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Acute Compartment Syndrome of the Leg

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Acute Compartment Syndrome of the Leg

complete
Updated: 2025-01-08
High Yield Overview

ACUTE COMPARTMENT SYNDROME OF THE LEG

Surgical Emergency | Four-Compartment Fasciotomy | Time-Critical | Clinical Diagnosis

6-8hrWindow before irreversible damage
Under 30Delta P threshold (mmHg)
2-9%Incidence with tibial fractures
4Compartments to release

LEG COMPARTMENTS

Anterior
PatternTibialis anterior, EDL, EHL, peroneal nerve
TreatmentLateral incision release
Lateral
PatternPeroneus longus/brevis, superficial peroneal nerve
TreatmentLateral incision release
Superficial Posterior
PatternGastrocnemius, soleus, plantaris
TreatmentMedial incision release
Deep Posterior
PatternTibialis posterior, FDL, FHL, posterior tibial NV
TreatmentMedial incision release

Critical Must-Knows

  • Clinical diagnosis - pain out of proportion, pain on passive stretch, tense compartments
  • Delta P less than 30mmHg = surgical indication (diastolic BP - compartment pressure)
  • Two-incision, four-compartment release - lateral and medial approaches
  • Do NOT wait for pulselessness - this is a late, irreversible sign
  • Remove all circumferential dressings - may reduce pressure by 30-65%

Examiner's Pearls

  • "
    The 6 P's are LATE signs - pain and pressure are early
  • "
    Deep peroneal nerve (anterior compartment) - first web space sensation
  • "
    Superficial peroneal nerve (lateral compartment) - dorsum of foot sensation
  • "
    Document pre-op neurovascular status meticulously for medicolegal protection
  • "
    Delayed primary closure at 3-5 days or STSG if unable to close

Viva Danger Zones - Compartment Syndrome

Classic Scenarios

Post-Nail Pain: Ascalating doses. Conscious but Painful: Don't trust pulses. Obtunded Polytrauma: High suspicion → Measure pressures.

Critical Numbers

6-8 Hours: Irreversible necrosis. Delta P less than 30: Surgical threshold.

Surgical Pitfall

Release ALL Four: Local/Partial release = Negligence. 2 incisions required.

Forbidden Phrases

NEVER Say: "Wait and see", "Pulses are normal so it's fine", or "Just release anterior".

At a Glance

Acute Compartment Syndrome - Quick Reference

ParameterKey Information
DefinitionElevated pressure in closed fascial space compromising tissue perfusion
Incidence2-9% of tibial fractures; 7.3/100,000 annual
DemographicsMale:Female 10:1; Peak age 20-35 years
Most common causeTibial shaft fractures
Time to necrosis6-8 hours of ischemia = irreversible
DiagnosisCLINICAL - pain on passive stretch, tense compartments
Pressure thresholdDelta P less than 30mmHg (DBP - compartment pressure)
TreatmentEmergent two-incision, four-compartment fasciotomy
Wound closureDelayed primary closure at 3-5 days or STSG

Epidemiology

  • Tibial fractures - 2-9% incidence
  • Male: Female = 10:1
  • Peak age: 20-35 years
  • 36% missed in polytrauma patients
  • Annual incidence: 7.3/100,000

High-Risk Injuries

  • Tibial shaft fractures - most common
  • High-energy trauma
  • Crush injuries
  • Ischemia-reperfusion after revascularization
  • Tight casts/dressings
  • Anticoagulation - lowers threshold

Key Clinical Points

  • Clinical diagnosis - don't delay for pressures
  • Pain with passive stretch - most sensitive
  • Pulses present in most cases
  • Time is muscle - fascia always wins
  • Document neurological status pre-op
  • Delayed closure or STSG at 3-5 days
Mnemonic

6 P's

P
Pain
Especially with passive stretch - EARLIEST sign
P
Pressure
Tense, woody compartments on palpation
P
Paresthesia
Nerve ischemia - numbness and tingling
P
Paralysis
Motor loss - LATE sign of established damage
P
Pallor
Skin color changes from ischemia
P
Pulselessness
VERY LATE - irreversible damage likely

Memory Hook:Pain and Pressure are early - the other 4 P's mean you're too late!

Mnemonic

COMPARTMENTS

C
Contain 4
Four compartments in the leg
O
Outer (lateral)
Peroneals, superficial peroneal nerve
M
Middle-front (anterior)
Tibialis anterior, EDL, EHL, deep peroneal
P
Posterior superficial
Gastroc-soleus complex
A
And posterior deep
Tibialis posterior, FDL, FHL, posterior tibial NV
R
Release ALL four
Through TWO incisions
T
Two incisions
Lateral for anterior+lateral, medial for posterior
M
Measure if equivocal
Delta P less than 30 = operate
E
Emergency
6-8 hours before irreversible damage
N
Never partial release
Inadequate decompression is dangerous
T
Timing is everything
Clinical diagnosis, don't delay for testing
S
STSG or delayed closure
At 3-5 days when swelling resolves

Memory Hook:COMPARTMENTS - remember all four need release through two incisions

Mnemonic

STRETCH

S
Severe pain
Out of proportion, not relieved by opioids
T
Tense compartments
Woody, firm on palpation
R
Range of motion painful
Passive stretch of muscles
E
Earliest signs
Pain with passive stretch and paresthesia
T
Test sensation
First web (deep peroneal), dorsum (superficial peroneal)
C
Check motor
EHL, tibialis anterior (anterior compartment)
H
High index of suspicion
In unconscious patients

Memory Hook:STRETCH the muscles to test for compartment syndrome

Overview and Epidemiology

Acute compartment syndrome (ACS) is a surgical emergency where elevated pressure within a closed fascial compartment compromises tissue perfusion. In the leg, untreated ACS leads to irreversible muscle necrosis within 6-8 hours and potential limb loss. The leg has four compartments, and tibial shaft fractures are the most common cause. Diagnosis is primarily clinical, but pressure measurement confirms equivocal cases. Emergent two-incision four-compartment fasciotomy is the treatment.

Time-Critical Emergency

Irreversible muscle necrosis begins at 6-8 hours of ischemia.

The sequence of deterioration:

  • 2-4 hours: Nerve dysfunction begins (paresthesia, weakness)
  • 4-6 hours: Ongoing nerve and muscle damage
  • 6-8 hours: Irreversible myonecrosis
  • Beyond 8 hours: Volkmann's contracture, rhabdomyolysis, limb loss

If clinical suspicion is high, proceed to fasciotomy - do NOT wait for pressure confirmation.

Etiology and Risk Factors

Causes of Acute Compartment Syndrome

CategoryExamplesRisk Level
FracturesTibial shaft (most common), forearm, femoral shaftHigh
Soft tissue injuryCrush injuries, muscle contusionsHigh
VascularIschemia-reperfusion after revascularizationHigh
IatrogenicTight casts, circumferential dressings, positioningModerate
BleedingAnticoagulation, coagulopathy, vascular injuryModerate
BurnsCircumferential burns, escharotomy neededModerate
OtherSnake bites, injection injuries, nephrotic syndromeLower

Anatomy and Pathophysiology

Four Compartments - Know Cold for Viva

The leg has four fascial compartments, each with specific contents:

  1. Anterior: Tibialis anterior, EHL, EDL, peroneus tertius, deep peroneal nerve, anterior tibial artery
  2. Lateral: Peroneus longus, peroneus brevis, superficial peroneal nerve
  3. Superficial Posterior: Gastrocnemius, soleus, plantaris, sural nerve
  4. Deep Posterior: Tibialis posterior, FDL, FHL, posterior tibial artery, tibial nerve

The anterior compartment is most commonly affected, but all four must be released.

Anterior Compartment

Contents:

  • Tibialis anterior (foot dorsiflexion)
  • Extensor hallucis longus
  • Extensor digitorum longus
  • Peroneus tertius
  • Deep peroneal nerve (first web space)
  • Anterior tibial artery

Fasciotomy: Lateral incision, 2cm lateral to tibial crest

Lateral Compartment

Contents:

  • Peroneus longus
  • Peroneus brevis
  • Superficial peroneal nerve (foot dorsum)

Fasciotomy: Lateral incision, same as anterior, posterior incision in fascia

Superficial Posterior

Contents:

  • Gastrocnemius
  • Soleus
  • Plantaris
  • Sural nerve

Fasciotomy: Medial incision, 2cm posterior to medial tibial border

Deep Posterior

Contents:

  • Tibialis posterior
  • Flexor digitorum longus
  • Flexor hallucis longus
  • Posterior tibial artery
  • Tibial nerve

Fasciotomy: Detach soleus from tibia to access

Mnemonic

PRESSURE

P
Pressure rises
In closed fascial space
R
Reduced perfusion
AV gradient decreases
E
Edema worsens
Capillary leak, venous congestion
S
Starving cells
Ischemia begins
S
Self-perpetuating
More edema = more pressure
U
Ultimate necrosis
At 6-8 hours
R
Rhabdomyolysis
And systemic effects
E
End-organ failure
Renal, cardiac if untreated

Memory Hook:Rising PRESSURE kills the compartment

Tissue Tolerance to Ischemia

TissueIschemia ToleranceClinical Implication
Nerve2-4 hoursParesthesia and weakness are early signs
Muscle4-6 hoursSalvageable if released early
Muscle6-8 hoursIrreversible necrosis begins
MuscleBeyond 8 hoursVolkmann's contracture inevitable
Skin8-12 hoursMore tolerant than muscle
BoneProlongedMost tolerant to ischemia

The Pressure-Perfusion Relationship

Critical Concept: Tissue perfusion depends on the arteriovenous pressure gradient, not absolute arterial pressure.

Delta P = Diastolic BP - Compartment Pressure

  • Delta P greater than 30mmHg: Adequate perfusion
  • Delta P less than 30mmHg: Inadequate perfusion - fasciotomy indicated
  • Absolute threshold of 30-45mmHg is less reliable, especially in hypotensive patients

In a hypotensive trauma patient (DBP 50mmHg), a compartment pressure of only 25mmHg gives Delta P = 25, which is inadequate despite seemingly "low" absolute pressure.

Classification Systems

Classification by Clinical Severity:

Compartment Syndrome Severity Grading

GradeClinical FeaturesManagement
ImpendingPain with stretch, borderline Delta P 25-35Close monitoring, serial assessment every 1-2 hours
Established EarlyPain out of proportion, tense compartments, Delta P less than 30Immediate fasciotomy within 30-60 minutes
Established LateParalysis, paresthesia, pressure less than 30 Delta PUrgent fasciotomy, consider outcomes discussion
IrreversiblePulselessness, fixed contracture, sensory loss completeAmputation may be required, fasciotomy contraindicated

The severity grading helps guide urgency and prognosis discussions with patients.

Classification by Affected Compartment:

Compartment-Specific Features

CompartmentNerve AffectedSensory LossMotor Loss
AnteriorDeep peronealFirst web spaceFoot dorsiflexion, EHL
LateralSuperficial peronealDorsum of footFoot eversion
Superficial PosteriorSuralLateral footPlantarflexion (weak)
Deep PosteriorTibialPlantar footToe flexion, tibialis posterior

The anterior compartment is most commonly affected (75%), but all four must be assessed and released if syndrome is present.

Pressure-Based Classification:

Pressure Thresholds for Fasciotomy

MeasurementThresholdRecommendation
Absolute pressureGreater than 30 mmHgTraditional threshold - consider fasciotomy
Absolute pressureGreater than 45 mmHgUniversal indication for fasciotomy
Delta P (DBP - ICP)Less than 30 mmHgPreferred threshold - fasciotomy indicated
Delta PLess than 20 mmHgUrgent fasciotomy required
Delta P25-35 mmHgBorderline - serial monitoring or proceed based on clinical picture

Delta P is more reliable than absolute pressure, especially in hypotensive patients.

Clinical Assessment

History and Examination

Key History Points

  • Mechanism: Tibial fracture, crush, prolonged limb compression
  • Time since injury - critical for prognosis
  • Pain character: Constant, severe, not relieved by analgesia
  • Symptoms: Numbness, tingling, weakness
  • Anticoagulation status
  • Polytrauma - altered consciousness masks symptoms

Examination Findings

  • Pain on passive stretch - most sensitive early sign
  • Tense, woody compartments on palpation
  • Pain out of proportion to injury
  • Sensory deficit (first web space = deep peroneal)
  • Motor weakness (foot drop = anterior compartment)
  • Pulses typically present - don't be reassured

Passive Stretch Testing

Passive Stretch Tests by Compartment

CompartmentPassive Stretch TestWhat Worsens Pain
AnteriorPlantarflex foot and toesStretches tibialis anterior, EDL, EHL
LateralInvert footStretches peroneus longus and brevis
Superficial PosteriorDorsiflex footStretches gastrosoleus complex
Deep PosteriorExtend toes + dorsiflex footStretches FDL, FHL, tibialis posterior

Compartment Pressure Measurement

When and How to Measure

Indications for Pressure Measurement:

  1. Equivocal clinical findings
  2. Unconscious/sedated patient
  3. Unable to assess clinically (intubated, regional block)
  4. Borderline symptoms with need for documentation

Technique:

  1. Use Stryker device or arterial line transducer
  2. Measure within 5cm of fracture site (highest pressure zone)
  3. Measure all four compartments - don't assume which is affected
  4. Compare to diastolic blood pressure

Thresholds:

  • Absolute pressure greater than 30mmHg: Traditional threshold
  • Delta P less than 30mmHg: More reliable, especially in hypotensive patients
  • Absolute greater than 45mmHg: Universally indicates fasciotomy needed

Pitfalls in Diagnosis

Do NOT rely on:

  1. Pulses - present in most cases of compartment syndrome
  2. Capillary refill - maintained until very late
  3. Single pressure reading - may need serial measurements
  4. "Soft" compartments - deeper compartments may be tense while superficial feels soft

High-risk patients needing extra vigilance:

  • Obtunded/intubated patients
  • Regional anesthesia (masks pain)
  • Young males with high pain tolerance
  • Those on anticoagulants
  • After revascularization
Bilateral lower extremity fasciotomies for severe compartment syndrome
Click to expand
Severe bilateral lower extremity compartment syndrome requiring fasciotomy of both legs and both thighs. This case demonstrates bilateral four-compartment fasciotomies with VAC dressings in place and surgical drains. Extensive compartment syndrome like this may occur secondary to systemic causes (e.g., Systemic Capillary Leak Syndrome) or prolonged limb compression during surgery. Early recognition and prompt surgical decompression are essential.Credit: Saugel B et al., Scand J Trauma Resusc Emerg Med - PMC2912233 (CC-BY)

Investigations

Essential Investigations

Pre-operative:

  • FBC, UEC, coagulation
  • CK (creatine kinase) - rhabdomyolysis
  • Lactate
  • Group and screen
  • ECG (hyperkalemia risk)

Intra-operative:

  • Serial CK post-fasciotomy
  • Monitor urine output (myoglobinuria)

Compartment Pressure Measurement

Equipment:

  • Stryker intracompartmental monitor
  • Or arterial line transducer + needle

Technique:

  • Insert perpendicular to compartment
  • Within 5cm of fracture site
  • Measure all 4 compartments
  • Zero at level of compartment
  • Delta P = DBP - compartment pressure

Laboratory Findings in ACS

Rhabdomyolysis markers:

  • CK (creatine kinase): Often greater than 10,000 U/L (can exceed 100,000)
  • Myoglobin: Causes myoglobinuria (cola-colored urine)
  • Potassium: Hyperkalemia - cardiac risk
  • Creatinine: Rising indicates acute kidney injury
  • Lactate: Elevated with tissue ischemia
  • Phosphate: Elevated from muscle breakdown

Immediate management of rhabdomyolysis:

  1. Aggressive IV fluids (target urine output 200-300mL/hr)
  2. Monitor for hyperkalemia
  3. Consider urinary alkalinization
  4. Avoid nephrotoxins
CT imaging showing compartment syndrome findings in the leg
Click to expand
CT imaging findings in acute compartment syndrome: (A) Axial CT demonstrating low attenuation (edema) within the left calf musculature (yellow arrow) indicating muscle swelling and ischemia, (B) CT venography showing bilateral lower extremities for vascular assessment, (C) CT angiography 3D reconstruction showing patent vessels. While CT is not the primary diagnostic modality, these findings can support clinical diagnosis and exclude vascular injury as the primary etiology.Credit: PMC5364107 (CC-BY)

Management Algorithm

📊 Management Algorithm
Acute Compartment Syndrome Management Algorithm
Click to expand
Visual Sketchnote Management Algorithm: Immediate decompression for Delta P < 30mmHg.Credit: OrthoVellum

Management

Initial Non-Operative Management:

0 minRecognition and First Response
  • Remove ALL circumferential dressings (can reduce pressure 30-65%)
  • Split cast to skin
  • Keep limb at heart level (elevation may reduce perfusion)
  • Call for senior help immediately
0-30 minAssessment and Decision
  • Rapid clinical assessment (pain, passive stretch, sensation)
  • If clinical diagnosis clear: proceed directly to theatre
  • If equivocal: measure compartment pressures
  • Consent for fasciotomy
  • Organize theatre urgently

Conservative Management Is Temporary

Conservative measures (cast splitting, elevation) are only temporizing while organizing theatre. If compartment syndrome is diagnosed or strongly suspected, fasciotomy is mandatory. Do not rely on conservative measures alone.

Conservative management truly only applies for impending compartment syndrome with borderline Delta P (25-35mmHg). Close monitoring every 1-2 hours with clear escalation plan is essential.

Absolute Indications for Fasciotomy:

Clinical Indications

  • Pain out of proportion to injury
  • Pain on passive muscle stretch
  • Tense, woody compartments
  • Neurological deficit (sensory or motor)
  • High clinical suspicion in obtunded patient

Pressure Indications

  • Delta P less than 30 mmHg
  • Absolute pressure greater than 45 mmHg
  • Borderline Delta P (25-35) with concerning clinical picture
  • Any pressure elevation in symptomatic patient

Relative Indications:

  • Prophylactic fasciotomy after prolonged ischemia and revascularization
  • High-risk fractures with swelling in polytrauma patient
  • Combined arterial injury with tibial fracture

When NOT to operate:

  • Established irreversible ischemia beyond 24 hours (risk of reperfusion syndrome)
  • In this case, amputation may be life-saving

Decision Making

If in doubt, operate. The consequences of a missed compartment syndrome (limb loss, contracture, medicolegal) far outweigh the morbidity of an "unnecessary" fasciotomy.

Surgical Technique

Six-panel anatomical diagram of two-incision four-compartment fasciotomy technique
Click to expand
Two-incision four-compartment fasciotomy technique: Top row shows cross-sectional anatomy with lateral and medial incision locations, highlighting the superficial peroneal nerve (caution - lateral incision) and posterior tibial neurovascular bundle (medial incision). Middle row demonstrates muscle anatomy including all four compartments: anterior (tibialis anterior, EDL), lateral (peronei), superficial posterior (gastrocnemius, soleus), and deep posterior (tibialis posterior, FHL, FDL). Bottom row shows complete decompression of all compartments through both incisions.Credit: Kashuk JL et al., Patient Saf Surg - CC BY 4.0
Two-panel clinical photos showing compartment syndrome and fasciotomy
Click to expand
Acute compartment syndrome - clinical appearance and treatment: (A) Left lower extremity showing classic signs of compartment syndrome with tense swelling and pallor indicating impaired perfusion. (B) Emergent fasciotomy with exposed viable muscle demonstrating adequate decompression. Note the 'bulging' of muscle through the fascial incision confirming compartment release.Credit: Open-i (NIH) - CC BY 4.0

Releases: Anterior + Lateral Compartments

Step 1Positioning and Incision
  • Supine with bump under ipsilateral hip
  • Lateral incision 2cm anterior to fibula
  • Full length from fibular head to lateral malleolus
Step 2Identify Structures
  • Find intermuscular septum between anterior and lateral compartments
  • Identify superficial peroneal nerve in distal third (protect it)
Step 3Release Lateral Compartment
  • Incise fascia longitudinally posterior to septum
  • Peroneal muscles should bulge
Step 4Release Anterior Compartment
  • Pass anterior to intermuscular septum
  • Incise anterior compartment fascia longitudinally
  • Tibialis anterior and EDL should bulge

Lateral Incision Key Points

  • Make incision FULL LENGTH - don't be conservative
  • Protect superficial peroneal nerve (crosses in distal third)
  • Both compartments released through single incision
  • Muscles should bulge and appear pink (viable)

Releases: Superficial + Deep Posterior Compartments

Step 1Positioning and Incision
  • Supine, leg externally rotated
  • Medial incision 2cm posterior to medial tibial border
  • Full length from tibial tuberosity to medial malleolus
Step 2Protect Structures
  • Identify and preserve great saphenous vein
  • Protect saphenous nerve (stays with vein)
Step 3Release Superficial Posterior
  • Incise investing fascia over gastrocnemius
  • Gastrocsoleus complex should bulge
Step 4Release Deep Posterior
  • Detach soleus origin from posterior tibial border
  • This exposes deep posterior compartment fascia
  • Incise deep fascia, protecting posterior tibial NV bundle
  • FDL, FHL, tibialis posterior should be visible

Medial Incision Key Points

  • Key step: detach soleus from tibia to access deep posterior
  • Protect posterior tibial neurovascular bundle (between FDL and tibialis posterior)
  • Saphenous vein and nerve - stay posterior to tibial border
  • Deep posterior release is MANDATORY - don't forget it

Post-Release Assessment and Wound Care:

Muscle Assessment

Viable muscle:

  • Pink color
  • Contractile when stimulated
  • Bleeds when cut

Keep all viable muscle

Non-Viable Muscle

Necrotic muscle:

  • Grey/purple color
  • Non-contractile
  • Does not bleed

Debride all dead muscle

Wound Management:

  • DO NOT close wounds primarily - must leave open
  • Thorough saline washout
  • Options for temporary coverage:
    • VAC (negative pressure wound therapy) - preferred
    • Vessel loop/shoelace technique for gradual closure
    • Moist gauze dressings
  • Plan return to theatre at 24-48 hours for second look
  • Delayed primary closure at 3-5 days when edema resolves
  • STSG if unable to close primarily

Never Close Primarily

Primary closure of fasciotomy wounds risks re-establishing compartment syndrome. Wounds must remain open and be closed in delayed fashion.

Mnemonic

FASCIOTOMY

F
Full-length incisions
Don't be conservative
A
Anterior and lateral
Via lateral incision 2cm anterior to fibula
S
Skin must be released
Not just fascia
C
Check all compartments
Are decompressed
I
Identify and protect
Superficial peroneal nerve laterally
O
Open deep posterior
By detaching soleus from tibia
T
Two compartments medially
Superficial and deep posterior
O
Operate on medial side
2cm posterior to tibial border
M
Muscles should bulge
And pink up (viable)
Y
Your wounds stay OPEN
Delayed closure 3-5 days

Memory Hook:FASCIOTOMY - complete release of all four compartments through two incisions

Complications

Mnemonic

VOLKMANN

V
Volkmann's contracture
Late ischemic contracture
O
Ongoing sepsis
From wound infections
L
Limb loss
Amputation if too late
K
Kidney injury
From rhabdomyolysis
M
Motor deficit
And weakness
A
Amputation
May be needed in severe cases
N
Nerve injury
And permanent sensory loss
N
Necrosis
Requiring extensive debridement

Memory Hook:VOLKMANN - the devastating consequences of missed compartment syndrome

Complications by Timing

TimingComplicationPrevention/Management
ImmediateRhabdomyolysisAggressive fluids, monitor CK, urine output
ImmediateHyperkalemiaECG monitoring, calcium gluconate, insulin/dextrose
ImmediateAcute kidney injuryIV fluids, avoid nephrotoxins, may need dialysis
Early (days)Wound infectionAntibiotics, debridement, VAC therapy
EarlyOngoing muscle necrosisSerial debridement until viable tissue
Late (weeks)Volkmann's contractureRequires tendon lengthening, releases
LatePermanent nerve damageMay need tendon transfers
LateAmputationMay be required for unsalvageable limb

Volkmann's Ischemic Contracture

Definition: Fixed flexion contracture of forearm/leg muscles due to ischemic fibrosis.

In the leg (less common than forearm):

  • Affected muscles: Deep posterior compartment (FDL, FHL, tibialis posterior)
  • Clinical appearance: Claw toes, equinovarus foot
  • Pathology: Muscle replaced by fibrous tissue, shortened and contracted

Treatment options:

  1. Mild: Stretching, splinting, physiotherapy
  2. Moderate: Muscle slide procedures
  3. Severe: Tendon lengthening, releases
  4. Very severe: May require amputation

Prevention: Early recognition and fasciotomy - this is the key message.

Medicolegal Considerations

Documentation and Medicolegal Protection

Compartment syndrome is one of the most litigated conditions in orthopaedics. Protect yourself:

  1. Document baseline neurovascular status - sensation, motor, pulses
  2. Time-stamp all assessments - shows vigilant monitoring
  3. Document clinical findings - "pain with passive stretch," "tense compartments"
  4. Record all interventions - cast splitting, elevation, pressure measurements
  5. Document discussions with patient/family about risks
  6. If pressures measured - record actual values and Delta P calculation
  7. If proceeding to surgery - document indication clearly
  8. Consent: Include amputation as a possible outcome if delayed presentation

Postoperative Care

First 48 Hours Post-Fasciotomy:

Monitoring

  • Serial CK levels (every 6-12 hours)
  • Urine output monitoring (target greater than 1mL/kg/hr)
  • Renal function (creatinine, urea)
  • Potassium levels (hyperkalemia risk)
  • ECG monitoring if hyperkalemia concerns
  • Limb neurovascular checks

Systemic Care

  • Aggressive IV fluids - aim for urine output 200-300mL/hr
  • Consider urinary alkalinization (target urine pH greater than 6.5)
  • Avoid nephrotoxic medications
  • DVT prophylaxis
  • Analgesia optimization
  • Consider ICU admission if significant rhabdomyolysis

Return to Theatre at 24-48 Hours:

  • Mandatory second look
  • Debride any further necrotic muscle
  • Assess wound for closure readiness
  • Washout

Adequate systemic resuscitation is critical to prevent acute kidney injury from rhabdomyolysis.

Wound Management Protocol:

Day 0-2Initial Coverage
  • VAC dressing preferred (promotes wound bed granulation)
  • Alternatively: moist gauze or vessel loop approximation
  • Do NOT attempt closure
Day 3-5Assess for Closure
  • Edema should be resolving
  • Wound edges should be approximating naturally
  • Consider delayed primary closure if edges meet without tension
Day 5-7Definitive Coverage
  • If edges meet: delayed primary closure
  • If significant gap: split-thickness skin graft (STSG)
  • Consider dermal substitutes for large defects

VAC Settings:

  • Continuous mode typically
  • 75-125 mmHg negative pressure
  • Change every 48-72 hours
  • Promotes wound contraction and granulation

Early involvement of plastic surgery may be helpful for complex wounds.

Early Rehabilitation:

  • Day 1-3: Gentle ankle ROM within comfort
  • Week 1-2: Progressive ankle and toe movements
  • Week 2-4: Weight bearing as tolerated (depends on associated injuries)
  • Week 4+: Progressive strengthening

Key Rehabilitation Goals:

  • Maintain ankle ROM (prevent equinus contracture)
  • Early mobilization to prevent DVT
  • Wound care education for patient
  • Scar management once healed

Rehabilitation Pearl

The priority is preventing equinus contracture of the ankle. Early gentle dorsiflexion exercises and splinting in neutral position are essential, especially if posterior compartment was involved.

Wound management progression after fasciotomy for compartment syndrome
Click to expand
Fasciotomy wound management using negative pressure wound therapy (NPWT/VAC): (a) Initial fasciotomy wound with VAC device applied, (b) wound showing early granulation with partial skin closure using vessel loops (shoelace technique), (c) VAC dressing application, (d) progressive closure achieved with gradual skin approximation, (e-f) final healed result with complete wound closure. This staged closure technique allows progressive soft tissue management and avoids the need for skin grafting in most cases.Credit: Topaz M et al., Indian J Plast Surg - PMC3495380 (CC-BY)

Outcomes and Prognosis

Outcomes by Timing of Fasciotomy

Time to FasciotomyExpected OutcomePrognosis
Less than 6 hoursFull recovery expectedExcellent - near-normal function
6-12 hoursVariable - some deficit possibleGood - most regain function with some residual
12-24 hoursSignificant deficit likelyFair - permanent weakness/sensory loss common
Greater than 24 hoursPoor - Volkmann's/amputationPoor - limb salvage may not be possible

Prognostic Factors

Favorable Factors

  • Early diagnosis (less than 6 hours)
  • Prompt complete fasciotomy
  • Single compartment involvement
  • Young, healthy patient
  • Isolated injury
  • Good systemic perfusion

Poor Prognostic Factors

  • Delayed diagnosis (greater than 12 hours)
  • Incomplete fasciotomy
  • Multiple compartment involvement
  • Associated vascular injury
  • Polytrauma/hypotension
  • Significant rhabdomyolysis
  • Deep posterior compartment involvement

Long-term Outcomes

After timely fasciotomy:

  • 80-90% achieve satisfactory functional outcome
  • Chronic pain in 10-15%
  • Sensory disturbance in 15-20%
  • Motor weakness in 10-15%
  • Cosmetic concerns from scars in 20-30%

After delayed fasciotomy (greater than 12 hours):

  • 50% or more have significant functional limitation
  • High rate of chronic pain
  • Volkmann's contracture in 10-30%
  • Amputation rate increases significantly

Evidence Base

McQueen et al. (1996) - Continuous Pressure Monitoring

III
McQueen MM, Court-Brown CM (1996)
Key Findings:
  • Continuous pressure monitoring in 116 tibial fractures.
  • Delta P less than 30mmHg was the optimal threshold for fasciotomy indication.
  • Absolute pressure greater than 30mmHg or greater than 45mmHg led to unnecessary fasciotomies.
Clinical Implication: Use Delta P (DBP - Compartment Pressure) rather than absolute pressure. Threshold is 30mmHg.
Source: JBJS Br

Whitesides et al. (1975) - Tissue Perfusion

III
Whitesides TE, Haney TC, Morimoto K, Harada H (1975)
Key Findings:
  • Tissue pressure measurements as a determinant for the need of fasciotomy.
  • Perfusion pressure = DBP - Intracompartmental Pressure.
  • Recommended fasciotomy when tissue pressure rose to within 10-30 mmHg of DBP.
Clinical Implication: Established the concept of perfusion pressure (Delta P) as the critical determinant of tissue viability.
Source: Clin Orthop Relat Res

Ulmer (2002) - Clinical Findings Predictive Value

III
Ulmer T (2002)
Key Findings:
  • Sens (13-19%) and PPV (11-15%) of clinical signs are POOR.
  • Possibility of ACS increases with number of signs present.
  • Pain on passive stretch is the most sensitive clinical finding.
Clinical Implication: Do not rely on a single sign. A high index of suspicion is required.
Source: J Orthop Trauma

Garfin et al. (1981) - Cast Splitting

III
Garfin SR, Mubarak SJ, Evans KL, Hargens AR, Akeson WH (1981)
Key Findings:
  • Splitting cast alone reduces pressure by 30%.
  • Splitting cast AND padding reduces pressure by 50-85%.
  • Spreading the cast alone is insufficient.
Clinical Implication: You must split the cast and the padding down to skin to effectively reduce pressure.
Source: J Bone Joint Surg Am

Bhattacharyya & Vrahas (2004) - Medicolegal Aspects

III
Bhattacharyya T, Vrahas MS (2004)
Key Findings:
  • Average medicolegal settlement for missed ACS was $1.1 million (in 2004).
  • Delay in fasciotomy greater than 8 hours resulted in significantly worse outcomes.
  • Poor documentation was a major liability factor.
Clinical Implication: Early diagnosis and documentation of serial exams/pressures is critical for both patient outcome and defensive practice.
Source: J Bone Joint Surg Am

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOCritical

EXAMINER

"A 25-year-old male has a tibial shaft fracture from a motorcycle accident. Six hours post-nailing, the nurse calls you because he's requiring increasing morphine and complaining of severe leg pain."

EXCEPTIONAL ANSWER

My immediate approach:

1. History (at bedside within minutes):

  • Character of pain: Is it constant, severe, worsening despite analgesia?
  • Location: Is it in the calf/leg beyond the fracture site?
  • Associated symptoms: Numbness, tingling, weakness?
  • Compare to earlier post-op pain level

2. Immediate actions before examination:

  • Remove ALL circumferential dressings - split any cast to skin
  • Position limb at heart level

3. Examination:

  • Palpate all four compartments - are they tense and woody?
  • Pain on passive stretch - plantarflex foot (anterior), dorsiflex (posterior)
  • Sensory testing - first web space (deep peroneal), dorsum of foot (superficial peroneal)
  • Motor testing - EHL, tibialis anterior, toe flexion
  • Pulses - but I recognize these are usually present in compartment syndrome

4. Decision:

  • If clinical features are convincing (pain out of proportion, passive stretch pain, tense compartments) - proceed DIRECTLY to four-compartment fasciotomy
  • If equivocal - measure compartment pressures in all four compartments
  • Calculate Delta P = diastolic BP minus compartment pressure
  • Delta P less than 30mmHg = indication for fasciotomy

5. Consent and theatre:

  • Explain urgency and risk of permanent damage if delayed
  • Consent for fasciotomy, possible muscle debridement, wound left open, possible skin graft, acknowledge rare risk of amputation
  • Theatre should be available within 30-60 minutes maximum
KEY POINTS TO SCORE
Pain out of proportion to injury is cardinal symptom
Passive stretch pain most sensitive early sign
Remove ALL circumferential dressings immediately
Clinical diagnosis - don't wait for pressure measurements if obvious
Delta P less than 30mmHg is surgical threshold
COMMON TRAPS
✗Waiting for pulses to disappear - late and unreliable sign
✗Blaming pain on fracture without examining compartments
✗Not splitting dressings to skin before assessment
✗Over-reliance on pressure measurements when clinical signs clear
LIKELY FOLLOW-UPS
"What is your Delta P threshold for fasciotomy?"
"How do you consent this patient?"
"What if this patient had regional anaesthesia?"
VIVA SCENARIOStandard

EXAMINER

"You're performing a fasciotomy for compartment syndrome."

EXCEPTIONAL ANSWER

Two-incision, four-compartment fasciotomy technique:

Patient positioning: Supine with bump under ipsilateral hip, entire leg prepped and draped.

Lateral incision (releases anterior and lateral compartments):

  • Incision 2cm anterior to fibula, from fibular head to lateral malleolus
  • Full-length skin incision - don't be conservative
  • Identify intermuscular septum between anterior and lateral compartments
  • Incise lateral compartment fascia longitudinally
  • Identify and protect superficial peroneal nerve in distal third
  • Pass anterior to septum, incise anterior compartment fascia
  • Confirm muscles are bulging and viable (pink, contractile)

Medial incision (releases superficial and deep posterior compartments):

  • Incision 2cm posterior to medial tibial border, from tibial tuberosity to medial malleolus
  • Identify and preserve great saphenous vein and saphenous nerve
  • Incise superficial posterior compartment fascia over gastrocnemius
  • For deep posterior: detach soleus from its tibial origin
  • This exposes the fascia of deep posterior compartment
  • Incise deep posterior fascia, protecting posterior tibial neurovascular bundle

Completion:

  • Assess all muscle for viability - debride any necrotic tissue
  • Thorough washout
  • Leave wounds OPEN - do not close
  • Apply VAC dressing or moist gauze with vessel loop approximation
  • Plan return to theatre at 24-48 hours for second look
  • Delayed primary closure or STSG at 3-5 days
KEY POINTS TO SCORE
Two-incision technique releases all four compartments
Lateral incision 2cm anterior to fibula for anterior and lateral
Medial incision 2cm posterior to tibial border for superficial and deep posterior
Full-length incisions - don't be conservative
Leave wounds OPEN - never close primarily
COMMON TRAPS
✗Single incision technique leaving compartments unreleased
✗Too short incisions - inadequate fascial release
✗Attempting primary closure - guaranteed failure
✗Missing the deep posterior compartment
LIKELY FOLLOW-UPS
"What is your plan for wound closure?"
"When would you consider negative pressure dressings?"
"How do you manage the open fasciotomy wound?"
VIVA SCENARIOCritical

EXAMINER

"A patient presents 24 hours after a tibial fracture with an obviously dead limb - no pulses, fixed claw toes, insensate. The registrar asks whether to do a fasciotomy."

EXCEPTIONAL ANSWER

This is a critically important clinical and ethical situation:

Key considerations:

  • Time elapsed: At 24 hours, irreversible necrosis has almost certainly occurred. The 6-8 hour window is long passed.
  • Clinical findings: Fixed claw deformity, no pulses, complete sensory loss suggest non-viable tissue.
  • Risk of fasciotomy in non-viable tissue: Reperfusion of necrotic muscle releases massive amounts of potassium, myoglobin, and inflammatory mediators causing life-threatening hyperkalemia, acute renal failure from myoglobinuria, systemic inflammatory response, and potential cardiac arrest.

My recommendation:

  • Fasciotomy is NOT indicated for established necrosis at 24+ hours
  • Instead, the patient needs honest discussion about likely amputation
  • Obtain urgent vascular surgery opinion
  • Assess for systemic effects (CK, K+, renal function)
  • Supportive care for rhabdomyolysis if present
  • Early amputation may be life-saving if systemic toxicity is developing

If uncertain about viability:

  • Angiography may help assess vascular status
  • If any question of salvageability, take to theatre for exploration under controlled conditions
  • Be prepared for immediate amputation if limb is non-viable
  • Have ICU available for post-operative care

Documentation: Meticulously document the clinical findings, timing, discussions with patient and family, and rationale for management decisions.

KEY POINTS TO SCORE
At 24 hours, irreversible necrosis has occurred - 6-8 hour window passed
Fasciotomy in necrotic tissue causes reperfusion injury
Risk of life-threatening hyperkalemia and renal failure
Discussion about likely amputation is needed
Early amputation may be life-saving
COMMON TRAPS
✗Performing fasciotomy on dead tissue - can kill the patient
✗Not recognizing signs of established necrosis
✗Delaying difficult conversation about amputation
✗Not checking for systemic effects (CK, K+, renal function)
LIKELY FOLLOW-UPS
"What is reperfusion injury?"
"How would you counsel this patient?"
"When would you involve vascular surgery?"
VIVA SCENARIOStandard

EXAMINER

"You're discussing compartment syndrome risk with a junior registrar."

EXCEPTIONAL ANSWER

Compartment syndrome is one of the most litigated conditions in orthopaedics.

Key medicolegal issues:

  • Missed diagnosis: Most common allegation - failure to recognize or delayed diagnosis
  • Inadequate monitoring: Failure to implement appropriate post-operative surveillance
  • Documentation gaps: Poor documentation of neurovascular exams
  • Communication failures: Not communicating with nursing staff about warning signs

Protection strategies:

  • Document baseline: Record detailed neurovascular status at presentation
  • Time-stamp everything: Shows vigilant monitoring
  • Clear clinical findings: Document pain quality, passive stretch response, compartment tension
  • Record interventions: Cast splitting, elevation, pressure measurements with actual values
  • Communication: Document discussions with patient and family about risks
  • Clear indication: If proceeding to surgery, document why clearly
  • Comprehensive consent: Include amputation as possible outcome if delayed presentation
  • Nursing communication: Written instructions on monitoring protocol and escalation triggers

Red flags that increase liability:

  • Regional anesthesia masking pain (document if used)
  • Obtunded patient without pressure monitoring
  • Gaps in neurovascular documentation
  • Delayed response to nursing concerns
KEY POINTS TO SCORE
Compartment syndrome is one of most litigated conditions in orthopaedics
Missed diagnosis is the most common allegation
Documentation of serial neurovascular exams is critical
Clear nursing communication protocols for escalation
Consent must include amputation as possible outcome
COMMON TRAPS
✗Inadequate documentation of neurovascular status
✗Not communicating monitoring protocol to nursing staff
✗Gaps in serial examination records
✗Regional anaesthesia without pressure monitoring protocol
LIKELY FOLLOW-UPS
"How often should neurovascular observations be documented?"
"What specific instructions do you give nursing staff?"
"How do you document clinical decision-making?"

MCQ Practice Points

Key Numbers for MCQs

  • 6-8 hours: Window before irreversible necrosis
  • Delta P less than 30mmHg: Threshold for fasciotomy
  • 45 mmHg absolute: Universal indication for surgery
  • 2-9%: Incidence with tibial fractures
  • 4: Number of leg compartments
  • 2: Number of incisions needed
  • 30-65%: Pressure reduction with cast splitting
  • 3-5 days: Delayed closure timing
  • 10:1: Male:female ratio
  • 36%: Missed in polytrauma patients

Classic MCQ Traps

  • Pulses present - doesn't exclude compartment syndrome
  • Pain is the earliest sign - not paralysis or pulselessness
  • All 4 compartments - must release all, not just anterior
  • Delta P not absolute pressure - use perfusion-based threshold
  • Don't close wounds - leave open for 3-5 days
  • Passive stretch - most sensitive clinical test
  • Anterior compartment - most commonly affected
  • Deep peroneal nerve - first web space sensation

Pressure Threshold

Q: What is the Delta P threshold for fasciotomy in compartment syndrome?

A: Delta P less than 30mmHg (diastolic BP minus compartment pressure). This is more reliable than absolute thresholds (30-40mmHg) as it accounts for patient's perfusion pressure.

Early vs Late Signs

Q: What are the early vs late clinical features of compartment syndrome?

A: Early (6 Ps in order): Pain out of proportion, Pressure (tense compartments), Pain with passive stretch, Paresthesia. Late (irreversible): Paralysis, Pulselessness. The key is that pulses are preserved until very late - don't wait for pulselessness!

Fasciotomy Technique

Q: How many incisions are required for complete four-compartment fasciotomy of the leg?

A: Two incisions: (1) Lateral incision 2cm anterior to fibula for anterior and lateral compartments; (2) Medial incision 2cm posterior to tibial border for superficial and deep posterior compartments. Wounds are left open with delayed closure at 3-5 days.

Deep Posterior Access

Q: How do you access the deep posterior compartment during medial fasciotomy?

A: Detach the soleus muscle origin from the posterior tibial border. This exposes the fascia of the deep posterior compartment, which contains tibialis posterior, FDL, FHL, and the posterior tibial neurovascular bundle.

Nerve Assessment

Q: Which nerve territories should be tested to assess compartment involvement?

A: First web space (deep peroneal nerve - anterior compartment), dorsum of foot (superficial peroneal nerve - lateral compartment), plantar foot (tibial nerve - deep posterior compartment), and lateral foot (sural nerve - superficial posterior).

Australian Context

Australian Guidelines and Practice

Australian Epidemiology

Australian-specific data:

  • Higher incidence in rural/remote areas due to:
    • Farm machinery injuries
    • Motorbike accidents on unsealed roads
    • Prolonged transport times
  • Indigenous Australians may present later
  • Mining industry injuries significant contributor

Transfer considerations:

  • Regional hospitals may need to perform fasciotomy before transfer
  • Cannot wait for metropolitan referral if greater than 6 hours

Medicolegal in Australia

Australian context:

  • High litigation area in orthopaedics
  • Civil Liability Acts vary by state
  • Open disclosure requirements (AHPRA)
  • Mandatory reporting if adverse outcome

Documentation standards:

  • Follow RACS clinical care standards
  • Time-stamped entries essential
  • Nursing communication in writing

PBS and Relevant Medications

Medications commonly used:

  • Analgesia: Morphine, fentanyl (PBS listed)
  • Hyperkalemia management: Calcium gluconate, insulin, salbutamol
  • Fluids: Normal saline, Hartmann's (hospital supplies)
  • Thromboprophylaxis: Enoxaparin (PBS authority for trauma)

eTG Recommendations

Per Therapeutic Guidelines (Antibiotic):

  • Fasciotomy wounds managed with regular washout
  • Prophylactic antibiotics for open wounds
  • Cefazolin 2g IV (or clindamycin if penicillin allergy)
  • Consider broader coverage if significant contamination

RACS and AOA Standards

Royal Australasian College of Surgeons guidance:

  • Compartment syndrome recognized as time-critical condition
  • Should be included in surgical safety checklists
  • Mandatory component of orthopaedic training curriculum
  • Regular audit of missed compartment syndromes recommended

Australian Orthopaedic Association:

  • Emphasis on early recognition protocols
  • Shared decision-making with patients
  • Clear documentation standards
  • Post-operative monitoring protocols essential

Acute Compartment Syndrome - Exam Day Essentials

High-Yield Exam Summary

Quick Stats
Reading Time132 min
Related Topics

Rhabdomyolysis

Volkmann's Ischemic Contracture

Fracture Healing

Acetabular Fractures