Summary

Acute compartment syndrome (ACS) is a limb-threatening emergency caused by increased pressure within a closed fascial compartment, compromising tissue perfusion. It most commonly occurs after tibial shaft fractures but can follow any injury causing swelling within a closed compartment. The classic sign is pain out of proportion on passive stretch. Fasciotomy is the only definitive treatment — delay causes irreversible muscle necrosis and permanent disability.

Key Facts

• Commonest cause: Tibial shaft fracture
• Early signs: Pain out of proportion, pain on passive stretch of muscles in the compartment
• Late signs: Paralysis, pulselessness (don't wait for these — irreversible damage by then)
• Diagnosis: Clinical; compartment pressure over 30 mmHg or within 30 of diastolic (delta P under 30)
• Treatment: Emergency fasciotomy within 6 hours
• Consequence of delay: Volkmann's ischaemic contracture, limb loss, rhabdomyolysis

Clinical Pearls

Pain on passive stretch of muscles in the compartment is the MOST RELIABLE early sign

Do NOT rely on pulses — arterial occlusion is a very late sign indicating irreversible damage

If clinical suspicion is high, perform fasciotomy — you can repair an unnecessary fasciotomy, you cannot repair a dead leg

Why This Matters Clinically

Compartment syndrome is a true surgical emergency where hours matter. Missed or delayed diagnosis leads to permanent disability (Volkmann's contracture), limb amputation, and death from associated rhabdomyolysis and renal failure. All clinicians managing trauma must be able to recognise the early signs and escalate urgently.

Systematic Limb Examination

1. Inspection:

• Swelling (tense, shiny skin)
• Colour
• Any constricting casts/dressings

2. Palpation:

• Compartment tension (woody hardness)
• Temperature
• Pulses (present does NOT exclude ACS)
• Capillary refill

3. Passive Stretch Test (Most Specific):

4. Neurological Examination:

• Sensation in nerve territory of compartment
• Motor power of compartment muscles

Compartment Pressure Measurement

Indications:

• Clinical uncertainty
• Unreliable patient (unconscious, child, regional block)
• Monitoring in high-risk patients

Technique:

• Stryker ICP monitor or needle manometry
• Measure pressure in all potentially affected compartments

Thresholds:

By Compartment (Leg - 4 Compartments)

By Timing of Fasciotomy

With Early Fasciotomy (under 6 hours)

• Full functional recovery: Expected in majority
• Near-normal limb function

With Delayed Fasciotomy

• Partial muscle necrosis: Weakness, contracture
• Permanent nerve damage: Sensory and motor
• Volkmann's contracture: Severe disability

Without Treatment

• Limb loss
• Systemic complications: Rhabdomyolysis → AKI → death

Key Guidelines

1. BOA Standards for Trauma (BOAST) — Compartment Syndrome
2. NICE Fracture Management Guidelines
3. Orthopaedic Trauma Association Position Statement

Key Evidence

• Stryker ICP monitoring validated for diagnosis
• Delta P under 30 mmHg has better predictive value than absolute pressure
• Irreversible damage occurs after 6-8 hours of ischaemia

What is Compartment Syndrome?

Compartment syndrome is when pressure builds up inside a muscle group after an injury, cutting off blood supply. It is an emergency that needs immediate surgery to relieve the pressure.

Warning Signs

After a leg or arm fracture, tell staff immediately if you have:

• Severe pain that is getting worse
• Pain when someone moves your fingers or toes
• Numbness or tingling
• Swelling that feels very tight

Treatment

• Emergency surgery (fasciotomy) to release the pressure
• The wound is left open and closed later
• Most people recover well if treated quickly

Resources

• NHS Compartment Syndrome