Preparation techniques for all-inside ACL cortical button grafts: a biomechanical study

Purpose Performing all-inside anterior cruciate ligament reconstruction using cortical button fixation, the tendon graft has to be secured in a closed loop with sutures. In the present study, the graft secured with four sutures was compared with two reduced-suture material graft preparation techniques. Methods A bovine tendon graft folded over two adjustable-length loop cortical button devices was secured using the following techniques: 1, four buried-knot sutures; 2, two sutures on the tibial end only; and 3, two sutures on the tibial graft end with additional suspension on the tibial cortical button. Each group consisted of eight specimens and underwent cyclic loading followed by a load-to-failure test. Results The least graft elongation after cyclic loading was observed for the graft with four sutures (6.1 ± 0.6 mm), followed by the graft with two sutures and additional suspension (6.3 ± 0.8 mm) and the graft with two sutures (7.0 ± 0.7 mm). The difference in graft elongation between four sutures and only two sutures was significant ( P < 0.05). The ultimate failure loads were highest for the graft with two sutures and additional suspension (801 ± 107 N), followed by the graft with four sutures (766 ± 70 N), and the graft with two sutures (699 ± 87 N). No significant (n.s.) differences were observed between the ultimate failure loads in the three groups. Conclusions For the reduction in suture material to two sutures, additional suspension can be used in order to reduce the graft lengthening. Performing a suture-reducing graft can save operating time and costs. However, each of the three all-inside button graft techniques showed considerable graft elongation indicating a risk of graft lengthening in the early postoperative period.