When can low‑dose aspirin be restarted after open reduction and internal fixation of a femur fracture with a dynamic hip screw (DHS) plate?

Resuming Low-Dose Aspirin After DHS Fixation of Femur Fracture

Low-dose aspirin should be restarted within 24 hours after open reduction and internal fixation of a femur fracture with DHS plating, once adequate hemostasis is achieved. 1, 2, 3

Primary Recommendation and Timing

The American College of Chest Physicians establishes the standard that aspirin should be resumed within 24 hours postoperatively when hemostasis is adequate. 1 This 24-hour window represents the optimal balance between minimizing thrombotic risk while allowing sufficient time for surgical hemostasis. 1, 2, 3

For patients with high cardiovascular risk (recent coronary stents, recent MI/stroke, or history of recurrent thrombotic events), aspirin resumption within 24 hours is particularly critical, as delaying beyond 24-48 hours significantly increases thrombotic risk and mortality. 1, 2, 3

Risk Stratification Algorithm

High Thrombotic Risk (Resume within 24 hours):

• Recent coronary stent placement (especially drug-eluting stents) 4
• Recent myocardial infarction or acute coronary syndrome 2, 3
• Recent stroke or TIA 2, 3
• History of recurrent thrombotic events 2, 3
• Aspirin for secondary cardiovascular prevention 1, 3

Moderate Risk (Resume within 24-48 hours):

• Stable coronary artery disease 2
• Uncomplicated surgery with good hemostasis 1, 2, 3

Lower Risk (Consider 48-72 hours or reassess need):

• Aspirin for primary prevention only 2
• Minor concerns about hemostasis 2, 3

Bleeding Risk Considerations

Orthopedic trauma surgery, including DHS fixation, does carry increased bleeding risk, but the evidence shows this must be balanced against thrombotic risk. 1, 3 Studies specifically in hip fracture surgery demonstrate that aspirin increases blood transfusion requirements by approximately 0.5 units on average but does not increase major bleeding complications or mortality. 5

If there are active bleeding concerns:

• Minor hemostasis concerns: Delay 24-48 hours while monitoring, but reassess daily 2, 3
• Major bleeding complications or expanding hematoma: Withhold until bleeding controlled, but reassess daily to avoid unnecessarily prolonged discontinuation beyond 48 hours 2, 3

Special Considerations for Coronary Stents

Patients with coronary stents require particular attention. Aspirin should be continued throughout the perioperative period regardless of stent type, as premature discontinuation markedly increases risk of catastrophic stent thrombosis, death, and myocardial infarction. 4, 1 If aspirin was stopped preoperatively (which ideally should not occur in stent patients), it must be restarted as soon as possible postoperatively. 4

For bare-metal stents, dual antiplatelet therapy should continue if surgery occurs within 4-6 weeks of placement. 1 For drug-eluting stents, aspirin should be maintained throughout, and if a P2Y12 inhibitor was held, restart aspirin first within 24 hours, followed by the P2Y12 inhibitor within 2-3 days. 2, 3

Evidence Supporting Early Resumption

The ACC/AHA guidelines emphasize that aspirin monotherapy need not be routinely discontinued for noncardiac surgery, and when stopped, increases procedural bleeding frequency (relative risk 1.5) but not severity of bleeding complications or perioperative mortality. 4 Research specifically in femoral neck fractures demonstrates aspirin is effective for VTE prophylaxis and safe in this population. 6, 7

Critical Pitfall to Avoid

Never withhold both antiplatelet agents simultaneously in patients on dual antiplatelet therapy—if aspirin must be held longer due to bleeding concerns, continue the P2Y12 inhibitor to prevent stent thrombosis. 3 The median time to stent thrombosis is only 7 days when both agents are stopped, versus 122 days when only the P2Y12 inhibitor is stopped while maintaining aspirin. 4