Comparison of Clinical Outcomes According to Preoperative Skin Preparation in Hip Arthroplasty for Hip Fracture: A 3-Arm Randomized Controlled Trial.

BACKGROUND: Patients with hip fractures undergoing arthroplasty are typically old and frail, and superficial surgical site infections (SSIs) can delay mobilization and prolong hospitalization. Preoperative skin antisepsis is a low-cost, universally used intervention. However, clinical practice varies, and evidence from elective arthroplasty may not fully generalize to urgent hip fracture surgery. Sequential dual-antiseptic protocols combining povidone-iodine (PVI) and chlorhexidine gluconate (CHG) are increasingly adopted; however, the optimal order for "scrub" versus "paint" remains unclear. We compared the prophylactic efficacy of 3 skin preparation protocols using different sequences of PVI and CHG. METHODS: In this single-center, prospective, randomized controlled trial, 108 patients undergoing hip arthroplasty for hip fracture were randomly allocated to 3 groups based on the antiseptic agents used for the mechanical "scrub" and final "paint" steps: group 1 (PVI scrub/PVI paint), group 2 (PVI scrub/CHG paint), and group 3 (CHG scrub/PVI paint). The primary outcome was the rate of positive skin culture results immediately before draping and pathogen identification results. The secondary outcome was the incidence of superficial SSI. RESULTS: Post-preparation culture positivity was significantly lower in the CHG-containing groups (group 2 and group 3: 5.6% each) than in the PVI-only group (group 1: 27.8%; p = 0.005). The incidence of superficial SSI differed significantly among the 3 protocols (p = 0.015). The highest superficial SSI rate was observed in group 1 (30.6%), followed by group 2 (13.9%). Group 3 had the lowest superficial SSI rate (5.6%). In multivariable logistic regression adjusted for confounders, group 1 was associated with a significantly higher risk of SSI than group 3 (adjusted odds ratio, 3.89; 95% CI, 1.22-12.37; p = 0.021). CONCLUSIONS: The sequence of antiseptic application significantly influenced microbiological outcomes, with CHG-containing protocols demonstrating lower post-preparation culture positivity. A protocol using a CHG scrub followed by PVI paint provided the most effective bacterial suppression. Differences in superficial SSI rates were also observed and may reflect the impact of improved microbiological control. Optimizing the order of antiseptic administration may contribute to improved infection prevention in this high-risk population.