Duration of Anticoagulation After Hip Fracture Fixed with Cephalomedullary Nail
Patients should receive VTE prophylaxis for 4 weeks postoperatively after hip fracture fixation with a cephalomedullary nail. 1
Evidence-Based Recommendation
The American Academy of Orthopaedic Surgeons 2022 Hip Fracture Clinical Practice Guideline provides a strong strength recommendation with moderate quality evidence that VTE prophylaxis should be used in hip fracture patients, with the specific case example demonstrating enoxaparin (Lovenox) administered for 4 weeks postoperatively. 1
Supporting Evidence for Extended Duration
Extended-duration anticoagulation (5-7 weeks) reduces symptomatic VTE compared to short-duration prophylaxis (7-14 days) in hip replacement surgery, with moderate quality evidence supporting this approach for major orthopedic procedures. 2
The risk of DVT persists for up to 2 months following major hip surgery due to continued immobility and patient-specific risk factors, with studies showing a 12-37% continuing risk of DVT when prophylaxis is stopped at hospital discharge. 1
Direct oral anticoagulants (DOACs) demonstrated significant benefit when extended, reducing symptomatic VTE (OR 0.20) and symptomatic DVT (OR 0.18) compared to placebo, without increased major bleeding risk. 2
Practical Implementation
Standard Prophylaxis Protocol
Initiate mechanical prophylaxis immediately: Sequential compression devices should be used while the patient is hospitalized. 1
Begin pharmacologic prophylaxis postoperatively: Low-molecular-weight heparin (LMWH) such as enoxaparin is the preferred agent. 1
Continue for 4 weeks minimum: This duration balances VTE prevention against bleeding risk in the hip fracture population. 1
Special Considerations for Patients on Chronic Anticoagulation
Warfarin should be recommenced 24 hours after surgery, though some protocols restart it on the day of surgery depending on bleeding risk and indication strength. 1
DOACs can reasonably be recommenced less than 48 hours after hip fracture surgery, considering blood loss and hemoglobin levels, based on international consensus. 3
Do not abruptly discontinue chronic anticoagulation postoperatively, as this exposes patients to increased risks of cardiac ischemia, stent occlusion, cerebrovascular accident, and limb ischemia—particularly critical for patients on dual antiplatelet therapy or within 6 months of treatment initiation. 1
Critical Pitfalls to Avoid
Premature Discontinuation
- Stopping prophylaxis at hospital discharge (7-14 days) is insufficient for hip fracture patients, as the thrombotic risk extends well beyond the typical hospital stay due to ongoing immobility and frailty in this elderly population. 1, 2
Bleeding Risk Overestimation
Minor bleeding is increased with extended LMWH (OR 2.01), but major bleeding is not significantly increased compared to placebo. 2
Anticoagulant use at admission does not independently increase transfusion requirements, surgical complications, or mortality when surgery proceeds appropriately. 4
The slightly increased peri-operative transfusion risk with anticoagulants/antiplatelet therapy does not translate to increased mortality. 1
Surgical Delay Concerns
Delaying surgery to reverse anticoagulation beyond 24-48 hours significantly increases mortality and morbidity, which outweighs theoretical bleeding concerns. 1
Early surgery is safe for patients on DOACs, with no difference in blood transfusion, major bleeding, or 30-day mortality when surgery occurs within 48 hours. 5
Algorithm for Decision-Making
For patients NOT on chronic anticoagulation:
For patients on chronic warfarin:
- Restart 24 hours postoperatively 1
- Bridge with LMWH until therapeutic INR achieved 1
- Continue anticoagulation per original indication
For patients on chronic DOACs:
- Resume within 48 hours postoperatively if hemostasis adequate 3
- Consider hemoglobin level and surgical bleeding 3
- Continue anticoagulation per original indication
For all patients: