If a cancer spreads to the bones it can lead to weakness in the bone. Sometimes the weakness will mean that the bone breaks, without any obvious cause, such as a fall or a blow.

In various parts of the body, such as the hands, arms, legs, feet and buttocks, the muscles are held together by a tough layer of fibrous tissue, called the fascia. This fascia binds the groups of muscles in these areas into compartments. The fascia cannot stretch. So if there is swelling within a compartment it leads to pressure on the blood vessels, nerves and muscles in that compartment, which may damage them. This is called compartment syndrome.

Compartment syndrome can be either acute (coming on suddenly) or chronic (coming on more gradually). Chronic compartment syndrome is a condition which some athletes develop as a result of extreme exercise during training.

The commonest cause of acute compartment syndrome is bleeding following a break in a bone. The bleeding causes swelling within a muscle compartment, and increases pressure on the tissues in that compartment.

The main symptom of compartment syndrome is severe pain a few hours after the break. If it isn’t treated quickly it may lead to muscle weakness, numbness in the affected limb, and whiteness of the surrounding skin.

The usual treatment for compartment syndrome is an operation to relieve the pressure.