Early Radiographic Union Score for Hip Is Predictive of Femoral Neck Fracture Complications Within 2 Years

OBJECTIVES: To determine if the Radiographic Union Score for Hip (RUSH) measured at 3 and 6 months after femoral neck fracture were predictive of reoperation for infection, nonunion, delayed union, avascular necrosis, or implant failure within 24 months of initial surgery.

DESIGN: Secondary analysis of a randomized controlled trial. Logistic regression was performed to investigate associations between lower RUSH and reoperation. Results were reported as odds ratios (OR), 95% confidence intervals (CIs), and associated P values. All tests were 2 tailed with alpha = 0.05.

SETTING: Eighty-one clinical sites across 8 countries.

PATIENTS/PARTICIPANTS: Data from 734 of the clinical trial participants with radiographs at 3 and 6 months after fracture fixation were included.

INTERVENTION: A reviewer blinded to patients' outcomes independently assigned a RUSH at each follow-up time point.

MAIN OUTCOME MEASURES: Revision surgery rate related to intervention.

RESULTS: Lower RUSH at 3 and 6 months were associated with increased odds of reoperation within 24 months of fracture fixation. For every 2-point decrease in RUSH at 3 months, there was a 16% increase in the odds of a patient experiencing a re-operation (OR, 1.16; 95% CI, 1.10-1.22; P < 0.0001). A similar association was observed at the 6-month assessment for every 2-point decrease (OR = 1.05; 95% CI, 1.01-1.09; P = 0.005).

CONCLUSIONS: Decreased radiographic healing as early as 3 months post fracture fixation is associated with developing patient important femoral neck fracture reoperations. This relationship may guide early treatment decisions, suggesting that 3- and 6-month RUSH are a useful surrogate measure of reoperations within 24 months of fracture fixation.

LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.