Implants failure in Hip with Intarmedullary Devices

Complications arising from fixation of unstable proximal femur fracture with PFN having 2 screws .


1.Z-effect


  lateral migration of caudal screw , varus collapse and perforation of femoral head by superior screw




2. Reverse Z-effect


  lateral  migration of superior screw , varus collapse and femoral head cut by inferior screw






Causes


 varus fixation of fractures , severe medial communition , inappropriate entry point and poor bone


  quality.




Intaoperative Procedures to stabilize unstable IT fractures


 Osteotomies and fixed with nail plate


  Design (Smith -Peterson nail plate  )


    e.g. 1. Dimon  -Hughston medial displacement Osteotomy


           2. Sarmiento Valgus Osteotomy


           3. Wayne -County lateral displacement Osteotomy


No evidence are there to support these osteotomies combined with sliding hip screw fixation .