Reintroduction of running after ACL reconstruction with a hamstring graft: can we predict short-term success?

CONTEXT Return to running (RTR) after anterior cruciate ligament reconstruction (ACL-R) is a crucial milestone. However, there is uncertainty on how and when to start a running program. OBJECTIVE To explore the feasibility of a structured program to reintroduce running after ACL-R and to evaluate the predictive value of potential predictors of short-term success. DESIGN Longitudinal cohort study. SETTING Local Research Center / participant's home. PATIENTS Thirty-five participants were recruited after ACL-R. INTERVENTION Program with a progression algorithm to reintroduce running (10 running sessions in 14 days). MAIN OUTCOME MEASURES The criterion for short-term success was no exacerbation of symptoms. Potential predictors included: (i) the International Knee Document Committee (IKDC) subjective knee form; (ii) ACL Return to Sport after Injury questionnaire; (iii) quadriceps and hamstring strength; (iv) Step-Down Endurance test; and (v) the modified Star Excursion Balance test. Descriptive statistics were performed to study the feasibility of the RTR program and Poisson regression analysis was used to evaluate predictors of success. RESULTS Of the 34 participants included, 33 completed the RTR program. Sixteen participants experienced some temporary exacerbation of symptoms, but only one had to stop the RTR program. Initial IKDC score was the only significant predictor of a successful RTR with an Area under the ROC curve of 80.4%. An ICKD cut-off of 63.7/100 differentiated responders and non-responders with the highest sensitivity and specificity (77.8% and 75.0%, respectively). There was a 3-fold greater chance of success with an IKDC score above this threshold. CONCLUSIONS Our results confirm the feasibility of our RTR program and progression algorithm after ACL-R. Clinicians should use an IKDC score of >64 as a criterion to reintroduce running after ACL-R to increase the likelihood of short-term success.