title: Normal sagittal of the anterior cruciate ligament can be reproduced using accessory anteromedial portal technique: a magnetic resonance imaging study.
abstract: BACKGROUND
  Over time, the need for anatomic anterior cruciate ligament (ACL) to restore normal kinematics and postoperative function of the knee has been accepted. The purpose of this study was to compare the sagittal alignment of reconstructed ACL, which is performed between transtibial (TT) technique and accessory anteromedial (AAM) portal technique and between the reconstructed and the normal side in the same patient. In addition, we used the head of a metallic femoral interference screw as a reference to measure the femoral tunnel position.
  
  
  METHODS
  This was a retrospective study with 15 patients in each group: accessory anteromedial portal technique (n = 15), TT technique (n = 15) and contralateral normal side of each technique group (15 knees per technique). Magnetic resonance images of the ACL sagittal angle and radiographs of the coronal screw angle were used for comparing the two groups. The paired t test was used to compare operated and contralateral normal knee and independent t test was used to compare the TT and the AAM groups.
  
  
  RESULTS
  The sagittal angle of ACL of AAM technique (51.6 ± 3.3°) was not different from the normal side (50.8 ± 2.1°) (P = 0.270), however that of the TT technique (59.9 ± 5.7°) was significantly different from the normal side (50.9 ± 2.4°) (P < 0.001). The sagittal angle of AAM technique was significantly lower than that of the TT technique (P < 0.001). The coronal angle of the screw to axis of the femur in AAM technique (51.7 ± 3.8°) was more horizontal than that of the TT technique (24.4 ± 8.9°) (P < 0.001). The center of the screw head of the AAM technique was 30.7 ± 3.1 % of the Blumensaat line and 39.2 ± 5.2 % of the condylar height.
  
  
  CONCLUSIONS
  The anatomic sagittal angle of ACL can be achieved using the AAM technique compared with the TT technique. In addition, the angle of the screw in coronal plane was more horizontal using the AAM technique than with use of the TT technique.
  
  
  METHODS
  Level III, diagnostic study.
authors.affiliation: Department of Orthopaedic Surgery, The Armed Forces Capital Hospital, 2 Yul-dong, Bundang-gu, Seongnam, Gyeonggi-do, Korea.
authors.forename: Yool
authors.initials: Y
authors.lastname: Cho
authors.forename: Jaeho
authors.initials: J
authors.lastname: Cho
authors.forename: Dongwook
authors.initials: D
authors.lastname: Kim
mesh_terms: D016118:Anterior Cruciate Ligament / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation / Q000379:methods*; D001863:Bone Screws; D005269:Femur / Q000601:surgery; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D011859:Radiography; D012189:Retrospective Studies; D013710:Tendons / Q000637:transplantation*; D016896:Treatment Outcome