Suh J.M.Lee D.K.Yoon A.Raykateeraroj N.Hardidge A.Grobler S.Kwon G.Pilcher D.Weinberg L.Mahidol University2026-05-132026-05-132026-05-01Trauma Surgery and Acute Care Open Vol.11 No.2 (2026)https://repository.li.mahidol.ac.th/handle/123456789/116709Introduction: The global population of nonagenarians and centenarians is expected to quadruple by 2050, resulting in increasing numbers of the oldest-old undergoing procedures such as hip replacement to maintain mobility and independence. Despite this trend, evidence on how surgical urgency affects outcomes in this population remains limited. Methods: We conducted a retrospective cohort study using data from the ANZICS Adult Patient Database (2010–2023), which captures 98% of intensive care units (ICUs) in Australia and 68% in New Zealand. The study included 1,578 nonagenarian and centenarian patients who underwent non-traumatic hip replacement and were admitted to intensive care. Outcomes examined were mortality at three time intervals (<30 days, 30–365 days and >365 days) and ICU and hospital length of stay. Analytical methods included propensity score matching, Cox regression, Kaplan-Meier curves and time-dependent area under the receiver operating characteristic curve analyses to assess the prognostic value of clinical scores and biomarkers. Results: Non-elective operation was associated with significantly higher mortality across all time points (HR 2.87 at <30 days; 3.02 at 30–365 days; 1.84 beyond 365 days). It was also linked to a 13.1% longer ICU stay (p=0.034). Acute Physiology and Chronic Health Evaluation III and Sequential Organ Failure Assessment scores showed strong predictive performance for short-term mortality, whereas age and sex had minimal prognostic value. Conclusion: Among nonagenarians and centenarians undergoing hip replacement, non-elective procedures were consistently associated with poorer outcomes, including higher mortality and longer ICU stay. Early risk stratification using routine clinical markers, together with proactive goals-of-care discussions, may improve perioperative management in this vulnerable population. Level of evidence: Level II Therapeutic/Care Management.MedicineArticleSCOPUS10.1136/tsaco-2025-0021942-s2.0-10503796404523975776