Good mid-term outcomes and low rates of residual rotatory laxity, complications and failures after revision anterior cruciate ligament reconstruction (ACL) and lateral extra-articular tenodesis (LET).

<bold>Background: </bold>Residual rotational instability remains a controversial factor when analysing failure rates of anterior cruciate ligament (ACL) reconstruction. Anatomical and biomechanical studies have demonstrated a very important role of anterolateral structures for rotational control. Revision ACL is considered one of the main indications for a lateral extra-articular tenodesis (LET). Yet, few series evaluating these procedures are published.<bold>Purpose: </bold>To perform a systematic review of studies that assessed outcomes in patients treated with revision ACL surgery associated with a lateral extra-articular procedure.<bold>Study Design: </bold>Systematic review.<bold>Methods: </bold>A comprehensive literature search was performed in February 2018 using PubMed, Scopus, Web of Search and Cochrane. Inclusion criteria were series of ACL revision reconstructions associated with lateral extra-articular procedures. Clinical outcomes (Lysholm, subjective IKDC, KOOS, Cincinnati and WOMAC), joint stability measures (Lachman test, pivot-shift, arthrometer assessment and navigation assessment), graft type, reported chondral and meniscal injury, radiographic outcomes, complications and failures were recorded. Articles were assessed for level of evidence and methodology using a modification of the ACL Methodology Score (AMS) system.<bold>Results: </bold>Twelve studies met the inclusion criteria out of the 231 abstracts; 9 retrospective evaluations, two prospective cohorts and one combination of two populations (a retrospective and prospective series). A total of 851 patients evaluated with a mean age of 28.8 years (range 16-68 years) and a weighted mean follow-up of 4.9 years (range 1-10 years). The mean time from primary ACL reconstruction to revision was 5.3 years (reported in 7 studies, including 710 patients). The Lysholm, IKDC, and KOOS scores indicated favorable results in studies that reported these outcomes. Objective evaluations reported 86% objective A and B IKDC results, 2.6 mm mean side-to-side arthrometric difference and 80% negative pivot-shift. About 74% of patients returned to their previous sport (evaluated in six studies). Few studies reported radiological evaluation. Fifty-nine complications (8.0%) and 24 failures (3.6%) were reported. The mean modified ACL Methodology Score was 55.5 (range 32-72).<bold>Conclusion: </bold>Good mid-term results were obtained for combined revision ACL reconstruction and lateral extra-articular procedures. Despite the fact that in clinical practice LET are a common indication associated with revision ACL, there are no high-level studies supporting this technique.<bold>Level Of Evidence: </bold>IV. [ABSTRACT FROM AUTHOR]