The purpose of this study was to examine DHS and retrograde IM nail configurations, with an emphasis placed on DHS side plate screw configuration and placement, in order to determine a suitable construct that will maximise strength and stiffness.
A total of 29 synthetic left femora (-Sawbones Model 1100; Pacific Research Laboratories, Vashon, Washington) were divided into three different groups to evaluate the biomechanical performance of different DHS and retrograde IM nail configurations.
Different versions of this latter model were tested by simulation, including single and dual positive feedback loops, and a composite negative feedback configuration wherein the retrograde signal represses the original anterograde entity, thus periodically resetting the system.
Firstly, Mathieu et al. used different kinds of nails (Elastic nails, Kirschner wires, and telescoping rods) and also different configurations (antegrade or retrograde).
The latter configuration generates an oscillating retrograde signal, with frequencies that decrease as a function of increasing cell length.
Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies.
The universal shape can actually be retrograde.
However, even though past studies have shown the efficacy of DHS and retrograde IM nail fixation for ispilateral fractures, the optimal screw configuration of the screws in the DHS side plate to the IM nail is not known.
A recent study examining three different configurations in intact cadaveric femora using DHS and retrograde IM nail showed that specimens with overlapping implants had higher load to failure.
Model configurations examined included a range of MTS per batch of between 20-400 (inconfigurationsuratiofs of different numbers of MTS per batch for anterograde versus retrograde signals), and activation or inhibition thresholds of between 10 and 100 MTS.
