Neuroimaging Analysis of Patients With Anterior Cruciate Ligament Reconstruction: Pain-Driven Inhibition of Return to Sports.

BACKGROUND

Fear of pain and reinjury significantly hinders return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR). However, the neural basis of this psychological barrier remains unclear.

HYPOTHESIS: ACLR patients will exhibit structural and functional brain changes in regions related to pain and emotion, influencing their psychological readiness to RTS.

STUDY

DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE: Level 3.

METHODS

We recruited 36 ACLR patients and 36 healthy controls, collecting visual analog scale (VAS) scores for knee pain, Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scores, and structural and functional magnetic resonance imaging data.

RESULTS

Significant smaller gray matter (GM) volume was observed in the thalamus (effect size, -0.813), periaqueductal gray (PAG) (effect size, -0.737), and prefrontal cortex (PFC) (effect size, -0.690) in ACLR patients. We also found weakened functional connectivity between the PAG and the anterior cingulate cortex (ACC). GM volume in the thalamus was correlated positively with ACL-RSI scores (r = 0.362). Notably, the effect of VAS scores on ACL-RSI was mediated by the reduced FC between PAG and ACC (direct effect, -2.071, indirect effect, -0.826).

CONCLUSION

This study reveals that the psychological readiness to RTS after ACLR may be due to peripheral nociceptive input causing changes in pain-related brain structures and functions.

CLINICAL RELEVANCE: Recognizing these neuropsychological changes may guide comprehensive rehabilitation strategies post-ACLR, emphasizing the need for interventions targeting central neural mechanisms alongside physical recovery.