These authors compares the antimicrobial efficacy and cytotoxicity of an irrigation solution containing polymyxin-bacitracin with other commonly used irrigation solutions in vitro.
They exposed Staphylococcus aureus and Escherichia coli to irrigation solutions containing topical antibiotics (500,000-U/L polymyxin and 50,000-U/L bacitracin; 1-g/L vancomycin; or 80-mg/L gentamicin), as well as commonly used irrigation solutions (saline solution 0.9%; povidone-iodine 0.3%; chlorhexidine 0.05%; Castile soap 0.45%; and sodium hypochlorite 0.125%). Following 1 and 3 minutes of exposure, surviving bacteria were manually counted. Failure to eradicate all bacteria in any of the 3 replicates was considered not effective for that respective solution.
Cytotoxicity analysis in human fibroblasts, osteoblasts, and chondrocytes exposed to the irrigation solutions was performed by visualization of cell structure and was quantified by lactate dehydrogenase (LDH) activity. Efficacy and cytotoxicity were assessed in triplicate experiments, with generalized linear mixed models.
Polymyxin-bacitracin, saline solution, and Castile soap at both exposure times were not effective at eradicating S. aureus or E. coli. In contrast, povidone-iodine, chlorhexidine, and sodiumhypochlorite irrigation were effective against both S. aureus and E. coli. Vancomycin irrigation was effective against S. aureus but not against E. coli, whereas gentamicin irrigation showed partial efficacy against E. coli but none against S. aureus.
Polymyxin-bacitracin, saline solution, and Castile soap at both exposure times were not effective at eradicating S. aureus or E. coli. In contrast, povidone-iodine, chlorhexidine, and sodiumhypochlorite irrigation were effective against both S. aureus and E. coli. Vancomycin irrigation was effective against S. aureus but not against E. coli, whereas gentamicin irrigation showed partial efficacy against E. coli but none against S. aureus.
Within fibroblasts, the greatest cytotoxicity was seen with chlorhexidine (mean 49.38%), followed by Castile soap (33.57%) and polymyxin-bacitracin (8.90%). Povidone-iodine showed the least cytotoxicity of the efficacious solutions (5.00%). Similar trends were seen at both exposure times and across fibroblasts, osteoblasts, and chondrocytes.
Conclusions: Irrigation with polymyxin-bacitracin was ineffective at eradicating these bacteria and were inferior to povidone-iodine. On the other hand, Chlorhexidine lavage conferred the greatest in vitro cytotoxicity.
The authors conclude that the addition of polymyxin-bacitracin to saline solution irrigation has little value and suggest that Povidone-iodine (Betadine) may be a more effective and safer option.
Conclusions: Irrigation with polymyxin-bacitracin was ineffective at eradicating these bacteria and were inferior to povidone-iodine. On the other hand, Chlorhexidine lavage conferred the greatest in vitro cytotoxicity.
The authors conclude that the addition of polymyxin-bacitracin to saline solution irrigation has little value and suggest that Povidone-iodine (Betadine) may be a more effective and safer option.
Comment: While this is not an in vivo study and while it does not test the effects of the different irrigating solutions against the organisms commonly causing shoulder periprosthetic infections (Cutibacterium, coagulase-negative Staph), these results are of interest to shoulder surgeons. First it points out that the effectiveness of various irrigation solutions cannot be assumed, but rather it needs to be tested against the organisms we commonly encounter. Secondly, it points out that irrigation solutions may have harmful effects on the cells of the patient. We note that the use of some of the irrigation solutions being marketed for the use in shoulder cases(see this link) may be called int o question by this article.
Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and this link. Also see the essentials of the ream and run.
=====
To see our new series of youtube videos on important shoulder surgeries and how they are done, click here.
Use the "Search" box to the right to find other topics of interest to you.To see our new series of youtube videos on important shoulder surgeries and how they are done, click here.
You may be interested in some of our most visited web pages arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'
Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and this link. Also see the essentials of the ream and run.
