[Mechanical study of stiffness in LIM-41 external fixator assemblages submitted to torsion strain]

The mechanical stiffness of LIM-41 external fixator assemlages submitted to torsional strain was studied. A condition of unstable fracture was reproduced. The authors evaluated the effect of of Schanz pin configurations, defined as "distal", "standard" and "proximal", and of the distance, 20 mm, 40 mm or 60 mm between the external fixator and the element employed to simulate bone. The authors conclude that stiffer LIM-41 assemblages are obtained if the "standard" or "proximal" configurations are employed, on which some pins are placed near the fracture simulation site, and if the external fixator body is fitted closer to the bone simulating element, having the former variable greater influence over the stiffness coefficient.