Compartment syndrome

Compartment syndrome is a painful and potentially serious condition caused by bleeding or swelling within an enclosed bundle of muscles (a muscle 'compartment').

What are 'compartments'?

Each group of muscles in the arms and legs, together with the nearby blood vessels and nerves, is contained in an enclosed space surrounded by layers of tissue called fascia.

Compartment syndrome occurs when pressure within a compartment increases and affects the function of the muscle and tissues.

What are the symptoms of compartment syndrome?

The symptoms depend on whether you have acute compartment syndrome – which happens suddenly, after injury – or chronic compartment syndrome, which comes on gradually.

Acute compartment syndrome 

Acute compartment syndrome causes intense pain, especially when the affected muscle is stretched. You may also have a tingling or burning feeling in the skin, and the muscle may feel tight.

It is a medical emergency because the high pressure inside the compartment can potentially cause permanent muscle and nerve damage.

Acute compartment syndrome usually happens after a fracture or a crush injury but can also be caused by severe bruising of a muscle. In rare cases it can occur without an injury.

Other possible causes include:

• having a plaster cast or tight bandage applied to a limb while the swelling is still happening – the cast or bandage becomes the 'compartment'
• having surgery to repair a damaged or blocked blood vessel, usually after someone has been unconscious for a long time – once blood can flow back into a muscle it could lead to swelling
• burns

Acute compartment syndrome will be diagnosed and treated by hospital doctors, usually when you are in the hospital emergency department after an accident.

Diagnosis is usually based on the symptoms and signs of the condition. However, if you are at high risk of compartment syndrome, or unconscious when you are brought into hospital, a pressure monitoring device may be attached to your affected limbs using needles.

Chronic compartment syndrome

Chronic compartment syndrome causes cramping pain during exercise, mostly in the leg, that eases when the activity is stopped.

You may also have difficulty moving the foot and visible muscle bulging.

It is much less serious than acute compartment syndrome. It comes on gradually, usually after a long period of repetitive-motion exercise, such as running or cycling.

Chronic compartment syndrome will probably be diagnosed by your GP – a diagnosis is made when other causes of muscle pain, such as tendonitis, have been ruled out.

What is happening?

The above symptoms happen because the swelling or bleeding increases the pressure inside the compartment.

When this pressure exceeds the pressure inside the veins, blood cannot flow properly. Oxygen and nutrients cannot get to the muscles and nerves, leading to tissue damage.

If you go on to develop numbness or paralysis, it usually means there is permanent tissue damage.

Which muscles are affected? 

Compartment syndrome usually occurs in the legs, feet, arms or hands, but it can occur wherever there is an enclosed compartment inside the body. The abdomen (tummy) and buttocks are less commonly affected.

When the abdomen is affected, this may cause kidney failure or heart problems. If it happens in the buttocks it can result in damage to the sciatic nerve (which runs down your lower back and legs) and disability.

How is it treated?

Acute compartment syndrome

Acute compartment syndrome must be treated in hospital using a surgical procedure called an emergency fasciotomy.

The doctor will make an incision to cut open your skin and fascia surrounding the muscles, to immediately relieve the pressure inside the muscle compartment and prevent permanent tissue damage. The wound will be closed 48-72 hours later. Occasionally, a skin graft may be required.

Chronic compartment syndrome

Chronic compartment syndrome is usually not dangerous and can sometimes just be relieved by stopping the exercise and choosing low-impact activities instead.

Physiotherapy, shoe inserts and non-steroidal anti-inflammatory medicines may help – speak to your GP about this.

Surgery (see above) will only be considered if your symptoms persist despite the above measures – in which case you will go on a waiting list, as chronic compartment syndrome is not a medical emergency.