Abstract
Background
A well conducted randomised study found similar functional results for patients with displaced femoral neck fracture comparing operation with a modern uncemented bipolar hemiarthroplasty with a cemented bipolar hemiarthroplasty. The mortality associated with the two procedures has not been sufficiently investigated.
Aim of study
To investigate the mortality and the risk factors for death among patients with displaced femoral neck fractures the first year after surgery, comparing operation with modern uncemented and cemented bipolar hemiarthroplasty (HA).
Methods
8,636 patients (65 years and older) with displaced femoral neck fractures (Garden 3 and 4) operated with a cemented (n = 6,907) or a uncemented bipolar HA (n = 1,729) were selected from the files of The Norwegian Hip Fracture Register 2005–2009. Mortality was assessed using Kaplan-Meier survival analysis and risk factors of death were investigated using Cox-regression analysis. A power analysis showed the study sample to be sufficient to detect a difference in mortality of 3% at one year postoperatively.
Results
Overall mortality one year postoperatively was 27%. We found no difference in the risk of death when comparing operation with cemented with uncemented bipolar HA one year (RR = 0.97, p = 0.51), 240 days (RR = 1.00, p = 0.95), 120 days (RR = 1.04, p = 0.57), and 30 days (RR = 1.12, p = 0.23) postoperatively. However, 10 days postoperatively there was an increased risk of death for patients operated with cemented HA compared to those operated with uncemented bipolar HA (RR = 1.34, p = 0.03). High age, male gender, cognitive impairment, increasing ASA score, and delay in surgery >48 hours after injury were all associated with an increased risk of death one year postoperatively.
Interpretation
The early increased risk of death for patients operated with a cemented HA might be caused by the bone cement implantation syndrome. Our results further indicate that the difference in mortality one year postoperatively is likely to be less than 3%.
