Return to sports (RTS) clearance after anterior cruciate ligament (ACL) reconstruction typically includes multiple assessments. The ability of these tests to assess the risk of a re-injury remains unknown.
To assess and rate RTS self-reported function and functional tests on prognostic value for re-injury risk after ACL reconstruction and RTS.
Systematic review on level 2 studies.
PubMed, Web of Knowledge, Cochrane Library and Google Scholar databases were searched for articles published before March 2018. Original articles in English or German that examined re-injury risks/rates following primary (index) ACL injury, ACL reconstruction, and RTS were included. All RTS functional tests used in the included studies were analysed by retrieving an effect size with predictive value (odds ratio, relative risk (risk ratio), positive predictive value, positive likelihood ratio or hazard rate).
A total of 276 potential studies were found; eight studies (moderate to high quality) on 6,140 patients were included in the final analysis. The re-injury incidence recorded in the included studies ranged from 1.5% to 37.5%. Four studies reported a combination of isokinetic
quadriceps strength at different velocities and a number of hop
tests as predictive with various effect sizes. One reported isokinetic
hamstring to quadriceps ratio (HR=10.6) as predictive. Two studies reported functional questionnaires (KOOS and TSK-11; RR=3.7-13) and one study showed that kinetic and kinematic measures during drop vertical jumps (DVJ) were predictive (OR=2.3-8.4) for re-injury and/or future revision surgery.
Based on level 2 evidence, passing a combination of functional tests with pre-determined cut-off points used as RTS criteria is associated with reduced re-injury rates. A combination of isokinetic
strength and hop
tests are recommended during RTS testing.