Dilute betadine lavage reduces implant-related bacterial burden in a rabbit knee prosthetic infection model

Treatment of acute postoperative arthroplasty infection with polyethylene exchange and retention of components has a limited success rate, potentially because of residual bacterial burden. We hypothesized that dilute Betadine (povidone-iodine) lavage would decrease bacterial burden in a rabbit knee infection model. We inserted a stainless steel screw with a polyethylene washer into the lateral femoral condyle in 16 bilateral rabbit knees, and the sites were infected with Staphylococcus aureus. After 1 week, all knees were treated with a polyethylene washer exchange and either a saline lavage or a 3.5% Betadine lavage. We assessed bacterial growth after 7 days. Betadine-treated knees showed a statistically significant decrease in the bacterial count on the stainless steel screw and polyethylene washer but no difference in soft-tissue growth. Betadine lavage as a treatment adjunct may improve component retention for acute arthroplasty infection.