Periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) is a devastating complication, making infection prevention strategies a particular area of interest. Chlorhexidine-gluconate (CHG) and povidone-iodine (PI) as irrigation solutions to prevent infection are of particular interest due to their accessibility, affordability and effectiveness1. The interaction between these irrigation fluids and the polyethylene (PE) implants is not well understood and concerns have been raised about potential material degradation of PE implants. This study sought to determine whether exposing PE orthopaedic implants to different concentrations of CHG or PI irrigation solutions would result in any material changes, as well as any measurable viscoelastic changes. We conducted aging studies to identify any evidence of environmental stress cracking (ESC) in polyethylene orthopaedic implants exposed to either a high or a low concentration of CHG (4 and 0.05%) or PI (10 and 0.35%) irrigation solution. Milli-Q water was used as the control. Specimens immersed in high concentrations of CHG or PI were observed for three weeks (500 hours) and low concentrations were observed for four weeks (672 hours). Damage to the implants was assessed through a combination of gross and microscopic examination, color gradient analysis, notch color intensification and dynamic mechanical analysis (DMA). Changes in the color of the PE specimens were observed during both gross and microscopic examinations, with a significant difference in the color gradient at the notch between low- and high-concentration PI when compared to a water control. However, there was no cracking observed and no significant differences in notch depth between the groups F(4,20) = 0.662, P = 0.625 (Figure 1). A post-hoc test with Bonferroni correction for pairwise comparisons revealed no statistically significant differences (gross or microscopic) in the DMA results between any of the groups. Figure 1 Microscopic images (200x) of cross-sectioned polyethylene samples after ESC in Milli-Q water, 0.05 and 4% chlorhexidine, and 0.35 and 10% povidone-iodine. Color intensification at the notch can be seen in both low- and high-concentration chlorhexidine and povidone-iodine solutions. Exposure of PE orthopaedic implants to CHG or PI irrigation solutions at high or low concentrations did not result in any significant ESC or differences in the overall viscoelastic properties of the PE specimens. For any figures or tables, please contact the authors directly.
Khalik et al. (Wed,) studied this question.