Biomechanical features of long bones indicate that external fixation of long
bone fractures have to be balanced according to general transversal stability
as more as possible. The aim of this work was to investigate the influence of
orientation pins to the general transversal stability of external fixation of
fractures of long bones. In this study we have used the model of fractured
long bone made of wood which was treated by Mitkovic external fixator with 4
pins, in 3 different situations: 1. all pins are in one axial plane, 2. each
2 pins are in 2 axial planes with angle distances of 60o, 3. each 2 pins are
in 2 axial planes wich are normal to each other. Means of relations of
measured movements of long bone model fragments during the use of
perpendicular force from 2 directions, normal to each other, after grouping
of results in 3 groups: 0,17, 0,46 i 0,72. Statistical analyses showed that
the differences between each of 3 groups were significant (p<0,05). It can be
concluded that it is better if pins are oriented in different axial planes,
with pretension that both planes are normal to each other, during external
fixation of long bone fractures.