Predictors of outcomes after internal fixation of periprosthetic femoral hip fractures Subgroup analysis of the peri-implant and peri-prosthetic fractures Spanish registry (PIPPAS).

Purpose: To identify risk factors predisposing patients to poor outcomes after fixation of periprosthetic hip fractures around femoral stems.

Methods: Prospective multicentre cohort study of fractures around a hip replacement stem managed by internal fixation. The primary outcome was one-year mortality, while secondary outcomes were local complications and healthcare burden-related outcomes (nursing facility utilization and hospital length of stay).

Results: One-year mortality was 16.2%. Age-adjusted Charlson Comorbidity Index score (OR=1.17; 95%CI=1.03-1.33)), Pfeiffer Short Portable Mental Status Questionnaire (SPMSQ) score (OR=1.16; 1.06-1.28), prosthetic dysfunction (OR=1.90; 1.00-3.61), and postoperative medical complications (OR=1.97; 1.06-3.68) were predictors of mortality. Patients with prior prosthetic dysfunction, lower Pfeiffer SPMSQ scores, Vancouver A fractures, and fractures fixed only using cerclages were at higher risk of local complications, which occurred in 9.3% of cases. Medical (OR=1.81; 1.05-3.13) and local complications (OR=5.56; 2.42-3.13) emerged as consistent risk factors for new institutionalization. Average hospitalization time was 13.9±9.2 days. Each day of fixation delay led to an average 1.4-day increase in total hospitalization.

Conclusion: Frail periprosthetic hip-fracture patients with poorer functional status, dysfunctional replacements, and postoperative complications are at increased risk of mortality. Postoperative complications are more common in patients with dysfunctional arthroplasties, Vancouver A fractures, and fixation using cerclages alone. Postoperative complications were the most consistent predictor of higher healthcare resource utilization.