Lateral Compartment Syndrome

The Oxford Dictionary of Sports Science and Medicine describes a compartment as “a well-defined region that contains a group of muscles within a particular segment of the body.”The lower leg is divided into four compartments by a layer of separating fascia. This fascia is tough and inelastic and serves to hold the muscle, nerves and blood vessels together.

Fascial compartments of the lower leg

The lateral compartment, as the name suggests, is located on the outer side of the lower leg; it contains the two peroneus muscles (brevis and longus). These muscles effect eversion and bending of the foot.

Any condition that leads to increased pressure within the closed compartment space compresses the local blood vessels, compromising the blood supply to the muscles and nerves within the compartment.If the rise in pressure is very rapid, it may lead to nerve and muscle tissue damage and if it is slow in progression (chronic), it gives rise to certain symptoms.This whole phenomenon is termed as Compartment Syndrome.

Cause:

An increase in pressure inside the fascial compartment may result from an increase in the compartment tissue substance; the non-resilient fascia does not accommodate the increase in size, thereby causing a build-up in pressure. This increase in compartment substance may occur due to:

  • Acute injury leading to pooling of blood and inflammatory fluid (Acute compartment syndrome)
  • Over-exertion of the muscles, leading to increased pressure inside the compartment (Chronic Exertional Compartment Syndrome); muscle hypertrophy (increase in muscle size due to exercise) may be a factor

Lateral compartment syndrome rarely occurs in isolation, and is usually seen when multiple compartments are involved.Scarring of the surrounding fascia, unconditioned hypertonic muscles and postural abnormalities increase the risk of developing compartment syndrome.

Symptoms:

  • There is pain and a feeling of pressure on the lateral side of lower leg.
  • Pain is usually severe and there may be associated tenderness and swelling.
  • The skin overlying the swollen leg appears pale, shiny and stretched.
  • Pain is aggravated by activity.
  • Numbness in the extremities, there may also be parasthesia (burning or tingling) due to nerve compression.

Diagnosis:

Diagnosis is usually carried out by combining presenting signs and symptoms with the results of other investigations. X-rays or CT scans help to reveal bone fractures and soft tissue injuries, as well as ruling out other conditions.A simple apparatus may be used to measure the pressure within the compartment.

Treatment:

Rest is the key to successful healing. However, if there is an injury and the condition is clearly acute, then immediate surgical intervention is required.

Surgical treatment includes making cuts in the surrounding fascia to decompress the tissues within the compartment. This procedure is termed fasciotomy. In severe cases, the wound may be left open for drainage. The closure is accomplished in a second surgical procedure about two to three days later.

Fasciotomy for Lateral Compartment Syndrome (second from right)

A conservative approach is quite effective in chronic cases.The RICE regime works well.Avoid any activity that leads to pain and use painkillers, if required.Stretching exercises help loosen stiff muscles and should be carried out in the healing phase, but care should be taken not to stretch to a painful limit.

Massage of the affected leg and correction of any postural or biomechanical irregularities aids in healing.