A flexion (forward bending) deformity of the fingers and wrist caused by injury to muscles of the forearm caused by compartment syndrome in the forearm.
Causes, incidence, and risk factors
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.
Signs and tests
Typical physical exam findings include severe pain when a muscle running through a compartment is passively moved. For example, when the doctor moves the fingers up and down in a compartment syndrome in the forearm, the patient will experience severe pain. The forearm may be tensely swollen and shiny. There is also pain when the forearm is squeezed. The test that will absolutely diagnose this condition involves directly measuring the pressure in the compartment by inserting a needle attached to a pressure meter into the compartment. When the compartment pressure is greater than 45 mmHg or when the pressure is within 30 mmHg of the diastolic blood pressure (the lower number of the blood pressure), then the diagnosis of compartment syndrome is made. Once established, someone with Volkmann's ischemic contracture will have his or her fingers and possibly wrist stuck in flexion.
Treatment
The best treatment is early surgery to release the pressure in the forearm before any permanent injury to the muscles and nerves. However, once a muscle contracture is established, reconstructive surgery to lengthen and sometimes transfer muscles is necessary to try to regain some hand function.
Expectations (prognosis)
The prognosis depends on the severity and stage of disease at which treatment is started.
If surgical release to relieve pressure is performed before permanent damage occurs, then the expected outcome is excellent. However, if there is high pressure in the forearm for an extended period of time, then the muscles and nerves can be permanently damaged. Nerves compressed for greater than 12 to 24 hours will become permanently damaged. Those with mild muscle contractures involving only a few fingers can expect better return to normal function than someone who loses normal function of all the muscles that move the fingers and wrist. People in this second group require major reconstructive surgery and do not do as well.
Complications
The condition of Volkmann's contracture is itself a complication of compartment syndrome. The more severe the contracture, worse the function of the hand and wrist. In severe cases, the hand may be nearly useless and without sensation.
Calling your health care provider
If you have suffered trauma to your elbow or forearm with a lot of swelling, contact your health care provider for proper treatment of your injury and evaluation for compartment syndrome. If you have had an injury in the past to your arm and have muscle contractures as a result, contact your health care provider for proper referral and treatment of your condition.
Prevention
While there is probably no way to prevent compartment syndrome, being very aware of this condition and early diagnosis and treatment will help to prevent many of the complications.