Purpose To compare patient-reported and clinician-reported outcomes, and radiographic results between patients who had had revision ACL reconstruction and those who had had primary ACL reconstruction.

Design Systematic review and meta-analysis

Data sources The MEDLINE, CINAHL, EMBASE and SPORTDiscus electronic databases were searched on 6 August 2015, using 3 main concepts: (1) revision ACL reconstruction, (2) primary ACL reconstruction and (3) treatment outcomes.

Eligibility criteria for selecting studies Articles that compared patient-reported or clinician-reported outcomes or radiographic results between patients who had had revision ACL reconstruction and those who had had primary surgery with a minimum of 2 years follow-up were included. The outcomes evaluated were the Lysholm Knee Scoring Scale, objective International Knee Documentation Committee (IKDC) classification, Tegner Activity Scale, side-to-side difference in anterior tibial translation measured with KT-1000/2000 arthrometer, pivot shift test, tibiofemoral osteoarthritis grading on plain radiographs and subsequent knee surgeries.

Results 8 studies (300 revision ACL reconstructions and 413 primary ACL reconstructions) were included in the meta-analysis. Patients who had had revision surgery reported inferior Lysholm Knee Scoring Scale scores (mean difference: 7.8 points), had inferior clinician-reported knee function as assessed with the objective IKDC classification (IKDC category A: 27% vs 57%; IKDC category C or D: 22% vs 8%) and pivot shift test (grade II or III: 7% vs 2%), and more radiographic evidence of tibiofemoral osteoarthritis (50% vs 25%) compared with patients who had had primary surgery.

Conclusions Revision ACL reconstruction restored similar anterior-posterior knee laxity compared with primary ACL reconstruction. Patients who had had revision surgery reported inferior Lysholm Knee Scoring Scale scores, had inferior clinician-reported knee function and more radiographic signs of tibiofemoral osteoarthritis compared with patients with primary ACL reconstruction.