Fasciotomy
Formal Definition
A surgical incision through the fascia to relieve elevated pressure within a muscle compartment; the definitive treatment for compartment syndrome; performed urgently to prevent ischemic necrosis of muscle and nerve, which becomes irreversible within 6-8 hours of elevated compartment pressure exceeding capillary perfusion pressure.
How It's Used on the Ward
"They need a fasciotomy" — the emergency procedure where you cut open the fascia to decompress a compartment before the muscle dies.
Example
""Motorcyclist with tibial fracture, 3-hour delay to OR: now has calf pain out of proportion to injury, tense calf on palpation, paresthesias in foot, pain with passive toe dorsiflexion — classic compartment syndrome. Compartment pressure 42 mmHg, delta P = 33 mmHg (threshold less than 30). Emergency 4-compartment fasciotomy of the leg.""
Clinical Context
Compartment syndrome diagnosis: clinical (pain out of proportion, pressure with palpation, pain with passive stretch, paresthesias, pallor — the 5 Ps) supported by compartment pressure measurement. Delta P = diastolic BP minus compartment pressure; less than 30 mmHg is the threshold for fasciotomy. 6-hour window: compartment pressure >30-40 mmHg for >6 hours causes irreversible ischemia. Most common locations: leg (4 compartments), forearm (3 compartments), thigh, hand, foot. After fasciotomy: wounds left open for 48-72 hours, then reassessed for delayed primary closure or skin graft.