Is left calf pain and tenderness 2 days after a left 5th toe fracture 8 days ago indicative of Deep Vein Thrombosis (DVT) or arterial obstruction?

Clinical Presentation Strongly Suggests DVT, Not Arterial Obstruction

This patient's presentation of calf pain and tenderness developing 2 days after a toe fracture is highly consistent with deep vein thrombosis (DVT), not arterial obstruction. Arterial obstruction would present with the "6 Ps" (pain, pallor, pulselessness, paresthesias, paralysis, poikilothermia), which are not described here 1.

Why This is DVT

The clinical scenario presents classic DVT risk factors and symptoms:

• Recent trauma (toe fracture 8 days ago) is a well-established risk factor for DVT, as fractures and immobilization significantly increase thrombotic risk 2, 3
• Calf pain and tenderness are the hallmark symptoms of isolated distal (calf) DVT, involving the peroneal, posterior tibial, or anterior tibial veins 2, 1
• Delayed onset (2 days after initial injury) fits the typical timeline for DVT development following lower extremity trauma 3

Immediate Diagnostic Approach

Step 1: Calculate Wells Score for DVT

Before ordering imaging, assess pretest probability using the Wells score 4, 5:

• Active cancer (treatment within 6 months or palliative): +1
• Paralysis, paresis, or recent plaster immobilization of lower extremity: +1
• Recently bedridden >3 days or major surgery within 12 weeks: +1
• Localized tenderness along deep venous system: +1
• Entire leg swollen: +1
• Calf swelling ≥3 cm compared to asymptomatic leg: +1
• Pitting edema confined to symptomatic leg: +1
• Collateral superficial veins (non-varicose): +1
• Previously documented DVT: +1
• Alternative diagnosis at least as likely as DVT: -2

Score ≥2 = DVT likely; Score <2 = DVT unlikely 4, 5

Step 2: Testing Based on Pretest Probability

If Wells score ≥2 (DVT likely):

• Proceed directly to complete duplex ultrasound (CDUS) from inguinal ligament to ankle 4, 5
• If ultrasound cannot be performed within 4 hours, start therapeutic anticoagulation immediately with low molecular weight heparin while awaiting imaging 2, 5

If Wells score <2 (DVT unlikely):

• Obtain high-sensitivity D-dimer first 4, 5
• If D-dimer negative: DVT excluded, no further testing needed 2, 1
• If D-dimer positive: Proceed to complete duplex ultrasound 2, 5

Step 3: Ultrasound Protocol

The complete duplex ultrasound must include 4, 5:

• Compression of deep veins from inguinal ligament to ankle at 2-cm intervals
• Specific evaluation of calf veins (posterior tibial and peroneal veins)
• Spectral Doppler waveforms of bilateral common femoral veins
• Popliteal vein spectral Doppler assessment
• Color Doppler imaging throughout

Critical point: Normal veins completely collapse under probe pressure; veins containing thrombus remain non-compressible 4

Management of Isolated Calf DVT

If isolated distal DVT is confirmed, two evidence-based options exist 2:

Option 1: Immediate Anticoagulation

Indicated if the patient has 2:

• Severe symptoms (significant pain/swelling)
• Risk factors for extension: positive D-dimer, extensive thrombosis (>5 cm length, involves multiple veins, >7 mm diameter), no reversible provoking factor, active cancer, history of VTE, or inpatient status
• High bleeding risk favors surveillance over immediate anticoagulation 2

Option 2: Serial Ultrasound Surveillance

• Repeat proximal ultrasound at 1 week (and potentially 2 weeks) to detect proximal extension 2, 5
• Start anticoagulation if extension detected
• Natural history studies show 15% of untreated symptomatic distal DVT extend proximally, with most extension occurring within 2 weeks 2

Common Pitfalls to Avoid

• Don't assume bilateral scanning is needed: In outpatients with unilateral symptoms, scanning only the symptomatic leg is appropriate initially 6
• Don't delay anticoagulation if high pretest probability and imaging delayed >4 hours: Start LMWH empirically 2, 5
• Don't use limited proximal-only ultrasound protocols: These require repeat scanning in 5-7 days and may miss calf DVT 4
• Don't confuse with arterial obstruction: Arterial occlusion presents with absent pulses, pallor, and paresthesias—not isolated calf tenderness 1

Why Not Arterial Obstruction

Arterial obstruction would present with:

• Acute onset (minutes to hours, not days)
• Absent distal pulses
• Pallor or mottling
• Cool extremity
• Paresthesias or paralysis
• Pain out of proportion to examination

None of these features are described in this presentation, making arterial pathology extremely unlikely 1.