Different impacts of dementia on two-year mortality after osteosynthesis and hemiarthroplasty in treating geriatric hip fractures.

BACKGROUND: Geriatric hip fractures are mostly managed by internal fixation (IF) or hemiarthroplasty (HA). Survivorship of dementia patients following these surgeries has not been extensively compared in literature. By analysis of nationwide database, this study aimed to investigate the impact of dementia on two-year mortality after IF and HA in treating geriatric hip fractures.

METHOD: From retrospective review of Taiwan's National Health Insurance Research Database, we enrolled 153,623 subjects aged 65 years and older with hospitalization for first hip fracture operated by IF (93,029 cases) or HA (60,594 cases) between 2000 and 2011. Postoperative mortality was compared between subjects with and without dementia after adjustments of age, gender, Charlson comorbidity index and hospital level.

RESULTS: The prevalence of dementia was 5.24% in the IF and 5.29% in the HA group. In the IF group, dementia increased adjusted hazard ratio of one-year (1.06, 95%CI:1.00-1.13) and two-year mortality (1.10, 95%CI:1.05-1.16). However, short and long-term mortality following HA was not significantly impacted by dementia (in-hospital OR:0.79, 95%CI:0.60-1.03; three-month HR:0.99, 95%CI:0.87-1.12; one-year HR:1.01, 95%CI:0.93-1.10; two-year HR:1.03, 95%CI:0.96-1.09). In a subgroup of dementia patients, mortality following IF was 15% higher than HA in one (p = 0.004) and two years (p < 0.001). The negative prognostic factors included female (HR:1.10; 95%CI:1.03-1.18) and aging 65-84 years (HR:1.15; 95%CI:1.00-1.32).

CONCLUSION: Dementia increased one and two-year mortality following geriatric hip fracture treated by IF, rather than HA. Dementia patients undergoing HA, especially female or 65-84 years old, sustained better one and two-year survival than those receiving IF.