Extremity Trauma

Fractures, Crush Injury & Amputation Management

Mid-shaft Femur Fractures

Recognition & Complications

Mid-shaft femur fractures are typically high-force injuries. Significant haemorrhage (up to 1.5L) can occur into the thigh compartment.

Signs: Shortening and rotation of the limb, swelling, severe pain, and deformity.

Traction Splinting

Traction splints (e.g., CT-6, Hare) are indicated specifically for isolated mid-shaft fractures. They restore anatomical alignment, reduce muscle spasm, and control haemorrhage by reducing the potential volume of the thigh compartment.

Contraindications for Traction Splinting:

  • Injury close to the knee or ankle.
  • Suspected pelvic fracture.
  • Partial amputation or avulsion with bone separation.
  • Suspected Neck of Femur (NOF) fracture.

Neck of Femur (NOF) Fractures

Common in the elderly following falls. Associated with high mortality (10% at 1 month, 33% at 1 year).

Assessment & Renal Complications

Typical Presentation: The affected leg is usually shortened and externally rotated. The patient may be unable to straight leg raise.

Renal Risk: Acute Kidney Injury (AKI) is present in 25% of NOF patients. Prolonged downtime increases the risk of dehydration and rhabdomyolysis. O'Connor (2019) highlights that pre-hospital fluid therapy is an often-overlooked intervention that may help prevent AKI.

Immobilisation: The "Lee and Porter" Technique

While definitive evidence for NOF immobilisation is scarce (Moore et al., 2021), the widely accepted anatomical splinting technique involves:

  1. Place padding (e.g., blanket/towel) between the legs.
  2. Secure the ankles with a figure-of-eight bandage.
  3. Apply broad bandages above and below the knees to secure the injured leg to the uninjured leg.

Note: Do not apply a traction splint for a NOF fracture as it may cause avascular necrosis of the femoral head.

Analgesia Considerations

Pain is often undertreated. Options include:

  • Systemic: IV Paracetamol/Morphine. Caution with Morphine in renal impairment/hypotension.
  • Ketamine: Effective, safe, and avoids renal risks of opioids.
  • Fascia Iliaca Compartment Block (FICB): Emerging as a gold standard pre-hospital intervention (where authorized) due to superior pain relief and reduced systemic side effects compared to opioids.

Traumatic Amputation

Management of the Patient

  1. Control Haemorrhage: Direct pressure is first line. If ineffective or impractical, apply an arterial tourniquet immediately.
  2. Treat Shock: IV access and fluid resuscitation if signs of hypoperfusion are present.
  3. Analgesia: High doses may be required.

Management of the Amputated Part

To maximise the likelihood of successful reattachment (replantation):

  1. Clean: Gently rinse off gross contamination with saline (do not scrub).
  2. Wrap: Wrap the part in sterile, saline-moistened gauze.
  3. Bag: Place the wrapped part in a sealed, watertight plastic bag.
  4. Cool: Place the sealed bag into a slush of ice and water.

DO NOT place the part directly in water (maceration) or directly on ice (frostbite/tissue damage).

Crush Injury & Crush Syndrome: Pathophysiology

Definitions

  • Crush Injury: The direct local injury resulting from the crushing force.
  • Crush Syndrome: The systemic manifestation of muscle cell damage (rhabdomyolysis) resulting from pressure.

Pathophysiology of Crush Syndrome

Prolonged pressure causes stretching of the sarcolemmal membrane (muscle cell wall). This increases permeability:

  1. Influx: Sodium, Water, and Calcium leak into the cell. This causes cell swelling (compartment syndrome) and intravascular hypovolemia (shock).
  2. Release (on reperfusion): When the crushing force is removed, toxic cell contents are released into systemic circulation:
    • Potassium (K⁺): Causes life-threatening arrhythmias and cardiac arrest.
    • Myoglobin: Preciptates in renal tubules, causing Acute Renal Failure (ARF).
    • Phosphate/Urate: Contribute to acidosis and renal failure.

Compartment Syndrome

Occurs when pressure within a fascial compartment exceeds capillary perfusion pressure (approx 30-40 mmHg). This leads to ischemia and necrosis. It is a common complication of crush injury and fractures.

The 5 Ps: Pain (out of proportion to injury), Pallor, Paresthesia, Pulselessness (late sign), Paralysis.

Pre-hospital Management of Crushed Limb

1. Release of Crushing Force

ANZCOR Guideline 9.1.7: "If it is safe to do so... remove all crushing forces from the person as soon as possible."

The crushing force should be released irrespective of the length of time trapped. Delays in release increase mortality.

2. Fluid Resuscitation (The Priority)

Fluid loading is protective against renal failure and shock. Ideally, initiate fluid therapy PRIOR to extrication/release of the load.

UK Faculty Consensus:

  • Initial Bolus: 2 Litres of Normal Saline (crystalloid).
  • Maintenance: 1.0 - 1.5 Litres per hour.
  • Avoid: Potassium-containing fluids (e.g., Hartmann's) if possible, to avoid exacerbating hyperkalaemia.

3. Tourniquet Use

Controversy: Historically, tourniquets were used to "hold back" toxins before release. Current evidence does not support this routine use.

Current Recommendation (ANZCOR): Do NOT routinely apply arterial tourniquets before removing the crushing force.

Exception: Tourniquets should only be applied if there is actual or suspected life-threatening bleeding (e.g., mangled limb, traumatic amputation) immediately following release.

4. ECG Monitoring

Monitor for signs of Hyperkalaemia immediately post-release:

  • Peaked T waves
  • Widened QRS complexes
  • Loss of P waves
  • Sine wave pattern

Treat hyperkalaemia aggressively with Calcium Gluconate/Chloride and Sodium Bicarbonate per local protocols.