COMPARTMENT SYNDROME
What is compartment syndrome?
The muscles in our body are enclosed by a soft tissue sheet (fascia) to form separate compartments. Each compartment also has nerves and blood vessels. The fascia that separates one compartment from another is tough and inelastic. An increase in the intra-compartmental pressure due to external or internal reasons is termed as compartment syndrome.
What happens in compartment syndrome?
Muscles are the primary target in compartment syndrome. The nerves are affected much later by reduced blood supply.
When there is an injury to a body part, bleeding or swelling occurs. Elevated fluid levels press other structures against the inelastic fascia. This raises pressure within the compartment. The flow of blood from arteries to veins is impeded. Consequently, more fluid oozes out of the blood vessels into the intracellular spaces. Within a few hours, the blood supply to the muscles is compromised. Lack of oxygen and fresh nutrients affects normal muscle function. This leads to ischemia (cell death due to lack of oxygen) and contracture of the muscles. The muscle belly is more vulnerable to ischemia. The muscles that bend the thumb and fingers (flexor pollicis longus and profundus) are most commonly affected in the compartment syndrome of forearm.
The muscles in leg and forearm are more affected. But compartment syndrome can occur in hands, arms, thighs, abdomen and back.
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Types of compartment syndrome
There are two types of compartment syndromes:
Acute compartment syndrome (ACS)is a medical emergency that occurs after an injury. Decompression surgery to cut open the fascia is done to relieve the pressure. This needs to be done immediately to avoid permanent muscle or nerve damage. A muscle can resist poor blood supply up to 4 hours after injury. But complete cell death occurs after 8 hours. Similarly, nerves can tolerate ischemia up to 1 hour but undergo irreversible damage 8 hours after injury.
Chronic compartment syndromeoccurs when the muscle volume increases after a prolonged activity. The inelastic fibrous sheath that surrounds the muscle does not stretch as the muscle enlarges. This occludes the blood vessels reducing normal blood supply. This is not a medical emergency. Resting and switching to an alternate activity helps to resolve the symptoms.
What are the symptoms of compartment syndrome?
The symptoms of compartment syndrome arise as a result of vascular compromise that affects muscle tissue.
Symptoms of acute compartment syndrome include:
- Severe pain in the muscles on stretching. The pain intensity may be disproportionate to the extent of injury.
- Forearm or leg muscles feel hard, tender or woody to touch
- Reduced arterial pulse (pulselessness) in the leg or forearm which occurs due to sluggish blood circulation. This makes the overlying skin pale (pallor). This is a very late symptom.
- Paresthesia or tingling in the arms or legs. This is usually a delayed symptom which indicates injury to the nerve.
- Progressive muscle weakness or paralysis
- Affected part is cold to touch.
- The symptoms worsen as time passes
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Symptoms of chronic compartment syndrome:
ü Pain or cramps in the muscles that eases on stopping the activity
ü Bulging tender muscles
ü Skin overlying the muscles is pale or cold to touch
ü Pins and needles or tingling sensation in the limb
ü Tendency of the symptoms to resolve after the activity has been stopped
What are the causes of compartment syndrome?
Acute compartment syndrome can be caused by:
- Fracture of the leg or forearm bones. It has been seen that fracture of upper tibia or fibula (leg bones) are more associated with compartment syndrome
- Crush injury
- Penetrating injury
- Gunshot or stab wound
- Motor vehicle accident
- Tight plaster cast or bandage
- Burns that cause the skin to become tight
- Streptococcus infection
- Sustained awkward body positions during long surgeries (gynaecology)
Chronic compartment syndrome may be caused by:
- Long duration high intensity workout
- Repeated limb movement as in running or cycling
- Playing on artificial turf instead of regular grass turf
- Running on a concrete track instead of running track
- Overtraining or poorly spaced out tournaments
What is the normal compartment pressure?
Measuring compartment pressure every hour after an injury is a reliable method to detect onset of compartment syndrome.
Normal compartment pressures range between 8mmHg to 10mmHg. Pressures more than 30 mmHg are considered diagnostic of acute compartment syndrome.
Chronic compartment syndrome occurs when intra compartment pressure is more than 15 mm Hg at rest, 30mmHg one minute post exercise and more than 20 mmHg 5 minutes post exercise.
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Complications of acute compartment syndrome
- Disability: As muscle is the first structure to be affected, inability to perform a particular movement is noticed quite early. In the forearm, the person may be unable to grip objects. Walking is impaired when leg muscles are affected.
- Wrist drop or foot drop: Once the muscle is injured, it heals through fibrosis. The new tissue does not have the same elastic and contractile properties as the muscle. This results in contractures. The wrist is fixed in flexed position and leg may be fixed in plantar flexion.
- Amputation: Delayed diagnosis may lead to extensive soft tissue loss in the affected limb, prompting cutting the affected part.
- Rhabdomyolysis: Muscle ischemia causes release of muscle protein, myoglobin in the blood stream. This reaches the kidney causing their shut down. Progressive organ damage following kidney failure can be life threatening.
Acute compartment syndrome (ACS): Risks factors and prognosis
There are a few factors that increase the risk of developing a compartment syndrome and also worsen the outcome.
- Males under 35 years of age are 10 times more prone to develop ACS as compared women at the same age. The mean age for women is around 44 years for the development of compartment syndrome.
- Vascular injury: Compartment syndrome is more seen after associated injury to blood vessels. The bleeding raises the volume of the compartment putting pressure on the inelastic fascia. Delayed bleeding can also complicate a compartment syndrome.
- Delayed diagnosis: As compartment syndrome is difficult to diagnose, it can often be missed at the triage. This may affect the prognosis, as a delay of 6 hours can result in permanent damage to the muscles and nerves.
- Delayed fasciotomy: Experts conclude that complete limb recovery is possible if the fasciotomy is done within 6 hours of injury. If fasciotomy is performed between six to twelve hours, only 68% recovered full limb function. A delay of more than 12 hours has very little chance of complete recovery.
Treatment of acute compartment syndrome
Treatment is focused on reducing the intra-compartmental pressure.
Temporary measures include cutting open tight or restrictive casts or bandages and keeping the patient hydrated. It has been seen that reduced fluids in the body, leads to drop in blood pressure. This further reduces the arterio-venous pressure gradient which further slows the circulation within the compartment. The affected limb is kept at heart level to ensure proper circulation. Infusion of oxygen at high pressures (hyperbaric oxygen) has been used to revitalise muscles in some cases.
Cutting up the skin and fascia (extensive fasciotomy) covering the compartment of the leg or the forearm is the only true solution to resolve the compartment syndrome.
Acute Compartment Syndrome: Physiotherapy after extensive fasciotomy
Fasciotomy involves cutting open the skin and fascia to release the compartment pressure. Soon after the surgery, the scar tissue formation begins and the wound begins to contract 5 days after surgery.
It is important to begin gentle stretching exercises and scar tissue mobilisation a week after surgery. Adequate tensile loads during stretching and mobilization helps to align the fibers properly increasing the mobility. This should be followed by range of motion exercises and neural mobilisation. As the muscles and neural tissue regain flexibility, focus is moved to increasing mobility of the surrounding fascia. This is achieved through various manual therapy techniques.
For an appointment call Naas Physio Clinic on: (045) 874 682
Chronic Compartment Syndrome:
This is also known as chronic exertional compartment syndrome (CECS) and is not life threatening. Strenuous exercises or exercising for a prolonged period of time results in increased blood supply to the muscles. The muscles get engorged and bulge outwards, pressing against the inelastic covering. This raises the intra-compartment pressure further disrupting normal blood supply. This condition can be reversed by cessation of causative activity.
Chronic compartment syndrome is also known as anterior compartment syndrome, anterior tibial pain, recurrent compartment syndrome or idiopathic compartment syndrome.
95% of CECS is found in the anterior and lateral compartment of the leg. The forearm, hand and thigh are comparatively less affected. 87% of chronic compartment syndrome cases are seen in sports persons with 69% of them being runners.
Physiotherapy Treatment of Chronic Compartment Syndrome
CECS is most often managed conservatively through physiotherapy. Initially the athlete is advised to rest and cross train. Cross training involves doing a different workout to maintain fitness without stressing the already injured muscle group.
Functional manual therapy (FMT) is an extremely effective technique to resolve exertional compartment syndrome. The technique stresses on improving inter and intra tissue mobility and accessory joint movement.
The initial sessions of FMT involve systematically mobilising the tight or inelastic fascia and interosseous membrane and stretching the muscles. Interosseous membrane is a tough sheet of tissue attached to inner margins of the tibia and fibula. Improved flexibility in this membrane allows easy movement between the two bones during running and pivoting movements.
FMT also mixes deep tissue mobilisation with active isometric muscle work to release the myofascial fascia. Isometric muscle work implies muscle contraction without movement. Deep tissue massage using the foam roller is equally effective in loosening the fascia. This improves muscle extensibility and excursion during an activity.
Apart from soft tissue techniques, FMT also incorporates joint mobilisation. Mobilising the ankle joint and the upper and lower tibio-fibular joints improves soft tissue mobility. Good joint mobility also ensures better biomechanics in the entire leg. This prevents any imbalance in muscle contraction in all compartments. Along with the leg, mobility of soft tissue and articular structures of the foot is also emphasised. As the leg and ankle and foot mobility are interdependent, it is important to stretch and mobilise the plantar fascia and mid foot joints.
The nerves are important soft tissue structures and neural mobility is extremely vital for smooth and pain free movement. FMT also uses specific techniques that mobilise the sciatic nerve and its branches in the leg and foot. Sciatic nerve is the largest nerve supplying the back of thigh and full leg and foot.
Once adequate soft tissue, neural and articular mobility is achieved through FMT, neuromuscular exercises are begun immediately. Using proprioceptive neuromuscular facilitation (PNF) for lower body muscle work, helps to regain balance and coordination. The PNF technique stimulates the receptors in the joints and muscles that are responsible for balance and coordination. These attributes are particularly beneficial for running.
This is followed by muscle strengthening. The exercise intensity is progressed slowly while looking out for any signs of increased compartment pressure. The intramuscular pressure increases more during eccentric exercises as compared to concentric exercises. Thus, eccentric exercises are introduced much later in the rehab phase.
As the muscle strength is regained, the athlete is moved to sports specific drills. The technique is reassessed. Sometimes incorrect footwork, or landing technique results in overuse of specific muscle group. Simultaneously, any dysfunction in the core is also checked and corrected as movement in the lumbo-pelvic-hip complex influences the knee-leg-ankle foot complex activity. Excessive or incorrect use of muscles may also lead to the development of compartment syndrome.
If the condition is not resolved by nonsurgical methods within 4-6 months of intensive physiotherapy, operative measures can be considered.
To find out more, contact us at Naas Physio Clinic on: (045) 874 682
or email us at info@physioclinic.ie
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