Leg Compartment Syndrome
Normal Anatomy
The leg is composed of two bones, the tibia and fibula, as well as large groups of muscles in the front, back, and outer sides of the leg. The tibia is the main weight-bearing bone of the leg, while the fibula functions primarily as a strut while also contributing to the stability of the knee joint above and the ankle joint below. Major nerves from the spinal cord run down the back of the knee into the leg and foot. Major blood vessels that originate in the trunk run down the leg into the foot as well. The muscles, nerves, and blood vessels in the front, back, and outer part of the thigh are separated into compartments by thickened collagen tissue called fascia.
Pathology
Compartment syndrome is an orthopedic emergency. Leg compartment syndrome occurs when the pressure within the front, back, or outer leg compartments rises above the blood pressure needed for the heart to pump blood to the thigh. When this occurs, the muscles and nerves within the compartment are at risk of dying with little or no chance of recovery. Leg compartment syndrome usually occurs after some sort of trauma such as a fall with or without a fracture. Patients may complain of increasing pain, pain that is out of proportion to the injury, and increase in pain medication requirements, numbness, tingling, or no symptoms at all. The leg may feel tense, the patient may have pain with stretch of the muscles affected, there may be a loss of sensation in the leg, a cool feeling of the skin, loss of pulses in ankle, or loss of function of the leg muscles. Because the signs and symptoms can be variable, physicians must maintain a high index of suspicion if the patient’s complaints and injury history are consistent with a compartment syndrome.
Treatment
If a thigh compartment syndrome is diagnosed, it must be treated within 6 hours of the injury. The treatment consists of a trip to the operating room where the connective tissue (fascia) that surrounds and separates each compartment must be surgically released. This release relieves the pressure within the compartment and allows the muscles and nerves within the compartment to receive their required blood supply. The surgical wounds are often not sutured back immediately to allow for the skin and soft tissue to accommodate any swelling that has occurred during the course of the surgery. The surgical wounds are then sutured back at a later a date. If they cannot be sutured back because of skin tightness, the use of a vacuum-assisted wound closure device may be used. Skin grafts may sometimes be needed to ultimately close the surgical wounds.