An exploratory study of peripheral joint deterioration and central sensorimotor network reorganization in people with knee osteoarthritis

Abstract

This exploratory study aimed to characterize the differential features and intrinsic associations between peripheral proprioceptive deficits, aberrant quadriceps activation, and central sensorimotor network reorganization in patients with knee osteoarthritis (KOA). Twenty-eight outpatients with KOA and twenty-eight healthy controls (HC) were prospectively recruited between October 2024 and May 2025. Absolute errors in knee joint position reproduction (JPR) were assessed. Surface electromyography (sEMG) of the quadriceps was recorded during treadmill walking and stair negotiation. Resting-state functional magnetic resonance imaging (rs-fMRI) was employed to characterize spontaneous brain activity and functional connectivity (FC). Intergroup differences were analyzed, and the correlations among these multimodal metrics were evaluated. Compared with HC, KOA patients exhibited significantly higher JPR errors at 30° and 60°. The RMS of RVM while up and down steps in KOA group had increased activation compared to HC group. Compared with HC group, ALFF increased in cuneus, decreased in superior temporal; fALFF increased in middle Cingulum and middle frontal, decreased in cerebellum; and DC increased in superior parietal and precuneus, but decreased in cerebellum in KOA group. KOA group showed stronger FC between left supplementary motor area and superior frontal; among right paracentral lobule, inferior temporal, middle temporal and superior frontal; among right posterior cingulate cortex, cerebellum, middle frontal and precentral. Correlational Analysis showed that the 45°JPR was negatively correlated with the FC value between SMA_L and superior frontal, the FC value between PoCG _R and middle frontal, respectively. The MDF of LRF in ascending stair was positively correlated with the FC value between SMA_L and superior frontal, the FC value between PoCG _R and middle frontal, respectively. These exploratory findings suggest a neurophysiological phenotype in KOA characterized by impaired proprioception, compensatory muscle hyperactivity, and central network reorganization. The observed brain-periphery interactions may be associated with​ neurophysiological alterations in KOA pathogenesis, but these results should be interpreted cautiously and require confirmation in larger samples with stricter multiple-comparison correction.