Definition
- Measures to prevent deep vein thrombosis and pulmonary embolism after surgery or injury
Epidemiology
- Highest risk after hip and knee arthroplasty, hip fracture surgery and major trauma
- Without prophylaxis, venographic DVT is common after arthroplasty but symptomatic VTE is uncommon
Risk Factors
- Previous VTE, active cancer, thrombophilia
- Age, obesity, immobility, oestrogen therapy and pregnancy
- Lower limb immobilisation and long operating time
- Assess bleeding risk alongside VTE risk
Mechanical Prophylaxis
- Early mobilisation
- Graduated compression stockings
- Intermittent pneumatic compression
- Foot pumps when the leg is in plaster or not accessible
- Mechanical methods are used when bleeding risk is high
Chemical Prophylaxis
| Agent | Action |
|---|---|
| Enoxaparin | Low molecular weight heparin, anti-Xa |
| Rivaroxaban, apixaban | Direct oral factor Xa inhibitors |
| Dabigatran | Direct thrombin inhibitor |
| Aspirin | Antiplatelet |
| Unfractionated heparin | Used in renal impairment |
- Extend prophylaxis to about 35 days after hip arthroplasty and 14 days after knee arthroplasty
- CRISTAL trial (JAMA 2022) found more symptomatic VTE with aspirin than enoxaparin after arthroplasty
- PEP trial (Lancet 2000) found aspirin reduced PE after hip fracture
- Balance bleeding risk, wound ooze and neuraxial anaesthesia timing
Guidelines
- Australian Commission on Safety and Quality in Health Care VTE Prevention Clinical Care Standard
- NICE NG89
- Extended prophylaxis for up to 35 days after hip arthroplasty
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.