Orthopedic Emergencies, Fractures & Splinting
Critical emergency orthopedics: acute compartment syndrome diagnostic thresholds (delta P <= 30 mmHg), Gustilo open fracture staging, knee/hip dislocation neurovascular jeopardy, Kocher septic arthritis criteria, and bedside splint application.
Resuscitation Quick Ribbon (First 2 Minutes)
Bottom-Line Clinical Pearl
Acute compartment syndrome is a surgical emergency diagnosed clinically by pain out of proportion to exam and pain with passive stretch; delta P (diastolic BP - compartment pressure) <= 30 mmHg mandates emergent double-incision fasciotomy. Never ice or elevate an ischemic compartment. Knee dislocations require Ankle-Brachial Index (ABI) and emergent CTA runoff due to a 30-40% popliteal artery injury rate.
1. Immediate Resuscitation & The First 5 Minutes
Every traumatic extremity injury demands an immediate neurovascular examination (pulses, capillary refill, motor function, and two-point sensory discrimination) documented prior to and following any splinting or reduction maneuver. If an extremity is gross deformed and pulseless, perform immediate inline axial traction to restore arterial flow before obtaining formal radiography.
Emergency Reduction Rule: If a limb is pulseless, pale, or cold following a fracture or dislocation, perform immediate gentle inline reduction to restore perfusion. Do not delay reduction for radiography if vascular compromise is evident. Always re-evaluate and document distal pulses immediately post-reduction.
2. Acute Compartment Syndrome (ACS)
Acute compartment syndrome occurs when elevated osteofascial tissue pressure exceeds capillary perfusion pressure, leading to ischemic necrosis of muscle and nerves. Permanent neuromuscular damage occurs within 4–8 hours of warm ischemia.
| The 6 P's | Clinical Significance | Timing in Disease Course |
|---|---|---|
| Pain out of proportion | Most sensitive early finding; refractory to high-dose parenteral opioids | EARLY (Critical window) |
| Pain on passive stretch | Exquisite pain when stretching ischemic compartment muscles | EARLY (Most sensitive physical exam test) |
| Paresthesias | Hypoesthesia or burning dysesthesia in sensory nerve distribution | EARLY to Intermediate (Nerves ischemic at 2 hr) |
| Pallor & Poikilothermia | Limb coolness and capillary refill delay | LATE |
| Pulselessness | Loss of arterial pulses (major arterial inflow is preserved until tissue pressure exceeds systolic BP) | VERY LATE (Indicates irreversible muscle necrosis) |
| Paralysis | Complete motor loss and flaccid paralysis | VERY LATE (Permanent contracture / Volkmann's) |
Diagnostic Manometry Threshold: In an alert patient, absolute compartment pressure > 30 mmHg or Delta Pressure (Diastolic BP minus Compartment Pressure) <= 30 mmHg confirms acute compartment syndrome. In obtunded or hypotensive patients, Delta P is the only reliable metric. Management: Immediately remove all constrictive casts and dressings to the skin (releases ~70% of pressure). Maintain limb at HEART LEVEL (NEVER elevate: decreases arterial perfusion pressure; NEVER apply ice: causes vasoconstriction). Emergent orthopedic/trauma surgery consult for multi-compartment fasciotomy.
3. Open Fractures & Gustilo-Anderson Classification
Any fracture with a communicating skin break is an open fracture until proven otherwise. Time to first IV antibiotic dose (< 60 minutes) is the single most important factor reducing osteomyelitis risk.
| Gustilo Grade | Wound & Soft Tissue Severity | Recommended Antibiotic Regimen |
|---|---|---|
| Type I | Wound < 1 cm, clean, minimal periosteal stripping | Cefazolin 2g IV q8h (Clindamycin 900 mg IV if penicillin anaphylaxis) |
| Type II | Wound 1–10 cm, moderate contamination/stripping | Cefazolin 2g IV q8h |
| Type III-A | Wound > 10 cm, high energy, adequate periosteal coverage | Cefazolin 2g IV + Gentamicin 5 mg/kg IV q24h |
| Type III-B | Extensive soft tissue loss, exposed bone requiring flap | Cefazolin 2g IV + Gentamicin 5 mg/kg IV q24h |
| Type III-C | Arterial injury requiring vascular repair | Cefazolin 2g IV + Gentamicin 5 mg/kg IV + Emergent Vascular Surgery |
| Farm / Soil / Fecal | Contamination with barnyard dirt, standing freshwater | Add Penicillin G 4 million units IV q4h OR Metronidazole 500 mg IV (covers Clostridium / anaerobes) |
4. High-Risk Fractures & Dislocation Pearls
These critical fractures and dislocations harbor severe risks of avascular necrosis, neurovascular injury, or chronic disability if missed in the ED.
| Injury | High-Yield Presentation & Anatomy | Emergency Management & Pitfalls |
|---|---|---|
| Scaphoid Fracture | Anatomic snuffbox tenderness; axial load through 1st metacarpal; fall on outstretched hand (FOOSH) | High risk of nonunion and avascular necrosis (AVN) of proximal pole. Initial X-ray negative in 15–20%. Place thumb spica splint; repeat X-ray or MRI in 10–14 days. |
| Boxer's Fracture | 5th metacarpal neck fracture from direct fist impact. Check for 'fight bite' (tooth laceration) | Check for extensor tendon laceration and Eikenella corrodens (treat with Augmentin; NEVER close bite wounds primarily). Ulnar gutter splint. Acceptable angulation: 5th MC <= 40 deg; 4th MC <= 20 deg. |
| Colles vs. Smith | Colles: Dorsal displacement ('dinner fork deformity'). Smith: Volar displacement ('garden spade') | Sugar-tong splint. Assess median nerve sensation (palmar aspect of index finger) and carpal tunnel syndrome. |
| Supracondylar Humerus (Peds) | Most common pediatric elbow fracture. Gartland Type I–III. Check anterior humeral line | Risk to brachial artery and Anterior Interosseous Nerve (AION: test 'OK' sign / index DIP flexion). If pulseless, gently extend and realign; emergent ortho consult. |
| Monteggia vs. Galeazzi (MUGR) | Monteggia: Ulna fracture with Radial head dislocation. Galeazzi: Radius fracture with Distal Radioulnar Joint (DRUJ) dislocation | Monteggia: radial nerve palsy (wrist drop). Galeazzi: ulnar nerve injury. Both require operative fixation in adults. |
| Knee Dislocation | Tibiofemoral dislocation from high-energy dashboard trauma or morbid obesity hyperextension | 30–40% risk of popliteal artery rupture. Measure Ankle-Brachial Index (ABI). If ABI < 0.9, obtain immediate CTA runoff. Normal ABI requires 24h serial vascular exams. Peroneal nerve injury -> foot drop. |
| Hip Dislocation | Posterior (90%): leg is shortened, ADDucted, and INTERNALLY rotated. Anterior (10%): ABducted, EXTERNALLY rotated | Sciatic nerve injury (check peroneal branch: dorsiflexion / 1st web space). Emergent closed reduction under procedural sedation < 6 hours to prevent femoral head osteonecrosis. |
5. Septic Arthritis vs. Crystal Arthropathy
A hot, swollen, acutely painful joint is an orthopedic emergency until septic arthritis is excluded by diagnostic arthrocentesis. Never inject corticosteroids into a joint before fluid analysis.
| Diagnostic Fluid Metric | Normal Joint | Non-Inflammatory (OA) | Inflammatory (Gout/RA) | Septic Arthritis |
|---|---|---|---|---|
| Clarity / Color | Clear, colorless | Clear, yellow | Translucent/opaque, yellow | Opaque, turbid, purulent |
| Viscosity | High (string sign > 5 cm) | High | Low | Very low |
| Synovial WBC (/uL) | < 200 | 200–2,000 | 2,000–50,000 | > 50,000 (often > 100,000) |
| PMN Percentage | < 25% | < 25% | > 50% | > 75–90% |
| Synovial Glucose | Equal to serum | Equal to serum | Mild decrease | Markedly decreased (< 50% blood glucose) |
| Gram Stain & Culture | Negative | Negative | Negative | Gram stain positive 60–80%; culture definitive |
Kocher Criteria for Pediatric Septic Hip: 1) Inability to bear weight on affected limb; 2) Fever > 38.5 deg C (101.3 deg F); 3) ESR > 40 mm/hr; 4) Peripheral WBC > 12,000/uL. 1/4 = 3% risk; 2/4 = 40%; 3/4 = 93%; 4/4 = 99% probability of septic arthritis. Mandates emergent ultrasound and bedside/OR hip arthrocentesis.
6. Master ED Splinting Guide
| Splint Type | Indications | Joints Immobilized | Anatomic Position |
|---|---|---|---|
| Volar Wrist Splint | Wrist sprains, carpal tunnel, minor metacarpal injuries | Wrist only | Wrist in 10–20 deg extension ('holding a soda can') |
| Sugar-Tong Forearm | Distal radius / ulna fractures (Colles, Smith), forearm shaft fractures | Wrist and elbow (prevents pronation/supination) | Elbow at 90 deg, wrist in neutral/slight extension |
| Thumb Spica | Scaphoid fracture, lunate dislocation, Gamekeeper's / Skier's thumb (UCL tear) | Thumb MCP and CMC, wrist | Thumb in 'wine glass' abduction, wrist extended 20 deg |
| Ulnar Gutter | Boxer's fracture (5th MC neck), 4th/5th proximal phalanx fractures | 4th & 5th digits, wrist | Wrist 20 deg extension, MCP joints flexed 70–90 deg, PIP/DIP extended |
| Radial Gutter | 2nd & 3rd metacarpal and proximal phalanx fractures | 2nd & 3rd digits, wrist | Wrist 20 deg extension, MCP joints flexed 70–90 deg |
| Coaptation Splint | Humeral shaft fractures | Shoulder to elbow | Elbow at 90 deg, collar and cuff sling |
| Posterior Long-Arm | Olecranon fractures, supracondylar fractures, radial head fractures | Elbow and wrist | Elbow at 90 deg, forearm neutral |
| Posterior Short-Leg + Stirrup (Sugar-Tong) | Distal tibia/fibula fractures, bimalleolar/trimalleolar, severe ankle sprains | Ankle and subtalar joint | Strict 90 deg ankle dorsiflexion (prevents Achilles contracture) |
| Knee Immobilizer / Posterior Long-Leg | Patellar fractures, extensor mechanism rupture, tibial plateau fractures | Knee joint | 0–10 deg of knee flexion |
7. Disposition & Medicolegal Pearls
- Always document pre- and post-reduction neurovascular status: A pulse that disappears following splinting is an iatrogenic emergency requiring immediate splint removal and re-alignment.
- Suspect scaphoid fracture in every FOOSH injury: If anatomic snuffbox tenderness is present, immobilize in a thumb spica splint regardless of normal initial X-rays.
- Open fracture antibiotics must not wait for the OR: Administer IV Cefazolin within 60 minutes of ED arrival; delay increases infection and osteomyelitis rates exponentially.
- Never elevate or ice a limb with suspected acute compartment syndrome: Decreasing local perfusion pressure accelerates ischemic muscle death.
Test Your Orthopedic Emergencies, Fractures & Splinting Knowledge
Directly launch a targeted 5-question practice block from our 8,400+ board question bank.