What are the monitoring and treatment protocols for a patient presenting with a calf bruise, considering potential complications such as deep vein thrombosis (DVT) or infection, and possible underlying conditions like bleeding disorders or impaired renal function?

Management of Calf Bruise

Immediate Assessment and Risk Stratification

For a simple calf bruise without additional risk factors, monitor for signs of compartment syndrome, infection, and deep vein thrombosis, while treating conservatively with rest, ice, compression, and elevation. 1, 2

Critical Red Flags to Monitor

• Compartment syndrome warning signs: Severe pain out of proportion to injury, pain with passive stretch, paresthesias, pallor, pulselessness, or tense swelling requiring immediate surgical consultation 3
• DVT indicators: Calf swelling ≥3 cm larger than the contralateral side, localized tenderness along deep venous distribution, pitting edema confined to the affected leg, entire leg swelling, or collateral superficial veins 4, 1
• Infection signs: Increasing redness spreading beyond the bruise margins, warmth, fever, purulent drainage, or systemic symptoms 2

When to Suspect DVT vs. Simple Bruise

Calculate the Wells score if any concerning features develop 1, 5:

• Recent immobilization ≥3 days or major surgery within 12 weeks (1 point)
• Active cancer (1 point)
• Localized tenderness along deep veins (1 point)
• Entire leg swollen (1 point)
• Calf swelling ≥3 cm difference (1 point)
• Pitting edema in symptomatic leg (1 point)
• Collateral superficial veins (1 point)
• Previous DVT (1 point)
• Alternative diagnosis as likely as DVT (-2 points)

If Wells score ≥2, proceed directly to complete duplex ultrasound from inguinal ligament to ankle. 1, 5 If Wells score <2 but symptoms persist or worsen, obtain high-sensitivity D-dimer first—if positive, proceed to complete duplex ultrasound. 1, 5

Treatment Protocol

Conservative Management for Simple Bruise

• Rest, ice, compression, elevation (RICE protocol) for the first 48-72 hours 3
• Compression stockings (20-30 mm Hg) if venous insufficiency symptoms develop 5
• Leg elevation above heart level when resting 5
• Avoid prolonged standing during healing 5
• Pain control with acetaminophen; avoid NSAIDs if bleeding risk is present 3

Special Populations Requiring Enhanced Monitoring

Patients on anticoagulation: A spontaneous calf hematoma can occur even in young patients taking anticoagulants like rivaroxaban, and may be mistakenly diagnosed as DVT. 6 Monitor for expanding hematoma, compartment syndrome, and obtain imaging (ultrasound or MRI) if swelling progresses despite conservative measures. 6

Elderly patients or those with bleeding disorders: Higher risk for spontaneous hematomas that can reach significant size and prove dangerous. 6 Lower threshold for imaging if bruise expands or symptoms worsen. 6

Monitoring Schedule

Days 1-3

• Daily assessment of bruise size, pain level, and neurovascular status 3
• Measure calf circumference at the same location daily to detect expansion 4, 1
• Check for compartment syndrome signs every 4-6 hours if pain is severe 3

Days 4-7

• If symptoms worsen or new findings develop (redness, warmth, increased swelling), obtain complete duplex ultrasound immediately 2
• If bruise is improving, continue conservative management 3

Week 2

• Repeat ultrasound if any DVT concern persists after initial negative study, as isolated calf DVT can propagate proximally in approximately 15% of cases within the first 2 weeks 4, 2

When Imaging is Mandatory

Obtain complete duplex ultrasound immediately if: 1, 2

• Persistent or worsening pain despite conservative measures
• New onset of redness and inflammation
• Calf swelling ≥3 cm larger than contralateral side
• Entire leg becomes swollen
• Patient has active cancer, recent surgery, or prolonged immobilization
• Patient is on anticoagulation and hematoma is expanding

The complete duplex ultrasound protocol must include: 4, 1

• Compression of deep veins from inguinal ligament to ankle at 2-cm intervals
• Specific evaluation of posterior tibial and peroneal veins in the calf
• Spectral Doppler of bilateral common femoral veins
• Color Doppler imaging throughout

Common Pitfalls to Avoid

• Do not assume a simple bruise excludes DVT when risk factors are present—approximately 30% of patients referred for suspected DVT actually have it 5
• Do not miss Baker's cyst, which can present with calf pain and swelling mimicking DVT or hematoma 7
• Do not delay repeat imaging if symptoms persist or worsen after initial negative ultrasound—this is the exact scenario where repeat imaging is mandated 2
• Do not use limited ultrasound protocols that exclude calf veins, as they require a second study in 5-7 days to safely exclude DVT 4

If DVT is Diagnosed

For isolated calf DVT with severe symptoms or risk factors for extension (positive D-dimer, extensive thrombosis, no reversible provoking factor, active cancer, history of VTE, inpatient status), initiate therapeutic anticoagulation immediately with low-molecular-weight heparin or fondaparinux. 4, 2, 8

For low-risk isolated calf DVT without severe symptoms, serial ultrasound surveillance at 1 and 2 weeks is an alternative to immediate anticoagulation, though most clinicians favor anticoagulation given the 5% risk of proximal extension. 4, 9

Therapeutic anticoagulation reduces proximal DVT or PE risk (odds ratio 0.33) but increases bleeding risk (odds ratio 4.87) after isolated calf DVT. 9