Antiseptics Commonly Used in Total Joint Arthroplasty Interact and May Form Toxic Products.

BACKGROUND: Multiple antiseptics have been described for use in total joint arthroplasty infection, and the use of multiple antiseptic solutions during a single operation has been described. Our clinical experience is that chlorhexidine (CHX) and Dakin's solution (NaOCl) interact and form a precipitate. The purpose of this study is to determine whether this reaction could be replicated in a laboratory setting, and to determine if other commonly used antiseptics also visibly react when mixed. METHODS: Four percent chlorhexidine gluconate (CHX), 0.5% sodium hypochlorite (NaOCl), 3% hydrogen peroxide (H2O2), and 10% povidone-iodine (BTD) solutions were obtained and all possible combinations were mixed. Any visible reactions were noted and recorded, and a literature search was performed to characterize the reaction and products. RESULTS: CHX and NaOCl, CHX and H2O2, and CHX and BTD reacted instantly, forming a precipitate. NaOCl and H2O2 reacted to produce a gas. NaOCl and BTD reacted and produced a color change. The literature review revealed that at least 2 of the reactions tested (CHX + NaOCl and NaOCl + H2O2) could result in byproducts toxic to humans. CONCLUSION: Surgeons must be aware of these interactions when using antiseptic solutions during procedures. Caution should be used combining or mixing antiseptics, and we recommend against concomitant introduction in a surgical wound.

Obesity Is Independently Associated With Early Aseptic Loosening in Primary Total Hip Arthroplasty.

BACKGROUND: Obesity affects millions of patients in the United States and is associated with several complications after total hip arthroplasty (THA). The effect of obesity on the rate and mode of primary THA failure remains poorly understood, especially given other potentially confounding patient characteristics. We hypothesized that, among patients with a failed primary THA, obesity is independently associated with aseptic loosening and a higher rate of early revision. METHODS: Six hundred eighty-four consecutive cases with failed THA referred to a single academic center for revision during a 10-year period were retrospectively reviewed. Multivariate logistic regression analysis was used to test the independent association between obesity and the timing as well as cause of THA failure. RESULTS: The rate of primary THA failure before 5 years was 48.8% in obese and 37.1% in nonobese patients (odds ratio [OR] = 1.57, P = .010). Primary THA failure before 5 years was more likely with increasing body mass index (BMI) (BMI: 35-40 kg/m2, OR = 2.31, P = .008; BMI >40 kg/m2, OR = 2.51, P = .049). The rate of primary THA failure for aseptic loosening before 5 years was 30% in obese and 18% in nonobese patients (OR = 1.88, P = .023). Obesity was not a risk for revision for infection, whereas an American Society of Anesthesiologists class ≥3 was independently associated with primary THA failure for infection (OR = 2.33, P < .001). CONCLUSION: Among patients with a failed THA, comorbidities may account for the risk of revision due to infection in obese patients. Obesity is independently associated with early primary THA failure for aseptic loosening.