Implant-associated infection after hip fracture surgery in elderly patients: Risk factors and mortality

Aims: Our study aimed to evaluate the prognosis of implant-related infection following hip fracture and presurgical, surgical and microbiological factors modifying outcomes. Methods: We retrospectively included patients aged 65 and older treated for infection following surgically managed hip fractures between 2012 and 2022. Periprosthetic and high-energy fractures were excluded. Data was obtained by clinical chart review, including: age, gender, Barthel index, Charlson Score, National Hip Fracture Database (NHFD) Mobility Score, surgery and infection type, causative pathogens, antimicrobial resistance, anti-biofilm antibiotic treatment and clinical situation at one-year follow up. The outcomes evaluated were failure/resolution of infection and one-year mortality. Results: We included 80 patients (67 women, 83.8 %) aged a median of 85 years (interquartile range: 78 - 88 years). Treatment failed in 38 (47.5 %) patients, and the one-year mortality was 37.5 %. Patients dying within 12 months after treatment were more likely to suffer acute vs. chronic infections (OR = 3.29 [95 %CI: 1.20-9.04]), be older and have more comorbidity, but baseline function and ambulation were not predictive. Treatment failure was higher among patients receiving non-antibiofilm controlling surgery, specifically surgical lavage (OR = 3.79 [95 %CI: 1.38-10,37]), as well as in older, more dependent patients. Receiving anti-biofilm antibiotics for more than 2 weeks was associated with less treatment failure (OR:0.32; [95 %CI: 0.13-0.80]) and 12-month mortality (OR:0.22 [95 %CI: 0.08-0.60]). Conclusions: Antibiofilm-controlling surgery and antibiotics improve treatment success following implant-related infection after hip fracture and should be considered regardless of fracture type. Acute infections are a "second hit" for frail patients recovering from initial surgery and are associated with increased mortality.