The posterior compartment is divided by deep transverse fascia into deep and superficial sections. As the superficial peroneal nerve also travels in this compartment, sensation to the lower leg and dorsum of the foot may be affected. Increased pressure in the lateral compartment may produce a deep peroneal nerve deficit, which manifests as weakness in dorsiflexion and inversion of the foot and sensory loss between the first and second toes. The neurovascular supply to the lateral compartment is provided by the peroneal artery and by branches of the superficial peroneal nerve and the proximal portion of the deep peroneal nerve. The muscles of the lateral compartment include the peroneus longus and the peroneus brevis. Late sequelae include foot drop, claw foot, and deep peroneal nerve dysfunction. Signs of compartment syndrome affecting the anterior compartment include loss of sensation between the first and second toes and weakness of foot dorsiflexion. The anterior compartment neurovascular bundle consists of the deep peroneal nerve and the anterior tibial artery. The anterior compartment muscles include the tibialis anterior, the extensor hallucis longus, the extensor digitorum longus and the peroneus tertius. The anterior compartment of the leg is the most common site for acute compartment syndrome. The tibialis posterior (hatched) is sometimes classified as its own separate compartment and not grouped with the deep posterior compartment. The leg contains four major myofascial compartments: the anterior compartment, the lateral compartment, the superficial posterior compartment, and the deep posterior compartment. The tibialis posterior is sometimes classified as its own separate compartment and not grouped with the deep posterior compartment. The leg is divided into four anatomic compartments (Figure 3) by fibro-osseous septa which limit the volume and distensibility of each defined compartment: the anterior, lateral, superficial posterior and deep posterior. 3ДЄdditional studies have suggested that patients with CECS have pathologically thickened fascia, which predisposes them to CECS. Although some studies have provided evidence for muscle ischemia giving rise to the pain associated with CECS, other studies have refuted such a model. The pathophysiology of CECS is not as clear as that of acute compartment syndrome. Chronic exertional compartment syndrome (CECS) can occur secondary to exertion because chronic muscle activity causes muscle hypertrophy and transiently can swell muscle fibers up to 20 times their resting size, thus causing increased pressure in noncompliant compartments.

Chronic compartment syndrome results most commonly from exertional causes such as exercise or overuse or from nonexertional causes such as a mass lesion, anomalous muscle or infection. Acute compartment syndrome occurs most commonly in association with fractures, particularly of the tibia, and with soft tissue trauma. The result is ischemic myoneural necrosis, with increasing edema causing a vicious cycle of increasing compartment pressure ultimately leading to a contracted, useless limb (Volkmann ischemic contracture).Д¬ompartment syndrome is classified generally as acute or chronic. Muscle ischemia can result when elevated intracompartmental pressure exceeds the intravascular pressure of thin-walled small vessels and these vessels collapse, thereby decreasing the arteriovenous pressure gradient and impeding blood flow. 1 If untreated, compartment syndromes may lead to muscle fibrosis and contracture. Introduction/BackgroundД¬ompartment syndrome is defined as elevated pressure in a relatively noncompliant anatomic compartment that can cause ischemia, pain and potentially neuromuscular injury, including myonecrosis and rhabdomyolysis. DiagnosisДЄcute compartment syndrome involving the lateral compartment of the right leg associated with a fibular fatigue fracture. A more distal T2-weighted image (2C) demonstrates similar findings with more pronounced soft tissue edema and a small fibular fatigue fracture (arrow).

In addition, edema-like signal is seen adjacent to the fascia within the subcutaneous fat. The fascia is bowed laterally and may be slightly thickened (arrowheads). The more proximal of the axial T2-weighted images (2B) demonstrates diffuse swelling and edema-like signal throughout the lateral compartment (arrows). Areas of diffuse T1 hyperintensity reflect regions of hemorrhage within the muscles (arrows). The axial T1-weighted image (2A) demonstrates slight volume increase in the lateral compartment musculature with lateral bowing of the overlying fascia (arrowheads).

Picture of compartments of leg