Abstract: BACKGROUND: Arthroplasty is the primary treatment for displaced femoral neck fractures in the elderly, and the choice of total hip arthroplasty versus hemiarthroplasty is currently the subject of considerable debate.
OBJECTIVE: To compare the mid- and long-term survival status of total hip arthroplasty versus hemiarthroplasty under a direct anterior approach for displaced femoral neck fractures in the elderly based on the propensity score matching method. 
METHODS: One hundred and forty-seven elderly patients (≥ 65 years of age) with displaced femoral neck fractures were admitted from January 2016 to January 2021, of whom 88 had total hip arthroplasty (total hip arthroplasty group) and 59 had artificial femoral head replacement (hemiarthroplasty group). For the patients’ preoperative comorbidities, the age-corrected Charlson Comorbidity Scale was used to quantify the scores and calculate patient frailty. The propensity score matching method was used to match the two groups 1:1 and to compare the operation time, bleeding, postoperative hospitalization time, hospitalization cost, nutritional index, postoperative complications, and mortality between the two groups after matching. Postoperative survival time was determined by Kaplan-Meier Survival analysis. 
RESULTS AND CONCLUSION: (1) After propensity score matching, a total of 42 matched pairs were successful in both groups, and the preoperative data of patients in both groups were balanced and comparable after matching (P > 0.05). (2) Compared with the hemiarthroplasty group, operation time (79.71 minutes vs. 59.07 minutes, P < 0.001), bleeding volume (839.64 mL vs. 597.83 mL, P=0.001), and hospitalization cost (56 508.15 yuan vs. 41 702.85 yuan, P < 0.001) were significantly higher in the total hip arthroplasty group. However, the mortality rate was lower in the total hip arthroplasty group than in the hemiarthroplasty group (36% vs. 57%, HR=0.44, 95%CI: 0.23-0.87, P=0.018), and the mean survival time was longer in the total hip arthroplasty group than in the hemiarthroplasty group (59.4 months vs. 43.7 months, P=0.024). (3) There were no statistically significant differences in postoperative hospitalization time, preoperative and postoperative nutritional indicators, and overall postoperative complication rate between the two groups (P > 0.05). However, in terms of postoperative pain, the incidence of pain was significantly higher in the hemiarthroplasty group than that in the total hip arthroplasty group (24% vs. 7%, P=0.035). (4) Overall, total hip arthroplasty has a better prognosis for survival, while hemiarthroplasty is more appropriate for patients with poor physical fitness. At the same time, postoperative pain may largely affect the quality and survival time of patients after hip arthroplasty.

Key words: direct anterior approach, displaced femoral neck fracture, elderly, total hip arthroplasty, hemiarthroplasty, age-corrected Charlson comorbidity scale, propensity score matching, survival status