Optimum surgical suture material and methods to obtain high tensile strength at knots: problems of conventional knots and the reinforcement effect of adhesive agent.

Background: Strong suture material and a firmly tight knot that never loosens are necessary for tendon suture, but the appropriate combination of suture materials and the methods to make a knot are matters of uncertainty.

Methods: The tensile strength of four conventional tendon suture materials (Surgilon, Ethibond, Ethilon, PDS II) and newly developed FiberWire were examined. An experienced orthopedic surgeon formed surgical knots with USP2 wire (0.5-0.599 mm in diameter) by making loops and then pulled them at 20 mm/min using Instron.

Results: With the conventional surgical suture method (the addition of one throw on a surgeon's knot), Surgilon proved to have the highest tensile strength (163.6 +/- 6.5 N). Other suture materials, when tied under the same conditions, slipped and did not reach the ultimate tensile strength. When four additional throws were made, FiberWire provided the highest tensile strength (316.6 +/- 12.2 N) among the five suture materials tested (others were 140-200 N). When an adhesive agent, cyanoacrylate, was applied to a knot, PDS II provided the highest tensile strength (182.0 +/- 10.1 N).

Conclusions: Our study suggests three suitable combinations of suture materials and methods for suture knot formation, depending on the site of surgery, that provide optimum treatment outcomes. Surgilon provides the most stable strength for general suture techniques. FiberWire is the strongest suture material for a site where a large number of throws is clinically possible. PDS II provides a strong suture when combined with cyanoacrylate reinforcement.