Biomechanical comparison of different surgical suture techniques for four-stranded all-inside cruciate ligament grafts

Background: All-inside cruciate ligament reconstruction is an emerging technique for treating anterior cruciate ligament and posterior cruciate ligament injuries. The all-inside technique uses a 4-stranded graft made of a single tendon that wraps around itself. Four strands of the graft must be immobilized to form a closed loop, and the free ends of the graft must be attached using a suture technique. There is currently no "optimal" or "standard" suture technique for attaching the free ends of grafts. Methods: Twenty porcine flexor tendons retrieved from hind limbs were prepared for quadrupled-strand grafts using four different methods:1. using the whipstitch technique and a new suture technique with a side-to-side graft configuration (w-s graft, new S-S graft), 2. using the Krackow suture technique and Kessler suture technique with an end-to-end graft configuration (Krackow graft, Kessler graft). Followed by tensile testing (including preconditioning). Finding: Among the tested techniques, the quadrupled-strand grafts formed with the new suture technique performed best in terms of ultimate failure load (931.03 +/- 20.53 N) and stiffness (236.85 +/- 9.73 mm), with a statistically significant difference between side-to-side grafts and end-to-end grafts in terms of ultimate failure load in both groups. The new side-to-side graft (5.30 min) showed the shortest graft preparation time. Interpretation: There is no doubt that the new suture technique described here has higher tensile and breaking forces than other four-strand suture techniques and is superior to other technologies in terms of preparation time, and side-to-side grafts performed better biomechanically than the end-to-end graft configuration.