Abstract:  

Abstract Background: Assessing athletes? readiness is a key component for successful outcomes after ACL-reconstruction (ACLR). Objectives: To investigate whether return-to-activity criteria, individually or in 5 combination, at 6 months after ACLR can predict return to participation in the same 6 preinjury activity level at 12 and 24 months after ACLR. 7 Methods: Ninety-five level I/II participants completed return-to-activity criteria testing 8 (isometric quadriceps index, single-legged hop tests, Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS), and Global Rating Score (GRS) at 6 months after ACLR. PASS group was defined as scoring >90% on all criteria and FAIL group as 11 scoring <90% on any criteria. At 12 and 24 months after ACLR, participants were asked 30 31 32 33 12 if they had returned to participate in the same preinjury activity level or not. All return-to- 13 activity criteria, except quadriceps index, were entered into the logistic regression 14 model. 34 35 36 37 38 39 40 41 18 42 15 Results: Eighty-one percent (81%) and 84.4% of the PASS group returned to 16 participation in the same preinjury activity level while only 44.2% and 46.4% of the FAIL 17 group returned at 12 and 24 months respectively after ACLR. The 6-meter timed hop, single hop, and triple hop limb symmetry indexes, GRS, and KOS-ADLS individually predicted the outcome of interest at 12 months after ACLR (Range: R2:0.12-0.22, 20 p<0.024). In combination, they explained 27% of the variance (p=0.035). All hop tests, 21 individually, predicted the outcome of interest at 24 months after ACLR (Range: 47 48 49 50 23 Conclusion: Returning to participation in the same preinjury activity level at 12 and 24 51 22 R2:0.26-0.37; P<0.007), in combination they explained 45% of the variance (p<0.001). British Journal of Sports Medicine Page 6 of 72 months after ACLR were higher in those who passed the criteria compared to those 25 who failed. Indivi