Background/Objectives: Chronic pain in osteoarthritis alters large-scale brain networks, including the insular cortex and default mode network. While total hip arthroplasty (THA) provides substantial relief, the early postoperative reorganization of functional connectivity (FC) remains unclear. This longitudinal fMRI study exploratively investigated how early improvements in pain intensity and catastrophizing are associated with insular FC alterations following THA. Methods: In this exploratory, longitudinal observational study, 10 female patients with hip osteoarthritis underwent resting-state fMRI and clinical assessments—Pain Visual Analogue Scale (VAS), Pain Catastrophizing Scale (PCS), and Japanese Orthopaedic Association (JOA) hip score—preoperatively and two weeks post-THA Whole-brain seed-to-voxel FC analyses were conducted using the bilateral anterior insular cortex as the seed. Changes in FC (ΔFC) were correlated with preoperative scores and postoperative clinical changes (ΔVAS, ΔPCS). Results: Following THA, VAS and PCS scores decreased significantly, while JOA scores improved. rs-fMRI analysis revealed that FC between the left anterior insula and major DMN regions as well as the right anterior cingulate cortex (ACC) increased significantly overall. Correlation analysis showed that greater reductions in pain intensity (ΔVAS) were significantly associated with increased ΔFC across these regions. Conversely, greater reductions in pain catastrophizing (ΔPCS) were associated with a suppression of these FC increases. Conclusions: Given the preliminary nature of this study, these findings suggest that the alleviation of pain catastrophizing following THA may be associated with the initial reorganization of the aIC network, rather than establishing a definitive causal relationship. Further large-scale longitudinal studies are required to confirm these potential neural signatures.
Chuda et al. (Thu,) studied this question.