A new femoral fixation device for anterior cruciate ligament reconstruction using the outside-in technique and hamstring tendon graft: A comparison between two devices in cadaveric human knee models

Abstract

Background: A new device (T-anchor) was developed for ACL reconstruction and is implanted via the outside-in technique using hamstring grafts. The purpose of this study was to compare the T-anchor with the EndoButton Direct. Methods: This study was conducted on 30 cadaveric knees (15 matched pairs). There were two groups of 15 each in the T-anchor and EndoButton Direct groups. After the harvest of grafts, fixation site profile and graft length were measured by loading the grafts onto both devices. They were then tested on a universal testing machine to assess elongation after cyclic loading, load to failure, ultimate load, and mode of failure. Results: The fixation site profile was lower in the T-anchor group than in the EndoButton Direct group (2.3 +/- 0.4 mm vs. 4.7 +/- 1.0 mm, P < 0.001). The length of the graft-device complex of the T-anchor specimens was longer than that of the EndoButton Direct specimens (125.0 +/- 8.9 mm vs. 115.0 +/- 8.7 mm, P < 0.001). The mean cyclic elongation was lower for the T-anchor group when compared with the EndoButton Direct group (2.4 +/- 0.6 mm vs. 3.9 +/- 2.6 mm, P = 0.015). There was no statistically significant difference in ultimate load and load to failure between the T-anchor and EndoButton Direct groups. For mode of failure, the T-anchor fared better (P = 0.013) with all failures attributed to specimens. Conclusions: In this cadaveric study, the new device, T-anchor, performed better than the EndoButton Direct with respect to the above-mentioned study parameters except for ultimate load and load to failure. (C) 2017 Elsevier B.V. All rights reserved.