What is the appropriate assessment and management for a patient with lower extremity pain after being hit by a wall?

Assessment and Management of Lower Extremity Trauma with Pain

Begin with plain radiographs of the injured extremity as the first-line examination, followed by focused clinical assessment of limb viability using bedside continuous-wave Doppler to evaluate arterial and venous signals. 1

Immediate Clinical Assessment

Rapid Viability Evaluation

• Assess the "6 P's" at bedside: Pain intensity, Pallor, Pulselessness (using handheld Doppler), Paresthesias, Paralysis, and Poikilothermia (cold limb) 1
• Use continuous-wave Doppler immediately: Loss of arterial signal indicates threatened limb; absence of both arterial AND venous signals suggests irreversible damage 1
• Determine symptom duration: If symptoms present <2 weeks, consider acute limb ischemia (ALI) requiring emergency evaluation 1
• Evaluate motor and sensory function: Progressive loss indicates worsening ischemia with 4-6 hour window for muscle viability 1

Critical Pitfall

Pulse palpation alone is inaccurate—always use Doppler examination to avoid missing arterial compromise. 1

Initial Imaging Strategy

Hemodynamically Stable Patient

• Start with plain radiographs of the affected extremity: Single-view or two-view films take minimal time and identify fractures, dislocations, and gross bone abnormalities 1
• Add CTA of the lower extremity if vascular injury suspected: Sensitivity 95-100% and specificity 87-100% for arterial injury, with critical time savings that reduce morbidity 1
• Reserve whole-body CT for high-energy mechanisms: MVC >35 mph, rollover, ejection, motorcycle crash, pedestrian struck, or fall >15 feet 1

When to Obtain CTA Specifically

CTA is indicated when you identify: 1

• Hard signs of vascular injury (absent pulses, expanding hematoma, bruit/thrill, active bleeding)
• Soft signs with high clinical suspicion (diminished pulses, large stable hematoma, proximity injury to major vessels)
• Knee dislocation or displaced tibial plateau fracture
• Complex fracture patterns near major vessels

Avoid MRA in Trauma

MRA requires prolonged imaging time that is dangerous in potentially unstable patients, and metallic fragments create safety hazards and image degradation. 1

Medical Management

Immediate Interventions

• Administer unfractionated heparin IV immediately unless contraindicated (active bleeding, recent surgery, thrombocytopenia) to prevent thrombus propagation 1
• If heparin-induced thrombocytopenia suspected: Switch to direct thrombin inhibitor rather than continuing heparin 1
• Provide analgesia: Opioids (IV morphine, fentanyl, or hydromorphone) provide superior pain relief compared to NSAIDs for acute fracture pain 2

Pain Management Hierarchy

Based on comparative effectiveness: 2

1. Regional nerve blocks (bupivacaine, levobupivacaine) > IV opioids
2. IV opioids (morphine, fentanyl, hydromorphone) > NSAIDs
3. NSAIDs provide similar relief to each other but inferior to opioids

Decision Algorithm for Limb Salvage vs. Amputation

Time 0 (Initial Presentation)

Prioritize life over limb: If additional salvage efforts increase mortality risk, perform damage control or immediate amputation. 1

Evaluate three domains: 1

• Systemic injury burden: Associated pelvic fractures or traumatic amputations increase mortality risk
• Extremity injury severity: Multiple tissue types injured (bone, nerve, vessel, soft tissue) worsen prognosis
• Patient physiology: Hemodynamic instability, coagulopathy, hypothermia

Time 1 and Beyond

Consider cumulative injury burden: A severe tibial fracture alone may warrant salvage, but the same fracture with severe hindfoot injury or requiring flap coverage around foot/ankle may favor amputation. 1

Critical Caveat

Scoring systems (MESS, LSI, PSI) lack sufficient evidence to guide treatment decisions—clinical judgment incorporating injury pattern, patient factors, and institutional resources remains essential. 1

Revascularization Timing

Category IIa (Marginally Threatened)

• Salvageable if promptly treated
• Arterial Doppler signal absent but venous signal present
• Mild sensory loss, no motor deficit 1

Category IIb (Immediately Threatened)

• Requires immediate revascularization (within 4-6 hours)
• No arterial or venous Doppler signals
• Moderate sensory loss, mild-moderate motor deficit 1

Category III (Irreversible)

• Do not attempt revascularization—perform primary amputation
• Profound sensory loss, paralysis, muscle rigor
• Major tissue loss or permanent nerve damage inevitable 1

Follow-up Considerations

Physical Therapy Prescription

Patients with unmet physical therapy needs show significantly worse outcomes in knee/ankle ROM, stair climbing, gait patterns, and walking speed at 3-24 months post-injury. 3 Involve a physical therapist in prescribing PT services rather than relying solely on orthopedic surgeon assessment, as PT-assessed needs better predict functional improvement. 3

Chronic Pain Prevention

High-intensity acute pain consistently predicts chronic pain development. 4 Additional risk factors include female gender, older age, lower education, lower limb injury, anxiety/depression, and pain catastrophizing. 4 Address pain aggressively during acute phase to prevent chronic pain transition.