Patients who develop acute kidney injury (AKI) after primary total hip arthroplasty (THA) are at increased risk for adverse outcomes, including complications and death, reports a study in Arthritis Research & Therapy.
On analysis of the US National Inpatient Sample from 1998 to 2014, the researchers identified a cohort of 4.1 million primary THAs. Of these, approximately 61,000 developed AKI: a rate of 1.5%. The primary outcome of interest was the rate of complications (including infection and revision arthroplasty) and mortality associated with AKI after THA. Healthcare utilization and transfusion were analyzed as secondary outcomes.
With adjustment for age, gender, race, income, underlying diagnosis, comorbidity, and insurance status, the risk of all primary outcomes was significantly higher for patients with AKI after THA. Associated odds ratios (ORs) were 2.34 for implant infection and 2.54 for revision surgery. AKI was also associated with a large increase in mortality risk: OR 8.52.
Secondary outcomes also showed significant AKI-associated increases in transfusion, OR 2.46; total hospital charges above the median, OR 2.29; discharge to a rehabilitation facility, OR 2.11; and hospital stay longer than 3 days, OR 4.34. Overall, AKI after primary THA was associated with a 2.3 to 2.5 relative risk of in-hospital complications, a 3.5-day longer hospital stay, and $37,000 excess mean hospital charges.
The analysis of nationwide data highlights elevated risks of complications and death and increased healthcare utilization and costs for patients with AKI after THA. Further studies are needed to determine the mechanisms of and potentially modifiable risk factors for AKI in patients undergoing hip replacement surgery [Singh J, Cleveland JD. Acute kidney injury after primary total hip arthroplasty: a risk multiplier for complication, mortality, and healthcare utilization. Arthritis Res Ther 2020; 22:31].
