Purpose: Methylrosaniline, more commonly known as Gentian violet, is an inexpensive dye that has been used in medicine for 100 years. It has been shown, in the international literature, to have antimicrobial effects against Staphylococcus aureus, Staphylococcus epider-midis, and Pseudomonas aeruginosa. Methylrosaniline has the potential to exert an antibiotic effect while theoretically having a reduced selection pressure for resistant bacteria.

Methods: Standardized specimens consisting of Simplex P cement combined with Gentian violet, powdered tobramycin, powdered erythromycin/colistin, and no antibiotic were fashioned. These four groups were then tested against the species S. aureus, S epidermidis, and P aeruginosa using a Kirby- Bauer Agar disk diffusion test.

Results: Gentian violet showed antimicrobial activity against S aureus, S epidermidis, but not P aeruginosa. Tobramycin demonstrated activity against against all three and the preparation of erythromycin/colistin was only effective against S aureus.

Conclusions: Gentian violet demonstrates antimicrobial activity against the two most common infections in primary total joint arthroplasty.