Return to sport (RTS) after ACL reconstruction (ACLR) has been recognized as an important outcome, which is associated with success of the surgery and has been increasingly reported on in recent years based on non-standardized evaluation methods.
To assess the methods used to determine return to sport after ACLR in the published literature, report on variability of methods and evaluate their strength in establishing accurate RTS data.
Study design: Systematic review of methodology.
Electronic databases (PubMed, Cochrane Library and Embase) were searched via a defined search strategy with no limits, to identify relevant studies from January 2008 to January 2020 for inclusion in the review. A priori defined eligibility criteria included studies specifically measuring and reporting on return to sport after ACLR with a clear methodology. Each included study was primarily assessed for the methodology used to determine return to sport and level of sport.
145 studies were included. Among the excluded studies, 54 studies reported on RTS after ACLR, but were not included due to unclear RTS evaluation method used. Of the included studies, five studies (3%) were level of evidence 1 and sixty-six studies (46%) were level of evidence 4. Thirty-six studies (25%) reported on return to a specific sport and 109 studies (75%) reported on return to multiple sports or general sport. Fourteen studies (10%) reported on RTS in the pediatric population, twenty-five (17%) in the adult population and one hundred and six (73%) reported on a mixed-aged population. Five definition categories of successful general RTS, four definition categories of successful return to pre-injury level of sport and four categories of different methods used to determine RTS were established. The most common method used to evaluate RTS was a non-validated study specific questionnaire (61 studies, 42%), which was administered in various ways to the patients. Time of RTS assessment was variable and ranged between 6 months to 27 years post-surgery.
This review demonstrates high variability in defining, evaluating and reporting patterns of RTS following ACLR. The findings of this study raise concerns regarding the reliability and validity of methods used to evaluate RTS. Our findings highlight the challenges in interpreting and using RTS data reported in literature and should serve to caution clinicians to carefully evaluate the methods used in studies reporting on RTS after ACLR. Future research should focus on establishing standardized and validated methods for RTS evaluation.