What is Acute Compartment Syndrome (ACS)?
Acute Compartment Syndrome is a serious medical emergency. It happens when swelling or bleeding increases pressure inside a closed muscle compartment. These compartments are surrounded by a strong layer of tissue called fascia, which does not stretch. When pressure rises, it cuts off blood flow to the muscles and nerves inside. If not treated quickly, this can cause permanent damage or even loss of the limb.
Where Can It Happen?
ACS most commonly affects the lower leg (especially the front part) and the forearm. It can also occur in the thigh, upper arm, hand, foot, buttock, or shoulder.
What Causes It?
The most common causes of ACS include:
- Broken bones (especially in the shin or forearm)
- Crush injuries or soft tissue trauma
- Burns
- Tight bandages, casts, or splints
- Bleeding inside the muscle (e.g., due to a medical condition or medication)
- Reperfusion after blood flow returns to a previously blocked area
- Intense exercise or physical activity (rarely)
What Are the Symptoms?
The classic early signs include:
- Severe pain, often worse than expected for the injury
- Pain that increases with movement or gentle stretch of the muscles
- A hard, swollen, or tense feeling in the affected area
- Numbness, tingling, or weakness
Late signs (indicating serious damage) may include:
- Paleness or coolness of the skin
- Weakness or paralysis
- Absent pulses (though pulses can still be present early on)
When Should I Get Help?
Seek emergency care immediately if:
- You or someone else has a very painful or tense limb after an injury
- Pain is not relieved by painkillers
- There’s a new numbness or inability to move the limb
ACS can develop within a few hours of an injury, so don’t delay.
How is it Diagnosed?
Doctors usually make the diagnosis based on your symptoms and examination. In some cases, especially if the patient is unconscious or unable to communicate, a small needle is used to measure pressure inside the compartment.
A very high pressure or a poor blood supply to the muscles means immediate surgery is needed.
What is the Treatment?
The only effective treatment for ACS is emergency surgery, called a fasciotomy. This involves cutting the fascia to relieve the pressure and restore blood flow.
- It must be done as soon as possible, ideally within 6 hours of symptoms starting.
- The wounds may be left open initially and closed in a second operation or covered with a skin graft.
What Can Happen if It’s Not Treated?
Without quick treatment, ACS can cause:
- Permanent muscle or nerve damage
- Severe deformity or contracture of the limb (e.g., twisted or stiff hand/arm)
- Loss of limb (amputation)
- Kidney failure due to muscle breakdown
- In rare cases, death
What Happens After Surgery?
Recovery depends on how early the treatment was given. After fasciotomy:
- Wounds need regular cleaning and may need dressing changes or further surgery
- Pain relief and infection prevention are part of care
- Physical therapy helps restore movement and strength
- Some patients may need mobility aids or support for daily activities
Summary: Key Points to Remember
- ACS is a medical emergency—early action can save your limb.
- Pain out of proportion to the injury is the most important early warning sign.
- Do not wait for numbness or loss of pulse—these are late and dangerous signs.
- Emergency surgery (fasciotomy) is needed to relieve the pressure.
- Fast treatment leads to the best chance of full recovery.
If in doubt, always seek immediate medical advice. Never ignore new or worsening pain in a recently injured limb.
Call to Action
If you have pain, book an appointment to be reviewed by Prof Imam or another member of our specialist team at The Arm Clinic. Early specialist care helps prevent long-term issues. Visit www.TheArmDoc.co.uk or book your consultation today. Phone: 020 3384 5588 | Email: Info@TheArmDoc.co.uk
Disclaimer
This information is for general educational purposes and should not be used as a substitute for professional medical advice. Consult a healthcare professional for individual guidance on your condition and treatment options.
This page was last clinically updated in May 2025