Return to Sport Assessment and Decision Making Following Anterior Cruciate Ligament Reconstruction (ACLR) Surgery

Abstract

The aim of this thesis was to explore return to sport (RTS) tests and criteria following anterior cruciate ligament reconstruction (ACLR) surgery, with a focus on both best-practice recommendations and real-world clinical outcomes. Despite the increasing use of RTS assessments to guide rehabilitation and reduce re-injury risk, substantial variability persists in test selection, performance thresholds, and their relationship to successful RTS. This research therefore sought to clarify what constitutes best-practice for RTS testing and to evaluate how these assessments perform in a clinical population. This thesis comprises two complementary studies. Firstly, a scoping review synthesised the literature on RTS assessments and decision-making criteria following ACLR surgery in athletes. 33 studies were included and analysed according to test type, performance thresholds, and RTS definitions. Secondly, a retrospective descriptive analysis used clinical data from a physiotherapy clinic specialising in knee injury rehabilitation in Aotearoa New Zealand (NZ). RTS test outcomes were reported across strength, hop, jump, and psychological domains, and associations with demographic and clinical variables were examined. The scoping review revealed marked heterogeneity in RTS testing, with little consensus on best-practice criteria. Most studies used strength and hop testing, with ≥90% limb symmetry index (LSI) as the primary threshold, but relatively few incorporated psychological or sport-specific measures. In the clinical cohort (n = 165), RTS test pass rates were generally modest, and only a small proportion achieved over 90% LSI across all domains. Several clinical variables influenced performance; however, demographic and clinical factors showed limited association with RTS level. Whilst psychological readiness was significantly associated with RTS outcomes, higher physical RTS test scores did not consistently predict full return to pre-injury sport. RTS testing following ACLR remains inconsistently defined and applied across both research and clinical settings. Although objective criteria are widely used to inform RTS decisions, the predictive value of current thresholds appears limited. These findings highlight the importance of developing more comprehensive, contextually informed RTS protocols that integrate physical, psychological, and sport-specific assessments. A multifactorial approach is recommended to optimise RTS decision-making and support improved long-term outcomes after ACLR. 3