Compartment syndrome is a serious condition that involves increased pressure in a muscle compartment. It can lead to muscle and nerve damage and problems with blood flow.
Causes, incidence, and risk factors
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 limb 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, although it can also occur in the hand, foot, thigh, and upper arm.
The hallmark symptom of compartment syndrome is severe pain that does not go away when you take pain medicine or raise the affected area. In more severe cases, symptoms may include:
Paleness of skin
Severe pain that gets worse
Signs and tests
A physical exam will reveal:
Pain when the compartment is squeezed
Severe pain when you move the affected area (for example, a person with compartment syndrome in the foot or lower leg will experience severe pain when moving the toes up and down)
Swollen and shiny skin
To confirm the diagosis, the health care provider will directly measure the pressure in the compartment. This is done using a needle attached to a pressure meter into the compartment. The needle is inserted into the affected area. Specific pressure measurements will lead to a diagnosis of compartment syndrome.
When the health care provider suspects chronic compartment syndrome, this test must be performed during and after the activity that causes pain.
Surgery is needed. Long surgical cuts are made through the fascia to relieve the pressure. The wounds can be left open (covered with a sterile dressing) and closed during a second surgery, usually 48 - 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 down to relieve the pressure.
With prompt diagnosis and treatment, the outlook is excellent for recovery of the muscles and nerves inside the compartment. However, the overall prognosis will be determined by the injury leading to the syndrome.
Permanent nerve injury and loss of muscle function can result if the diagnosis is delayed. 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 - 24 hours of compression.
Complications include permanent injury to nerves and muscles that can dramatically impair function. (See: Volkmann's ischemia)
In more severe cases, amputation may be required.
Calling your health care provider
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; however, early diagnosis and treatment will help prevent many of the complications.
Persons with casts need to be made aware of the risk of swelling. They should see their health care provider or go to the emergency room if pain under the cast increases despite pain medicines and raising the area.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.