IS THE USE OF DUAL ANTIBIOTIC-LOADED BONE CEMENT ASSOCIATED WITH A REDUCED RISK OF REVISION AND MORTALITY AFTER HEMI- AND TOTAL HIP ARTHROPLASTY FOR FRACTURE, COMPARED TO SINGLE ANTIBIOTIC CEMENT? A REGISTER-BASED EVALUATION OF CURRENT PRACTICE

Aims Femoral neck fractures treated with arthroplasty carry an elevated risk of periprosthetic joint infection (PJI). Dual antibiotic loaded bone cement (ALBC) has been proposed to mitigate this risk. This study aimed to compare the cumulative incidence of all-cause revision between single ALBC and dual ALBC in hip fracture arthroplasty. Secondary aims were to compare the incidence of infection and mortality. Method From the Dutch Arthroplasty Register, we identified all cemented hemiarthroplasties (HA) and total hip arthroplasties (THA) for femoral neck fractures performed between 2007 and 2023. Analyses were performed separately for HA and THA. Cumulative incidences of all-cause revision and infection revision were estimated using competing risk analyses, with death as a competing event. Incidence of mortality was calculated with the Kaplan-Meier method. Cause-specific Cox regression models, adjusted for age, sex, smoking status, ASA classification, and prior surgeries, generated adjusted hazard ratios (HRs). Results A total of 41,047 procedures were analyzed (34,211 HA, 6,836 THA). Dual ALBC was used in 2.6% of all cases (2.7% in HA, 2.0% in THA); 97.4% of procedures used single ALBC (97.3% in HA, 98.0% in THA). Dual ALBC patients were slightly younger (mean 78.5 vs. 80.4 years; p<0.001), had slightly lower BMI (mean 24.2 vs 24.6; p=0.02), were more often smokers (14.4% vs. 9.0%; p<0.001), and more frequently had previous surgeries (3.4% vs. 1.4%; p<0.001). ASA class distribution was not significantly different (p=0.89). For HA, the cumulative incidence of all-cause revision at 1, 2, and 5 years was 1.8%, 2.3%, and 3.0% for single ALBC versus 2.1%, 2.5%, and 3.7% for dual ALBC. For THA, all-cause revision at 1, 2, and 5 years occurred in 2.7%, 3.3%, and 4.6% of single ALBC cases and 3.6%, 5.1%, and 6.8% of dual ALBC cases. Adjusted HRs demonstrated no significant difference in revision rates between ALBC types (adjusted HR in HA=1.01 [95% CI 0.69-1.47]; adjusted HR in THA=1.27 [95% CI 0.65-2.48]). The cumulative incidence and adjusted hazard ratios of infection revisions did not differ significantly between single and dual ALBC. However, dual ALBC use in hemiarthroplasty was associated with significantly higher mortality (adjusted HR=1.13 [95% CI 1.03-1.23]). Conclusions In this registry-based study, dual ALBC did not demonstrate superior outcomes compared to single ALBC in arthroplasty for femoral neck fractures. While dual ALBC use was relatively rare and potentially reserved for higher-risk patients, these data do not support a routine shift toward dual ALBC in this setting.