Volkmann's contracture occurs when there is a lack of blood flow (ischemia) to the forearm, usually caused by increased pressure in the arm from swelling (compartment syndrome).
Trauma to the arm, including crush injury or fracture, can lead to swelling which increases pressure in the arm. The increased pressure compresses blood vessels and can decrease blood flow to the arm. A prolonged decrease in blood flow will injure the muscle, causing it to shorten and become stiff.
When the muscle shortens, it pulls on the joint at the end of the muscle just as it would if it were normally contracted, but because it is stiff the joint remains bent and cannot straighten. This condition is called a contracture.
In Volkmann's contracture, the muscles involved are on the palm side of the forearm and they normally cause the fingers to form a fist and flex down the wrist.
There are three levels of severity in Volkmann's contracture:
- mild – flexion contracture of two or three fingers only with no or limited loss of sensation
- moderate – all fingers are flexed and the thumb is stuck in the palm; the wrist may be stuck in flexion and there is usually loss of some sensation in the hand
- severe – all muscles in the forearm that both flex and extend the wrist and fingers are involved, severely disabling condition
The injury classically associated with this condition is an elbow fracture in children. Other conditions that can cause increased pressure in the forearm include any forearm fracture, burns, bleeding disorders, excessive exercise, injection of certain medications into the forearm, and animal bites.
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