Geriatric Distal Femur Fractures Treated with Arthroplasty Are Associated With Lower Mortality but Greater Costs Compared To Open Reduction and Internal Fixation at 30 days.

INTRODUCTION: Distal femur fractures (DFF) are common injuries with significant morbidity. Surgical options include open reduction and internal fixation (ORIF) with plates and/or intra-medullary devices or a distal femur endoprosthesis (DFR). A paucity of studies exist that compare the two modalities. The present study utilized a 1:2 propensity score match to compare 30-day outcomes of geriatric patients with distal femur fractures who underwent an ORIF or DFR.

METHODS: The NSQIP data from 2008 to 2019 was utilized to identify all patients who sustained a DFF and underwent either ORIF or DFR. This yielded 3,197 patients who underwent an ORIF vs 121 patients who underwent a DFR. A final sample of 363 patients (242 patients with ORIF vs 121 with DFR) was obtained after a 1:2 propensity score match. Costs were obtained from the national inpatient sample database using multiple regression analysis and validated with a 7:3 train-test algorithm. Independent samples t-tests and chi-square analysis were conducted to assess cost and outcome differences, respectively.

RESULTS: Patients who received a DFR had higher transfusion rates than ORIF (p= 0.021) and higher mean inpatient hospital costs (p= 0.001). Subgroup analysis for patients 80 or older revealed higher 30-day unplanned readmission (0% vs 18.2% ; p <0.001) and 30-day mortality ( (0% vs 18.2% ; p <0.001) rates for patients undergoing ORIF compared to DFR. The total number of DFR cases needed to prevent one ORIF-related 30-day mortality for distal femur replacement for patients 80 years was 6 (95% CI: 3.02 to 19.9). The mean hospital costs associated with preventing one case of death within 30 days from operation by undergoing DFR compared to ORIF was $176,021.39.

CONCLUSION: Our results demonstrate higher rates of transfusion and increased inpatient costs among the DFR cohort compared to ORIF. However, we demonstrate lower rates of mortality for patients 80 and older who underwent DFR vs. ORIF. Future studies randomized control trials are necessary to validate the results of this study.