Region-Specific Compartment Syndrome

Acute compartment syndrome is a time-critical failure of tissue perfusion inside a closed fascial space. The diagnosis is usually clinical, but the practical problem is regional. A leg, forearm, hand, foot, thigh and buttock do not fail in the same way, and they are not decompressed in the same way.

The common teaching phrase is "pain out of proportion". That is useful, but incomplete. A treating surgeon also needs to know which compartment is at risk, which nerve is threatened, which passive movement stretches the involved muscles, when pressure measurement adds value, and whether the planned fasciotomy actually releases the threatened compartment.

High-risk settings include:

• tibial shaft, tibial plateau, distal tibia and high-energy ankle trauma
• forearm fractures, paediatric supracondylar fracture, floating elbow and vascular injury
• hand crush, injection, burn, infection or prolonged compression
• calcaneus fracture, Lisfranc injury, Chopart injury and foot crush
• femoral fracture, thigh contusion, anticoagulation-related bleeding and vascular injury
• gluteal compression after loss of consciousness, prolonged surgery, trauma or vascular procedures

The underlying pathophysiology is the same in every region: swelling, bleeding, external compression or reperfusion raises compartment pressure, venous outflow fails first, capillary perfusion falls, tissue oedema increases, and muscle and nerve ischaemia accelerates. The regional anatomy determines what fails first and how it must be released.

LegForearmHandFootThigh and Gluteal

The leg has four clinically important compartments:

• Anterior: tibialis anterior, extensor hallucis longus, extensor digitorum longus, deep peroneal nerve and anterior tibial vessels.
• Lateral: peroneus longus and brevis with the superficial peroneal nerve.
• Superficial posterior: gastrocnemius, soleus and plantaris.
• Deep posterior: tibialis posterior, flexor hallucis longus, flexor digitorum longus, tibial nerve and posterior tibial vessels.

Anterior compartment syndrome may produce first web space paraesthesia and pain with passive plantarflexion of the ankle or toes. Posterior compartment involvement may produce pain with passive dorsiflexion and tibial nerve symptoms. The deep posterior compartment is a classic missed release.

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The forearm is usually considered as volar, dorsal and mobile-wad compartments. The volar side contains superficial and deep flexors; the median nerve, ulnar nerve and anterior interosseous nerve are clinically important. Pain with passive finger extension is the classic volar stretch sign.

Forearm compartment syndrome can follow distal radius fracture, both-bone forearm fracture, paediatric supracondylar fracture, vascular injury, transradial access complication, burns, tight casts, bleeding disorders or contrast extravasation.

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The hand is different because it is a small-compartment problem. The clinically relevant spaces include thenar, hypothenar, adductor, dorsal interosseous and palmar interosseous compartments. Carpal tunnel or Guyon canal decompression may be needed depending on nerve compression and the injury pattern.

Hand compartment syndrome is commonly caused by crush injury, injection injury, extravasation, infection, burns, prolonged compression and high-energy hand fractures. A swollen hand that is painful between the metacarpals is not just a soft-tissue injury until compartment syndrome has been considered.

Foot compartment anatomy is debated in the literature, with models ranging from several broad spaces to multiple individual compartments. For clinical practice, the important point is not the exact count; it is that the foot can develop compartment syndrome after crush, calcaneal fracture, Lisfranc injury, Chopart injury, high-energy midfoot trauma and vascular compromise.

Clinical signs are less reliable than in the leg. Severe foot pain, tense plantar swelling, pain with toe movement, sensory disturbance and high-risk mechanism should prompt pressure measurement when the diagnosis is uncertain.

The thigh has anterior, medial and posterior compartments. Thigh compartment syndrome is rare, but the size of the muscle mass means that delayed diagnosis can produce major rhabdomyolysis, renal injury, neurological deficit and death.

The gluteal region contains powerful muscle compartments and the sciatic nerve is at risk. Gluteal compartment syndrome is classically associated with prolonged immobilisation after loss of consciousness or substance use, but also occurs after trauma, vascular surgery, pelvic procedures and prolonged operative positioning.

Classification in compartment syndrome is less about named eponyms and more about risk stratification. The useful classifications are clinical:

The examination is structured, repeated and documented. The question is not "does the patient have all six Ps?" The question is "is this region behaving like a threatened closed compartment?"

The differential matters because several conditions mimic compartment syndrome, and missing the real diagnosis in either direction is dangerous: an unnecessary fasciotomy is a large open wound, while a missed compartment syndrome costs the limb.

Compartment syndrome is not diagnosed by X-ray, CT or MRI. Imaging is used to define fractures, dislocations and vascular injury, but it should not delay decompression when clinical ACS is clear.

Algorithm

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Pressure measurement is most useful when:

• the patient is obtunded, ventilated, intoxicated, sedated or unreliable
• pain assessment is difficult because of paediatric age, communication problems or regional anaesthesia
• the examination is equivocal but the injury is high risk
• there is vascular repair, reperfusion, crush injury or prolonged compression
• small compartments of the foot or hand are suspected and clinical signs are subtle

Commonly used thresholds include:

The operative principle is simple: release every involved compartment completely, assess muscle viability and leave the wounds open. The technique varies by region.

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The worst complication is missed or incomplete decompression. After that, morbidity comes from muscle necrosis, nerve injury, wound problems and systemic effects.

Fasciotomy is the start of treatment, not the end. After release, the goals are to confirm decompression, prevent systemic complications, keep viable tissue alive and close the wound safely.

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Immediate care includes:

• leave fasciotomy wounds open
• use non-adherent dressings or negative pressure therapy according to local practice
• repeat neurovascular and compartment examination
• monitor CK, potassium, creatinine, urine output and acidosis in large muscle injuries
• return to theatre around 24 to 48 hours for second look when indicated
• debride clearly non-viable muscle
• close only when swelling allows, using delayed primary closure, gradual approximation or split-skin grafting
• splint safely and involve therapy early, especially for hand and forearm

Outcome depends on time to diagnosis, mechanism, region, completeness of release, muscle viability, nerve injury and wound management. Limb survival is not the same as functional recovery.

Better outcomes are associated with:

• early recognition and decompression
• reliable serial examinations in high-risk patients
• complete release of all involved compartments
• coordinated vascular and orthopaedic management in reperfusion injuries
• early second look and debridement when muscle viability is uncertain
• early oedema control and rehabilitation

Poor prognostic patterns include:

• delayed presentation with neurological deficit
• thigh or gluteal syndrome with very high CK and renal injury
• compartment syndrome after prolonged compression or substance-related immobilisation
• missed foot or hand syndrome leading to chronic pain, stiffness and deformity
• incomplete fasciotomy requiring delayed revision

Controversies and Areas of Uncertainty

Several questions remain genuinely unresolved, and examiners reward candidates who can discuss them without overstating the evidence:

• The exact pressure threshold. Delta pressure under 30 mmHg is the most validated trigger, but the optimal cut-off and duration are debated, and one-time readings overcall the diagnosis. Some advocate continuous monitoring or higher delta thresholds to reduce unnecessary fasciotomy.
• Continuous monitoring versus serial clinical examination. Continuous monitoring helps in unreliable patients but is not universally available and can generate false positives; serial examination remains central where the patient is alert.
• Foot compartment release. The number of foot compartments, whether to decompress, and the surgical approach are all contested; some surgeons favour non-operative management given uncertain functional benefit and high wound morbidity.
• Gluteal compartment syndrome management. Recent evidence suggests neurologically intact patients may be managed medically with close surveillance, whereas those with an established deficit benefit from fasciotomy.
• Emerging diagnostics. Near-infrared spectroscopy, biomarkers and ultrasound elastography are investigational and not yet a substitute for clinical judgement and pressure measurement.

Acute compartment syndrome is a worldwide emergency, and the core principles are consistent across examination systems: early senior review, repeat documented examination, rapid theatre access, multidisciplinary coordination with vascular, plastic, hand and foot-and-ankle and critical-care teams, and local antimicrobial and perioperative protocols for open wounds. Reported incidence is heavily skewed toward young men with tibial diaphyseal fractures (around 2 to 3 percent of tibial shaft fractures, much higher in high-energy or multiply-injured patients).

There is no dedicated international registry for acute compartment syndrome; trauma registries (for example TARN in the UK and the German DGU TraumaRegister) capture it as a complication of fractures and crush injury rather than as a standalone dataset. The validated postfasciotomy classification (Bouklouch and Duckworth) is an emerging tool for standardised outcome reporting and audit.

High- versus limited-resource practice variation: where continuous pressure monitoring and rapid theatre access are available, equivocal cases can be monitored safely; where they are not, the threshold for clinical fasciotomy is appropriately lower, and delayed presentation after prolonged transport or compression is more common. The principle of releasing every threatened compartment completely does not change with resource setting.

Practical documentation should include:

• time of injury and time of first concern
• analgesia escalation and serial examination findings
• passive-stretch findings by region
• sensory and motor status by nerve distribution
• pressure readings if measured, with blood pressure and time recorded
• timing of fasciotomy, compartments released and muscle viability
• plan for second look, renal monitoring, closure and rehabilitation