The effect of surgery type on mortality in elderly patients with pertrochanteric femoral fracture: A Korean nationwide cohort study

BACKGROUND/OBJECTIVE: The purpose of this study is to analyze the effect of surgical methods on mortality and the relative risk of patients who underwent internal fixation (IF) or hemiarthroplasty (HA) after being diagnosed as a pertrochanteric fracture over 65 years old in a Korean nationwide cohort with a single insurance medical system. METHODS: The Korean National Health Insurance Service-Senior cohort (NHIS-Senior, NHIS-2018-2-111) was used in this study. The eligibility criteria for incident hip fracture patients were the following: (1) first-time admission to acute care hospitals (index admission) with pertrochanteric fracture (ICD-10 S721), (2) three years of hip fracture-free period, (3) recipients of typical surgeries including IF, HA, (4) age between 65 and 99. RESULTS: a total of 7223 patients were enrolled in the cohort. There were 1662 patients (23%) in the HA group and 5561 patients (77%) in the IF group. Mortality rates of the IF group and HA group were 13.46 and 17.94 cases per 100 person-years, respectively. In the multivariable-adjusted Cox proportional hazard model, the HA group had 1.22 times more hazard of all-cause mortality than IF group (aHR 1.22, 95% CI 1.13-1.32). In subgroup analysis, aged 65-79 and female patients showed a prominent association between surgery type and mortality (aHR 1.52, 95% CI 1.29-1.79). CONCLUSIONS: In patients with pertrochanter fracture over 65 years, 1.22-fold mortality rate was observed when HA was performed compared to that of IF, and the difference in mortality was particularly prominent within 1-year after surgery.