Is DVT (Deep Vein Thrombosis) prophylaxis necessary for patients undergoing patella fracture and repair?

DVT Prophylaxis for Patella Fracture and Repair

DVT prophylaxis is necessary for patients undergoing patella fracture repair, especially for those with additional risk factors, as the incidence of postoperative DVT in these patients is substantial at approximately 4.1%. 1

Risk Assessment for Patella Fracture Patients

The risk of DVT in patella fracture patients is influenced by:

• Age > 65 years (OR 4.44) 1
• Presence of arrhythmia (OR 4.41) 1
• Intraoperative blood loss 1
• Prolonged preoperative stay 1
• Extended surgical duration 1
• Elevated LDL-C levels (>3.37 mmol/L) 1

Recommended Prophylaxis Approach

For Low-Risk Patients:

• Early ambulation is the minimum recommended prophylaxis for patients with isolated patella fractures without additional risk factors 2
• Consider mechanical prophylaxis such as graduated compression stockings (GCS) 2

For Moderate to High-Risk Patients:

• Pharmacological prophylaxis with LMWH is preferred over unfractionated heparin due to higher effectiveness in preventing DVT (RR 0.68) 2
• For patients with multiple risk factors (age >65, previous VTE history, cancer, prolonged immobility), combine pharmacological and mechanical prophylaxis for optimal protection 2
• The combination of mechanical and pharmacological prevention strategies has been demonstrated to be superior to either modality alone (RR 0.34 for DVT) 2

For Patients with High Bleeding Risk:

• Use mechanical prophylaxis (intermittent pneumatic compression devices) until bleeding risk decreases 2
• Sequential compression devices (SCDs) provide adequate DVT prophylaxis with a low failure rate (3-8%) 3
• Foot pumps are a reasonable alternative when lower extremity injuries preclude the use of SCDs 3

Duration of Prophylaxis

• Minimum duration of 7-10 days is recommended for orthopedic surgeries 4
• Consider extended prophylaxis (additional 3 weeks) for high-risk patients, as risk of VTE persists for up to 3 months after surgery 4
• For patients with isolated patella fractures, most DVTs occur within the first week postoperatively (median 4.0 days, range 1.0-8.0 days) 1

Mechanical vs. Pharmacological Prophylaxis

• Mechanical prophylaxis reduces the risk of DVT (RR 0.55) but pharmacological prophylaxis is more effective (RR 0.48) 2
• LMWH is associated with lower incidence of DVT and PE compared to unfractionated heparin, with fewer bleeding complications 2
• For elderly patients (>65 years), the initial dose of LMWH enoxaparin should be 30 mg every 12 hours 2
• In case of renal failure, unfractionated heparin should be used (5000 U every 8 h) 2

Common Pitfalls and Caveats

• Aspirin alone is not recommended as the sole method of thromboprophylaxis for patella fractures, despite causing less bleeding 2
• Delaying prophylaxis increases DVT risk - each day of preoperative delay increases odds by 1.43 times 1
• Overlooking DVT risk in "minor" orthopedic procedures like patella fracture repair can lead to preventable complications 2
• Most DVTs in patella fracture patients involve the posterior tibial vein (37.9%) and peroneal vein (37.9%), followed by popliteal vein (20.7%) 1
• Don't assume bilateral prophylaxis is unnecessary - DVT can occur in both injured and uninjured limbs 1

Risk Stratification Algorithm

1. Assess patient-specific risk factors (age, comorbidities, previous VTE)
2. Evaluate procedure-specific risks (surgical duration, blood loss)
3. Determine appropriate prophylaxis based on combined risk:
   • Low risk: Early ambulation + mechanical prophylaxis
   • Moderate risk: LMWH + mechanical prophylaxis
   • High risk: LMWH + mechanical prophylaxis with extended duration
   • High bleeding risk: Mechanical prophylaxis only until bleeding risk decreases 2