Is anticoagulation necessary after shoulder arthroplasty in patients with a history of thromboembolic events or risk factors for bleeding?

Anticoagulation After Shoulder Arthroplasty

Routine pharmacologic anticoagulation beyond low-dose aspirin is not necessary for most patients undergoing shoulder arthroplasty, but mechanical prophylaxis should be used universally, with risk-stratified chemical prophylaxis reserved for high-risk patients. 1

Standard Prophylaxis Approach

For Average-Risk Patients

• Mechanical prophylaxis (sequential compression devices) should be used intraoperatively and during the immediate postoperative period for all shoulder arthroplasty patients. 1

• Low-dose aspirin (81 mg daily) for 6 weeks postoperatively is the preferred chemical prophylaxis for standard-risk patients, with a demonstrated VTE rate of only 0.56% and minimal bleeding complications (0.19%). 2

• The American Academy of Orthopaedic Surgeons consensus recommendation supports routine use of mechanical and/or chemical prophylaxis despite limited evidence, acknowledging that shoulder arthroplasty carries lower VTE risk than lower extremity procedures. 1

Rationale for Conservative Approach

• The overall VTE incidence after shoulder arthroplasty is substantially lower than lower extremity arthroplasty: 0.53% versus 1.2% in Medicare populations, with some studies reporting ranges from 0.2% to 0.63%. 2, 3, 4

• Shoulder arthroplasty demonstrates a VTE rate approximately 3-5 times lower than hip arthroplasty (5.0 per 1000 vs 15.7 per 1000) and approximately 5 times lower than knee arthroplasty (5.0 per 1000 vs 26.9 per 1000). 4

• The bleeding risk must be weighed against the lower baseline VTE risk, as wound hematoma rates are similar between shoulder and lower extremity procedures despite lower VTE rates. 3

High-Risk Patient Identification and Management

Patients Requiring Enhanced Prophylaxis

Chemical prophylaxis beyond aspirin should be considered for patients with specific high-risk features, including: 2, 3, 4

• History of prior VTE (most significant risk factor)
• Active malignancy or metastatic disease
• Known thrombophilia or hypercoagulable state
• Cardiac arrhythmia
• Congestive heart failure
• Coagulopathy
• Obesity
• Fracture as primary indication (hemiarthroplasty for fracture carries higher risk than elective total shoulder arthroplasty)
• Advanced age with multiple comorbidities
• Prolonged immobility or bed confinement expected postoperatively

Enhanced Prophylaxis Options for High-Risk Patients

• For patients with demonstrated VTE risk factors, consider therapeutic anticoagulation with agents beyond aspirin, such as low-molecular-weight heparin or novel oral anticoagulants, after careful assessment of bleeding risk. 3

• Each high-risk patient should undergo individualized risk stratification weighing their specific thrombotic risk against bleeding potential, as medically high-risk patients demonstrate significantly higher VTE rates (P = 0.018). 2

Special Considerations for Patients with History of Thromboembolic Events

Patients on Chronic Anticoagulation

• For patients on chronic warfarin therapy who require shoulder arthroplasty, warfarin should be discontinued 4 days before the procedure. 1

• Postoperative intravenous heparin should be considered only for patients with recent arterial or venous thromboembolism (within 1 month), continuing until therapeutic anticoagulation is re-established with warfarin. 1

• The decision to bridge with heparin depends on the timing of the prior thromboembolic event and the patient's ongoing thrombotic risk versus surgical bleeding risk. 1

Patients with Mechanical Heart Valves or Atrial Fibrillation

• Shoulder arthroplasty is classified as a procedure with low-to-moderate bleeding risk (2-day major bleeding risk 0-2%), which influences perioperative anticoagulation management decisions. 1

• For patients with high thrombotic risk (e.g., mechanical mitral valve, recent stroke, CHADS₂ score ≥5), bridging anticoagulation may be warranted despite the surgical bleeding risk. 1

• For patients with lower thrombotic risk (e.g., bileaflet aortic valve without atrial fibrillation, CHADS₂ score 0-2), temporary interruption of anticoagulation without bridging is generally acceptable. 1

Clinical Presentation and Diagnosis

VTE Characteristics After Shoulder Arthroplasty

• A notably high proportion of VTE events after shoulder arthroplasty present as pulmonary embolism (4 of 6 patients in one series, representing 67%), which is a higher percentage than seen with lower extremity arthroplasty. 5, 4

• Deep vein thromboses occur in both upper extremity (ipsilateral to surgery) and lower extremity locations, requiring comprehensive evaluation when VTE is suspected. 5

• The typical presentation occurs within the first 90 days postoperatively, with diagnosis confirmed by duplex ultrasound for DVT and chest CT for PE. 2, 6, 5

Critical Pitfalls to Avoid

• Do not routinely use the same aggressive anticoagulation protocols employed for lower extremity arthroplasty, as the VTE risk profile is substantially different and bleeding complications may outweigh benefits. 3

• Do not overlook preoperative risk stratification, as failure to identify high-risk patients (particularly those with prior VTE, malignancy, or cardiac disease) leads to inadequate prophylaxis in those who need it most. 2, 3

• Do not dismiss subtle postoperative symptoms such as unexplained dyspnea or ipsilateral arm swelling, as the high proportion of pulmonary embolisms requires vigilant surveillance. 5, 4

• Do not assume all patients require the same prophylaxis regimen—the evidence supports risk-stratified approaches rather than universal aggressive anticoagulation. 1, 2, 3