title: Clinical and second-look arthroscopic study comparing 2 tibial landmarks for tunnel insertions during double-bundle ACL reconstruction with a minimum 2-year follow-up.
abstract: BACKGROUND
  Few studies have reported the clinical results of tibial tunnel placement during double-bundle anterior cruciate ligament (ACL) reconstruction. It is important to recognize arthroscopic tibial landmarks during this procedure.
  
  
  OBJECTIVE
  During arthroscopic double-bundle ACL reconstruction, anterior tibial landmarks such as the intermeniscal (transverse) ligament and the Parsons knob for the anteromedial (AM) tunnel provide better knee stability and clinical outcomes than do posterior tibial landmarks such as the fovea anterior to the tibial intertubercle ridge for the posterolateral (PL) tunnel.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  A total of 121 patients underwent primary unilateral double-bundle ACL reconstructions using autogenous medial hamstring tendons. Fifty-nine patients from December 2008 through July 2009 underwent reconstructions using posterior tibial landmarks (PL group), and 62 patients from August 2009 through February 2010 underwent reconstructions using anterior tibial landmarks (AM group). Forty-seven patients (follow-up rate, 79.7%) in the PL group and 52 patients (follow-up rate, 83.9%) in the AM group underwent second-look arthroscopy and clinical evaluations under anesthesia at 1 year postoperatively and 3-dimensional computed tomography (3-D CT) evaluations at 3 weeks postoperatively.
  
  
  RESULTS
  Lachman test results indicated no significant differences, and pivot-shift test results were significantly lower in the AM group (P = .007). Mean side-to-side differences using the Telos device at 130 N were significantly lower in the AM group (1.4 ± 1.6 mm) compared with the PL group (2.4 ± 2.5 mm) (P = .012). Results for lack of extension were not significantly different, while those for lack of flexion were significantly better in the AM group than in the PL group (P = .036). No significant differences were observed in the Lysholm scores between the groups. In measurements of the tibial tunnel position by 3-D CT, with regard to anteroposterior depth, the AM bundle of the PL group was 41.6% ± 7.4% and the AM group was 29.1% ± 5.3% (P < .001), and the PL bundle of the PL group was 55.6% ± 7.7% and the AM group was 46.4% ± 5.8% (P < .001). No significant differences were found in mediolateral width. In second-look arthroscopy, there were significant differences with respect to the synovial cover with regard to the AM bundle (P = .024).
  
  
  CONCLUSIONS
  Patients in the AM group showed better knee stability and range of motion than those in the PL group. Transverse ligaments and Parsons knobs proved to be useful landmarks during ACL reconstruction.
authors.affiliation: Department of Orthopedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan. marine_ohsawa@yahoo.co.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohsawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Kimura
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hagiwara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yorifuji
authors.forename: Kenji
authors.initials: K
authors.lastname: Takagishi
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; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D024162:Second-Look Surgery; D013977:Tibia / Q000601:surgery*; D055815:Young Adult