A healthy 20‑year‑old patient sustained a heavy wood sheet impact to the right foot and now has pain and swelling; what are the differential diagnoses and recommended acute management?

Acute Foot Trauma from Heavy Object Impact

Differential Diagnosis

In a 20-year-old with foot trauma from a dropped heavy wood sheet, the differential diagnosis must include fractures, soft tissue injuries, and compartment syndrome as the most critical considerations.

Fracture Patterns to Consider

• Metatarsal fractures are among the most common injuries from crush mechanisms, particularly involving the midfoot and forefoot 1
• Lisfranc injury (tarsometatarsal joint disruption) should be suspected with midfoot pain and swelling, as these injuries are frequently missed on initial evaluation 1
• Calcaneal fractures can occur from axial loading mechanisms 1
• Phalangeal fractures of the toes are possible with direct impact 1
• Occult fractures may not be visible on initial radiographs but can be detected with advanced imaging 1, 2

Soft Tissue Injuries

• Tendon injuries including rupture or partial tears of the extensor or flexor tendons 1
• Ligamentous injuries particularly of the Lisfranc ligament complex 1
• Plantar plate injuries at the metatarsophalangeal joints 1
• Contusions and hematomas of the soft tissues 3

Critical Time-Sensitive Diagnosis

• Acute compartment syndrome is the most urgent diagnosis to exclude, as crush injuries are a major risk factor and irreversible damage occurs within 6–8 hours 1, 4, 5
• Clinical signs to assess immediately: pain out of proportion to injury (earliest and most reliable sign), pain with passive stretch of foot muscles (most sensitive early finding), increasing compartment tension, paresthesias, and motor weakness 1, 4, 5
• Late signs indicating missed diagnosis: pulselessness, pallor, and paralysis represent irreversible tissue damage 1, 4, 5

Acute Management Algorithm

Immediate Assessment (First 30 Minutes)

Step 1: Rule Out Compartment Syndrome

• Assess for pain out of proportion to injury – this is the earliest warning sign 4, 5
• Test passive stretch of foot muscles – pain with passive dorsiflexion/plantarflexion is the most sensitive early clinical finding 5
• Examine for paresthesias in the foot, indicating nerve ischemia 4, 5
• Palpate compartments for increased tension, though this alone is unreliable (sensitivity only 54%) 5
• Check motor function – weakness is a late sign indicating substantial damage 5
• If compartment syndrome is suspected: measure compartment pressures immediately if diagnosis uncertain, particularly if patient cannot reliably report pain 5
• Fasciotomy is indicated when compartment pressure ≥30 mmHg or differential pressure (diastolic BP minus compartment pressure) ≤30 mmHg 6, 4, 5
• Position limb at heart level – do not elevate as this decreases arterial perfusion 4, 5
• Remove any constricting items immediately 5

Step 2: Initial Imaging Based on Ottawa Foot Rules

• Apply Ottawa foot rules to determine need for radiographs: imaging indicated if pain in midfoot zone AND either inability to bear weight (four steps) immediately and in emergency department OR bone tenderness at navicular or base of fifth metatarsal 1
• Order standard three-view radiographs (AP, lateral, and 45-degree oblique) if Ottawa rules are positive 1
• Add weightbearing views if Lisfranc injury is suspected and patient can tolerate them, as non-weightbearing films are unreliable for this injury 1
• Radiographs have 99% sensitivity for detecting foot fractures when Ottawa rules are applied correctly 1

Secondary Assessment (After Initial Stabilization)

Step 3: Evaluate for Specific Injury Patterns

• For suspected Lisfranc injury: obtain AP view with 20-degree craniocaudal angulation in addition to standard views; consider CT if radiographs are equivocal, as 25–33% of midfoot fractures are missed on plain films 1
• For suspected occult fracture: if radiographs are negative but clinical suspicion remains high, MRI is the most sensitive modality for detecting occult fractures and bone stress changes 1
• For suspected tendon injury: both MRI and ultrasound have high sensitivity (83% for MRI) for acute tendon rupture or dislocation 1

Step 4: Monitor for Compartment Syndrome Development

• Repeat clinical examination every 30 minutes to 1 hour for the first 24 hours in patients with crush injury, as compartment syndrome can develop over time 1, 4
• Key monitoring parameters: escalating pain despite analgesia, progressive paresthesias, increasing compartment tension, and developing motor weakness 4, 5
• Do not wait for late signs (pulselessness, pallor, paralysis) as these indicate irreversible injury 4, 5

Definitive Management

Step 5: Treatment Based on Findings

• If compartment syndrome is diagnosed: emergent fasciotomy of all involved compartments must be performed immediately; delays beyond 6–8 hours result in irreversible muscle necrosis and nerve damage 6, 4, 5
• For fractures: management depends on fracture type and displacement; most metatarsal fractures can be managed conservatively, while Lisfranc injuries typically require surgical fixation 1
• For open fractures or wounds: radical debridement and temporary stabilization with K-wires or external fixation until definitive treatment 3, 7
• Pain management: multimodal analgesia is appropriate, but escalating pain despite adequate analgesia is a hallmark of compartment syndrome and should prompt immediate surgical evaluation 4

Critical Pitfalls to Avoid

• Never rely solely on palpation to exclude compartment syndrome – sensitivity is only 54% 5
• Never elevate the limb excessively if compartment syndrome is suspected, as this decreases perfusion pressure 4, 5
• Never delay fasciotomy waiting for late signs (pulselessness, pallor, paralysis) – these indicate irreversible damage has occurred 1, 4, 5
• Never miss Lisfranc injuries by failing to obtain weightbearing views when clinically indicated 1
• Never apply Ottawa rules if there are exclusionary criteria such as intoxication, distracting injuries, or diminished sensation 1
• Never assume normal radiographs exclude significant injury – 25–33% of midfoot fractures are missed on plain films in trauma patients 1
• Never increase pain medication alone for escalating pain without reassessing for compartment syndrome – this masks the critical diagnostic sign 4

Special Considerations for This Mechanism

• Crush injuries from heavy objects carry high risk for compartment syndrome development even without fracture 1, 4
• Monitor for rhabdomyolysis if compartment syndrome develops: check CPK levels (>1000 IU/L indicates rhabdomyolysis), monitor for myoglobinuria, and maintain urine output >2 mL/kg/h 1, 4, 5
• Wooden foreign body penetration is possible with wood sheet trauma; if penetrating injury suspected and radiographs negative, ultrasound has 90% sensitivity for wooden foreign bodies 1