Better rotational control but similar outcomes with the outside-in versus the transtibial drilling technique for anterior cruciate ligament reconstruction: a systematic review of comparative trials

Abstract

Introduction: This study was a systematic review comparing the clinical outcomes of using the transtibial (TT) versus the outside-in (OI) technique for anterior cruciate ligament (ACL) reconstruction.

Materials and methods: A comprehensive literature search was conducted using multiple databases, including Medline, Embase, and Cochrane. All databases were searched from the earliest records through August 2017 using the following Boolean operators: transtibial AND (outside-in OR out-in OR two incisions) AND anterior cruciate ligament. All prospective and retrospective controlled trials were retrieved that directly compared physical examination and knee function scores and patient-rated outcomes between the TT and OI techniques.

Results: Four prospective and three retrospective articles were identified by the search, and the findings suggested that the OI was superior to the TT technique for preparing the femoral tunnel based on the pivot shift test (p = 0.05). There was no statistically significant difference between the two treatment groups in International Knee Documentation Committee (IKDC) grades, IKDC scores, Lysholm scores, Tegner scores, or the Lachman test.

Conclusions: No statistically significant differences were found in clinical functional results when comparing patients who underwent ACL reconstruction with the TT or OI techniques. However, the OI technique was found to be advantageous in conferring increased rotational stability as revealed by the pivot shift test. Additional studies with larger sample sizes are needed to make more precise conclusions.

Level of evidence: Therapeutic study (systematic review), Level III.

Keywords: Anterior cruciate ligament reconstruction; Femoral tunnel; Outside-in; Transtibial.