The Relationship of Knee-related Quality of Life with Function, Psychological Factors, Strength, Performance, and Postural Stability After ACL Reconstruction: A Cross-Sectional Study

Background: Patients after anterior cruciate ligament reconstruction (ACLR) have decreased health-related quality of life (QoL) compared with healthy control participants. Few studies have verified the predictors of QoL using Quality of Life Outcome Measure Questionnaire for Chronic Anterior Cruciate Ligament Deficiency (ACL-QoL), and no study has verified the relationship of psychological factors and knee function with ACL-QoI. in patients after ACLR. Hypothesis: Knee functional status, muscle strength, performance in hop tests, postural stability, and psychological factors would be the predictors of QoL after ACLR. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: A total of 131 participants who had undergone ACLR at least 6 months previously were evaluated. QoL was assessed using ACI.-QoI.; knee functional status, using International Knee Documentation Committee Subjective Knee (IKDC) and global rating scale (GRS); psychological readiness, using Anterior Cruciate Ligament Return to Sport after Injury Scale (ACL-RSI); kinesiophobia; using Tampa Scale for Kinesiophobia (TSK-17); knee strength, using isokinetic dynamometer; performance, using single-leg hop tests; and postural stability, using Biodex Balance System. Pearson's linear con center dot elation and stepwise hierarchical multiple linear regression analyses were performed to verify the predictors of QoL.. Results: ACL-QoL showed a moderate correlation with IKDC (r = 0.69), GRS (r = 0.55), ACL-RSI (r = 0.50), and TSK-17 (r = -0.49). ACL-QoL presented none to low correlations with the variables of muscle strength, postural stability, and performance in hop tests. The variables related to the knee functional status and psychological factors (IKDC, GRS, ACL-RSI, and TSK-17) were found to be the predictors of QoL (R-2 = 0.56; P = 0.01). Conclusion: Knee functional status, psychological readiness, and kinesiophobia were the predictors of knee-related QoL in patients after ACLR.