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

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. 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. The fixation site profile was lower in the T-anchor group than in the EndoButton Direct group (2.3±0.4mm vs. 4.7±1.0mm, 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±8.9mm vs. 115.0±8.7mm, P<0.001). The mean cyclic elongation was lower for the T-anchor group when compared with the EndoButton Direct group (2.4±0.6mm vs. 3.9±2.6mm, 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. 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.