Effect of suturing the femoral portion of a four-strand graft during an ACL reconstruction

Abstract

Purpose A suture passed along the part of the graft that will be inserted into the femoral tunnel is widely used by surgeons, because it could prevent the graft sliding on the femoral fixation device during pulling from the tibial side. The aim of this study was to evaluate the biomechanical effects of suturing the intratunnel femoral part of the graft during an anterior cruciate ligament (ACL) reconstruction. Methods Bovine digital extensor tendons and tibias were harvested from 20 fresh-frozen mature bovine knees ranging in age from 18 to 24 months. Quadruple-strand bovine tendons were passed through the tibial tunnel and secured distally with a bioabsorbable interference screw. In one half of all grafts (N = 10), the looped-over part of the graft was sutured in a whipstitch technique over a distance of 30 mm (Group 1). In one half of all grafts (N = 10), the looped-over part was left free from any suture (Group 2). The grafts were preconditioned at 50 N for 10 min, followed by cyclic loading at 1 Hz between 50 N and 250 N for 1,000 cycles. Load-to-failure test was then carried out at a rate of 1 mm/s. Results There was no statistically significant difference between mean stiffness at pullout and yield load between the two groups. In all specimens on Group 1, failure occurred following to partial breaking and then slipping of the tendons between the screw and the tunnel. Concerning Group 2, in six cases failure occurred as described for Group 1 specimens. In the remaining four cases, failure occurred entirely through the ligament mid-substance. Conclusions Suturing in a whipstitch fashion the femoral portion of the graft doesn't affect the mechanical proprieties of the ACL graft. When suspension fixation device is used, suturing the looped-over part of the graft could be helpful in order to provide equal tension in all of the strands of the graft at time of tibial fixation.

Does thread shape affect the fixation strength of the bioabsorbable interference screws for anterior cruciate ligament reconstructions? A biomechanical study

“…A load protocol of 50–250 N over 1000 cycles represents an aggressive, but typical, rehabilitation protocol [19]. During our tests, 10% of each type of screw failed, which is a similar failure ratio reported by other researchers that used interference screws and similar load protocols [15, 18].…”

“…The 1000 cycles approximated one week of flexion-extension loading on an ACL reconstruction [18]. This testing simulated an aggressive, but typical, rehabilitation protocol after an ACL reconstruction [19]. The 300 N load is the upper force expected during normal daily activities, so cyclic testing up to 300 N simulated peaks occurring postoperatively [16].…”

Does the 5-strand-graft have superior biomechanical behaviour than 4-strand-graft during ACL reconstruction?

“…Another explanation could be that the whip-stitched portion of the 5-strands-graft might exhibit a different intrinsic stiffness rather than a free quadruple bundle. In fact, if a part of the graft is stitched, and the stitching is able to stiffen the graft locally, the overall stiffness of the graft will then be higher (6). This finding significantly differs from what have been reported recently in literature (18,19), and could depend by many factors such us stripling technique, suture used for graft preparation and biomechanical protocol of graft testing.…”

“…All tendon grafts were immediately wrapped in a normal saline soaked gauze, stored at -38 °C and then thawed at room temperature 12 h before use. Continuous saline graft irrigation was performed throughout the preparation and mechanical testing to prevent drying (6). As per standard intra-operative technique, each tendon ends were separately whipstitched with no.…”

Whether Sutures Reduce the Graft Laceration Caused by Interference Screw in Anterior Cruciate Ligament Reconstruction a Biomechanical Study in Vitro

“…During ACL reconstruction, suturing the free ends of ACL grafts in a whipstitch fashion is a simple procedure, which helps surgeons to handle the graft and maintain an equal tension among the graft strands [13]. Previous studies had demonstrated that suturing the free ends of the graft significantly affected the biomechanical properties of graft-bone complex [14,15].…”