• Clinical science

Compartment syndrome

Summary

Compartment syndrome is a condition in which increased pressure within a muscle compartment (containing nerves and vasculature, enclosed by unyielding fascia) leads to impaired tissue perfusion. It most commonly affects the lower legs, but can also occur in other parts of the extremities or the abdomen. Compartment syndrome may be acute (e.g., after trauma) or chronic (e.g., collectively excessive training in athletes). Acute compartment syndrome is a surgical emergency that initially presents with rapidly progressive pain, paresthesia, and pallor. Pronounced neurological symptoms with motor deficits, absent pulses, and poikilothermia occur later on and indicate irreversible damage. This diagnosis should be suspected in the presence of typical clinical findings and then confirmed via measurement of compartment pressures. Acute compartment syndrome requires early fasciotomy (an incision through the fascia) within six hours of onset to prevent severe ischemic necrosis. Chronic compartment syndrome is also often associated with pain; it can be exacerbated by exercise and relieved by rest, and is usually managed with conservative treatment. The prognosis of compartment syndrome is generally good with early and appropriate management.

Etiology

The etiology of compartment syndrome

External compressing forces

Internal expanding forces

Trauma-related
  • Burn eschars
  • Constrictive bandage/cast

Non-traumatic

  • Incorrect positioning limbs (e.g., immobile patient)

Peripheral circulation is reduced in polytrauma patients with shock. Therefore, increased compartment pressure in polytrauma patients is associated with an early, high risk of muscle ischemia!

References:[1]

Classification

Pathophysiology

External or internal forces as initiating event → increased compartment pressuredecreased tissue perfusion → lower oxygen supply to muscles → irreversible tissue damage to muscles and nerves after 4–6 hours of ischemia

References:[1]

Clinical features

Compartment syndrome may occur in any enclosed muscle compartment inside the body. The most common sites are the lower legs and arms. Less common sites include the feet, hands, thighs, and gluteal region.

Acute compartment syndrome (ACS)

Typically presents with a rapid progression of symptoms.

Early presentation

  • Pain
    • Often out of proportion to the extent of injury
    • Worse with passive stretching or extension of muscles
    • Very tight, wood-like muscles that are extremely tender to touch
  • Paresthesia (e.g., pins and needles)
  • Soft tissue swelling
  • Initially, peripheral circulation and distal pulses are maintained.

Late presentation

  • Muscle weakness to paralysis
  • Absent (or weak) distal pulses
  • Cold peripheries
  • Pallor or cyanosis
  • Worsened pain and swelling

6 P's of acute limb ischemia: Pain, Pallor, Paresthesias, Poikilothermia, Pulselessness, and Paralysis!

Arterial pulse is usually still palpable; pulselessness is a sign of very severe compartment syndrome!

Chronic compartment syndrome

  • Usually affects the lower leg
  • Muscle pain, weakness, and swelling exacerbated by exercise and relieved with rest [2]


References:[3][4]

Subtypes and variants

Anterior compartment syndrome of the lower leg

Abdominal compartment syndrome

References:[3][5]

Diagnostics

Compartment pressure measurement is necessary to confirm the diagnosis. Further laboratory tests are unnecessary but should be performed in trauma-related compartment syndrome to assess for rhabdomyolysis. Imaging may be useful to identify an underlying etiology.

  • Compartment pressures (initial and confirmatory test): measurement of tissue pressure with a manometer and calculation of delta pressures (delta pressure = diastolic - (compartment) tissue pressure)
    • Delta pressure in manifest compartment syndrome: ≤ 30 mm Hg
  • Laboratory tests specific for rhabdomyolysis
  • Imaging
  • Pulse oximetry: not diagnostic but can help identify limb hypoperfusion

References:[1][3]

Differential diagnoses

History Clinical presentation Tests Treatment
Acute compartment syndrome
  • Traumatic or non-traumatic
  • Deep pain out of proportion to the injury
  • 6 P's
  • Delta pressure ≤ 30 mm Hg
  • Surgical and supportive treatment
Deep vein thrombosis
  • Immobility, surgery
  • Pregnancy
  • Clotting disorder
  • Often asymptomatic
  • Nonspecific pain and calf swelling
Acute limb ischemia
  • Acute onset (embolism) or subacute onset (arterial thrombosis)
  • 6 P's
  • Anticoagulation
  • Revascularization (interventional or surgical)
Rhabdomyolysis
  • Myalgia
  • Generalized weakness
  • Darkened urine (red to brown)
  • IV fluid administration

References:[1]

The differential diagnoses listed here are not exhaustive.

Treatment

  • Surgical treatment: required for all cases of acute compartment syndrome!
  • Supportive treatment
    • Indicated as perioperative care
    • Eliminate any underlying cause, e.g., remove restrictive cast/dressing
    • Cooling and positioning of the limb at heart level to relieve pressure
    • Close monitoring
    • Correct any fluid imbalances
    • Supplemental oxygen
    • Analgesia

Elevated positioning may worsen ischemia by reducing blood flow!

Acute compartment syndrome is a surgical emergency and requires an early fasciotomy!

References:[3][6][2]

Complications

References:[3][6][7]

We list the most important complications. The selection is not exhaustive.

Prognosis

The prognosis depends on the amount of time that has elapsed prior to performing the fasciotomy:

  • ≤ 6 h: almost complete recovery
  • 6–12 h: first necroses; normal limb function returns in 68% of cases
  • ≥ 12 h: necroses; normal limb function returns in 8% of cases

References:[8][1]