Photoelastic Study of Wound Closure Stresses in Barbed Versus Traditional Smooth-Surface Sutures

Sutures are used widely in the medical community for wound closure. Traditional sutures have a smooth surface and secure a wound by means of a knot tied at either end, which tensions the suture and holds the wound closed. However, biomechanical testing of traditional sutures has demonstrated that the knot is the most common site of failure due to a decrease in the tensile strength. In an effort to minimize knot failure of monofilament sutures, barbed sutures have been developed that obviate the need for knots during wound closure. In this study, the photoelastic coating method was employed to perform a comparative measurement of the stresses induced in the wound region for barbed versus monofilament sutures under wound flexure. Because of the difficulty in using actual sutured wounds, a wound analog model was employed made of a special foam material commonly used by surgeons for practicing wound closure skills. An examination of the changes that occurred in the incision line fringe numbers during flexure of the wound analog model was then used as an in vitro measurement of the effectiveness of barbed versus monofilament sutures in retaining simulated wound closure stress magnitude and distribution.