Evaluating different closed loop graft preparation technique for tibial suspensory fixation in ACL reconstruction using TightRope™

Takahisa Sasho; Toshihide Sasaki; Hiroko Hoshi; Ryuichiro Akagi; Takahiro Enomoto; Yusuke Sato; Ryosuke Nakagawa; Masamichi Tahara; Satoshi Yamaguchi

doi:10.1016/j.asmart.2018.01.002

Evaluating different closed loop graft preparation technique for tibial suspensory fixation in ACL reconstruction using TightRope™

Asia Pac J Sports Med Arthrosc Rehabil Technol. 2018 Mar 7:12:5-11. doi: 10.1016/j.asmart.2018.01.002. eCollection 2018 Apr.

Authors

Takahisa Sasho^{1

2}, Toshihide Sasaki¹, Hiroko Hoshi¹, Ryuichiro Akagi¹, Takahiro Enomoto¹, Yusuke Sato¹, Ryosuke Nakagawa¹, Masamichi Tahara³, Satoshi Yamaguchi¹

Affiliations

¹ Department of Orthopaedic Surgery, Graduated School of Medicine, Chiba University, 1-8-1, Inohana, Cyuou, Chiba, 260-8677, Japan.
² Musculoskeletal Disease and Pain, Center for Preventive Medical Sciences, Chiba University, 1-8-1, Inohana, Cyuou, Chiba, 260-8677, Japan.
³ Department of Orthopaedic Surgery, Chiba-East-Hospital, 673, Nitona, Cyou, Chiba, Japan.

Abstract

In most anterior cruciate ligament (ACL) reconstructions, grafts are fixed to the femoral side first followed by the tibial side. Various techniques have been reported to achieve optimal tension on the grafts, but once the grafts are fixed it is difficult to adjust graft tension further. To enable post fixation tension control we have invented a new graft configuration using an adjustable loop-device (TightRope^TM, Arthrex, FL, USA) on the tibial side. In this paper, biomechanical properties of this configuration using soft tissue were examined in terms of graft diameter and various suture techniques (referred to as base suture) to make a closed circle to support TightRope^TM. Two experiments were conducted under different conditions. In each experiment, cyclic load, followed by a pull-to-failure load, was applied to the grafts and elongation and failure mode were recorded. (1) To evaluate the effects of diameter, 5.0 or 6.0 mm grafts were prepared by a single locking loop stitch as the base suture (SLL5, SLL6). (2) To evaluate different base sutures, 5.0 mm tendons were used, and grafts were prepared using five kinds of base sutures (SLL, ZLL: zigzag locking loop, DZLL: double zigzag locking loop, DK: double Krackow, DK w/o TR: double Krackow without TightRopeTM). In the first experiment, tearing was observed in 2 of 6 cases in the SLL5 test group, whereas no tearing was observed with SLL6. In the second experiment, no tearing was observed with DZLL or DK. Elongation was smaller in these two groups compared to the other groups. Mechanical strength decreases with a smaller graft diameter. Biomechanical properties differed with different base sutures and, among them, the double-zigzag-suture stitch and double Krackow provided less elongation and higher ultimate load in this graft configuration.