Compartment Syndrome Diagnosis

By Dr. Akshima Sahi, BDSReviewed by Gaea Marelle Miranda, M.Sc.

Compartment syndrome is a dangerous condition which occurs when excess pressure builds within the muscles. It is a painful condition that could manifest in both acute and chronic forms.

Muscles, nerves, and blood vessels in arms and legs are composed of small groupings known as compartments. They are covered by a non-stretchable membrane known as fascia, which keeps these compartments intact.

Swelling and bleeding within compartments lead to excessive pressure in the capillaries, nerves, and muscles because the fascia keeps the compartments surrounded regardless of physiological abnormalities. An immediate effect of this is restricted blood flow. A reduction in the blood supply to muscles and nerve cells results in ischemia (lack of oxygen) and cellular death (necrosis) of the affected tissue.

Compartment syndrome mostly affects the anterior (front) compartment of the lower leg but could also affect other compartments in the legs, arms, hands, feet, and buttocks. Due to the lack of nutrients and oxygen supply, this condition could also result in the surgical removal of all or part of the affected limb (amputation), if not treated well in time.

Diagnosing Acute Compartment Syndrome

Acute Compartment Syndrome (ACS) is a surgical emergency that develops from a severe injury, fracture, prolonged limb compression, or burns. The progression of such conditions results in an increased interstitial or intra-compartmental pressure (ICP) within the compartment of the affected muscle.

The diagnosis of ACS is done on the basis of the patient's symptoms, physical examination, and ICP measurement. An ICP level that is higher than 30 mmHg indicates ACS. As such, five Ps—including pain, paresthesia, pallor, paralysis, and high intra-compartment pressure—are considered when diagnosing ACS.

New medical techniques used in diagnosing ACS include near-infrared spectroscopy (NIRS), ultrasonic devices, and laser doppler flowmetry.

Diagnosing Chronic Compartment Syndrome

Chronic Compartment Syndrome (CCS), also known as Chronic Exertional Compartment Syndrome (CECS), results from the long-term and repetitive use of the muscles and is generally associated with pain. This condition occurs when there is increased amount of blood flow to the muscles (usually from high-intensity exercises) that facilitates the expansion of the blood vessel and builds pressure. Eventually, this pressure would restrict the blood flow and lead to permanent damage.Young adults, runners, athletes, and military personnel usually experience this condition.

Diagnosing CCS would require physical examination that is facilitated by a physician. The doctor may look for the signs of tenderness, swelling, muscle bulge (herniation), or tension in various parts of the body. The patient’s medical history and pain history are also considered.

Confidently diagnosing CCS is challenging because other medical conditions could also cause exertional leg pain. In order to rule out other conditions, imaging tests such as x-ray or magnetic resonance imaging (MRI) could be used. These are helpful in revealing stress fractures or tendinitis. Newer MRI models could also be used in assessing fluid volumes within compartments. Meanwhile, an electromyogram (EMG) could assess nerve entrapment, which is also a common reason for anterior exertional leg pain. Another technique is NIRS which utilizes light wavelengths to measure tissue oxygen saturation in the blood and assesses blood flow in the affected muscle.

The key diagnostic technique used to confirm CCS is by measuring the patient’s ICP level. A handheld needle device called strkyercatheter could determine such. This is done post- anesthesia, when normal saline is injected in the compartment of the affected tissue. The target location of the needle is determined by externally compressing the compartment. Doing this would allow the device to reflect increased pressure.

Diagnosisng CCS though ICP level is done before and after exercise. A resting pressure greater than 15 mmHg and post-exercise pressure greater than 20 mmHg are significant markers in confirming a CCS diagnosis. At present, this test is the gold standard for diagnosing chronic exertional compartment syndrome.

Once a correct diagnosis is achieved, an immediate fasciectomy is performed to treat the condition; hence, a correct diagnosis is instrumental in relieving the patient from compartment syndrome.

Further Reading

• All Compartment Syndrome Content
• What is Compartment Syndrome?
• Compartment Syndrome Treatment
• Compartment Syndrome Symptoms