Can the outside-in half-tunnel technique reduce femoral tunnel widening in anterior cruciate ligament reconstruction? A CT study

  • Riccardo Maria Lanzetti
  • Domenico LuparielloEmail author
  • Angelo De Carli
  • Edoardo Monaco
  • Matteo Guzzini
  • Mattia Fabbri
  • Antonio Vadalà
  • Andrea Ferretti
Original Article • KNEE - IMAGING



There are different techniques for drilling the femoral tunnel in the anterior cruciate ligament reconstruction (ACLR), but their influence in the bone tunnel enlargement in unknown. The purpose of this study was to compare two different surgical techniques for evaluating femoral tunnel enlargement in ACLR. The hypothesis was that tunnel placement using the outside-in technique leads to less tunnel enlargement compared to the transtibial technique.


Forty-four patients treated for ACLR between March 2013 and March 2014 were prospectively enrolled in this study. According to the surgical technique, subjects were assigned to Group A (Out-in) or Group B (Transtibial). All patients underwent CT examination in order to evaluate the femoral tunnel enlargement at four different levels. Moreover, all patients were evaluated with the Lachman test and pivot shift test, and the KT1000 arthrometer was used to measure the anterior laxity of the knee. A subjective evaluation was performed using the 2000 International Knee Documentation Committee Subjective Knee score, Lysholm knee score and Tegner activity scale. All patients were assessed after 24 months of follow-up.


At the final follow-up, there were statistically significant differences (p < 0.05) in femoral tunnel enlargement between the two groups at all four femoral levels in favor of the out-in group. No statistical significant differences were found in the objective and subjective clinical outcomes between the two groups (p > 0.05).


In ACLR with a suspension system, the outside-in technique leads to less enlargement of the femoral tunnel lower than the transtibial technique.


CT imaging Femoral tunnel enlargement Anterior cruciate ligament reconstruction Drilling technique 


Compliance with ethical standards

Conflict of interest

Lanzetti, Lupariello, De Carli, Monaco, Guzzini, Fabbri, Vadalà and Ferretti have nothing to disclose.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.


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Copyright information

© Springer-Verlag France 2017

Authors and Affiliations

  • Riccardo Maria Lanzetti
    • 1
  • Domenico Lupariello
    • 1
    Email author
  • Angelo De Carli
    • 1
  • Edoardo Monaco
    • 1
  • Matteo Guzzini
    • 1
  • Mattia Fabbri
    • 1
  • Antonio Vadalà
    • 1
  • Andrea Ferretti
    • 1
  1. 1.Orthopaedic Unit and “Kirk Kilgour” Sports Injury CentreS. Andrea Hospital, University of Rome “La Sapienza”RomeItaly

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