LOWER LEG - COMPARTMENT SYNDROME

 The Injury

Compartment syndrome is common in the lower leg of athletes who follow high mileage training programs. The pain is brought on by activity, due to the anatomy of the muscles.

• The lower leg is divided into compartments by a layer of fascia (Fash-ee-ah). The fascia is a sheet or band of fibrous tissue that surrounds muscles and other internal organs.
• The anterior compartment is at the front between the tibia (shin bone) and fibula (splint bone). It contains the muscles that pull the foot and toes up towards the knee.
• The medial compartment is on the inside aspect of the shin. The muscles which bend the toes during pushing off are in this compartment. The posterior compartment is the largest, and contains the calf muscles which attach to the Achilles tendon and push the ankle downwards during running and jumping.
• The lateral compartment on the outside of the shin contains the muscles which turn the sole of the foot outward.

Compartment syndrome occurs when the volume of the muscles, blood vessels and nerves become too big for the space within the compartment. This leads to an increase in pressure within the compartment and compresses all structures within the compartment. There are two main causes:

• swelling or bleeding within the compartment due to direct trauma
• an increase in muscle size in the compartment due to physical activity

 Signs and Symptoms

• Usually it takes about 20 minutes of running before the pain gradually rises to the point where the person can no longer continue. The pain is cramp-like and is due to the constriction of blood vessels which prevent blood and oxygen from reaching the muscles. This can lead to permanent tissue damage. Usually, however, the pain is transient and will ease with rest.
• Diagnosis can be confirmed with MRI scans and measurement of compartment pressure. This is done by inserting a catheter into the compartment and measuring pressure with a transducer.

 Treatment

• In cases where the pain comes on with exercise, and is relieved after rest, conservative treatment such as physiotherapy and the prescription of orthotics may reduce the severity of the symptoms, but cannot get rid of the problem.
• The most effective treatment is surgery. This consists of an operation called a superficial fasciotomy which involves splitting the fascia (Fash-ee-ah) which makes up the compartment. The fascia is a sheet or band of fibrous tissue that surrounds muscles and other internal organs. This should be followed by aggressive rehabilitation under the supervision of a physiotherapist.