Compartment syndrome happens when pressure in the muscles builds to dangerous levels. Think of a shaken can of soda. This decreases blood flow to the affected area, which prevents nutrients and oxygen carried in the blood from reaching nerve and muscle cells. It is very painful and usually occurs in the front of the calf. It can also occur in other compartments of the leg, as well as in the arms, hands, and feet.
How exactly does this happen?
Groups of muscles, nerves, and blood vessels covered by a tough membrane (called a fascia) are called compartments. The role of the fascia, which does not stretch or expand easily, is to keep all tissues in place. Because the fascia doesn’t stretch easily, any swelling or bleeding in a compartment puts pressure on the capillaries, nerves, and muscles inside the compartment.
This can decrease the amount of nutrient and oxygen-rich blood reaching the cells and nerves. Without a steady supply of blood, cells can be damaged.
Two kinds of compartment syndrome
There are two types of compartment syndrome: acute and chronic. Acute compartment syndrome tends to be caused by a severe injury, such as a car accident or a broken bone. It is a medical emergency, and without treatment can lead to permanent muscle damage. People who think they have compartment syndrome should go to the emergency room.
Chronic compartment syndrome is not a medical emergency. Also known as exertional compartment syndrome, it is usually caused by athletic exertion.
Causes of acute compartment syndrome
One possible cause of acute compartment syndrome is when blood flow is restored after blocked circulation. This may happen after a surgeon repairs a damaged blood vessel that has been blocked for several hours. Lying too long in the same position can also block blood vessels. Other possible causes include a fracture, crush injuries, anabolic steroid use, casts or bandages that are too tight, or burns.
Causes of chronic compartment syndrome
This type of compartment syndrome usually occurs during or shortly after exercising. Repetitive motion activities, such as running, cycling, swimming and elliptical training are more likely to cause chronic compartment syndrome.
Symptoms to watch for
Those with acute compartment syndrome may have the following signs and symptoms, listed as the five “P”s:
- Pain: the most common sign that people describe as being extreme and out of proportion to the injury. It is persistent, progressive, and does not stop. It is made worse by touch, pressure, elevation, and stretching.
- Passive stretch: muscles lacking in blood are very sensitive to stretching, so extending the affected limb leads to extreme pain.
- Paresthesia: this is a weird sensation, such as tingling or pricking, sometimes described as pins and needles.
- Pallor: the affected limbs may be a pale or dusky color because of the lack of blood.
- Pulse: there may be weak or no pulse from the affected compartment.
Chronic compartment syndrome is characterized by pain, cramping and swelling during exercise and usually subsides when the activity stops. It tends to happen in the leg, and the symptoms may include numbness, difficulty moving the foot, and visible muscle bulging.
When to call the doctor
People should see a doctor at the first sign of:
- Pain or swelling and tingling or numbness in the leg or foot
- Weakness of the lower leg, ankle, or foot
- Warmth in the affected area
- Foot drop (difficulty lifting the front part of the foot or toes)
- Pain when flexing or pointing the big toe
In diagnosis of acute compartment syndrome, a doctor will measure the compartment pressure and offer treatment. To diagnose chronic compartment syndrome, other conditions must be ruled out first.
A doctor may examine an individual for tendonitis or give them an X-ray to make sure the bone is not fractured. The pressures in the compartment may be measured before and after exercise and compared.
Athletes with chronic compartment syndrome usually experience pain and tightness 20-30 minutes after exercise.
If compartment syndrome is suspected, patients should be directed to the emergency room. The only option to treat acute compartment syndrome is surgery. The procedure, called a fasciotomy, involves a surgeon cutting open the skin and the fascia to relieve the pressure.
Options to treat chronic compartment syndrome include physical therapy, shoe inserts, and anti-inflammatory medications. People may also be advised to avoid the activity causing the problem.
Surgery is also an option if all other treatments have failed. Here, a doctor makes a cut in the fascia to give the muscles room to swell. If surgery is undertaken, some people may need a course of physical therapy to help with the recovery process. This may help to restore a full range of motion and muscle strength.
In acute compartment syndrome, the pressure needs to be relieved quickly. If it is not, cells may become permanently damaged or even die.
Early diagnosis of compartment syndrome is vital to avoid long-term disability. Quick treatment can make sure the blood supply is restored to the affected area before any long-term damage occurs.
This is not the case in chronic compartment syndrome, which is usually resolved by stopping the exercise causing the problem. It is not usually dangerous.