Physical inactivity 5-8 years after anterior cruciate ligament reconstruction is associated with knee-related self-efficacy and psychological readiness to return to sport.

Objectives: To investigate whether patient demographics and patient-reported outcomes (PROs), respectively, are associated with physical inactivity (PI) 5-8 years after primary anterior cruciate ligament reconstruction (ACLR). Methods: This case control observational study included individuals who had undergone primary ACLR between the ages of 15 and 65 years and had responded to PROs 18 months postoperatively. These individuals were asked to answer a questionnaire regarding their present level of physical activity (PA) at 5-8 years after ACLR. Patient-demographic data and results from the Knee injury and Osteoarthritis Outcome Score, the Knee Self-Efficacy Scale and the ACL Return to Sport (RTS) after Injury scale from 18 months after ACLR were extracted from a rehabilitation-specific register. Univariable logistic regression analyses were performed with PI (<150 min PA per week/≥150 min PA/week) as the dependent variable. Results: Of 292 eligible participants, 173 (47% women; mean±SD age = 31±11 years) responded to the PA questionnaire. In all, 14% (n=25; 28% women) were classified as physically inactive. Participants with lower levels of present and future self-efficacy, OR 1.35 (CI 1.05 to 1.72) and OR 1.20 (CI 1.12 to 1.45), and lower levels of psychological readiness to RTS, OR 1.19 (CI 1 to 1.43), at the 18-month follow-up, had higher odds of being physically inactive 5-8 years after ACLR. None of the patient demographic variables was able to predict PI. Conclusion: Lower levels of knee-related self-efficacy and psychological readiness to RTS, 18 months after ACLR, were associated with PI 5-8 years after surgery.