Abstract
Venous thromboembolism (VTE) events are rare, but serious complications of total joint
replacement affect patients and health care systems due to the morbidity, mortality,
and associated cost of its complications. There is currently no established universal
standard of care for prophylaxis against VTE in patients undergoing revision total
knee arthroplasty (rTKA). The aim of this study was to determine whether a protocol
of 81-mg aspirin (ASA) bis in die (BID) is safe and/or sufficient in preventing VTE
in patients undergoing rTKAs versus 325-mg ASA BID. In 2017, our institution adopted
a new protocol for VTE prophylaxis for arthroplasty patients. Patients initially received
325-mg ASA BID for 1 month and then changed to a lower dose of 81-mg BID. A retrospective
review from 2011 to 2019 was conducted identifying 1,438 consecutive rTKA patients
and 90-day postoperative outcomes including VTE, gastrointestinal, and wound bleeding
complications, acute periprosthetic joint infection, and mortality. In the 74 months
prior to protocol implementation, 1,003 rTKAs were performed and nine VTE cases were
diagnosed (0.90%). After 26 months of the protocol change, 435 rTKAs were performed
with one VTE case identified (0.23%). There was no significant difference in rates
or odds in postoperative pulmonary embolism (PE; p = 0.27), DVT (p = 0.35), and total VTE rates (p = 0.16) among patients using either protocol. There were also no differences in bleeding
complications (p = 0.15) or infection rate (p = 0.36). No mortalities were observed. In the conclusion, 81-mg ASA BID is noninferior
to 325-mg ASA BID in maintaining low rates of VTE and may be safe for use in patients
undergoing rTKA.
Keywords deep venous thrombosis - pulmonary embolism - aspirin - venous thromboembolism prophylaxis
- revision total knee arthroplasty - bleeding - infection - mortality
