• Clinical science

Compartment syndrome

Abstract

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 which 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

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

  • Acute compartment syndrome: predominantly trauma-induced; a surgical emergency!
  • Chronic compartment syndrome: also known as exertional compartment syndrome; usually not a medical emergency

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

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!

Chronic compartment syndrome

  • Pain exacerbated by exercise and relieved with rest[2]

Arterial pulse is usually still palpable; pulselessness is a sign of very severe compartment syndrome!
References:[3][4]

Subtypes and variants

Anterior compartment syndrome of the lower leg

  • Most common type of acute compartment syndrome
  • Clinical presentation
    • Motor: toe dorsiflexion weakness
    • Sensory: loss of sensation/paresthesia in the nerve territory
  • Treatment: surgery (dermato-fasciotomy)

Abdominal compartment syndrome

  • Etiology:
  • Pathophysiology: ↑ intra-abdominal pressure organ dysfunction
    • Cardiovascular: ↓ cardiac output
    • Renal: ↓ glomerular perfusion and urine output
    • Gastrointestinal: intestinal hypoperfusion and ischemia
    • Pulmonary: ↓ pulmonary volume; ↑ peak airway pressures
    • Cerebral: ↑ intracranial pressure
  • Clinical features: may develop within hours or over days
    • Critically ill patient
    • Cardiovascular: signs of increased central venous pressure (e.g., distended jugular veins), hypotension, tachycardia
    • Renal: oliguria; , progressive renal failure
    • Gastrointestinal: tight, distended abdomen, nausea, vomiting
    • Pulmonary: tachypnea, wheezing
    • Cerebral: signs of increased intracranial pressure
  • Diagnostics:
    • Best initial test: indirect measurement of intra-abdominal pressure
    • CT imaging: increased abdominal diameter, compression of the inferior vena cava, intestinal wall thickening, bilateral inguinal herniation
    • Abdominal x-ray: not useful for detecting abdominal compartment syndrome
  • Treatment
    • Abdominal decompression
      1. Laparotomy for decompression
      2. Temporary abdominal closure (e.g., patch technique, vacuum-assisted closure)
      3. Definitive closure
    • Supportive management

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 (e.g., creatine phosphokinase (CPK), renal function tests)
  • Imaging
    • X-rays
    • Doppler ultrasound
    • Angiography
  • 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
  • Doppler ultrasound (best initial test)
  • Digital subtraction angiography (confirmatory test)
  • 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!
    • Also indicated if conservative treatment fails in chronic compartment syndrome.
    • Fasciotomy (tissue and fascia incisions): relieves the pressure, thus restoring perfusion
    • Fibulectomy: if fasciotomy fails; to decompress all compartments of the lower leg
    • Escharotomy: In the case of circumferential compression by a burn eschar
    • Last resort: amputation
  • Supportive treatment
    • Indicated as perioperative care
    • May be considered as sole treatment for chronic compartment syndrome
    • Eliminate any underlying cause, e.g., remove restrictive cast/dressing
    • Cooling and positioning of the limb at heart level to relieve pressure
    • Close monitoring with frequent examination of the affected limb; if in doubt, proceed with early surgical treatment!
    • 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

  • Muscle and soft tissue necrosis with a higher risk of infection
  • Nerve lesions (esp. the tibial nerve and peroneal nerve) with sensory and motor deficits or paralysis
  • Fracture malalignment
  • Rhabdomyolysis with potential Crush syndrome
  • Muscle contractures
  • Rebound compartment syndrome
    • Occurs 6–12 hours after surgical reperfusion
    • Etiology: increased capillary permeability and edema, often due to insufficient fasciotomy incisions
  • Volkmann contracture
    • Permanent flexion contracture due to shortening of forearm muscles (“claw-like deformity” of the hand, fingers, and wrist)
    • Direct complication of insufficient treatment or undiagnosed compartment syndrome

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]