Adjunctive intraoperative pulsed direct current with cefazolin: a rabbit proof-of-concept model for prevention of prosthetic joint infection.

INTRODUCTION

Perioperative bacterial contamination and rapid biofilm formation render prosthetic joint infection (PJI) a devastating complication in arthroplasty, where biofilms exhibit extreme resilience against conventional antibiotics. While low-amperage electrical stimulation can potentiate antibiotic activity in vitro, the prophylactic efficacy of high-amperage stimulation in vivo to prevent initial bacterial seeding remains untested.

METHODS

This study evaluated whether a brief, high-intensity pulsed direct current (pDC) applied during implantation, combined with systemic antibiotics, could prevent early colonization of implants and adjacent tissues. In a translational, proof-of-concept rabbit model, custom cobalt-chromium femoral implants were inoculated with Staphylococcus aureus ATCC 25923 and bilaterally inserted across four conditions: saline lavage (control); lavage + pDC (1 A, 2 Hz, 30 s); lavage + systemic cefazolin; or lavage + cefazolin + pDC. At 72 hours post-surgery, implants, peri-implant bone, and soft tissues underwent sonication and quantitative culture.

RESULTS

Saline lavage and pDC monotherapy failed to prevent heavy surface colonization and systemic dissemination, while cefazolin prophylaxis alone reduced bacterial bioburden but failed to achieve sterility. Remarkably, the combination of cefazolin and pDC achieved absolute clearance, rendering all implants, bone, and soft tissues culture-negative and preventing detectable systemic dissemination, with no clinical adverse events.

DISCUSSION: A single 30-second intraoperative pulse of high-amperage pDC, combined with standard cefazolin prophylaxis, completely prevented early periprosthetic infection by inhibiting initial bacterial attachment before mature biofilm assembly. These preliminary findings demonstrate a potential bioelectric-antibiotic synergy, providing a rapid, non-pharmacological, and workflow-compatible strategy to counter initial bacterial adhesion and the subsequent establishment of biofilms on orthopedic hardware.