title: Can we use intraoperative femoral tunnel length measurement as a clue for proper femoral tunnel placement on coronal plane during ACL reconstruction?
abstract: BACKGROUND
  Successful anterior cruciate ligament (ACL) reconstruction is dependent on correct placement of both tibial and femoral tunnels. The purpose of this study is to investigate whether we can use intraoperative femoral tunnel length measurement to estimate the correct femoral tunnel placement on coronal plane.
  
  
  METHODS
  This prospective study comprised 164 consecutive patients who underwent ACL reconstruction surgery. Transtibial or anteromedial portal technique is used for drilling the femoral tunnels. The length of the femoral tunnel was measured during the operation. The femoral tunnel coronal plane angle was calculated on the postoperative tunnel radiographs. A statistical comparison was made of the lengths of the tunnel, the techniques used drilling and the femoral tunnel angles.
  
  
  RESULTS
  The far anteromedial portal was used in 81 (49%) cases and the transtibial technique in 83 (51%) cases. The mean femoral tunnel length was 42 ± 6.4 mm and the mean femoral tunnel coronal angle was 41.1° ± 11.6. The tunnel angle in the transtibial technique was determined as significantly low compared to the far anteromedial portal technique (32.6°:49.8°) and the tunnel length was significantly longer (45.8:38.1 mm) (p < 0.001). In the statistical analysis, it was found that a patient with a tunnel length of 41 mm and above had a 92.1% likelihood of femoral tunnel angle below 45°.
  
  
  CONCLUSIONS
  Femoral tunnel length can be used as a clue for intraoperative evaluation of the femoral tunnel position. If the femoral tunnel length is greater than 41 mm, the coronal plane orientation of the femoral tunnel will be improper and not at a desired position.
authors.affiliation: Department of Orthopedics and Traumatology, Private Ortopedia Hospital, Adana, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Celiktas
authors.forename: Ozkan
authors.initials: O
authors.lastname: Kose
authors.forename: Yaman
authors.initials: Y
authors.lastname: Sarpel
authors.forename: Mahir
authors.initials: M
authors.lastname: Gulsen
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D005260:Female; D005269:Femur / Q000033:anatomy & histology*; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D011446:Prospective Studies; D055815:Young Adult