Mechanical properties of sutures used in anchoring of ACL-grafts

The fixation of hamstring grafts in ACL reconstruction requires a connector device. During the process of ingrowing the graft stability depends entire ly on the fixation. The following study focused on the mechanical condition s of no 6 Ethibond, 5 mm Mersilene tape and 5 mm Polylene tape. The materia l were tested as loops with a length of 30 mm including the knot similar to intraoperative conditions. The ultimate tension load and elongation of the conditioned and unconditioned loops were investigated under cyclic load of 50 N and 100 N using a tension load machine. The ultimate tension load inc reased significantly on ly for Mersilene from 416 N to 462 N. However, the highest ultimate tension load showed Polylene with 479 N. The oscillating l oad up to 100 N revealed for unconditioned loops an elongation of 4.1 mm fo r Ethibond, 2.9 mm for Polylene and 5.4 mm for Mersilene. The elongation de creased significantly for the conditioned loops to a maximum of 1.4 mm. Con cerning the amplitude during the period of oscillating load there was found a significant reduction as well. Based on our results Polylene showed the best mechanical properties. Regardless the intraoperatively used material w e advocate the conditioning of the loops before anchoring the hamstring gra ft in ACL reconstruction.