Psychological Patient-reported outcome measure after anterior cruciate ligament reconstruction: Evaluation of subcategory in ACL-Return to Sport after Injury (ACL-RSI) scale

Background: It has been recognized that psychological factors influence the return to sports after anterior cruciate ligament reconstruction (ACLR). The ACL-return to sports after injury (RSI) scale was developed based on subcategories of emotions, confidence in physical performance and risk appraisal. However, it has not been clarified describing which is the most influential psychological factor of the ACL-RSI scale.

Hypothesis: Risk appraisal is the most influent for return to sports in the subcategories of the ACL-RSI scale.

Patients and methods: A total of 85 competitive patients who had undergone ACLR were evaluated at 6, 12 and 24 months after surgery. They were classified the return to sports (RTS) group and non-return to sports (NRTS) group. Evaluations were several clinical and functional scores including Cincinnati knee rating system, Knee Osteoarthritis Outcome Score (KOOS), Lysholm score, limitation in activities of daily living (ADL) and sports which estimated by Visual Analog Scale (VAS) score, Isokinetic Muscle Strength (quadriceps and hamstrings), single hop test and anterior laxity. They were investigated their relationship with the ACL-RSI scale including each subcategory.

Results: The total ACL-RSI scale significantly improved at each point. Of the subcategories, only risk appraisal was not significantly different at each point (p=0.21 and p=0.13). There was a significant difference at 24 months after ACLR between the RTS group and NRTS group. In terms of risk appraisal, compared with emotion and performance confidence, the difference in the mean value was the most divergent (RTS group: 55.9±22.7 and NRTS group: 23.8±19.3) and took time to improve through 24 months. Among various clinical and functional scores, there were significant differences in the VAS score for sports, KOOS-symptoms, sports and QOL, Cincinnati Knee Rating System-cut, and single hop test values between two groups. Of these, the KOOS-QOL and VAS score for sports showed particularly strong correlations with ACL-RSI risk appraisal (r=0.75 and -0.68, respectively).

Conclusion: Of the ACL-RSI scale, risk appraisal took the longest time to improve and strongly affected the return to sports. The KOOS-QOL and VAS score for sports were most strongly correlated with the ACL-RSI risk appraisal. It seems that it is important to reduce the psychological risk as soon as possible after ACL injury in ACLR patients.

Level of evidence: II.