Total Hip Arthroplasty for Femoral Neck Fractures: Improved Outcomes With Higher Hospital Volumes.

OBJECTIVES

To determine if hospital arthroplasty volume affects patient outcomes after undergoing total hip arthroplasty (THA) for displaced femoral neck fractures.

METHODS

The Statewide Planning and Research Cooperative System database from the New York State Department of Health was used to group hospitals into quartiles based on overall THA volume from 2000 to 2010. The database was then queried to identify all patients undergoing THA specifically for femoral neck fracture during this time period. The data were analyzed to investigate outcomes between the 4 volume quartiles in 30-day and 1-year mortality, 1-year revision rate, and 90-day complication rate (readmission for dislocation, deep vein thrombosis, pulmonary embolism, prosthetic joint infection, or other complications related to arthroplasty in the treatment of femoral neck fractures with THA).

RESULTS

Patients undergoing THA for femoral neck fracture at hospitals in the top volume quartile had significantly lower 30-day (0.9%) and 1-year (7.51%) mortality than all other volume quartiles. There were no significant differences on pairwise comparisons between the second, third, and fourth quartiles with regard to postoperative mortality. There was no significant difference in revision arthroplasty at 1 year between any of the volume quartiles. On Cox regression analysis, THA for fracture at the lowest volume (fourth) quartile [hazard ratio (HR), 1.91; P = 0.016, 95% confidence interval (CI), (1.13-3.25)], second lowest volume (third) quartile (HR, 2.01; P = 0.013, 95% CI, 1.16-3.5) and third lowest volume (second) quartile (HR, 2.13; P = 0.005, 95% CI, 1.26-3.62) were associated with increased risk for a 1-year postoperative mortality event. Hospital volume quartile was also a significant risk factor for increased 90-day complication (pulmonary embolism/deep vein thrombosis, acute dislocation, prosthetic joint infection) following THA for femoral neck fracture. Having surgery in the fourth quartile (HR, 2.71; P < 0.001, 95% CI, 1.7-4.31), third quartile (HR, 2.61; P < 0.001, 95% CI, 1.61-4.23), and second quartile (HR, 2.41; P < 0.001, 95% CI, 1.51-3.84), all were significant risk factors for increased 90-day complication risk.

CONCLUSIONS

The results of this population-based study indicate that THA for femoral neck fractures at high-volume arthroplasty centers is associated with lower mortality and 90-day complication rates but does not influence 1-year revision rate. THA for femoral neck fractures at top arthroplasty volume quartile hospitals are performed on healthier patients more quickly. Patient health is a critical factor that influences mortality outcomes following THA for femoral neck fractures.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.