title: Differences in graft orientation using the transtibial and anteromedial portal technique in anterior cruciate ligament reconstruction: a magnetic resonance imaging study.
abstract: The purpose of this study was to evaluate differences in graft orientation between transtibial (TT) and anteromedial (AM) portal technique using magnetic resonance imaging (MRI) in anterior cruciate ligament (ACL) reconstruction. Fifty-six patients who were undergoing ACL reconstruction underwent MRI of their healthy and reconstructed knee. Thirty patients had ACL reconstruction using the TT (group A), while in the remaining 26 the AM (group B) was used. In the femoral part graft orientation was evaluated in the coronal plane using the femoral graft angle (FGA). The FGA was defined as the angle between the axis of the femoral tunnel and the joint line. In the tibial part graft orientation was evaluated in the sagittal plane using the tibial graft angle (TGA). The TGA was defined as the angle between the axis of the tibial tunnel and a line perpendicular to the long axis of the tibia. The ACL angle of the normal knee in the sagittal view was also calculated. The mean FGA for group A was 72 degrees, while for the group B was 53 degrees and this was statistically significant (P < 0.001). The mean TGA for group A was 64 degrees, while for the group B was 63 degrees (P = 0.256). The mean intact ACL angle for group A was 52 degrees, while for the group B was 51 degrees. The difference between TGA and intact ACL angle was statistically significant (P < 0.001) for both groups. Using the AM portal technique, the ACL graft is placed in a more oblique direction in comparison with the TT technique in the femoral part. However, there are no differences between the two techniques in graft orientation in the tibial part. Normal sagittal obliquity is not restored with both techniques.
authors.affiliation: Department of Orthopaedic Surgery, Medical School, University Hospital of Larissa, University of Thessalia, Mezourlo, 41110 Larissa, Greece. hantesmi@otenet.gr
authors.forename: Michael Elias
authors.initials: ME
authors.lastname: Hantes
authors.forename: Vasilios C
authors.initials: VC
authors.lastname: Zachos
authors.forename: Athanasios
authors.initials: A
authors.lastname: Liantsis
authors.forename: Aaron
authors.initials: A
authors.lastname: Venouziou
authors.forename: Apostolos H
authors.initials: AH
authors.lastname: Karantanas
authors.forename: Konstantinos N
authors.initials: KN
authors.lastname: Malizos
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D013710:Tendons / Q000637:transplantation*; D014182:Transplantation, Autologous