SUMMARY

• Leg Compartment Syndrome is a devastating lower extremity condition where the osseofascial compartment pressure rises to a level that decreases perfusion to the leg and may lead to irreversible muscle and neurovascular damage.

• Diagnosis is made with the presence of severe and progressive leg pain that worsens with passive ankle motion. Firmness and decreased compressibility of the compartments is often present. Needle compartment pressures are diagnostic in cases of inconclusive physical exam findings and in sedated patients.

• Treatment is usually emergent fasciotomies of all 4 compartments. 

EPIDEMIOLOGY

• Anatomic 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

ETIOLOGY

• 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 (decreased venous outflow relative to arterial inflow) 

         

      • myoneural ischemia

• Risk factors 

   

  • diaphyseal fractures

  • young age (highest prevalence in 12-19 year olds)

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 the clinical situation is usually the 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

    • low rates of interobserver reliability have been noted with measurements  

       

    • 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

• Clinical

  • based primarily on physical exam in patient with intact mental status

  • continuous intramuscular compartment pressure monitoring is highly sensitive and specific for the diagnosis of acute compartment syndrome in obtunded or intubated patients 

     

    • usually performed in the anterior compartment of the lower leg

    • higher spatial variations in compartment pressure measurements are found:

      • within 5cm of the fracture

      • within the central aspect of the muscle belly

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