Factors Affecting Subjective and Objective Outcomes and Return to Play in Anterior Cruciate Ligament Reconstruction: A Retrospective Cohort Study.

To analyze the prognostic factors influencing subjective and objective outcomes and return to play (RTP) after anterior cruciate ligament reconstruction (ACL-R).  Primary ACL-Rs using a transtibial technique performed between 2008 and 2012 were included. Data regarding patients, surgery, sports, and rehabilitation, including an on-field rehabilitation (OFR) and duration of the rehabilitation program, were collected. The International Knee Documentation Committee (IKDC) subjective and objective evaluation forms, and the Knee Injury and Osteoarthritis Outcome Score and Lysholm questionnaires were used for the assessment of subjective and objective outcomes. The Subjective Patient Outcome for Return to Sports and ACL-return to sport after injury (RSI) scores were used for RTP evaluation. Several potential predictors of outcome were tested with a univariate analysis. All the variables with  < 0.1 were retested in a logistic regression model to evaluate their association with the outcomes.  In total, 176 cases were included with an average follow-up of 44.1 months. Of the patients, 92.2% were rated as normal or nearly normal at the IKDC evaluation. In addition, 90.1% of the patients returned to sport, with 57.6% returning to the same preinjury level. Objective outcomes were negatively influenced by late rehabilitation (odds ratio [OR] = 2.75). Performing an OFR phase during the rehabilitation was associated with better subjective outcomes (OR = 2.71). Length of rehabilitation strongly influenced the RTP rate (OR = 13.16). Conversely, higher ACL-RSI score was inversely related to RTP. Objective IKDC score was inversely related to the ACL-RSI (OR = 0.31), whereas subjective score was correlated with both the total ACL-RSI score (OR = 0.15) and the level of activity (OR = 0.20).  This study confirmed the role of rehabilitation on subjective and objective outcomes and on RTP. Particularly, the complete adherence to a rehabilitation program, including an OFR phase, resulted in better subjective outcomes and higher RTP rate. The relationship between psychological factors, measured through the ACL-RSI score, and RTP was confirmed.  Level III, observational study without a control group.