of Navigation for the Treatment of Pertrochanteric Fractures With the Gamma 3 Nail

The main orthopedic complication after fixation of a proximal femoral fracture with a cephalo-medullary nail is the cut-out of the cephalic screw from femoral head resulting in a protrusion of this screw in the coxo-femoral joint, mostly during the first 6 months after the operation. In most cases, the surgeon has to remove the primary implant and perform a total hip arthroplasty to his patient, therefore rising the morbidity and social costs linked to the treatment of the initial fracture.

Baumgartner showed the importance of the position of the cephalic screw for predicting failure of the implant and proposed a new measurement to evaluate this position, the tip-apex distance which is the sum of the distance from the tip of the cephalic screw to the apex of the femoral head on an anteroposterior radiograph and this distance on a lateral radiograph, after controlling for magnification. He showed a lower TAD was associated with a lower risk of cut-out.

The aim of this study is to evaluate the help of a 3D reconstruction software linked to the standard fluoroscopy in achieving the lowest TAD and therefore minimizing the cut-out rate.