External fixation of the leg using unilateral biplanar frames.

A simple and reliable method is described for testing the stability of external fixators under stresses similar to those found in clinical practice. Unilateral uniplanar, unilateral biplanar, and bilateral uniplanar frames were used. It seemed important to measure deformations under bending stresses in different planes, because we have found a variable rigidity in some of the frames in the different planes. Our results show that a unilateral biplanar frame without transfixation pins can be set up with an overall rigidity as good as that of a bilateral frame. Using this on the leg, one can avoid putting pins through the anterolateral compartment.