Initial selection of venous thromboembolism prophylaxis in patients undergoing major orthopedic surgery*

THA: total hip arthroplasty; TKA: total knee arthroplasty; HFS: hip fracture surgery; CrCl: creatinine clearance; UFH: unfractionated heparin; HIT: heparin-induced thrombocytopenia; LMWH: low molecular weight heparin; DOAC: direct oral anticoagulant; ASA: aspirin; INR: international normalized ratio.

* This algorithm is intended for adult patients undergoing major orthopedic surgery (eg, THA, TKA, HFS) that is not the result of severe blunt or penetrating traumatic injury. Patients who undergo major orthopedic surgery are generally considered high risk of venous thromboembolism. However, the range of risk within this "high risk" category is wide.

¶ Options for mechanical thromboprophylaxis include intermittent pneumatic compression (which is our preference), graduated compression stockings, and the venous foot pump. Pharmacologic prophylaxis should be started as soon as the bleeding risk is acceptable. Inferior vena cava filters are not used prophylactically in these patients.

Δ Warfarin is a reasonable alternative if heparin injections are undesirable.

◊ Heparins should not be used in patients with HIT or a history of HIT. Fondaparinux is an option for patients with known or suspected HIT provided CrCL >30 mL/min; for THA or TKA, a DOAC is also an option if there is concern for HIT. Refer to UpToDate content discussing management of HIT.

§ Among the DOACs, we prefer rivaroxaban or apixaban, rather than dabigatran or edoxaban since there are more data to support their use in this setting.

¥ Elective or semi-elective surgery in patients with reversible conditions that contraindicate pharmacologic thromboprophylaxis can be delayed until the condition is under control (eg, treat coagulopathy, improve platelet function, control hypertension).

‡ The administration of pharmacologic prophylaxis depends on the timing of neuraxial anesthesia and is not a contraindication per se. Refer to UpToDate content discussing anticoagulants and timing of neuraxial anesthesia.

† Not available in the United States.

** In patients with moderate kidney impairment (CrCl 30-50 mL/min) dose reduction may be warranted. Refer to drug monographs. Apixaban undergoes less kidney clearance and may be preferred.

¶¶ ASA is not administered as the primary agent for thromboprophylaxis in patients with THA or TKA but may be administered in select patients later during the course of recovery. If ASA is used as the sole agent for thromboprophylaxis, we prefer 81 mg orally twice daily.