Impact of Charlson indices and comorbid conditions on complication risk in bilateral simultaneous total knee arthroplasty.

Background: The purpose of this study was to evaluate the influence of Charlson indices and comorbid conditions on the risk of perioperative complications in bilateral simultaneous total knee arthroplasty (BSTKA).

Methods: In our retrospective analysis, 556 patients including 133 males and 423 females (mean age 65.8years), who had undergone bilateral simultaneous total knee arthroplasty between 2011 and 2014 were included. Risk factors (Charlson comorbidity index (CCI), age-adjusted Charlson comorbidity index (ACCI), and comorbid illnesses) and perioperative complications were noted, and subsequently, statistical tests were applied.

Results: There was significant association between Charlson indices and most of the complications (P<0.05) with high-risk ACCI groups (a score>5) bearing maximum odds for cumulative major complication (OR 4.165, P<0.001, 95% CI 1.874 to 9.256). In addition, hypertension, non-ischemic cardiac illness, and moderate to severe chronic kidney disease proved be to be determinants for major complications (P=0.031, P=0.041, and P=0.014, respectively). We also found significant associations between organ-specific illnesses and complications such as cardiac, pulmonary, neurological and renal complications (P<0.05).

Conclusions: Both CCI and ACCI are predictors of post-operative complications with ACCI being the better predictive determinant. Hence, these predictors should be used for risk stratification prior to patient selection for BSTKA. The influence of hypertension, non-ischemic cardiac illness and moderate to severe chronic kidney disease should also be considered during patient selection. Moreover, optimum organ function at the time of surgery should be a priority to avoid these complications.