Original ContributionIncidence of acute kidney injury after elective lower limb arthroplasty

•The overall incidence of acute kidney injury after elective hip or knee arthroplasty is approximately 6%.•The incidence in patients with normal preoperative renal function is 4.5%.•Presence of chronic kidney disease (eGFR <60 mL/[min 1.73 m2]) is a major risk factor for developing AKI and increases the risk to 16%.

Study objectiveThe aim of this study was to establish the incidence of acute kidney injury (AKI) in patients undergoing elective hip and knee arthroplasty.DesignThis was a retrospective cohort study.SettingThe study was conducted in a district general hospital in the United Kingdom.PatientsAll patients undergoing elective hip and knee arthroplasty over a period of 6 months were included in the study.MeasurementPreoperative and postoperative serum creatinine concentration was recorded in all patients. AKI was defined according to the Acute Kidney Injury Network classification as an increase of serum creatinine concentration of >26.5 μmol/L (≥0.3 mg/dL) or increase to 1.5-fold from baseline.Main resultsThree hundred thirty-seven patients were included in the study. Forty-eight had preexisting stage 3 chronic kidney disease (CKD). The overall incidence of AKI in our study was 6.2%. The incidence in patients with preexisting stage 3 CKD (estimated glomerular filtration rate <60 mL/[min 1.73 m2]) was 16.3%, whereas in patients without preexisting stage 3 CKD, the incidence was 4.5%.ConclusionWe identified stage 3 or higher CKD as a major risk factor for developing postoperative AKI. Preexisting CKD raised the risk of developing AKI 4-fold. We recommend that all patients undergoing lower limb arthroplasty should have renal function assessed preoperatively. In the perioperative period, renal function should be monitored in all patients. This is of particular importance in patients with estimated glomerular filtration rate <60.