Effect of Acetylsalicylic Acid Dose and Time Discontinued Preoperatively on Outcomes After Total Knee and Hip Arthroplasty.

ABSTRACT

The purpose of this study was to determine if acetylsalicylic acid (ASA) dose or time discontinued preoperatively affected surgical outcomes in total joint arthroplasty (TJA). The authors hypothesized that ASA worsens surgical outcomes in patients receiving higher doses and in those who discontinue ASA closer to the operative date. A total of 2853 TJAs (1802 primary total knee arthroplasties and 1051 total hip arthroplasties) performed at a tertiary medical center were reviewed. Postoperative outcomes of patients receiving ASA prior to TJA, dosing of ASA (81 mg or 325 mg) preoperatively and postoperatively, and the time of preoperative discontinuation (no ASA, <4 days, <7 days, and 7 or more days) were compared. Preoperative ASA was a risk factor for readmission (odds ratio [OR], 1.86; P<.001) and 90-day postoperative events (OR, 1.26; P=.004). Among patients receiving ASA, the dose was not a risk factor for any of the studied outcomes. Discontinuing ASA 7 or more days prior to TJA was protective for hematomas (OR, 0.64; P=.038), emergency department visits (OR, 0.79; P=.006), readmission (OR, 0.65; P<.001), and 90-day postoperative events (OR, 0.72; P<.001). These outcomes had a time effect the risk was greater for those who discontinued therapy closer to the operative date. Patients who discontinued ASA 7 or more days prior to TJA had a lower incidence of hematomas, emergency department visits, readmissions, and 90-day postoperative events. This study's findings support discontinuing ASA at least 7 days prior to TJA. [Orthopedics. 2019; 42(5)286-293].