SUMMARY
Acute Compartment Syndrome is a time-sensitive orthopedic emergency caused by increased pressure within a closed fascial compartment, leading to impaired tissue perfusion and ischemia.
If not treated promptly, irreversible muscle and nerve necrosis may develop within hours.
Diagnosis is primarily clinical and should not be excluded by the presence of distal pulses or normal capillary refill.
Definitive treatment requires urgent surgical fasciotomy.
EPIDEMIOLOGY
Incidence
• Most commonly associated with fractures
• Tibial shaft fractures are the most frequent cause
• Frequently implicated in orthopedic malpractice claims due to delayed diagnosis
ETIOLOGY & PATHOPHYSIOLOGY
Etiology
• Tibial shaft and tibial plateau fractures
• High-energy blunt soft tissue injury
• Intracompartmental hemorrhage, especially in anticoagulated patients
• Reperfusion injury following prolonged ischemia
• IV fluid extravasation
• Prolonged external compression (e.g. unconscious or immobilized patients)
Pathophysiology
• Hemorrhage and edema increase intracompartmental volume
• Rising pressure compresses capillary microcirculation
• Reduced tissue perfusion leads to ischemia
• Ischemia triggers inflammatory edema, worsening pressure
• Irreversible muscle and nerve injury typically occurs after 4–6 hours
ANATOMY
Commonly Involved Compartments
Forearm Compartments
• Volar compartment – most commonly involved
– Superficial layer: flexor carpi radialis, flexor carpi ulnaris, palmaris longus, pronator teres
– Deep layer: flexor digitorum profundus, flexor pollicis longus, pronator quadratus
• Dorsal compartment
– Contains wrist and finger extensors
• Mobile wad of Henry (lateral compartment)
– Brachioradialis
– Extensor carpi radialis longus
– Extensor carpi radialis brevis
Lower Leg Compartments
• Anterior compartment
– Tibialis anterior
– Extensor hallucis longus
– Extensor digitorum longus
– Deep peroneal nerve
• Lateral compartment
– Peroneus longus
– Peroneus brevis
– Superficial peroneal nerve
• Superficial posterior compartment
– Gastrocnemius
– Soleus
• Deep posterior compartment
– Tibialis posterior
– Flexor digitorum longus
– Flexor hallucis longus
– Posterior tibial artery and nerve
Upper Leg (Thigh) Compartments
• Anterior compartment
– Quadriceps femoris
– Femoral nerve
• Medial compartment
– Adductor muscle group
– Obturator nerve
• Posterior compartment
– Hamstring muscles
– Sciatic nerve
Foot Compartments
• Medial compartment
– Abductor hallucis
– Flexor hallucis brevis
• Central compartment
– Flexor digitorum brevis
– Quadratus plantae
• Lateral compartment
– Abductor digiti minimi
– Flexor digiti minimi
• Interosseous compartments
– Dorsal interossei
– Plantar interossei
• Calcaneal compartment
– Quadratus plantae (deep)
Hand Compartments
• Thenar compartment
– Thenar muscles
• Hypothenar compartment
– Hypothenar muscles
• Adductor compartment
– Adductor pollicis
• Interosseous compartments
– Dorsal interossei
– Palmar interossei
• Central compartment
– Lumbricals
– Flexor tendons
PRESENTATION
Symptoms
• Severe pain disproportionate to the injury
• Pain poorly responsive to analgesics
• Progressive tightness or pressure sensation in the limb
Physical Examination
• Firm, tense compartment on palpation
• Pain with passive stretching of involved muscles
• Paresthesia and motor weakness are late findings
• Distal pulses are usually present and do not exclude ACS
IMAGING & PRESSURE MEASUREMENT
Radiographs
• Used to identify associated fractures
• Do not rule out compartment syndrome
Compartment Pressure Measurement
Indications
• Unconscious or sedated patients
• Unreliable clinical examination
Diagnostic thresholds
• Absolute pressure ≥ 30 mm Hg
• Δ Pressure (diastolic BP − compartment pressure) < 30 mm Hg
TREATMENT
Initial Measures
• Remove all constrictive dressings or casts
• Position limb at heart level
• Stabilize associated fractures
Operative Treatment
Emergent fasciotomy is the definitive treatment.
Lower Leg
• Two-incision technique
• Anterolateral incision
– Decompresses anterior compartment
– Decompresses lateral compartment
• Posteromedial incision
– Decompresses superficial posterior compartment
– Decompresses deep posterior compartment
Forearm
• Volar fasciotomy (Henry approach)
– Decompresses superficial and deep volar compartments
• Carpal tunnel release
– Required for complete distal decompression
• Lacertus fibrosus release
– Prevents persistent proximal compression
• Dorsal compartment release
– Performed through a separate incision
• Mobile wad of Henry release
– Performed when clinically indicated
Upper Leg (Thigh)
• Single or dual longitudinal incisions
– Based on compartment involvement
• Anterior compartment release
– Quadriceps compartment
• Medial compartment release
– Adductor compartment
• Posterior compartment release
– Hamstring compartment
Foot
• Multiple dorsal incisions
– Decompresses interosseous compartments
– Decompresses central compartment
• Medial incision
– Decompresses medial compartment
– Decompresses calcaneal compartment
Hand
• Dorsal incisions
– Decompress interosseous compartments
• Thenar incision
– Decompresses thenar compartment
• Hypothenar incision
– Decompresses hypothenar compartment
• Adductor compartment release
– Required for thumb ischemia
• Carpal tunnel release
– Often performed concurrently
POSTOPERATIVE MANAGEMENT
• Fasciotomy wounds are left open initially
• Second-look surgery at 48–72 hours
• Delayed primary closure or split-thickness skin grafting as indicated
COMPLICATIONS
• Muscle necrosis and permanent functional loss
• Nerve injury with sensory and motor deficits
• Volkmann ischemic contracture
• Rhabdomyolysis and acute renal failure
• Wound infection and need for skin grafting
PROGNOSIS
• Outcome is directly related to time to decompression
• Early fasciotomy yields good functional results
• Delayed treatment results in irreversible tissue damage