INTRODUCTION: The older population, especially centenarians, is growing. Hip fractures significantly affect this demographic
however, studies on centenarians are limited. This study aimed to compare hip fracture mortality and associated risk factors between centenarians, nonagenarians, and octogenarians with focus on centenarians. METHODS: Data from the Korean Health Insurance Review and Assessment database were retrospectively analyzed. Individuals aged ≥ 80 years with an ICD-10 diagnosis code (S72) and procedure codes indicative of hip fracture surgery between 2012 and 2022 were included. The primary outcome was mortality at 1, 3, 6 months, and 1 year postoperatively. The secondary outcomes included the prevalence of comorbidities and postoperative complications. RESULTS: 131,746 patients were included (106,244 [80.6 %] octogenarians, 24,842 [18.9 %] nonagenarians, and 660 [0.5 %] centenarians). Centenarians had lower Charlson Comorbidity Index than that of nonagenarians and octogenarians (4.4, 4.9, and 5.7, respectively
P <
0.000). However, perioperative medical complications such as acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), pneumonia, sepsis, and urinary tract infection increased linearly with age, significantly affecting centenarians. Mortality rates were highest in centenarians, especially within the first 3 postoperative months. The risk factors for 3-month mortality included the male sex (odds ratio [OR] 1.79, 95 % confidence interval [CI] 1.01-3.12, P = 0.046), and heart failure (OR 1.72, 95 % CI 1.07-2.79, P = 0.026) preoperatively, and AKI (OR 3.92, 95 % CI 1.97-7.82, P <
0.000), ARDS (OR 2.92, 95 % CI 1.04-8.23, P = 0.04), pneumonia (OR 1.91, 95 % CI 1.11-3.29, P = 0.02), and sepsis (OR 10.01, 95 % CI 3.52-28.45, P <
0.000) postoperatively. CONCLUSION: Despite having fewer comorbidities, centenarians had the highest postoperative mortality, primarily due to organ dysfunction such as pneumonia, AKI, ARDS, and sepsis, rather than vascular events. Tailored medical management strategies focusing on these complications are crucial for improving centenarians outcomes.