Asymmetry in Femoral Tunnel Socket Length During Anterior Cruciate Ligament Reconstruction With Transportal, Outside-In, and Modified Transtibial Techniques

摘要

Purpose: To investigate the mismatch between the length at the center and the length on the shortest and longest peripheral sides of the femoral tunnel socket, reamed with the transportal (TP), outside-in (OI), and modified transtibial (TT) techniques, in anterior cruciate ligament (ACL) reconstruction. Methods: Femoral tunnel drilling was simulated on 3dimensional bone models from 40 subjects. The tunnel directions used with the TP, OI, and modified TT techniques were previously described. By use of the resulting angle, a femoral tunnel socket of 9 mm in diameter was drilled from the center of the femoral ACL insertion. The virtual femoral tunnel was extracted, and the length mismatch was measured between the center and the shortest and longest peripheral sides of the tunnel socket. Results: The mean socket length mismatch between the center and the shortest peripheral part of the femoral tunnel socket was 4.2 +/- 0.9 mm with the TP technique, 5.2 +/- 1.3 mm with the OI technique, and 3.2 +/- 0.8 mm with the modified TT technique. The mean socket length mismatch between the center and the longest peripheral part of the femoral tunnel socket was 3.5 +/- 0.9 mm with the TP technique, 4.8 +/- 1.5 mm with the OI technique, and 3.3 +/- 1.2 mm with the modified TT technique. The length mismatch was significantly higher when the tunnel socket was created by the OI technique (P < .01). Conclusions: A length mismatch with the tunnel socket exists after reaming with either the TP, OI, or modified TT technique. In particular, there was a significant increase in length mismatch when the tunnel socket was created by the OI technique, and the length mismatch would easily become greater than 5 mm. The surgeon should recognize this mismatch when it is created and measure the femoral tunnel socket.