Extremity Trauma

Initial Approach - Limb Lifesavers

• Stop the Bleed: Direct pressure, elevation. Tourniquet if uncontrollable (record time).
• Check Vessels: Pulses (distal), cap refill (<2s), Doppler. Hard signs (pulsatile bleed, absent pulse) → urgent intervention.
• Nerve Check: Motor & sensory function. Document deficits.
• Align & Splint: Reduce gross deformities. Immobilize joint above & below.
• Compartment Watch: High suspicion. Key: pain out of proportion, paresthesia. 📌 5 Ps (Pain, Pallor, Paresthesia, Pulselessness, Paralysis - late).

⭐ Irreversible neuromuscular damage in compartment syndrome can occur within 4-6 hours of ischemia. Early fasciotomy is limb-saving.

Fracture Care - Bone Basics & Fixes

• Bone Anatomy: Diaphysis, Metaphysis, Epiphysis. Cortical (compact), Cancellous (spongy). Periosteum (vital for healing).
• Fracture Healing Stages (📌 "HI So Hard, Remodel"):
  • Hematoma & Inflammation (Day 1-7): Clot, inflammatory cells, granulation.
  • Soft Callus (Week 2-3): Fibrocartilage, early stability.
  • Hard Callus (Week 4-12): Woven bone replaces soft callus. Clinical union.
  • Remodeling (Months-Years): Woven bone to lamellar bone. Radiological union.
• Fixation Principles (AO):
  • Anatomic reduction
  • Stable internal fixation
  • Preservation of blood supply
  • Early, active mobilization
• Fixation Methods:
  • Non-operative: Casts (POP, synthetic), Splints, Traction (skin/skeletal).
  • Operative (ORIF): Screws, Plates, Intramedullary nails, Wires. External fixators.

⭐ Compartment syndrome is a surgical emergency post-fracture; requires immediate fasciotomy if intracompartmental pressure > 30 mmHg (or ΔP < 30 mmHg, i.e., diastolic BP - compartment pressure).

Joint Injuries - Dislocation Dilemmas

• Principles: Joint incongruity. Urgent reduction post-Neurovascular (NV) assessment. Always obtain pre & post-reduction X-rays.
• Shoulder Dislocation:
  • Anterior (>95%): Most common. Risk to axillary nerve. Arm typically abducted & externally rotated.
  • Posterior: Associated with seizures, electrocution. Arm adducted & internally rotated. "Light bulb" sign on AP X-ray.
• Hip Dislocation:
  • Posterior (~90%): Dashboard injury. Sciatic nerve risk. Limb short, adducted, internally rotated.
• Knee Dislocation: High-energy. Popliteal artery injury risk (up to 50%). ⚠️ Vascular assessment (ABI) is paramount, even with palpable pulses.
• Elbow Dislocation: Usually posterior. Risk to brachial artery, median/ulnar nerves.

⭐ Knee Dislocation & Popliteal Artery: Always suspect popliteal artery injury in knee dislocations. An Ankle-Brachial Index (ABI) <0.9 is abnormal and warrants further investigation (e.g., CT angiography).

Complications - Aftermath Alert

• Early:
  • Compartment Syndrome: ⚠️ Fasciotomy if intracompartmental pressure > 30 mmHg or ΔP (DBP - ICP) < 20-30 mmHg.
  • Neurovascular Injury: Check pulses, sensation, motor. Doppler/Angio if needed.
  • Fat Embolism Syndrome (FES): 📌 Gurd's criteria (petechiae, resp. distress, CNS signs). 24-72 hrs post long bone #.
  • Infection: Gas gangrene (Clostridium). Prophylactic antibiotics (open #).
  • DVT/PE: Prophylaxis crucial.
• Late:
  • Nonunion/Malunion: Surgical correction often.
  • Avascular Necrosis (AVN): Scaphoid, femoral head, talus.
  • Osteomyelitis: Chronic bone infection.
  • Complex Regional Pain Syndrome (CRPS): Pain, swelling, autonomic dysfunction.
  • Post-traumatic Osteoarthritis.

⭐ Volkmann's Ischemic Contracture: A dreaded sequela of untreated compartment syndrome in the forearm, leading to claw-like deformity.

High‑Yield Points - ⚡ Biggest Takeaways

• Compartment syndrome: clinical diagnosis, intracompartmental pressure > 30 mmHg; requires immediate fasciotomy.
• Hard signs of vascular injury (e.g., pulsatile bleeding, absent distal pulse) mandate surgical exploration.
• Mangled Extremity Severity Score (MESS) > 7 strongly predicts amputation.
• Always assess distal neurovascular status meticulously after extremity trauma.
• Open fractures need urgent irrigation, debridement, and IV antibiotics (e.g., Cefazolin).
• Fat Embolism Syndrome: petechiae, CNS changes, respiratory distress post-long bone fracture.