COMPARATIVE-STUDY OF THE HOLDING STRENGTH OF SLIPKNOTS USING ABSORBABLE AND NONABSORBABLE LIGATURE MATERIALS

The holding and tensile characteristics of five extracorporeal slipkno ts in relation to absorbable and nonabsorbable ligature materials have been evaluated in a standardized in vitro test rig. The knots studied : Tayside, Roeder, Melzer (modified Roeder), Cross square, and Blood k nots were tied with the following materials: silk, polyamide, Dacron, polydioxanone (PDS), and lactomer (Polysorb). Following construction a nd slippage (run down) to a fixed-diameter loop around a cylinder, the knots were locked (tightened) using a standardized force after which they were removed from the test rig and subjected to holding strength (force required to induce reverse slippage) and other tensile characte ristics (stress, strain, elasticity) by a tensiometer. Analysis of the data has demonstrated the following: (1) The safest slip knots (resis t slippage) are the Tayside, Melzer, and Roeder knots tied with lactom er and Dacron. (2) The holding strengths of the Cross square and Blood knots are weak with all ligature materials tested. (3) Polydioxanone is a safe ligature material for the Melzer and Tayside but not the Roe der knot. (4) Extracorporeal slipknots tied with silk and polyamide ar e less secure than the equivalent knots tied with Dacron, lactomer, an d polydioxanone.