Tension Band Wires

Abstract

The tension band principle states that if a column is subjected to eccentric loading, there are not only axial compressive forces but also additional bending forces that give rise to further compressive stresses and tensile stresses. In our example, the resultant compressive stresses equal 110 kilopounds/cm² and the tensile stresses equal 90 kilopounds/cm² (Fig. 7-1 A). These bending stresses can be neutralized by a chain, which represents a tension band. The resultant compression on the column now corresponds to the pressure exerted by the tension band placed on the tension side of the column at an equal distance from the center of the column as the 100 kilopound weight on the compression side. The compression forces have now been neutralized by the tension forces, and the compression on the column equals 200 kilopounds/ cm² (Fig. 7-1 B). Therefore eccentric bending or compressive stresses can be neutralized by similar tension forces eccentrically placed on the opposite side. The result is a summation of the forces in compression on the column or structure involved. In this case, we are talking about bone.