Saccades serve as a complementary behavioral biomarker for detecting mild cognitive impairment in elderly knee/hip arthroplasty patients

Background This study aimed to identify the optimal method for detecting mild cognitive impairment (MCI) in elderly knee/hip osteoarthritis (OA) patients, a vulnerable group at high risk for postoperative delirium, by comparing neuropsychological tests, molecular biomarkers, and saccadic eye movements. Methods In this prospective cohort study, 316 patients (≥65 years) scheduled for knee/hip arthroplasty underwent preoperative assessments using neuropsychological tests (MMSE, MoCA, CDR), blood/CSF molecular analysis, and saccadic tasks. Participants were classified as MCI ( n = 90) or non-MCI ( n = 226) by geriatricians based on standard diagnostic criteria. Results No significant molecular differences were found between MCI and non-MCI patients. While MMSE, MoCA, and CDR scores were significantly lower in the MCI group, saccadic parameters showed superior diagnostic accuracy. A model based on saccades achieved an AUROC of 0.90, outperforming the MMSE model (AUROC = 0.85). Conclusions Saccadic analysis outperformed standard cognitive screening and molecular tests in detecting MCI, indicating its potential as a superior, non-invasive preoperative assessment tool. Trial number The study was registered with the Chinese Clinical Trial Registry (ChiCTR2200062483, August 8, 2022).