Trends in Patient-Reported Outcomes After Anterior Cruciate Ligament Reconstruction: A Systematic Review

Background: Despite the prevalence of patient-reported outcomes (PROs) to evaluate results after anterior cruciate ligament (ACL) reconstruction, there exists little standardization in how these metrics are reported, which can make wider comparisons difficult. Purpose: To systematically review the literature on ACL reconstruction and report on the variability and temporal trends in PRO utilization. Study Design: Systematic review. Methods: We queried the PubMed Central and MEDLINE databases from inception through August 2022 to identify clinical studies reporting ≥1 PRO after ACL reconstruction. Only studies with ≥50 patients and a mean 24-month follow-up were considered for inclusion. Year of publication, study design, PROs, and reporting of return to sport (RTS) were documented. Results: Across 510 studies, 72 unique PROs were identified, the most common of which were the International Knee Documentation Committee score (63.3%), Tegner Activity Scale (52.4%), Lysholm score (51.0%), and Knee injury and Osteoarthritis Outcome Score (35.7%). Of the identified PROs, 89% were utilized in <10% of studies. The most common study designs were retrospective (40.6%), prospective cohort (27.1%), and prospective randomized controlled trials (19.4%). Some consistency in PROs was observed among randomized controlled trials, with the most common PROs being the International Knee Documentation Committee score (71/99, 71.7%), Tegner Activity Scale (60/99, 60.6%), and Lysholm score (54/99, 54.5%). The mean number of PROs reported per study across all years was 2.89 (range, 1-8), with an increase from 2.1 (range, 1-4) in studies published before 2000 to 3.1 (range, 1-8) in those published after 2020. Only 105 studies (20.6%) discretely reported RTS rates, with more studies utilizing this metric after 2020 (55.1%) than before 2000 (15.0%). Conclusion: There exists marked heterogeneity and inconsistency regarding which validated PROs are used in studies related to ACL reconstruction. Significant variability was observed, with 89% of measures being reported in <10% of studies. RTS was discretely reported in only 20.6% of studies. Greater standardization of outcomes reporting is required to better promote objective comparisons, understand technique-specific outcomes, and facilitate value determination.