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 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