Chronic Exertional Compartment Syndrome

By Asheesh Bedi, MD and Adnan Cutuk, MD

 

What is Chronic Exertional Compartment Syndrome?

Compartment syndrome is a condition defined as increased pressure within the muscle and its surrounding tissue envelope (“fascia”) resulting in a reduced blood flow, pain, and possible muscle injury within the compartment. This condition can be either acute or chronic. Acute Compartment Syndrome (ACS) is an orthopedic emergency often associated with large increase in tissue pressure. It usually follows fractures, soft tissue crush injuries, blood vessel injuries or other traumatic decrease in blood flow. ACS requires urgent surgical attention to avoid permanent damage to the involved muscles. Patients with ACS present with severe pain worsened by a passive stretch, muscle compartment tightness, paresthesia (sensory deficit/tingling), pallor (pale/pink skin) and absence or decrease in distal pulses. ACS has been described in almost all fascia-enclosed compartments of the body including leg, thigh, hand, forearm, foot, etc.

Contrary to the Acute Compartment Syndrome, Chronic Exertional Compartment Syndrome (CECS) is not a medical emergency. CECS is more common in running athletes and is characterized by exercise-induced increases in compartment soft tissue pressures that are reproducible with activity and resolve with rest. The muscular compartment becomes tight and painful preventing further athletic participation. The pain is always associated with exercise and tends to resolve with the cessation of activity without any persistent clinical sequalae but returning with the next bout of exercise. The areas most commonly affected by the CECS are lower leg, forearm, and thigh muscles.

 

Anatomy of Exertional Compartment Syndrome

The most common location for the CECS is the lower leg. The lower leg is between the knee and the ankle has 4 muscular compartments identified based on their location: anterior, lateral, deep posterior, and superficial posterior compartment. In addition to muscle bellies, each compartment also contains one major nerve and contain major blood vessels. The anterior compartment contains the muscle bellies that extend the toes and the foot along with the anterior tibial artery and the deep peroneal nerve supplying sensation to the skin between the first and second toes.

The superficial posterior compartment consists of the gastrocnemius and soleus muscles flex the foot (“tip toes” position), and the sural nerve which provides sensation to the skin over the lateral aspect of the foot. The deep posterior compartment contains the toe flexors, the posterior tibial artery/vein and the tibial nerve which supplies the skin on the bottom of the foot. Finally, the lateral compartment contains the muscle that rotate the foot outward (“evertors”) and the superficial peroneal nerve which is responsible for supplying sensation to the skin over the top of the foot. All four muscle compartments are fully encased by tough connective tissue (“fascia”) that is relatively inelastic and does not expand much. It is this tough fascia that fails to expand with muscle swelling that contributes to the development of compartment syndrome.

 

Risk factors of developing CECS

The normal response to exercise is an increase in blood flow. This increase in the blood flow to the working muscles provides necessary delivery of oxygen and nutrients to the working tissues. These working muscles can swell up and increase up to 20% in their volume. This increase in the muscular tissue volume can lead to increase in pressure within the fixed volume of the compartment due to the tight surrounding envelope (“fascia”). As long as the blood flow is sufficient to keep up with the necessary oxygen requirement of the working muscles, no symptoms of CECS develop. However, if the increased compartmental pressures result in a decrease in the tissue perfusion, oxygen delivery becomes insufficient and the muscle is “starved” of oxygen (“ischemia”). This results in pain and can cause significant muscle injury.

It is unclear why patients with CECS develop increased muscle pressures with exercise. Perhaps altered regulation in the ability to control blood flow along with the relative inelasticity of fascial tissue creates the conditions necessary for the development of the CECS.

 

Symptoms of CECS

CECS almost universally presents as pain that develops during running or repetitive exercises. As the exercise continues, the dull ache or pain becomes severe enough that the athlete is required to stop the exercise. The onset of pain and the intensity is generally very reproducible and often occurs at the predictable time in their exercise routine. Patients frequently experience the sensation of swelling and cramping in addition to pain. They may also perceive numbness, tingling and even weakness in the area supplied by the nerve from the affected compartment. Cessation of exercise usually results in a prompt resolution of symptoms. Athletes usually do not have any history of trauma, and most report symptoms in both limbs. Arm CECS is rarer, although it will present develop similar symptoms of cramping, pain, tingling and weakness with upper extremity exercise.  

 

Diagnosing CECS

The clinical diagnosis of the CECS is often difficult due to essentially normal examination at the time of rest. Inspection of the resting muscle compartments affected by the CECS yields no abnormal signs. Therefore, diagnosis necessitates provocative exercise to elicit the signs and symptoms of the CECS. Athletes must be allowed to exercise in the activity or sport that brings out the symptoms and should be examined immediately after the constellation of symptoms is reproduced. Inspection of the affected lower extremity after the symptoms develop may demonstrate visible swelling in the front or side of the leg in 45% of patients with CESC. These swellings (“fascial herniations”) are usually 1-2 cm in size and occur on the side of the leg. Neurologic examination may reveal decrease in the sensation of light touch/vibration.

A direct measure of pressures can be performed after the onset of symptoms with a special pressure monitor. Generally, these measurements should demonstrate some abnormalities consistent with CECS.

-a resting pressure of 15 mmHg and/or
-an intramuscular pressure of 30 mmHg after 1 minute of rest following the exercise induced symptoms and/or
-a pressure of 20 mmHg after 5 minutes of rest following the exercise.

These measurements depend on correct technique using the pressure monitor, correct limb positioning, and successful reproduction of symptoms with selected exercise.

 

Treatment of CECS in athletes

Nonoperative management of athletes with CECS always includes activity modification and essentially giving up aggravating activity or sport. This is often not a compatible option with dedicated, elite athletes. Presently there are no medical remedies available to treat CECS.

Because most patients with CECS wish to remain active, surgical treatment is the standard of care. This procedure involves incising the tough compartment envelope (“fascia”) and as a result allowing the increase in compartmental volume with exercise without obligatory increase in pressure which results in CECS Several fasciotomy techniques exist. Open two incision fasciotomy involves longitudinal incisions on the inside and outside of the leg and the longitudinal fascial release of two compartments through each incision. A minimally invasive release through small incisions can be achieved through two limited longitudinal incisions, but with the assumption of slightly greater risk to the nerves and blood vessels that cannot be seen. Camera-assisted (“endoscopically assisted”) two incision fasciotomy has also been described with reported the same safety margin as the single incision technique. Some surgeons utilize single-incision techniques for ACS and CECS fascial release but it is more technically demanding and potentially less reliable in a complete release of the fascia.

 

Complications of surgery for CECS

Most common complications of the surgical fasciotomy procedures include an insufficient release with recurrence of symptoms reported in up to 17% of patients. In addition hemorrhage, hematoma formation, wound infection, nerve injury, vascular injury, persistent edema, perceived weakness and deep vein thrombosis have all been reported with incidence ranging from 4-13%. Despite these reported complications, a well-done operation can yield 80-100% successful resolution of symptoms in athletes.

 

Recovery and return to play timeline after CECS surgery

Immediately after surgery, the athlete undergoes pain and swelling management with medications, elevation, and icing. Active range of motion exercise is not restricted postoperatively and is encouraged to begin immediately. Crutches are utilized for comfort and weight bearing is not restricted. Once the incisions are healed patient can begin progressive activities as tolerated and generally can return to full activities in 3-4 weeks after the procedure. Therefore, patients are expected to return to light activity in 2-4 weeks and full sporting ctivities in 4-6 weeks.