Resistance of cerclage to knot failure.

The comparative ability of loop-knotted and twist-knotted cerclage to withstand tensile forces was tested. Two twist-knot devices and one loop-knot device were used to apply cerclage wires to a 5-cm diameter split circular jaw mounted on a tensile testing machine. Twist-knot devices were tested with 0.8-, 1.0-, or 1.2-mm wire, and the loop-knot device was tested with 0.8-, 1.0-, or 1.25-mm wire. For all wire sizes, the twisted knot provided greater resistance to knot failure than did the loop-knot. Of the 2 twist-knot devices, the Rhinelander wire tightener-twister produced the greatest resistance to knot failure. Knot resistance increased with increase in wire size for all devices tested.