A
Aspirin combined with mechanical compression devices
B
Routine use of inferior vena cava (IVC) filters
C
Continuous passive motion (CPM) machines alone
D
Vitamin K supplementation
Explanation:The correct option is 'a'. Current AAOS guidelines support the use of Aspirin (often 81mg twice daily) along with mechanical prophylaxis (Sequential Compression Devices - SCDs) as an effective, low-risk strategy for VTE prophylaxis in standard-risk total joint arthroplasty patients, minimizing bleeding risks associated with stronger anticoagulants.
Reference: American Academy of Orthopaedic Surgeons. Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty. Evidence-Based Clinical Practice Guideline. 2011.