Outcomes Study in Patients Receiving Aspirin With Mechanical Compression Devices Versus Aspirin Alone Following Knee and Hip Arthroplasty

Inclusion Criteria: * All total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), total hip arthroplasty (THA), and surface replacement arthroplasty (SRA) patients age 18 or older and undergoing an elective primary or revision procedure will be eligible to participate in this study. Exclusion Criteria: Patients will be excluded if they are on chronic Coumadin therapy, require prolonged immobilization (i.e. cast/knee immobilizer; inability to be full weight-bearing and out of bed on postoperative day 1), and are scheduled to have multiple surgeries in close proximity to one another. Based on our institution's risk stratification protocol, all patients deemed "high risk" and meeting one of the following criteria will also be excluded as they would receive Coumadin for VTE prophylaxis: 1. Patients will be excluded if they are on chronic Coumadin therapy 2. History of DVT/PE 3. Active Cancer 4. Hypercoaguable States (Protein C, Protein S, Factor V Leiden, etc.) 5. Family history of thrombosis -note: we may remove this criteria after further discussion 6. Patients requiring prolonged immobilization (i.e. cast/knee immobilizer), 7. Patients having multiple surgeries in close proximity to one another. 8. Patients with known allergy or hypersensitivity to Aspirin or Platelet count \< 60, 000 9. Patients receiving bilateral joint replacement Patients who consent to the study and cancel/do not have a surgery scheduled within six months of signing the consent form will not be included. immobilization (i.e. cast/knee immobilizer; inability to be full weight-bearing and out of bed on postoperative day 1), and are scheduled to have multiple surgeries in close proximity to one another. Based on our institution's risk stratification protocol, all patients deemed "high risk" and meeting one of the following criteria will also be excluded as they would receive Coumadin for VTE prophylaxis: 1. Patients will be excluded if they are on chronic Coumadin therapy 2. History of DVT/PE 3. Active Cancer 4. Hypercoaguable States (Protein C, Protein S, Factor V Leiden, etc.) 5. Family history of thrombosis -note: we may remove this criteria after further discussion 6. Patients requiring prolonged immobilization (i.e. cast/knee immobilizer), 7. Patients having multiple surgeries in close proximity to one another. 8. Patients with known allergy or hypersensitivity to Aspirin or Platelet count \< 60, 000 9. Patients receiving bilateral joint replacement Patients who consent to the study and cancel/do not have a surgery scheduled within six months of signing the consent form will not be included. (Note: The surgery does not have to occur within six months of signing the consent form but must be scheduled/re-scheduled within six months of signing the consent form.) If these patients decide to schedule surgery after the six months has passed, they will be re-consented at the time they schedule surgery. Patients who are not willing to participate will also be excluded from the study. \-