Introduction
  • Devastating condition where an osseofascial compartment pressure rises to a level that decreases perfusion
    • may lead to irreversible muscle and nerve damage
  • Epidemiology
    • location
      • compartment syndrome may occur anywhere that skeletal muscle is surrounded by fascia, but most commonly
        • leg (details below)
        • forearm
        • hand
        • foot
        • thigh
        • buttock
        • shoulder
        • paraspinous muscles
  • Pathophysiology
    • etiology
      • trauma
        • fractures (69% of cases)
        • crush injuries
        • contusions
        • gunshot wounds
      • tight casts, dressings, or external wrappings
      • extravasation of IV infusion
      • burns
      • postischemic swelling
      • bleeding disorders
      • arterial injury
    • pathoanatomy
      • cascade of events includes
        • local trauma and soft tissue destruction> 
        • bleeding and edema > 
        • increased interstitial pressure > 
        • vascular occlusion > 
        • myoneural ischemia
Anatomy
  • 4 compartments of the leg 
    • anterior compartment
      • function
        • dorsiflexion of foot and ankle
      • muscles
        • tibialis anterior 
        • extensor hallucis longus 
        • extensor digitorum longus 
        • peroneus tertius 
    • lateral compartment
      • function
        • plantarflexion and eversion of foot
      • muscles
        • peroneus longus 
        • peroneus brevis 
      • isolated lateral compartment syndrome would only affect superficial peroneal nerve 
    • deep posterior compartment
      • function
        • plantarflexion and inversion of foot
      • muscles
        • tibialis posterior 
        • flexor digitorum longus 
        • flexor hallucis longus 
    • superficial posterior compartment
      • function
        • mainly plantarflexion of foot and ankle
      • muscles
        • gastrocnemius 
        • soleus 
        • plantaris 
Presentation
  • Symptoms 
    • pain out of proportion to clinical situation is usually first symptom  
      • may be absent in cases of nerve damage
      • pain is difficult to assess in a polytrauma patient and impossible to assess in a sedated patient
      • difficult to assess in children (unable to verbalize)
  • Physical exam
    • pain w/ passive stretch
      • is most sensitive finding prior to onset of ischemia
    • paresthesia and hypoesthesia
      • indicative of nerve ischemia in affected compartment
    • paralysis
      • late finding
      • full recovery is rare in this case
    • palpable swelling
    • peripheral pulses absent
      • late finding
      • amputation usually inevitable in this case
Imaging
  • Radiographs
    • obtain to rule-out fracture
Studies
  • Compartment pressure measurements
    • indications
      • polytrauma patients
      • patient not alert/unreliable
      • inconclusive physical exam findings
    • relative contraindication
      • unequivocally positive clinical findings should prompt emergent operative intervention without need for compartment measurements
    • technique 
      • should be performed within 5cm of fracture site
      • anterior compartment
        • entry point
          • 1cm lateral to anterior border of tibia within 5cm of fracture site if possible
        • needle should be perpendicular to skin
      • deep posterior compartment
        • entry point
          • just posterior to the medial border of tibia
        • advance needle perpendicular to skin towards fibula
      • lateral compartment
        • entry point
          • just anterior to the posterior border of fibula
      • superficial posterior
        • entry point
          • middle of calf within 5 cm of fracture site if possible
  • Diagnosis
    • based primarily on physical exam in patient with intact mental status
Treatment
  • Nonoperative
    • observation
      • indications
        • diastolic differential pressure (delta p) is > 30 
        • presentation not consistent with compartment syndrome
    • bi-valving the cast and loosening circumferential dressings 
      • indications
        • initial treatment for swelling or pain that is NOT compartment syndrome
      • splinting the ankle between neutral and resting plantar flexion (37 deg) can also decrease intracompartmental pressures 
    • hyperbaric oxygen therapy
      • works by increasing the oxygen diffusion gradient 
  • Operative
    • emergent fasciotomy of all four compartments
      • indications
        • clinical presentation consistent with compartment syndrome
        • compartment pressures within 30 mm Hg of diastolic blood pressure (delta p)  
          • intraoperatively, diastolic blood pressure may be decreased from anesthesia
            • must compare intra-operative measurement to pre-operative diastolic pressure   
            • attempt to restore systemic blood pressure prior to measurement 
      • contraindications
        • missed compartment syndrome
  • Special considerations
    • pediatrics  
      • children are unable to verbalize feelings
        • if suspicion, then perform compartment pressure measurement under sedation 
    • hemophiliacs
      • give Factor VIII replacement before measuring compartment pressures
Techniques
  • Emergent fasciotomy of all four compartments
    • dual medial-lateral incision   
      • approach 
        • two 15-18cm vertical incisions separated by 8cm skin bridge
          • anterolateral incision
          • posteromedial incision
      • technique
        • anterolateral incision 
          • identify and protect the superficial peroneal nerve
          • fasciotomy of anterior compartment performed 1cm in front of intermuscular septum
          • fasciotomy of lateral compartment performed 1cm behind intermuscular septum
        • posteromedial incision 
          • protect saphenous vein and nerve
          • incise superficial posterior compartment
          • detach soleal bridge from back of tibia to adequately decompress deep posterior compartment 
      • post-operative
        • dressing changes followed by delayed primary closure or skin grafting at 3-7 days post decompression
      • pros
        • easy to perform
        • excellent exposure
      • cons
        • requires two incisions
    • single lateral incision 
      • approach 
        • single lateral incision from head of fibula to ankle along line of fibula
      • technique
        • identify superficial peroneal nerve
        • perform anterior compartment fasciotomy 1cm anterior to the intermuscular septum
        • perform lateral compartment fasciotomy 1cm posterior to the intermuscular septum
        • identify and perform fasciotomy on superficial posterior compartment
        • enter interval between superficial posterior and lateral compartment
        • reach deep posterior compartment by following interosseous membrane from the posterior aspect of fibula and releasing compartment from this membrane
          • common peroneal nerve at risk with proximal dissection
      • pros
        • single incision
      • cons
        • decreased exposure