Does total hip arthroplasty in elderly patients with femoral neck fractures reduce complications? A Japanese DPC study

Background: The global increase in femoral neck fractures due to aging and osteoporosis is a major clinical challenge. The debate on the optimal surgical intervention for femoral neck fractures remains unresolved. This large-scale study explores femoral neck fractures among the elderly, focusing on the comparative outcomes of Total Hip Arthroplasty (THA) versus Bipolar Hemiarthroplasty (BHA) in Japanese patients. Methods: Using the Japanese National Administrative Diagnosis Procedure Combination (DPC) database, we studied cases of femoral neck fracture from April 2016 to March 2023, and after propensity score matching by age, sex, and comorbidities, we examined the association between THA, complications, and clinical outcomes, and the usefulness of THA for elderly patients with femoral neck fracture. Results: One-to-one propensity score matching identified 7741 pairs of THA and BHA cases. There was no difference in length of stay between the THA and BHA groups. Significantly more blood transfusions were required in the THA group. There was no significant difference in mortality between the THA and BHA groups, but there was a reduced risk of pneumonia in the THA group, with a ratio of 0.547 (95% CI: 0.418–0.715). On the other hand, the THA group had a higher risk of pulmonary embolism, with a ratio of 1.607 (95% CI: 1.379–1.874). The THA group shows improved discharge rates directly home from the facility where the operation was performed, with a ratio of 1.798 (95% CI: 1.675–1.929). Conclusion: The findings of this research indicate that THA is more effective than BHA in enabling elderly Japanese patients with femoral neck fractures to be discharged directly home and in preventing pneumonia, despite concerns about pulmonary embolism. These findings suggest that THA may improve functional prognosis in elderly patients with femoral neck fractures, although there is a trade-off with an increased risk of pulmonary embolism.