title: Graft-bending angle and femoral tunnel length after single-bundle anterior cruciate ligament reconstruction: comparison of the transtibial, anteromedial portal and outside-in techniques.
abstract: We used immediate post-operative in vivo three-dimensional computed tomography to compare graft bending angles and femoral tunnel lengths in 155 patients who had undergone single-bundle reconstruction of the anterior cruciate ligament using the transtibial (n = 37), anteromedial portal (n = 72) and outside-in (n = 46) techniques. The bending angles in the sagittal and axial planes were significantly greater but the coronal-bending angle was significantly less in the transtibial group than in the anteromedial portal and outside-in groups (p < 0.001 each). The mean length of the femoral tunnel in all three planes was significantly greater in the transtibial group than the anteromedial portal and outside-in groups (p < 0.001 each), but all mean tunnel lengths in the three groups exceeded 30 mm. The only significant difference was the coronal graft- bending angle in the anteromedial portal and outside-in groups (23.5° vs 29.8°, p = 0.012). Compared with the transtibial technique, the anteromedial portal and outside-in techniques may reduce the graft-bending stress at the opening of the femoral tunnel. Despite the femoral tunnel length being shorter in the anteromedial portal and outside-in techniques than in the transtibial technique, a femoral tunnel length of more than 30 mm in the anteromedial portal and outside-in techniques may be sufficient for the graft to heal.
authors.affiliation: Seonam Hospital, Department of Orthopaedic Surgery, Seoul, Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Shin
authors.affiliation: Anam Hospital, Department of Orthopaedic Surgery, Korea University, College of Medicine, Seoul, Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Ro
authors.affiliation: Anam Hospital, Department of Orthopaedic Surgery, Korea University, College of Medicine, Seoul, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Jeon
authors.affiliation: Anam Hospital, Department of Orthopaedic Surgery, Korea University, College of Medicine, Seoul, Korea.
authors.forename: D H
authors.initials: DH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001182:Arthroscopy / Q000379:methods; D015331:Cohort Studies; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
keywords: 3D-CT; Anterior cruciate ligament reconstruction; Anteromedial portal; Curved planar reformation; Outside-in; Transtibial