• Compartment syndrome is defined as an elevated intramuscular pressure within a myofascial compartment that impedes blood flow and impairs nerve and muscle function.
• It may be acute or chronic.
• There are currently no radiographic studies available to accurately diagnose acute or chronic compartment syndrome. Post-exercise magnetic resonance imaging (MRI) has been hypothesized to show high signal intensity changes in affected compartments compared with resting MRI, but it is not considered the reference standard.
Acute Compartment Syndrome
• Typically secondary to trauma such as an underlying fracture, crush injury, or contusion
• May also be associated with reperfusion after ischemia and circumferential burns
• Most common locations include lower leg, forearm, thigh, and upper arm
• Most common clinical scenario is a tibia fracture and resultant compartment syndrome of the lower leg
SIGNS AND SYMPTOMS
• Adults (the 5 P’s)
— Pain out of proportion to clinical setting and with passive range of motion of adjacent joints
— Paresthesia in the area supplied by the affected nerve
— Involved compartments are tense to palpation
• Children (the 3 A’s)
— Increase in analgesic needs
• Arterial occlusion
• Deep vein thrombosis
• For an awake, alert patient the diagnosis is clinical based on appropriate clinical history and physical examination findings.
• In the comatose patient or in equivocal cases the compartment pressures can be measured using a compartment pressure monitor or an arterial line setup.
• Resting compartment pressures less than 30 mm Hg are considered normal.
• Delta-P is the difference between diastolic blood pressure and measured compartment pressure. Delta-P < 20 to 30 mm Hg indicates the need for fasciotomy.
• Acute compartment syndrome requires immediate orthopaedic consultation for consideration of emergent fasciotomies of the affected compartments.
• Failure to perform emergent surgery and fasciotomies for acute compartment syndrome leads to irreversible nerve and muscle damage and poor outcomes.
WHEN TO REFER