Trauma to the extremities

INTRODUCTION

• Isolated limb injury with associated vascular damage has a 10% mortality/limb loss rate
• Femoral and popliteal vessels most commonly injured
• Penetrating trauma with proximal arterial haemorrhage is most likely to lead to mortality
• Blunt trauma with distal vascular injury is most likely to lead to early limb loss
• The extent of injury to nerves/bones and soft tissues now determines limb loss vs. vascular injury thanks to rapid diagnostic techniques and operative repair

CLINICAL ASSESSMENT

• Do NOT deviate from primary/secondary survey routine other than direct pressure to stop external haemorrhage

CLINICAL ASSESSMENT

• Hard signs of vascular injury
  • Absent or diminished peripheral pulses
  • Obvious arterial bleeding
  • Large expanding or pulsatile haematoma
  • Audible bruit
  • Palpable thrill
  • Distal ischaemia (paraesthesia, pain, pallor, paralysis, coolness)

• Soft signs
  • Small, stable haematoma
  • Injury to anatomically-related nerve
  • Unexplained hypotension
  • History of haemorrhage
  • Proximity of injury to major vascular structures
  • Complex fracture
  • Previously applied tourniquet

CLINICAL ASSESSMENT

• Ankle-brachial index
  • Perform in the absence of hard signs
  • Compare to non-affected limb
  • ABI <0.9 is considered abnormal and is concerning for arterial injury
  • Detects occlusive arterial injury with 95% accuracy
  • Normal ABI does not rule out arterial injury as does not detect non-occlusive pathology e.g. intimal flaps, small pseudoaneurysms and AV fistulas seen in 10% of cases

DIAGNOSIS

• If any hard signs – Consult vascular surgery immediately
• If any soft signs (incl. ABI <0.9), order CT angiography 
• DDx
  • Arterial/venous injury
  • Nerve damage
  • Bullet embolisation
  • Compartment syndrome

IMAGING

• Low-energy gunshot fracture patterns
  • Drill-hole
    • Seen in porous, low-density cancellous bone
    • Distal femur, pelvis and proximal humerus
  • Unicortical
    • Seen in metaphyses of long bones due to tangential impact
  • Distant spiral
    • Mostly femur
  • Comminuted
    • Mostly diaphyseal bone with multiple bone fragments

IMAGING

• CT angiography
  • Non-invasive, provides higher resolution images and is less expensive than catheter angiography
  • Assists in evaluation of extravascular injuries
  • Sensitivity and specificity equivalent to conventional angiography for clinically significant arterial injuries
  • Limitations include scatter artifact interference from bullet fragments, poor visualisation of tibial vessels and inability to perform therapeutic interventions within study

IMAGING

• Ultrasonography
  • Colour-flow duplex USS has sensitivity 50-100% for evaluating vascular injuries
  • Should not be used as primary diagnostic strategy

TREATMENT

• Control bleeding
  • Direct pressure, pressure bandage or tourniquet (up to 6 hours safely)
  • Do not clamp vessels blindly as risks nerve damage
• Fractures and joint damage
  • Treat as open fracture with debridement, washout, IV Cefazolin + Gent
  • Synovial fluid is an organic acid that can dissolve lead bullets causing systemic lead toxicity

TREATMENT

• Wound management
  • Copious irrigation 500-1000mL tap water/saline at high pressure (15-20psi)
  • Antiseptic solution may be harmful
  • If >3-4 hours old, gently scrub wound
  • Factors that affect infection risk:
    • Bacterial inoculum, tissue devitalisation, blood supply, time to presentation and Rx, presence of FB and host immune status

TREATMENT

• Wound closure
  • If minimal contamination, wound well irrigated then can close
  • Need close follow-up
  • If retained FB, major tissue destruction or contamination, delayed closure at 72-96 hours is recommended
  • Uncomplicated extremity gunshot or knife wounds have 2% infection rate and DO NOT need prophylactic antibiotics
    • Consider if hand injuries, immunocompromised
    • Give if significantly contaminated or bony/joint involvement

SOFT TISSUE FOREIGN BODIES

• Plain X-ray
  • Glass, metal, bone or gravel
  • May not see wood or other organic material (USS better at this)
• CT is gold standard
• Organic material is more reactive and has a much higher rate of infection than glass or metal and so should not be left in situ
• A bullet should generally be left in situ unless risk of migration into surrounding vital structures or within joint capsule

DISPOSITION

• All patients without hard signs require CT angiography and period of observation
  • 24 hours is reasonable
  • Need to consider complications such as wound infection, missed nerve/tendon/joint injuries, delayed vascular injury and compartment syndrome
  • Need close follow-up

WOUND CLOSURE

• Delayed primary wound closure
  • Consider if:
    • Bite wounds
    • Puncture wounds
    • Non-viable tissue
    • Contaminated
    • Crush injuries
    • Already signs of infection
    • Wounds >24 hours old that were insufficiently cleansed/debrided/decontaminated
    • Wounds >24 hours in setting of immunosuppression, diabetes, CKD, smoking, obesity or chronic steroid use
  • Alternative is healing by secondary intention
  • Close on day 4 or 5 if no evidence of infection (similar results to primary closure)

WOUND IRRIGATION

• Tap or saline are equal
• Can use 1:10 dilute betadine (povidone-iodine) with saline for bite or contaminated wounds
  • Do not use chlorhex or betadine surgical scrub as toxic to tissues
• Pressure
  • High-pressure, low volume and low-pressure, high volume irrigation are equal
  • No evidence that high pressure irrigation increases spread of bacteria into surrounding tissues but can damage surrounding tissue
  • If highly contaminated wound, high-pressure clearance of bacteria may outweight slight tissue damage
• Volume
  • 100mL/cm linear laceration

PRETIBIAL SKIN FLAP MANAGEMENT

• Do not suture (unless young and fit)
• Best healing by secondary intention
• Prone to necrosis if sutured
• Gently appose skin edges with steristrips and apply non-adherent silicon dressing with double layer tubigrip
• If 50% dermal layer involved, can use hydrogel sheet dressing
• If deeper than this, likely requires debridement and skin grafting

TOURNIQUET USE

• ED indications
  • Alternative haemorrhage techniques ineffective
  • Haemodynamically unstable with ongoing haemorrhage requiring rapid control
  • Multitrauma with active arterial bleeding but other injuries take priority
• If placed in ED, leave on until review in theatre
• Pneumatic tourniquet should be used >100mmHg above systolic
• Must ensure effective (i.e. no peripheral pulse beyond tourniquet and no active bleeding)

PRE-HOSPITAL TOURNIQUET

• If in place:
  • Do not remove until haemodynamically stable 
  • Assess early for adequacy: May replace, tighten or add a second tourniquet
• Removal procedure
  • Place pneumatic tourniquet above pre-hospital one but leave deflated
  • Ensure pain controlled/sedated
  • Equipment for haemorrhage control prepared
  • Presence of appropriate inpatient team to prevent re-trial later
  • If bleeds again, trial direct pressure, indirect arterial pressure, compression bandage and elevation but may require inflation of pneumatic cuff

TOURNIQUET

• Reperfusion injury
  • Risk of hyperkalaemia, hypocalcaemia, rhabdo, lactic acidosis, shock
  • Can pre-treat with bicarb, calcium and fluids
  • Risk if >2 hours
  • Can lower cuff gradually over 2 min or lower for 30 seconds, then re-inflate for 3 minutes repeated 3 times

TOURNIQUET

• Tourniquet and CT-A
  • If unstable, leave in place
  • If stable, remove prior to CT-A with attempted control of bleeding with other techniques

Morel-Lavallee lesion

• Closed degloving injuries associated with severe trauma
• Classically occur over greater trochanter of the femur
• Can also occur over lumbar region, knee and scaphula region
• Skin and subcutaneous tissues separate from the fascia violently
• The potential space produced can then fill with serous fluid or blood
• May become chronic collection

Last Updated on March 8, 2023 by Andrew Crofton