Context: Fear has been cited as the primary barrier for return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR). Understanding the neural factors contributing to fear after ACLR may help identify interventions for this population.
Objective: The objective of this study was to characterize the underlying neural substrate of injury-related fear in patients after ACLR versus healthy matched controls during a picture imagination task (PIT) consisting of sports-specific images and activities of daily living images.
Design: Case-Control Study
Setting: Research Laboratory
Patients or Other Participants: A total of 24 right-hand dominant participants (12 left-sided ACLR and 12 controls) were enrolled. Participants underwent full brain functional magnetic resonance imaging (fMRI).
Main Outcome Measure(s): Functional data were acquired with Blood Oxygen Level Dependent (BOLD) echoplanar imaging. Independent t-tests were used to identify significant between group differences in BOLD signal changes during all images of the PIT. Paired t-tests were used to examined differences in BOLD signal change between sports-specific images and activities of daily living (ADLs) in the ACLR group.
Results: Increased activation in the inferior parietal lobule (IPL) and the mediodorsal thalamus (MDT) were observed during PIT in the ACLR group. Inability to suppress the default mode network (DMN) in the ACLR group was observed. The ACLR group exhibited increased activation in the cerebellum and inferior occipital regions during the sports-specific task when compared to ADLs, but no other regions of interest demonstrated statistically significant differences.
Conclusion: These findings suggest that ACLR patients may be more disposed to processing fear, anxiety, and/or pain for sports-specific activities and activities of daily living. Psychosocial interventions may be warranted after ACLR to reduce injury-related fear and mitigate potentially maladaptive neuroplasticity after ACLR.