This retrospective study compared the change in serum creatinine between African American and Caucasian total knee arthroplasty (TKA) patients. The authors hypothesized that African Americans would demonstrate significantly greater change, and that a significantly greater proportion would demonstrate creatinine changes consistent with acute kidney injury (AKI).
Primary TKAs performed at a single institution between July 2011 and June 2016 were identified: 1035 primary TKAs met inclusion and exclusion criteria (110 African American, 925 Caucasian, excluding Hispanic and Asian patients). None were excluded based on gender, age, body mass index, preoperative diagnosis, or comorbidities. All patients had preoperative and postoperative creatinine levels available in the electronic medical records. Each patient received the same preop and postop protocol for nonsteroidal anti-inflammatory drug use along with other drugs administered including anesthesia. All patients received 1 g of intravenous vancomycin with some patients additionally receiving 1 g of vancomycin powder administered locally at the end of surgery. All patients were controlled for fluid intake and blood loss, along with no patient receiving a transfusion or intravenous contrast. Patient demographics and preoperative/postoperative serum creatinine were recorded and then analyzed for presence of AKI (≥0.3 mg/dL). Preoperative/postoperative serum creatinine concentrations were compared between African American and Caucasian patients using 2 × 2 repeated measures analysis of variance. Prevalence of patients in each group demonstrating AKI was calculated using Fisher's exact test.
African American patients had significantly greater serum creatinine preoperatively (1.00 ± 0.26 vs 0.90 ± 0.22, P < .001) and a significantly greater increase postoperatively (0.10 vs 0.03, P < .001). A significantly greater number of African American patients demonstrated AKI (10.9% vs 5.1%, P = .03). Furthermore, a significantly greater number of African American patients stayed in the hospital an additional 2 or more days for renal issues (2.7% vs 0.4%, P = .03).
Altered renal function was significantly more common in African American TKA patients. Future studies are necessary to determine if tailoring anti-inflammatories, perioperative medications, and preoperative comorbidities reduce the risk of renal injury and/or a longer hospital stay for this subset of patients.