Two-incision four-compartment release for acute compartment syndrome | advanced
Surgical Imaging
Location: The superficial peroneal (fibular) nerve exits the crural fascia 8-12 cm proximal to the lateral malleolus, running in the intermuscular septum between the anterior and lateral compartments in the distal leg.
Risk: Division during the distal lateral incision causes numbness on the dorsum of the foot and a painful neuroma. Identify the nerve under direct vision before completing the distal fascial release.
Location: The great saphenous vein and saphenous nerve run along the posteromedial border of the tibia in the subcutaneous plane.
Risk: Injury during the medial incision causes numbness along the medial foot and a painful neuroma. The incision should be placed 1-2 cm posterior to the posteromedial tibial border to avoid these structures.
Location: The posterior tibial artery, veins and tibial nerve lie between the superficial and deep posterior compartments, running along the posterior surface of the tibia.
Risk: The bundle is vulnerable during deep posterior compartment release if the fascia is divided too far posteriorly. Keep the blade or scissors directed toward the tibia and away from the bundle.
The trap: Incomplete release of the deep posterior compartment is the most frequent technical failure and leads to persistent or recurrent compartment syndrome.
The fix: The medial incision must extend the full length of the leg. The deep posterior fascia lies immediately behind the tibia; confirm release by passing a finger or instrument along its entire length.
The trap: Pallor, pulselessness, paraesthesia and paralysis are late, unreliable signs that indicate muscle necrosis has already begun. Waiting for these signs delays fasciotomy and worsens outcome.
The fix: Operate on the basis of pain out of proportion, pain on passive stretch, and tense swelling. Compartment pressure monitoring is only an adjunct when the diagnosis is uncertain.
The rule: A measured pressure within 30 mmHg of diastolic blood pressure (delta P less than 30 mmHg) is the accepted threshold for fasciotomy in equivocal cases.
Clinical note: Absolute pressures greater than 30 mmHg are sometimes quoted but are less reliable because they do not account for systemic hypotension. Always interpret pressures in the context of the patient's blood pressure.
A.L.S.D.COMPARTMENTS — Four Leg Compartments and Their Contents
P.A.S.T.DIAGNOSIS — Clinical Features of Acute Compartment Syndrome
L.A.T.E.R.A.L. + M.E.D.I.A.L.TECHNIQUE — Two-Incision Four-Compartment Release
Surgical Indications
Absolute Indications
- Clinical diagnosis of acute compartment syndrome (pain out of proportion, pain on passive stretch, tense swelling)
- Delta pressure (diastolic blood pressure minus compartment pressure) less than 30 mmHg when clinical assessment is equivocal
- Compartment syndrome secondary to reperfusion injury after vascular repair or prolonged tourniquet time
- Crush injury with prolonged compression and evolving compartment syndrome
Relative Indications
- Prophylactic fasciotomy in high-risk situations (prolonged ischaemia greater than 4-6 hours, massive transfusion, severe swelling)
- Equivocal clinical picture in an obtunded or intubated patient with elevated compartment pressures
- Suspected missed compartment syndrome with ongoing muscle necrosis
Contraindications
Absolute:
- Established muscle necrosis with systemic sepsis where amputation is more appropriate
- Patient unfit for any surgical intervention (rare)
Relative:
- Very distal leg injuries where fasciotomy wounds would compromise flap or graft coverage
- Paediatric patients — lower threshold for compartment pressure monitoring due to difficulty in clinical assessment
Evidence for Timing and Technique
Timing of Fasciotomy
- Irreversible muscle damage begins after 4-6 hours of ischaemia
- Best functional outcomes when fasciotomy is performed within 6 hours of symptom onset
- Delayed fasciotomy (greater than 12 hours) is associated with higher rates of infection, amputation and permanent disability
- Even late fasciotomy may be indicated if viable muscle remains, but the risk-benefit ratio changes
Two-Incision versus One-Incision Technique
- The two-incision technique (lateral plus medial) is the standard of care and reliably decompresses all four compartments
- Single-incision techniques have been described but carry higher risk of incomplete deep posterior release
- Endoscopic or limited-incision techniques are not recommended in the acute setting
Compartment Pressure Thresholds and Outcomes
Key Evidence
Acute compartment syndrome of the leg: the importance of early diagnosis and fasciotomy
Compartmental pressure measurements: an experimental investigation
Two-incision versus one-incision fasciotomy for acute compartment syndrome of the leg
Complications of fasciotomy for compartment syndrome of the leg
Missed compartment syndrome after tibial fractures: incidence and outcomes
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 32-year-old man sustains a closed tibial shaft fracture in a motor vehicle collision. Six hours after injury he develops severe leg pain requiring increasing analgesia. The leg is swollen and tense. Pain on passive stretch of the anterior compartment is 8/10. How do you manage this patient?”
“You are performing a two-incision leg fasciotomy. After releasing the lateral compartment you notice a nerve exiting the fascia 10 cm proximal to the lateral malleolus. What is this structure and how do you proceed?”
“A 45-year-old man underwent leg fasciotomy 18 hours after a crush injury. At second-look debridement the entire anterior compartment is necrotic. What are the functional consequences and how do you counsel the patient?”