What causes compartment syndrome?
Thick layers of tissue called fascia separate groups of muscles in the arms and legs from each other. Inside each layer of fascia is a confined space, called a compartment, that includes the muscle tissue, nerves, and blood vessels. (They are surrounded by the fascia much like wires surrounded by insulation.) Unlike a balloon, fascia do not expand, so any swelling
in a compartment will lead to increasing pressure in that compartment, which will compress the muscles, blood vessels, and nerves. If this pressure is high enough, blood flow to the compartment will be blocked, which can lead to permanent injury to the muscle and nerves. If the pressure lasts long enough, the limb may die and need to be amputated.
Swelling leading to compartment syndrome is associated with high-energy trauma, such as from a car accident or crush injury, or surgery. Compartment syndrome may also occur due to tight bandages or casts; with significant swelling, pressure will build up and can cause compartment syndrome. Chronic compartment syndrome can be caused by repetitive activities like running that increase the pressure in a compartment only during that activity. Compartment syndrome is most common in the lower leg and forearm, although it can also occur in the hand, foot, thigh and upper arm.
Acute CS usually happens when you break a bone with trauma, like being in a car accident or falling off a bike. Caregivers fix your broken leg or arm, but it may continue swelling. Bad swelling causes casts, splints, or bandages to get too tight. CS happens if the swelling and pressure is not stopped. CS can also be caused by bad swelling after surgery, snakebites, with burns, clotting problems, and some medicines. Chronic CS occurs when a muscle is overused and it starts swelling. It happens most often in people who do sports like marathon running or long distance biking. Stopping the activity usually decreases all symptoms. |
