Fascias and boxes

Fascia is collagenous, fibrous connective tissue that forms joint and organ capsules and also encloses muscles, bones, nerve tracts and blood vessels. The entire lower leg musculature is surrounded by the so-called fascia cruris. Depending on their function, individual muscle groups are divided into different compartments by further fascia and separated from each other.

This separation results in functional units, which are called musculature in anatomy. In the lower leg, the following boxes are found: The fasciae surrounding the muscle tissue cause compression, which can prevent swelling after stress or injury.

Extensor box: Musculus tibialis anterior, Musculus extensor digitorum longus, Musculus extensor hallucis longus
Flexor Lodge: Musculus triceps surae, Musculus tibialis posterior, Musculus flexor hallucis longus, Musculus flexor digitorum longus, Musculus popliteus
Fibularisloge: Musculus fibularis longus, Musculus fibularis brevis

However, the anatomical separation of the individual muscle groups by fascia carries the risk of bleeding into the muscle boxes after injuries.

Compartment syndrome is usually caused by trauma such as bone fractures or as a result of blunt force. Surgery or muscular overload, as can occur in competitive and amateur athletes, can also trigger compartment syndrome through bleeding or edema formation. Due to the reduced extensibility of the coarse connective tissue of the fascia, the pressure within a muscle compartment can rise sharply, which also compresses vascular nerve bundles of the lower leg.

This results in an impairment of the blood supply and neuromuscular function. Early symptoms are severe pain in the affected extremity in combination with a feeling of tension and increasing sensory disturbances such as numbness and tingling. Mobility can sometimes be severely restricted.

Due to the increasing pressure in the loge, venous drainage is increasingly impeded. If arterial blood flow is initially maintained, a vicious circle is set in motion, which leads to a further increase in pressure. As a result, the arterial blood flow stops and the musculature is increasingly undersupplied.

At this stage, motor deficits and pulselessness occur in the area after the affected musculature.Due to the threat of extensive tissue loss, the compartment syndrome is an absolute emergency that requires urgent treatment. The therapy of choice for traumatic compartment syndrome is surgical splitting of the fascia of the affected musculature and the adjacent compartments to relieve pressure. Once the swelling has subsided, the artificial incision can either be sutured or covered by a skin graft. If the compartment syndrome is not treated in time, the affected muscle tissue may be massively destroyed, in extreme cases necessitating amputation of the extremity.