Compartments of the lower leg
Compartment syndrome is a condition that results from compression of the structures within the compartment due to increasing pressure. This increasing pressure compresses the blood vessels, decreasing oxygenation and leading to tissue damage. It may result from bleeding into the compartment space or due to accumulation of fluid (edema). The unyielding fascia does not provide space to expand, increasing the pressure within the compartment.
Anterior compartment syndrome:
The anterior compartment is located on the outer front of the lower leg and has two bony walls, plus the tough fascia that covers the tibialis anterior and three other small muscles involved in upward deflection of the foot.
Anterior compartment syndrome may be acute resulting from an accidental trauma causing bone fracture or muscle contusion, or it may be chronic that results from excessive physical exertion and is a common complaint among sportspersons and athletes. The latter condition is also called chronic exertional compartment syndrome.
- Severe pain on the outer front of the leg that does not respond well to painkillers (even morphine); aggravated by activity
- Pale skin, appearing glossy and stretched due to swelling
- Nerve compression leads to parasthesia (altered sensation such as pins and needles or burning) in the area supplied by the nerve.
- Weakness in the muscles when the foot is bent upwards against pressure
- There may be an obvious bruise, indicating the underlying injury.
- Decreased blood flow may cause numbness in the toes
The diagnosis is usually made by relating the signs and symptoms to an underlying cause such as tibia or fibula fracture or a muscle injury. There are, however, diagnostic tools available to measure the pressure within a compartment. This helps in accurate assessment of the condition and in devising a suitable management plan.
Acute Compartment Syndrome:
This is a medical emergency and requires immediate surgical intervention. The pressure is released by making long incisions in the covering fascia (fasciotomy). The wound may be left open for two or three days. Untreated cases may lead to kidney failure or other life-threatening complications.
Chronic Compartment Syndrome:
- Chronic or exertional compartment syndrome may be treated with conservation or using a surgical approach. Conservative management includes:
- Cessation of physical activities that exacerbate symptoms; upper body exercises can be carried out to maintain fitness.
- Ice application and elevation of the leg to reduce pain and swelling; do not elevate above heart level as this may further reduce blood supply to the area.
- Massage and stretching exercises involving anterior compartment muscles
If symptoms do not subside with a conservative approach, fasciotomy is performed to relieve the pressure in the muscle compartment. Surgical treatment is shown to be effective in about 90% of cases.