Single Functioning Kidney Patients Face Increased Odds for Defined Complications Following Total Knee Arthroplasty

Total knee arthroplasty (TKA) patients may present with a single functioning kidney (SFK) for reasons including congenital agenesis, living donation, or resection due to malignancy. While many SFK patients are asymptomatic, this may predispose them to adverse events following TKA. The present study investigated the correlation of SFK and its various etiologies on postoperative outcomes following TKA.

A national database from 2010 to 2022 was used to identify 1,089,735 adult patients undergoing primary TKA. Then, 5,821 patients who had SFK were identified and matched 1:4 with control patients based on age, sex, Elixhauser comorbidity index (ECI), year of surgery, and history of chronic kidney disease (CKD). The 90-day adverse events were abstracted and compared by multivariable regression. The 5-year revision rates were compared using Cox proportional hazards regressions. The relative odds ratio (OR) of adverse events for different etiologies of SFK were compared using multivariable regressions.

On multivariable analyses, SFK patients had higher odds of aggregated adverse events driven by sepsis (OR [odds ratio] 1.75), urinary tract infection (OR 1.51), acute kidney injury (OR 1.30), and pneumonia (OR 1.27) (P < 0.001 for each). The SFK patients had equivalent rates of revision surgery within five year compared to controls (hazard ratio 0.93, P = 0.500). The TKA patients who were kidney donors did not have significantly increased odds of these adverse events compared to control patients, while SFK patients who had a history of renal malignancy or renal agenesis did have significantly higher odds of most of these "at-risk" adverse events.

Total knee arthroplasty patients who had SFK were associated with increased odds of several defined 90-day perioperative adverse outcomes. These results provide robust data on risks in an understudied population, which can be used to guide patient counseling and risk mitigation for SFK patients.