🚨syndrome

Acute Compartment Syndrome

Q: Why are pulses usually present in compartment syndrome?

Compartment syndrome affects the microcirculation within the compartment. The major arteries are usually not occluded, so distal pulses remain palpable. The ischemia occurs at the capillary level when compartment pressure exceeds capillary perfusion pressure (~25-30 mmHg).

Q: What is Volkmann's ischemic contracture?

Volkmann's contracture is the late consequence of untreated forearm compartment syndrome. Ischemic muscles necrose and are replaced by fibrotic tissue, which contracts. This results in a characteristic forearm flexion deformity with wrist flexion, finger flexion at MCPs and IPs, and thumb adduction.

Acute compartment syndrome is a surgical emergency where increased pressure within a closed fascial compartment compromises perfusion, leading to muscle and nerve ischemia. The leg (especially after tibial fracture) is most commonly affected. Delayed treatment causes irreversible muscle necrosis (Volkmann's contracture in the arm).

Anatomical Basis

Muscles are enclosed within tight fascial compartments. When pressure rises (from bleeding, edema, or external compression), the non-compliant fascia cannot expand. When compartment pressure exceeds perfusion pressure, blood flow stops, causing ischemia. The leg has 4 compartments; the forearm has 2-3 depending on classification.

Relevant Structures

Fascial compartmentsEnclosed musclesNerves within compartmentsArterial supplyLeg: Anterior, lateral, deep posterior, superficial posterior compartmentsForearm: Volar and dorsal compartments

Mechanism

Fractures (tibial shaft most common), crush injuries, reperfusion after vascular injury, tight casts/dressings, prolonged limb compression, burns, snake bites. Normal compartment pressure is 0-8 mmHg; symptoms begin at 20-30 mmHg; irreversible damage occurs when perfusion is compromised.

Clinical Presentation

•Pain out of proportion to injury (earliest and most sensitive sign)
•Pain with passive stretch of muscles in the compartment
•Paresthesias (sensory nerve ischemia)
•Paralysis (motor nerve and muscle ischemia) - LATE sign
•Pallor - LATE sign
•Pulselessness - VERY LATE sign (compartment syndrome is a clinical diagnosis - don't wait for this)
•Tense, swollen compartment on palpation

Physical Examination

→Palpate for tense compartments
→Pain with passive stretch (e.g., toe dorsiflexion stretches deep posterior compartment)
→Test sensation (anterior compartment: deep peroneal nerve = first web space)
→Test motor function (anterior compartment: toe extension)
→Pulses usually PRESENT until very late
→Compartment pressure measurement: Stryker needle or arterial line transducer

Treatment

✓SURGICAL EMERGENCY: Fasciotomy
✓Remove all constrictive dressings/casts immediately
✓Position limb at heart level (elevation decreases arterial perfusion pressure)
✓Fasciotomy: Release all involved compartments through adequate incisions
✓Leave wounds open, delayed primary closure or skin grafting in 3-5 days
✓Debride necrotic muscle if present
✓Supportive care: hydration for rhabdomyolysis, monitor renal function

Prognosis

Time-critical: Irreversible muscle damage begins after 6-8 hours of ischemia. Early fasciotomy (<6 hours) has excellent outcomes. Delay beyond 12 hours often results in permanent damage. Complete recovery possible with early intervention.

Study Tips

💡5 Ps: Pain (especially with passive stretch), Pressure, Paresthesias, Paralysis, Pulselessness (LATE)
💡Pain out of proportion is the earliest sign - don't wait for other Ps
💡Pulses are often PRESENT - compartment syndrome is NOT vascular occlusion
💡Delta pressure <30 mmHg (diastolic BP - compartment pressure) = needs fasciotomy
💡In unconscious/obtunded patients, must have high index of suspicion

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Acute Compartment Syndrome FAQs

Common questions about this condition

Compartment syndrome affects the microcirculation within the compartment. The major arteries are usually not occluded, so distal pulses remain palpable. The ischemia occurs at the capillary level when compartment pressure exceeds capillary perfusion pressure (~25-30 mmHg).

Volkmann's contracture is the late consequence of untreated forearm compartment syndrome. Ischemic muscles necrose and are replaced by fibrotic tissue, which contracts. This results in a characteristic forearm flexion deformity with wrist flexion, finger flexion at MCPs and IPs, and thumb adduction.

All Clinical Cases

🤚 Carpal Tunnel Syndrome 🦴 Scaphoid Fracture 😐 Bell's Palsy 👋 Radial Nerve Injury (Wrist Drop)🩹 Inguinal Hernia (Direct and Indirect)🧠 Middle Cerebral Artery Stroke 🏃 Anterior Cruciate Ligament (ACL) Tear 🦴 Thoracic Outlet Syndrome 🚨 Acute Compartment Syndrome 🦴 Hip Fracture (Femoral Neck and Intertrochanteric)