Return to sports following ACL reconstruction: where do we stand in 2020?

Despite the development of return to sport (RTS) guidelines over recent years, there is a lack of a scientific consensus on the RTS criteria used to release a patient to unrestricted sport activity after ACL reconstruction (ACLR). A proportional meta-analysis, showed that only 23% of patients after ACLR passed RTS test batteries before RTS. Although passing RTS criteria reduce the risk of subsequent graft rupture by 60%, it increases the risk of a contralateral ACL rupture by 235%. These equivocal findings in terms of validity of RTS tests after ACLR leaves clinicians with high level of uncertainty in clinical decision-making. Dingenen & Gokeler proposed that RTS should be viewed as continuum after ACL injury and ACLR. Moreover, one of the possible solutions why patients do not meet the RTS criteria is simply due to the lack of implementation of evidence- based rehabilitation in terms of specificity and training load. Too often, the end phase of the rehabilitation is not extensive or specific enough, thereby exposing athletes to specific training loads and training characteristics that they cannot handle from a physical, neurocognitive as well as from a psychological perspective. Della Villa et al. introduced the concept of an On Field Rehabilitation (OFR) model to bridge the gap between standard rehabilitation and return to training. This allows for a gradual progression of each part and thus ensures correct function and that no adverse knee reaction is noted before moving on to the next level. Returning an athlete to full participation should be a graduated continuum and not based on a set of tests at one single point in time. The above findings pertaining to the high incidence of recurrent injuries, question whether the current RTS tests provide relevant information for guiding the decision making. There is a need for more ecological valid research approaches to test an athlete returning to sports after an ACLR in more complex sports-specific demanding tests, which are more reflective of the demands while on the field. Based on a RTS continuum approach, training and tests should include physical, cognitive and psychological loads in a gradual fashion that prepare the athlete for a safer RTS