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. The compartment includes the muscle tissue, nerves, and blood vessels. Fascia surrounds these structures, similar to the way in which insulation covers wires.

Fascia do not expand. Any swelling in a compartment will lead to increased pressure in that area, which will press on the muscles, blood vessels, and nerves. If this pressure is high enough, blood flow to the compartment will be blocked. This can lead to permanent injury to the muscle and nerves. If the pressure lasts long enough, the muscles may die and the arm or leg will no longer work. It may need to be amputated.

Swelling that leads to compartment syndrome occurs from trauma such as a car accident or crush injury, or surgery. Swelling can also be caused by complex fractures or soft tissue injuries due to trauma.

Long-term (chronic) compartment syndrome can be caused by repetitive activities, such as running. The pressure in a compartment only increases during that activity.

Compartment syndrome is most common in the lower leg and forearm. It can also occur in the hand, foot, thigh, and upper arm.

Compartment syndrome causes severe pain that does not go away when you take pain medicine or raise the affected area. In more severe cases, symptoms may include:

• Decreased sensation
• Numbness and tingling
• Paleness of skin
• Severe pain that gets worse
• Weakness

A physical exam will reveal:

• Pain when the area is squeezed
• Extreme pain when you move the affected area (for example, a person with compartment syndrome in the foot or lower leg will have severe pain when moving the toes up and down)
• Swelling in the area

To confirm the diagnosis, the doctor or nurse may need to directly measure the pressure in the compartment. This is done using a needle attached to a pressure meter, which is placed into the body area. The test must be done during and after an activity that causes pain.

Surgery is needed immediately. Delaying surgery can lead to permanent damage.

Long surgical cuts are made through the muscle tissue to relieve the pressure. The wounds can be left open (covered with a sterile dressing) and closed during a second surgery, usually 48 to 72 hours later.

Skin grafts may be needed to close the wound.

If a cast or bandage is causing the problem, the dressing should be loosened or cut to relieve the pressure.

With prompt diagnosis and treatment, the outlook is excellent that the muscles and nerves inside the compartment will recover. However, the overall outlook is determined by the injury that led to the syndrome.

If the diagnosis is delayed, permanent nerve injury and loss of muscle function can result. This is more common when the injured person is unconscious or heavily sedated and cannot complain of pain. Permanent nerve injury can occur after 12 to 24 hours of compression.

Complications include permanent injury to nerves and muscles that can dramatically impair function. This is called Volkmann's ischemia.

In more severe cases, amputation may be required.

Call your health care provider if you have had an injury and have severe swelling or pain that does not improve with pain medications.

There is probably no way to prevent this condition. Early diagnosis and treatment helps prevent many of the complications.

If you wear a cast, be aware of the risk of swelling. See your health care provider or go to the emergency room if pain under the cast increases, even after you have taken pain medicines and raised the area.