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Objectives and questions: The growing demand for total shoulder arthroplasty (TSA) reflects an aging population in whom neurocognitive impairment is increasingly prevalent. Mild cognitive impairment (MCI) affects approximately 15% of adults aged ≥50 years and is associated with higher perioperative complication rates. While chronic pain has been linked to cognitive impairment in older adults, its influence on postoperative pain perception and recovery after TSA remains poorly understood.

Purpose: To evaluate whether patients with mild cognitive impairment experience greater pain, altered pain sensitivity, and differences in shoulder function following total shoulder arthroplasty compared with cognitively normal patients.

Material and methods: This secondary analysis included patients aged ≥65 years from an ongoing longitudinal cohort study who completed a preoperative Montreal Cognitive Assessment (MoCA), adjusted for educational level. Patients were classified as cognitively normal or as having mild-to-moderate cognitive impairment. Shoulder-specific function, range of motion, patient-reported pain outcomes, and quantitative sensory testing (QST) were assessed preoperatively and at 3 and 6 months postoperatively.

Results: Forty-five patients were included (22 cognitively normal, 23 with MCI; mean age 75 ± 5 years; 47% female). Preoperatively, patients with MCI reported significantly greater pain interference compared with cognitively normal patients (p = 0.044), despite similar pain severity, shoulder function, and range of motion. QST demonstrated significantly lower pressure pain thresholds at both affected and non-affected sites in the MCI group (p = 0.003–0.041), indicating heightened pain sensitivity. At 3 and 6 months following TSA, pain interference remained significantly higher in patients with MCI (p = 0.039 at both time points), with persistently lower pressure pain thresholds (p = 0.005–0.031). Improvements in shoulder function and range of motion were comparable between groups. Lower MoCA scores were consistently associated with greater pain interference and psychological distress across all time points (p < 0.05), whereas associations with pain severity diminished over time. No consistent relationship was observed between cognitive status and measures of central pain facilitation.

Discussion and conclusions: Mild cognitive impairment is associated with increased pain interference and heightened pain sensitivity before and after total shoulder arthroplasty, despite similar functional recovery. These findings suggest that cognitive status influences pain processing and the functional impact of pain rather than objective shoulder outcomes. Routine cognitive screening may help identify patients at risk for persistent pain interference and guide individualized perioperative pain management strategies following TSA.