Impact of Preexisting Dementia on Mortality, Readmissions, and Complications After Surgical Repair of Hip Fractures: A Cohort Analysis

Abstract

OBJECTIVES: As the population ages, hip fractures are projected to increase. These fractures carry high morbidity and mortality in older adults. Dementia, common among these patients, may further worsen outcomes. This study evaluates the impact of preexisting dementia on mortality after surgical repair of femoral neck and intertrochanteric fractures, with the study hypothesis that the presence of preoperative dementia can result in increased mortality postoperatively. METHODS: Using the TriNetX Research Network, 68,639 patients aged 65 to 90 years who underwent surgical treatment of femoral neck or intertrochanteric fractures from 2015 to 2025 were identified. Patients were grouped based on the presence or absence of a dementia diagnosis before fracture. Surgeries included hemiarthroplasty, internal fixation, or intramedullary nailing. Propensity score matching adjusted for age, sex, and comorbidities. The primary outcome was all-cause mortality at 90 days, 2, and 5 years for patients who had sufficient follow-up data. Secondary outcomes included 90-day readmissions and complications (pneumonia, stroke, urinary tract infection, and heart failure). Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated. RESULTS: Patients with dementia had higher mortality at all time points. In intertrochanteric fractures, dementia patients had increased mortality at 90 days (RR, 0.61; 95% CI, 0.57 to 0.65; P < 0.001), 2 years (RR, 0.68; 95% CI, 0.65 to 0.70; P < 0.001), and 5 years (RR, 0.76; 95% CI, 0.73 to 0.78; P < 0.001). In femoral neck fractures, mortality was also higher at 90 days (RR, 0.56; 95% CI, 0.49 to 0.63; P < 0.001), 2 years (RR, 0.64; 95% CI, 0.59 to 0.70; P < 0.001), and 5 years (RR, 0.71; 95% CI, 0.67 to 0.76; P < 0.001) in patients with dementia. At 90 days for both fracture types, the risk of mortality was nearly double among dementia patients. Similarly, 90-day readmissions and postoperative complications, including pneumonia, stroke, urinary tract infection, heart failure, and revision surgery, were statistically significantly higher among dementia patients. CONCLUSION: Preexisting dementia is associated with higher mortality after hip fracture repair in older adults, approaching nearly double at 90 days. Readmissions and complications are also markedly higher among dementia patients. These findings underscore the importance of tailored perioperative planning, enhanced care pathways for patients with cognitive impairment, and shared decision making between the patient, caregivers, and the care teams.