Compartments Syndrome: Pathophysiology, Clinical Features, Diagnosis and Treatment

Compartment syndrome is muscle swelling within a fascial compartment resulting in increase intracompartmental pressure and tissue hypoperfusion

Muscle swell because of damage caused by trauma which lead to inflammation process

If left untreated, ischemia and tissue necrosis occur and debridement procedures has to be done and limb amputation maybe needed

Compartment Syndrome Pathophysiology

Muscle and soft tissue damage in arm or leg after trauma give rise to edema or inflammation => this will increase the pressure within one of the fascial compartments => reduced capillary flow => muscle ischemia => further edema => more pressure => more ischemia => after 6 hours necrosis of nerve and muscles within the compartment starts
Nerve capable of regeneration but muscle once infarcted is replaced by fibrous tissue

The earliest feature is severe pain and it maybe the only feature available, patient feel tightness of their limb and it is about to burst
The ischemia mostly occur in capillary level, so pulses may still be felt and the skin is not pale => not reliable for diagnosis
Paralysis (motor dysfunction) and paresthesia (sensory dysfunction) may occur and should be repeatedly checked => not reliable for diagnosis
Pain on passive stretching of the muscles within the affected compartment because Ischemic muscle is highly sensitive to stretch, e.g. active extension of the toes lead to increased pain in the calf
Diagnoses is supported by measuring the intercompartment pressure, split pressure catheter is inserted into the compartment and pressure is measured close to the level of the fracture, differential pressure is the difference between diastolic pressure and compartment pressure, if less than 30 mmHg is indication for immediate compartment decompression
The diagnosis is mainly clinical, pressure calculation is supportive, immediate open fasciotomy is done if there is high clinical suspicion even if the pressure difference more than 30 mmHg

Compartment syndrome is a surgical emergency
The threatened compartment should be decompressed
Casts, bandages and dressings must be removed
The limb should be flat (not elevated) , because elevation decrease blood reaching it thus aggravating muscle ischemia
Monitor differential compartment pressure through pressure catheter, if it falls below 30 mmHg then immediate open fasciotomy is performed
if the differential compartment pressure still higher than 30 and there is strong clinical indicator for compartment syndrome (severe pain, paralysis, paresthesia…), the limb should be examined every 30 minutes interval and if there is no improvement in the clinical signs for 2 hours then open fasciotomy should be done too
Sometimes pressure catheter not available, (most developing countries hospitals don’t have it), so diagnosis is even harder
Muscle die after about 6 hours, so you need to take action quickly
After fasciotomy, the wound should be left open and inspected 2 days later, if there is tissue necrosis then debridement is done and wounds sutured, if the tissues are healthy then sutured directly

Fasciotomy is procedure by which you open the fascia that covers a group of muscles together (compartment) to relieve pressure
Leg compartments; by Henry Vandyke Carter, Public domain, via Wikimedia Commons
Leg compartments; by Henry Vandyke Carter, Public domain, via Wikimedia Commons
The leg is the most common area affected by compartment syndrome
Leg contains four compartments and all has to be opened to relieve the pressure
General anesthesia is used
Here will explain the double incision fasciotomy of the leg, there is another method using single incision fasciotomy of the leg and also there is decompression methods for the forearm, hand, foot …

The posterior superficial and deep compartments are accessed through medial longitudinal incision 3 cm behind the posterior border of the tibia
Avoid injuring saphenous vein and nerve by taking a slow dissecting approach
Make incisions along the length of the posterior superficial and deep compartments to release them

Anterior and lateral compartments are accessed through lateral incision placed halfway between the tibial crest and the line of the fibula
Avoid injuring the superficial peroneal nerve which has a variable course through the leg by using slow dissecting approach
The anterior and lateral compartments are released by opening the fascia and intermuscular septum