What is the recommended prophylaxis for venous thromboembolism (VTE) after hip arthroplasty?

VTE Prophylaxis After Hip Arthroplasty

For patients undergoing hip arthroplasty, prophylaxis with low-molecular-weight heparin (LMWH) should be started 12 hours before or after surgery and continued for 10-14 days, with extension up to 35 days recommended to reduce the risk of venous thromboembolism. 1

Recommended Pharmacological Options

• LMWH is the preferred first-line option for VTE prophylaxis after hip arthroplasty, with enoxaparin 30 mg twice daily or 40 mg once daily being the most widely used regimen 1
• Fondaparinux 2.5 mg subcutaneously once daily is an effective alternative (reduce to 1.5 mg daily if CrCl 30-50 mL/min) 1
• Rivaroxaban 10 mg orally once daily with or without food is FDA-approved for VTE prophylaxis following hip replacement surgery 2
• Unfractionated heparin 5000 U subcutaneously twice or thrice daily can be used when LMWH is contraindicated 1
• Adjusted-dose warfarin (target INR 2.0-3.0) is an option but not preferred over newer agents 1

Duration of Prophylaxis

• Minimum duration: 10-14 days of prophylaxis is recommended for all patients undergoing hip arthroplasty 1
• Extended prophylaxis: Continue for up to 35 days (approximately 4-5 weeks) after surgery, especially for patients at high risk of VTE 1, 3
• Extended prophylaxis with LMWH reduces postdischarge VTE by approximately two-thirds after hip replacement 4

Timing of Initiation

• For LMWH: Initiate 12 hours before or after surgery 1
• For rivaroxaban: Start 6-10 hours after surgery once hemostasis is achieved 1
• For fondaparinux: Begin 6-8 hours after surgery once hemostasis is established 1

Mechanical Prophylaxis

• Intermittent pneumatic compression (IPC) devices should be used in addition to pharmacological prophylaxis for a goal of 18 hours daily 1
• For patients at high risk of bleeding, mechanical prophylaxis with IPC may be used alone until bleeding risk diminishes 1
• Early ambulation should be encouraged as part of a multimodal approach 1

Special Considerations

• For patients with a history of VTE, anticoagulation is strongly recommended over aspirin alone 5
• Patients with renal impairment (CrCl <30 mL/min) should avoid LMWH and fondaparinux; consider unfractionated heparin or adjusted-dose warfarin 1
• For patients who cannot use heparins, consider aspirin, fondaparinux, or IPC 1
• Cancer patients should receive extended prophylaxis with LMWH for 4 weeks 1

Common Pitfalls and Caveats

• Despite clear guidelines, approximately 42-58% of at-risk patients do not receive appropriate VTE prophylaxis 1
• Fear of bleeding complications often leads to inadequate prophylaxis, but the risk of VTE outweighs bleeding risk in most patients 3
• Discontinuing prophylaxis too early (before 10 days) increases VTE risk, especially as hospital stays have shortened 4, 6
• Individualized risk assessment using validated tools (like Caprini score) helps determine patients who would benefit most from extended prophylaxis 1, 7
• Patients discharged before completing the minimum 10-day course must continue prophylaxis at home 3

The evidence strongly supports a minimum of 10-14 days of prophylaxis with consideration of extended prophylaxis up to 35 days, particularly for high-risk patients undergoing hip arthroplasty. LMWH remains the most well-studied option, though newer oral anticoagulants like rivaroxaban offer convenient alternatives with comparable efficacy.