Flexor tendon repair using sutures with different cross sectional areas -

Abstract

Tendon repair surgeries are critical and challenging since the repair site must be capable of sustaining passive and active immobilization forces with a configuration that would ensure the integrity of the tendon to regenerate and heal. In addition, minimum adhesion should be guaranteed between the tendon and its surrounding. This can be attained by allowing early mobilization. Thus, the suture should withstand relatively high value forces. Previous work had focused on having sutures with multiple strands. This was found to jeopardize the integrity of the tendon since it might lead to crossing through the blood vessels. This also depends on the skill of a surgeon to avoid having strands crossing and breaking one another. The goal of this proposal is to assess the validity of using a single suture for tendon. The focus in this work is on investigating the effect of having a single barbed suture wires for tendon repair surgeries. The target is to maximize the stress that the suture can withstand which is accomplished by a novel approach of investigating the effect of the suture cross-sectional area. Seven different cross-sectional areas were considered with three different depths of cut and three angles of cut. Two loading conditions were also analyzed where a finite element analysis was used to identify barbed suture parameters that maximize its strength. Rather than using circular suture material, an elliptical cross sectional area is considered with different ratios of minor to major axes (ρ = b-a). In addition different depths of cut and angles of cut are also tested in ANSYS Workbench using finite element analysis techniques. The results show that a barbed suture with the following parameters of 0.18 mm depth of cut, 150° angle of cut, and ρ = 3, produced the lowest stresses within the material of the barb itself, while parameters with 0.18mm depth of cut, 160° angle of cut, and ρ = 4 demonstrated lowest stress within the entire suture. The stress values in these two best conf