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Compartment Syndrome

Compartment syndrome is a painful condition that occurs when pressure within the muscles builds to dangerous levels. This pressure can decrease blood flow, which prevents nourishment and oxygen from reaching nerve and muscle cells. though this condition can occur in many areas of the body, this article will focus on compartment syndrome in the lower leg.

Compartment syndrome can be either acute (having severe symptoms for a short period of time) or chronic (long-lasting).

  • Acute compartment syndrome is a medical emergency. It is usually caused by a severe injury and is extremely painful. Without treatment, it can lead to permanent muscle damage.
  • Chronic compartment syndrome, also known as exertional compartment syndrome, is usually not a medical emergency. It is most often caused by athletic exertion and is reversible with rest.

Anatomy

Compartments are groupings of muscles, nerves, and blood vessels in your arms and legs. Covering these tissues is a tough membrane called a fascia. The role of the fascia is to keep the tissues in place, and, therefore, the fascia does not stretch or expand easily.

Major muscle compartments in lower leg
The area between the knee and ankle has four major muscle compartments: anterior, lateral, superficial posterior, deep posterior.
Figure A: Reproduced and adapted with permission from Gruel CR: Lower Leg, in Sullivan JA, Anderson SJ (eds): Care of the Young Athlete. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000. Figure B: Reproduced and adapted from The Body Almanac. © American Academy of Orthopaedic Surgeons, 2003.

Description

Compartment syndrome develops when swelling or bleeding occurs within a compartment. Because the fascia does not stretch, this can cause increased pressure on the capillaries, nerves, and muscles in the compartment. Blood flow to muscle and nerve cells is disrupted. Without a steady supply of oxygen and nutrients, nerve and muscle cells can be damaged.

In acute compartment syndrome, unless the pressure is relieved quickly, permanent disability and tissue death may result. This does not usually happen in chronic (exertional) compartment syndrome.

Compartment syndrome most often occurs in the anterior (front) compartment of the lower leg (calf). It can also occur in other compartments in the leg, including the thigh, as well as in the arms, hands, feet, and buttocks.

Cause

Acute Compartment Syndrome

Acute compartment syndrome usually develops after a severe injury, such as a car accident or a broken bone. Rarely, it develops after a relatively minor injury.

Conditions that may bring on acute compartment syndrome include:

  • A fracture.
  • A badly bruised muscle. This type of injury can occur when a motorcycle falls on the leg of the rider, or a football player is hit in the leg by another player's helmet. It can also happen after overly vigorous exercise that causes muscle tissue to break down (rhabdomyolysis)
  • Reestablished blood flow after blocked circulation. This may occur after a surgeon repairs a damaged blood vessel that has been blocked for several hours. A blood vessel can also be blocked during sleep. Lying for too long in a position that blocks a blood vessel, then moving or waking up can cause this condition. Most healthy people will naturally move when blood flow to a limb is blocked during sleep. The development of compartment syndrome in this manner usually occurs in people whose brain function is impaired. This can happen after severe intoxication with alcohol or other drugs.
  • Crush injuries.
  • Anabolic steroid use. Taking steroids is a possible factor in compartment syndrome.
  • Constricting bandages. Casts and tight bandages may lead to compartment syndrome. If symptoms of compartment syndrome develop, remove or loosen any constricting bandages. If you have a cast, contact your doctor immediately.

Chronic (Exertional) Compartment Syndrome

The pain and swelling of chronic compartment syndrome is caused by exercise. People who participate in activities with repetitive motions, such as running or marching, are more likely to develop chronic compartment syndrome. This is usually relieved by discontinuing the exercise, and is usually not dangerous.

Symptoms

Acute Compartment Syndrome

The classic sign of acute compartment syndrome is severe pain, especially when the muscle within the compartment is stretched.

  • The pain is more intense than what would be expected from the injury itself. Using or stretching the involved muscles increases the pain.
  • There may also be tingling or burning sensations (paresthesia) in the skin.
  • The muscle may feel tight or full.
  • Numbness or paralysis are late signs of compartment syndrome. This usually indicates permanent tissue injury.

Chronic (Exertional) Compartment Syndrome

Chronic compartment syndrome causes pain or cramping during exercise. This pain goes away when activity stops. It most often occurs in the leg.

Symptoms may also include:

  • Numbness
  • Difficulty moving the foot, sometimes with a sense of the foot slapping downward when running
  • Visible muscle bulging

Doctor Examination

Acute Compartment Syndrome

Go to an emergency room immediately if there is concern about acute compartment syndrome. This is a medical emergency. Your doctor will examine you to determine whether you have acute compartment syndrome. They may also measure the compartment pressure in your affected limb.

Chronic (Exertional) Compartment Syndrome

To diagnose chronic compartment syndrome, your doctor must rule out other conditions that could also cause pain in the lower leg. For example, your doctor may press on your tendons to make sure you do not have tendinitis. They may order an X-ray to make sure your shinbone (tibia) does not have a stress fracture.

To confirm chronic compartment syndrome, your doctor will measure the pressures in your compartment before and after exercise. If pressures remain high after exercise, you have chronic compartment syndrome.

Treatment

Acute Compartment Syndrome

Acute compartment syndrome is a surgical emergency. There is no effective nonsurgical treatment.

Your doctor will make an incision and cut open the skin and fascia covering the affected compartment. This procedure is called a fasciotomy.

Sometimes, the swelling is severe enough that the skin incision cannot be closed immediately. The incision is repaired later when swelling subsides. Sometimes a skin graft is used.

Chronic (Exertional) Compartment Syndrome

Nonsurgical treatment. Physical therapy, orthotics (inserts for shoes), and anti-inflammatory medicines may be of limited benefit in relieving symptoms and generally do not allow return to full activity.

  • Your symptoms may subside if you avoid the activity that caused the condition.
  • Cross-training with low-impact activities may be an option.
  • Some athletes have symptoms that are worse on certain surfaces (concrete vs. running track, or artificial turf vs. grass). Symptoms may be relieved by switching surfaces.
  • Changing from heel strike to toe running may modify symptoms depending on the compartments involved.

Surgical treatment. If conservative measures fail, surgery may be an option. Similar to the surgery for acute compartment syndrome, the operation is designed to open the fascia so there is more room for the muscles to swell.

Usually, the skin incision for chronic compartment syndrome is shorter than the incision for acute compartment syndrome. Also, this surgery is typically an elective procedure — not an emergency.

Surgery for chronic exertional compartment syndrome of the leg produces excellent results in the anterior and lateral compartments, and less predictable results when the posterior compartments are involved. An accurate diagnosis is key to achieving a significant benefit from surgery.

To assist doctors in the management of acute compartment syndrome, the American Academy of Orthopaedic Surgeons has conducted research to provide some useful guidelines. These are recommendations only and may not apply to every case. For more information: Acute Compartment Syndrome - Clinical Practice Guideline | American Academy of Orthopaedic Surgeons (aaos.org)

Last Reviewed

May 2022

Contributed and/or Updated by

Jocelyn Ross Witstein, MD, FAAOS

Peer-Reviewed by

Thomas Ward Throckmorton, MD, FAAOS

AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS Find an Orthopaedist program on this website.