Outcomes after fixation for undisplaced femoral neck fracture compared to hemiarthroplasty for displaced femoral neck fracture among the elderly

Background: This study compared the rates of mortality, medical complication, and reoperation after fixation surgery for displaced femoral neck fracture with those after hemiarthroplasty surgery for undisplaced femoral neck fracture using competing risk analysis in inpatients aged 60 years and above from a population database in Taiwan. Methods: We identified 13,772 subjects who underwent fixation for undisplaced cervical fracture and 13,772 matched controls who underwent hemiarthroplasty for displaced cervical fracture from 1998 to 2007, and followed them up until the end of 2009. The outcomes of patients who received internal fixation for undisplaced fracture and those of patients who received hemiarthroplasty for displaced fracture were compared. Results: The 3-month, 2-year, and 10-year mortality rates were 4.9 %, 22.1 %, and 67.1 % for fixation, and 5.6 %, 23.8 %, and 71.0 % for hemiarthroplasty, respectively. The 3-month, 2-year, and 10-year cumulative incidence rates of the first reoperation were 7.4 %, 18.1 %, and 27.7 % for fixation and 6.3 %, 12.0 %, and 22.3 % for hemiarthroplasty, respectively. The 3-month cumulative incidence rates of the first medical complication were 14.4 % for fixation and 15.4 % for hemiarthroplasty, respectively. Hemiarthroplasty had a 1.09 times (95 % CI: 1.05-1.12) higher hazard ratio for overall death than fixation. However, fixation had a 1.36 times (95 % CI: 1.29-1.43) higher subdistribution hazard ratio for first reoperation than hemiarthroplasty after adjusting for gender, age, and comorbidities. Conclusions: The short-term overall mortality and medical complication rate of fixation for undisplaced fracture were slightly lower than those of hemiarthroplasty for displaced fracture. However, the short-term cumulative incidence of first reoperation after fixation was significantly higher than that for hemiarthroplasty. Further prospective studies or clinical trials based on the competing risk model, and which include important risk factors, are necessary to quantify the adjusted effects more precisely.