5-Factor Modified Frailty Index as a Predictor of Outcomes After Hemiarthroplasty or Total Hip Arthroplasty for Femoral Neck Fracture.

Introduction: Although the 5-factor modified frailty index (mFI-5) has been shown to be an independent predictor of complications after primary total hip arthroplasty (THA), its predictive value has not been evaluated in the setting of hip fracture. We therefore assessed the utility of mFI-5 score as an independent predictor of morbidity and mortality in patients who underwent THA or hemiarthroplasty for femoral neck fracture.

Methods: The American College of Surgeons National Surgical Quality Improvement database was queried for all patients with femoral neck fractures treated with THA or hemiarthroplasty between 2006 and 2020. A multivariate logistic regression analysis was done using mFI-5 as a predictor while controlling for baseline demographic and clinical variables.

Results: In total, 45,185 patients (hemiarthroplasty: 37,645; THA: 7,540) were identified. For hemiarthroplasty patients, the mFI-5 strongly predicted risk of any complication (OR, 1.1; 95% CI, 1.1 to 1.2; P < 0.001), bleeding (OR, 1.2; 95% CI, 1.1 to 1.3; P < 0.001), and readmission (OR, 1.2; 95% CI, 1.1 to 1.3; P < 0.001). For THA patients, the mFI-5 was a strong predictor of any complication (OR, 1.2; 95% CI, 1.0 to 1.3; P = 0.023), pneumonia (OR, 1.4; 95% CI, 1.0 to 2.0; P = 0.047), and readmission (OR, 1.3; 95% CI, 1.1 to 1.6; P = 0.004).

Discussion: The mFI-5 is an independent predictor of morbidity and complications after hemiarthroplasty and THA for femoral neck fracture. Importantly, readmission risk was predicted by the mFI-5. The mFI-5 may present a valuable clinical tool for assessment of high-risk patients who might require additional resources and specialized care after femoral neck fracture.