Anterior compartment syndrome implies development of increased pressure within the anterior compartments of the body. The lower leg is the most common site. The cause is usually trauma and the typical presentation includes pain, pallor and paresthesia. This condition is regarded as a medical emergency and an early diagnosis with serial examination together with compartment pressure evaluation is necessary. Fasciotomy is the main therapeutic strategy.
The earliest and most important symptom that occurs in patients with all forms of compartment syndrome, including anterior, is pain, which progresses and becomes more intense over time . Most patients report extreme pain which may be out of proportion to the severity of injury, as the skin overlying the anterior segment ay be intact although under pressure and shows no signs of trauma. Muscle stretching or passive limb movement can exacerbate the pain. In addition to pain, the other symptoms that are encountered include paresthesia, paralysis, pallor and pulselessness, comprising the 5 P's of compartment syndrome. Paresthesia, diminished 2-point discrimination, as well as sensory loss are neurological deficits that are often observed , while pale skin overlying the affected compartment is also a hallmark of this condition.
The diagnosis of ACP almost solely depends on the skill of the physician and the degree of clinical suspicion about this condition. A thorough physical examination should be performed and a detailed patient history should be obtained. Events preceding the development of symptoms and their duration (long standing symptoms are noted in chronic exertional CP), as well as use of anticoagulant medications should be noted. Physical examination can reveal other accompanying findings supporting the diagnosis e.g. signs of trauma. Patients with suspected ACP should be examined several times in a relatively short period to assess potential progression of symptoms and decide on appropriate therapy.
In addition to physical examination, compartment pressure can be determined using various available techniques. If the ACP occurs in the lower leg, a syringe with a pressure monitor is introduced 1 cm medial to the anterior tibial border into the anterior compartment and pressure measurements obtained. The threshold for abnormally high compartment pressure is controversial, and large-scale studies have determined significant overlap between pressure values of actual patients with control subjects . However, values that are an indication for surgical treatment are either 30 mm Hg below the mean arterial blood pressure or 20 mm Hg below diastolic arterial pressure , which indicates that arterial blood pressure should be monitored closely as well. If threshold values are reached, immediate surgical treatment should be performed.
This syndrome can present significant challenges in the diagnostic workup. Since irreversible tissue changes and permanent disability can occur within a very short time, this condition is reported to be one of the most common causes of medicolegal conflicts, especially when there is inadequate medical documentation, failure to conduct serial physical examination as well as follow-up tests . Hence medical personnel should be on a high alert when CS is suspected.
When the diagnosis of ACS is based on concrete findings, immediate surgical treatment is indicated for almost all patients . Initial decompression and complete fasciotomy is performed. This comprises of removal of overlying fascia surrounding the compartment. Depending on the severity of trauma, bone reposition or grafting may be performed along with ligation or suturing of blood vessels and debridement of necrotic tissue. In most cases of ACP involving the lower leg, removal of all four fascia is recommended to improve treatment outcomes. Various surgical approaches exist when it comes to management of ACP in the arms and legs and either one or more incisions are made. In some cases, skin grafting may be recommended, so that the effects achieved by fasciotomy are maximized.
This condition should be treated as an emergency, as extensive tissue necrosis and irreversible injury can occur if it is not diagnosed and treated early. With early therapy patients have an excellent prognosis , and only a minority of patients may have residual complaints. Without treatment, however, the condition may result in paralysis, or in some cases, limb amputation. Some studies have established that almost 75% of limb amputations occurred because of delayed treatment or incomplete fasciotomy .
The causes of anterior compartment syndrome may be divided into those causing acute and those causing chronic or exertional forms of the syndrome. Trauma is the most common cause of acute compartment syndrome and includes injuries from motor vehicle accidents, fractures, contusions or crush injuries . Acute CS can occur after surgical repair of vascular injury. This is associated with reestablishment of blood flow and subsequent increase in local pressure. Prolonged limb immobilization by casts or bandages can also cause increase in local pressure. On the other hand, chronic forms of CS is seen in athletes, in whom prolonged activity leads to compression of local tissues with strenuous muscle activity. Muscle hypertrophy can also be a contributing factor to its development .
The anterior compartments of the body that may be affected include:
Data regarding the incidence and prevalence of CS is significantly related to traumatic events, since the vast majority of cases occur under these circumstances. Prevalence rates of CS in terms of specific compartments currently do not exist. It is estimated that around 18% of all tibial fractures eventually progress to CS, with virtually all requiring surgical treatment . Other studies found an incidence of only 1.2% for similar type of injury . CS is estimated to occur in approximately 6% of all foot injuries following motorcycle accidents . Regarding chronic forms of CS, about 14% of patients who had lower leg pain due to unknown cause were found to have chronic CS .
The pathogenesis of ACS starts with alterations in normal blood flow, usually as a result of trauma. Several theories exist regarding the initial events that occur after trauma, but vessel injury leads to extravasation of blood into the interstitium, leading to edema . Continuous pooling of blood and fluid in the interstitium occurs because of increased capillary permeability as well, since it is stimulated by sudden oxygen deprivation of local tissue. Once the interstitial pressure exceeds the diastolic pressure, tissue perfusion is affected adversely. In an attempt to provide oxygen and nutrients to ischemic and hypoxic tissues, the circulatory system further increases the permeability of capillaries. However, this creates a vicious cycle and eventually leads to severe acidosis and ischemia.
Initially, it was established that 5-6 hours are sufficient for development of irreversible muscle damage, but recent experiments have shown that as little as 3 hours are sufficient to cause significant damage . Because of extensive muscle necrosis, significant amounts of myoglobin are released and may rapidly cause kidney injury. For these reasons, clinical suspicion and an early diagnosis may lead to significantly better patient outcomes.
Because the majority of events that trigger this condition are unexpected, prevention is rarely possible. However, in case of chronic exertional compartment syndrome affecting the anterior segment, with recurrent pain, an early diagnosis may significantly reduce the amount of damage to local tissues.
Compartment syndrome (CP) is a term that describes pressure changes in various compartments leading to extensive tissue necrosis and irreversible injury to local structures. Anterior compartment syndrome (ACP) implies that this condition occurs within the anterior compartments of the body. The lower leg is most commonly affected. The anterior compartment in the leg includes tibialis anterior, extensor hallucis longus and extensor digitorum longus muscles, both tibial artery and vein and the deep peroneal nerve. Anterior compartments of the thigh, arm and forearm can also be affected , while some compartments of the hand and foot could be potentially classified into this group of disorders as well. ACP can be either acute or chronic and different causes are responsible for the two forms. Acute ACP is in most cases caused by trauma, including fractures and motor vehicle accidents, while the chronic form is primarily seen in athletes, in which persistent repetitive muscle activity leads to intracompartmental pressure elevation . This form is also known as chronic exertional compartment syndrome and is most commonly seen in runners with lower leg involvement. Certain predisposing factors have been identified, such as muscle hypertrophy, concomitant bleeding disorders and use of anticoagulant therapy. Although the exact mechanism of how CP occurs is unknown, the presumable theory is that the increase in intracompartmental pressure results from bleeding and consequent edema, which results either from indirect vascular injury or from increased permeability of the capillaries due to oxygen deprivation. In either case, a vicious cycle of ischemia and tissue hypoxia occurs, which leads to acidosis and severe tissue necrosis within hours after onset. Because irreversible tissue injury can occur within a few hours, an early diagnosis can prevent permanent damage and even limb amputation in some cases, which is why attending physicians should always exclude this condition during physical examination and workup. The initial presentation of ACP is severe pain, accompanied by pallor of the overlying skin. Neurological deficits, including sensory loss and paresthesia are often present. Patient history is a vital component of the diagnostic workup and information regarding recent trauma or other factors that can provoke ACP may provide significant clues. The diagnosis is based on clinical grounds, with serial examinations, along with invasive measurement of compartment pressures to confirm the diagnosis. Treatment principles include fasciotomy of the affected compartment, together with other necessary measures. This condition should be considered a medical emergency and the time of initiation of therapy significantly influences patient outcomes.
Anterior compartment syndrome is a condition that implies very large sudden increase in pressures of certain parts of the body,leading to extensive tissue damage. For this reason, it is considered to be a medical emergency. Virtually all muscles in the body are, along with the accompanying blood vessels and nerves, are grouped into "compartments" which are created by a layer of connective tissue called the fascia. This tightly encloses the muscles and vessels. In the setting of trauma, which is the most common cause of this syndrome, injury to blood vessels leads to bleeding into the compartment in which the vessel is located. This results in swelling followed by increase in pressure. This pressure disables normal oxygen and nutrient transport to desired tissues, leading to hypoxia and cell death if left untreated. In the case of anterior compartment syndrome, the anterior (or front) compartments can be affected, specifically the front portions of the arm, forearm, thigh and lower leg. In addition to trauma, other factors may predispose individuals to this condition, such as use of anticoagulant drugs, immobilization due to previous trauma with casts or splints and certain surgical procedures that involve restoration of blood flow. A particular form of this syndrome, called chronic exertional compartment syndrome is seen most commonly in athletes who run. This includes recurrent development of symptoms after vigorous muscle exercise. The initial presentation of patients starts with appearance of severe pain at the site of injury, and becomes progressively worse. In addition to pain, symptoms include reduced sensation, pale skin overlying the affected compartment, while paralysis may ensue if treatment is delayed. The diagnosis of anterior compartment syndrome needs to be performed urgently and almost exclusively relies on the ability of the physician to clinically recognize the condition. Since irreversible injury may occur within hours of onset, an initial diagnosis can be made after series of physical examinations performed in a short period of time. Patients may provide significant information such as recent trauma or history of similar symptoms which may further support the diagnosis. To confirm the diagnosis, a syringe is introduced into the affected compartment to measure compartment pressure. Once the diagnosis is established, immediate surgical treatment is indicated. It comprises of removal of fascia that covers the affected compartment. This procedure is known as fasciotomy. Improper or delay in treatment may lead to paralysis and even limb amputation as a result of severe and irreversible muscle damage. This condition should be suspected in all patients who experience recent trauma and complain of severe localized pain.