Compartment syndrome

The arm and leg muscles are divided into groups known as compartments. Each group consists of multiple muscle strands positioned side by side. The muscle compartments are covered by connective tissue (fascia) with little elasticity. Blood vessels and nerves run through and between the neighboring compartments.

With compartment syndrome, fluid accumulates in the muscle tissue within a compartment. This can be caused by a bone fracture, for example to the lower leg or forearm. The fluid retention leads to the tissue swelling, which disrupts the circulation and can damage nerves.

Compartment syndrome often occurs in the legs or forearm. However, the feet, hands, buttocks, abdomen and chest can also be affected. 

If left untreated, compartment syndrome can lead to a restricted blood flow to parts of the muscles, causing them severe damage. However, compartment syndrome can be treated successfully.

The symptoms of compartment syndrome occur gradually. In the case of a bone fracture, for example, they can start within a few hours of the injury and quickly get worse.

Typical symptoms include:

• severe and persistent pain that is described as deep and burning
• sensory disturbances such as tingling or numbness
• swollen, hardened muscles

The connective tissue sheaths that surround muscle compartments are very firm and stretch little. If the muscle tissue within a compartment swells as a result of an injury such as a bone fracture, the pressure rapidly increases. This interrupts the blood flow and leads to a lack of oxygen in the tissue. 

The shin and forearm bones are particularly prone to injury, especially during exercise. Bone fractures are the primary cause of compartment syndrome, accounting for about 75 percent of all incidences. However, bleeding in the muscles can also cause compartments to swell.

In the case of children, compartment syndrome is often caused by bone fractures near the elbow joint or forearm. 

Other causes can include:

• crush injuries, for example as a result of an accident
• burns
• constrictive bandages, splints or plaster casts
• bleeding in the muscles
• vascular diseases and thromboses

Compartment syndrome is most common in people under the age of 35. It is about ten times more common in men than women.

Up to 10 percent of people who break their shin bone develop compartment syndrome. 

If athletes experience leg pain after persistent muscle strain, this is caused by compartment syndrome in about one third of men and women. Runners are particularly susceptible.

If acute compartment syndrome is diagnosed and treated within 6 hours of an injury, the tissue often heals without lasting damage.

If left untreated or only treated at a later stage, muscle tissue and nerves are sometimes severely damaged. The following complications can then occur:

• chronic pain
• shortened muscles
• muscle weakness
• numbness and paralysis
• infections

In rare cases, the arm and leg mobility can be permanently restricted. 

However, serious consequences are also possible, such as:

• the death of muscle tissue (necrosis)
• the breakdown of muscles (rhabdomyolysis) with subsequent acute kidney failure

As these consequences can be life-threatening, it can sometimes be necessary to amputate the affected limbs.

If there is a risk of compartment syndrome after an injury, the affected limbs are placed at heart level and any constrictive bandages, casts or splints are removed. 

If compartment syndrome occurs despite these measures and the pressure in the compartment is too high, surgery is required. In a procedure called fasciectomy or fasciotomy a cut is made in the connective tissue sheath around the affected muscle group allowing the swollen muscle tissue to expand and instantly reducing the pressure in the compartment.

Doctors also provide supportive treatment such as painkillers. To prevent tissue damage, oxygen and fluid are sometimes given as an infusion.

Compartment syndrome can sometimes leave limbs weak or stiff. Occupational therapy or physiotherapy exercises can help to re-strengthen and loosen the muscles.

After a few weeks, the muscles can usually be moved without pain.