buletinul institutului politehnic din iaşi - Universitatea Tehnică ...

Bul. Inst. Polit. Iaşi, t. LVIII (LXII), f. 4, 2012 251
ii) the most loaded zone is the interface bone-Kirschner broaches, being
possible destruction of bone tissue at the considered value of traction force;
iii) the values between which the mechanical strees varies are the smallest
among the three analyzed osteosynthesis techniques; thus, this last surgical
technique is recommended from biomechanical point of view;
iv) deformations produced in the model are smaller with respect to those
from the technique with only broaches and wire (previous case);
v) theoretically, as resulting from simulation, there are not relative
displacements between fracture fragments, these being very smal, by the order
of microns, being insignificant;
vi) theoretically, if destruction of the porous bone tissue arround the
broaches would not occur, the patient could stress the ankle in normal gait
condition, without relative displacement of the fracture fragments.
Fig. 9 – General view for tibia-broaches-cortical screw-bracing wire.
The osteosynthesis technique with Kirschner broaches, cortical screw and
bracing wire ensures a very good stability of fracture fragments, even when the
ankle is loaded with forces equal to the entire body weight. In reality, due to
patient immobilisation until the bone is completely recovered, as well as due to
the fact that mechanical load acting on the ankle is smaller, of approximately 30
… 50 N, fracture fragments have not any relative displacement one to each
other.