Is Homan's sign reliable for diagnosing Deep Vein Thrombosis (DVT) in a patient with left calf pain?

Homan's Sign is Not Reliable for Diagnosing DVT

Homan's sign should not be used to diagnose or exclude deep vein thrombosis, as it has very poor predictive value for the presence or absence of DVT. 1

Why Homan's Sign Fails as a Diagnostic Tool

The fundamental problem with Homan's sign (calf pain with dorsiflexion of the foot) is that it lacks both sensitivity and specificity for DVT:

• Clinical diagnosis of DVT using individual physical findings is nonspecific and unreliable, with approximately 70% of patients referred for clinically suspected DVT not having the diagnosis confirmed by objective testing 2
• Homan's sign performs no better than any other isolated symptom or clinical sign for detecting DVT 1
• The highly variable nature of DVT presentation and numerous pathologic mimics (Baker cyst, cellulitis, lymphedema, musculoskeletal disorders) make physical examination findings alone insufficient for diagnosis 3

The Proper Diagnostic Approach Instead

Rather than relying on Homan's sign or other individual physical findings, use a structured clinical prediction model combined with objective testing 3:

Step 1: Calculate Wells Score for Pretest Probability

The Wells score stratifies patients into risk categories based on multiple clinical features 3:

• Low probability: 5% prevalence of DVT (Wells score <2) 3
• Moderate probability: 17% prevalence 3
• High probability: 53% prevalence (Wells score ≥2) 3

Step 2: Choose Diagnostic Pathway Based on Pretest Probability

For Low-to-Moderate Pretest Probability:

• Begin with high-sensitivity D-dimer testing 3, 4
• If D-dimer is negative, DVT is excluded (99% negative predictive value) 3
• If D-dimer is positive, proceed to compression ultrasound 3

For High Pretest Probability:

• Proceed directly to proximal compression ultrasound or complete duplex ultrasound without D-dimer testing 3, 4, 5
• If ultrasound is positive, initiate anticoagulation immediately without confirmatory venography 3
• If initial proximal ultrasound is negative, perform additional testing with highly sensitive D-dimer, whole-leg ultrasound, or repeat proximal ultrasound in 1 week 3

Step 3: Definitive Imaging with Ultrasound

Complete duplex ultrasound is the preferred diagnostic modality 3, 5:

• Compression of deep veins from inguinal ligament to ankle at 2-cm intervals 3
• Includes evaluation of posterior tibial and peroneal veins in the calf 3, 5
• Spectral Doppler of bilateral common femoral veins and popliteal vein 3
• Color Doppler imaging throughout 3
• Sensitivity of 94.2% and specificity of 93.8% for proximal DVT 3

Critical Clinical Pitfalls to Avoid

• Never rely on absence of Homan's sign to exclude DVT 1
• Do not use D-dimer as initial test in high-probability patients, as it delays definitive diagnosis 4
• Do not accept limited proximal-only ultrasound in patients with severe calf symptoms, as complete evaluation including calf veins is necessary 4, 5
• In hospitalized patients, clinical prediction models work poorly and diagnosis should rely on objective testing with ultrasound, D-dimer, and/or venography 6

When to Start Anticoagulation Before Imaging

If ultrasound cannot be performed within 4 hours and pretest probability is high (Wells score ≥2), start therapeutic anticoagulation immediately with low molecular weight heparin while awaiting imaging 5. This prevents potentially fatal pulmonary embolism, which occurs in 50-60% of untreated proximal DVT cases with 25-30% mortality 4.