Femoral Tunnel Position on Conventional Magnetic Resonance Imaging After Anterior Cruciate Ligament Reconstruction in Young Men: Transtibial Technique Versus Anteromedial Portal Technique

Abstract

The purpose of this study was to compare clinical outcomes after single-bundle anterior cruciate ligament (ACL) reconstruction with a free Achilles tendon allograft using either a transtibial or an anteromedial portal technique and then to quantify the difference in femoral tunnel position between these 2 approaches. This assessment was to be performed with a new method using conventional magnetic resonance imaging (MRI) with a digital imaging system. In this prospective randomized comparative study, 53 young male patients with ACL rupture underwent ACL reconstruction with the transtibial technique (group 1) or the anteromedial portal technique (group 2). We assessed clinical outcomes with the Lachman test, pivot shift test, International Knee Documentation Committee (IKDC) classification, Lysholm score, Tegner activity scale, and single leg hop (SLH) test. Radiologic assessments included the position of the femoral tunnel aperture and the posterior cruciate ligament (PCL) index on conventional MRI and the side-to-side difference (SSD) on stress radiographs. Sixty-one participants had follow-up. The mean follow-up period was 30.2 months. At the last follow-up, there were no significant differences between the 2 groups in results from the Lachman test, pivot shift test, IKDC classification, Tegner activity scale, and SLH test. The Lysholm score and SSD results in group 2 were superior to those in group 1 (P < .001). The femoral tunnel aperture was positioned more posteriorly in group 2 than in group 1 (P < .001). Changes in the PCL index were greater in group 1 than in group 2 (P < .001). The position of the femoral tunnel aperture created with the anteromedial portal technique was more posterior than that made with the transtibial technique. Knees reconstructed with the anteromedial portal technique were more stable in Telos testing, and were 3 points higher on the Lysholm score. However, there were no statistically significant differences in the Tegner activity scale or IKDC classification between the 2 groups. Therapeutic level I, randomized controlled clinical trial.