By Nita Sharma Das, PhD, ND.
In recent medical practice, one of the most common findings observed in the orthopedic department is of acute compartment syndrome and related disability. The compartment syndrome occurs due to a severely painful condition within an enclosed bundle of muscle in lower or upper extremities or other parts of the body due to pressure build-up. Although the pathophysiology is known, it often becomes difficult to diagnose the condition.
The compartment syndrome usually develops in legs, arms, feet, or hands; however, it may develop in an enclosed compartment anywhere inside the body. Delayed treatment can lead to acute compartment syndrome related disability.
Basic Anatomy of Compartment
Anatomical structure of our body is complicated. Certain body parts, muscle, nerve, and blood vessels are connected with each other and form an enclosed 'compartment', which are covered with a stiff and tough membrane known as fascia. A traumatic injury in a particular compartment can damage the underneath tissue structures and if remained untreated, can lead to the development of compartment syndrome.
The lower legs are the most commonly affected region in compartment syndrome. Anatomically, lower leg has four compartments, namely the anterior, superficial posterior, deep posterior and lateral. The adjoining muscle and nerve tissues in each compartment get affected with compartment syndrome, like in case of anterior compartment, the long toe extensors, the tibialis anterior muscle and the deep peroneal nerves get affected. Similarly, in the superficial posterior compartment, the soleus, the gastrocnemius muscles, and the sural nerve gets affected; in the deep posterior compartment, the long toe flexors, the tibialis posterior muscle, the tibial nerve and the peroneal artery are affected. While in lateral compartment, brevis and peroneus longus muscles, and superficial peroneal nerve become affected.
Types of Compartment Syndrome
The compartment syndrome has been classified into acute and severe, depending upon the underlying cause of the disease.
Acute compartment syndrome develops due to sudden traumatic injuries, such as bone fracture or forceful blow on a compartment. This type of syndrome requires maximum medical attention and immediate intervention to avoid permanent damage and disability.
Chronic compartment syndrome is typically explained as exertional chronic compartment syndrome. In most cases, repetitive traumatic injury or continuous overuse leads to chronic compartment syndrome. Tedious exercises like running or cycling for long-distance can result in exertion, causing chronic compartment syndrome. An immediate reduction in pain and other associated symptoms can be observed after cessation of the tedious physical activity. Chronic compartment syndrome is not typically considered as an emergency situation requiring immediate medical assistance, even the scope of permanent disability is also very low.
Pathophysiological Changes in Compartment Syndrome
A traumatic injury affecting any compartment present in that particular location results in inflammation. The inflammation gradually extends and obstructs blood flow that further increases fluid pressure in the compartment. This causes tremendous pain and the adjoining nerves and muscles get damaged in the progressive condition. Disability occurs at an advanced stage.
The natural tissue homeostasis can get affected due to several possible risk factors including soft tissue injury, muscle hernia, hemorrhage, tedious exercise and any tight dressings in the injured area. Consequently, inhibiting capillary blood flow and elevating pressure within the tissue structures, it leads to hypoxia and tissue necrosis in the confined compartment. Therefore, pathophysiological factors in compartment syndrome have the ability to increase the interior volume in the compartment, which subsequently can shrink the local fascial capacity and metabolic malfunctioning and can interrupt the microvasculature.
Acute compartment syndrome may develop in an individual having a history of tibial fracture or a soft-tissue injury; whereas chronic compartment syndrome is frequent in athletes or individuals who perform eccentric exercises. Improving awareness about compartment syndrome may help in early diagnosis and case management.