Skip to main content

08.05.2017 | Original Article | Ausgabe 4/2017 Open Access

Journal of Orthopaedics and Traumatology 4/2017

In–out versus out–in technique for ACL reconstruction: a prospective clinical and radiological comparison

Journal of Orthopaedics and Traumatology > Ausgabe 4/2017
Edoardo Monaco, Mattia Fabbri, Andrea Redler, Raffaele Iorio, Jacopo Conteduca, Giuseppe Argento, Andrea Ferretti



Several studies have recently shown better restoration of normal knee kinematics and improvement of rotator knee stability after reconstruction with higher femoral tunnel obliquity. The aim of this study is to evaluate tunnel obliquity, length, and posterior wall blowout in single-bundle anterior cruciate ligament (ACL) reconstruction, comparing the transtibial (TT) technique and the out–in (OI) technique.

Materials and methods

Forty consecutive patients operated on for ACL reconstruction with hamstrings were randomly divided into two groups: group A underwent a TT technique, while group B underwent an OI technique. At mean follow-up of 10 months, clinical results and obliquity, length, and posterior wall blowout of femoral tunnels in sagittal and coronal planes using computed tomography (CT) scan were assessed.


In sagittal plane, femoral tunnel obliquity was 38.6 ± 10.2° in group A and 36.6 ± 11.8° in group B (p = 0.63). In coronal plane, femoral tunnel obliquity was 57.8 ± 5.8° in group A and 35.8 ± 8.2° in group B (p = 0.009). Mean tunnel length was 40.3 ± 1.2 mm in group A and 32.9 ± 2.3 mm in group B (p = 0.01). No cases of posterior wall compromise were observed in any patient of either group. Clinical results were not significantly different between the two groups.


The OI technique provides greater obliquity of the femoral tunnel in coronal plane, along with satisfactory length of the tunnel and lack of posterior wall compromise.

Level of evidence

II, prospective study.
Über diesen Artikel

Weitere Artikel der Ausgabe 4/2017

Journal of Orthopaedics and Traumatology 4/2017 Zur Ausgabe


Neu im Fachgebiet Orthopädie und Unfallchirurgie

Mail Icon II Newsletter

Bestellen Sie unseren kostenlosen Newsletter Update Orthopädie und Unfallchirurgie und bleiben Sie gut informiert – ganz bequem per eMail.