Carpal Tunnel Syndrome is one of the most common disorders of the upper extremity. It also seems to be one of the most misunderstood and over-diagnosed disorders.
The carpal tunnel is a tunnel formed across the palm side of the wrist and into the hand. The roof of the tunnel consists of a piece of "gristle" called the transverse carpal ligament. The sides and floor of the tunnel are made up of the bones of the wrist. Through this tunnel runs the tendons that flex the fingers of the hand along with the median nerve. The median nerve supplies some of the muscles of the thumb along with the sensory fibers to the thumb, index finger, long finger and half of the ring finger. Carpal Tunnel Syndrome occurs most commonly when some initiating factor causes swelling of the tendon lining tissues within the carpal tunnel. This swelling takes up space and causes the median nerve to be compressed against the transverse carpal ligament. This compression results in the various symptoms of Carpal Tunnel Syndrome.
Carpal Tunnel Syndrome can be caused by many things. One possible cause is overuse of the upper extremities in jobs that require repetitive use or unnatural positions of the hands. Lack of exercise, smoking and weight problems can also predispose one to carpal tunnel problems. Conditions such as pregnancy, thyroid disease, diabetes, rheumatoid arthritis and deformity or swelling of the wrist due to trauma can also contribute to Carpal Tunnel Syndrome. Most cases of Carpal Tunnel Syndrome have no single identifiable cause.
Symptoms can vary in severity but are centered around tingling, numbness or discomfort in the sensory distribution of the median nerve. In more severe cases, weakness and atrophy (shrinking) of the muscles at the base of the thumb may occur. Some people experience pain that radiates from the hand up to the forearm or even toward the shoulder. Night time numbness and tingling are also common. In advanced cases, complete loss of sensation in the median nerve distribution may occur.
Diagnosis can usually be made with an accurate history and a careful physical exam. Confirmation of the diagnosis can be made with a Nerve Conduction Study. In this test, electrical impulses are sent down the median nerve from various places on the forearm and wrist. The study measures the speed at which these impulses travel across the carpal tunnel. The slower the speed, the more advanced the disease.
Occasionally, an injection of corticosteroids into the carpal tunnel will be used to aid in making the diagnosis. The idea is that if the steroids help relieve the inflammation in the carpal tunnel, the symptoms will decrease. If the symptoms decrease, the diagnosis of Carpal Tunnel Syndrome is more certain. If the symptoms persist, another diagnosis may be present.
Treatment depends on the severity and cause of the condition. In the early stages of a job related Carpal Tunnel Syndrome, changing the work activities may be all that is required. Occasionally, an ergonomic evaluation of the work site is helpful in determining the problem and suggesting solutions. Cessation of smoking, addition of aerobic activities to the daily lifestyle, and weight reduction may also help. If nighttime symptoms are a problem, wrist splints can be worn to keep the wrists in a neutral position while sleeping. Splints should be avoided during the day because they can cause problems in other areas of the upper extremities.
More persistent or progressive cases may require surgery. The aim of carpal tunnel release surgery is to cut the transverse carpal ligament that runs over the carpal tunnel to relieve the pressure on the median nerve. Most patients notice some degree of relief within hours. More severe cases may improve gradually over several months time. The final degree of relief depends on the severity of the Carpal Tunnel Syndrome prior to surgery. In most cases, surgery is not an absolute necessity until numbness and tingling are present constantly or the muscles at the base of the thumb begin to shrink. Traumatic Carpal Tunnel Syndromes (those caused by fracture, dislocation or other injury) almost always require immediate surgery.
Currently at the Orthopedic Institute, two different carpal tunnel release surgeries are offered. The first is the traditional "Open Carpal Tunnel Release". In this procedure, an incision of about 3 inches is made across the wrist and into the hand towards the palm. Careful retraction of nerves and blood vessels allows the transverse carpal ligament to be fully visualized. The ligament is carefully cut and the median nerve can also be fully visualized as it travels through the tunnel. Any compression of the nerve or abnormalities of the anatomy can be appreciated. The inflamed tendon lining tissues can be removed if needed. Recovery from an Open Carpal Tunnel Release usually requires 3 weeks of splinting and minimal use of the hand. After 3 weeks, the splint is removed, but activities are restricted for a total of 6 weeks. These precautions are taken to avoid having the nerve and or tendons slip through the cut portion of the transverse carpal ligament. After about 6 weeks, there is sufficient healing of the ligament to prevent such a problem. On the average, most patients return to their jobs (with limitations) after about one month. Restrictions are lifted after 6 to 8 weeks depending on the job.
The "Indiana Technique" or "Minimally Open Carpal Tunnel Release" is a relatively new technique that is a safe option for patients with no unusual factors contributing to their carpal tunnel syndrome. The Indiana Technique uses an incision of approximately one inch in the palm and heel of the hand. Space creating instruments are slid into the carpal tunnel area to make room for a specially designed knife that is used to cut the ligament. Although visualization of most of the surrounding structures is adequate, the entire ligament and course of the nerve are not seen. Therefore, there is a slightly greater risk of damage to the nerve or surrounding structures. The advantage of the Indiana Technique is that since only the ligament is cut, there are enough supporting structures remaining to allow earlier use of the hand. A soft dressing is applied without a splint. Many patients are comfortable enough to return to their jobs within 3 weeks. Of course, this estimate varies with the type of work performed.
As with any surgery, there are certain risks involved with either carpal tunnel release technique. These include but are not limited to problems with anesthesia, wound infection, excessive bleeding, damage to vessels, nerves (including the median nerve and its branches) and surrounding tissues and excessive scar tissue.
Most patients are able to exercise their hand on their own and post operative therapy is rarely required. On occasion, a patient will find that there is a problem with persistent pain or recurring symptoms when the work that contributed to the Carpal Tunnel Syndrome is resumed. There is no guarantee that carpal tunnel release surgery will enable a patient to return to the line of work that may have caused the Carpal Tunnel Syndrome.
Although aches and pains of the upper extremities are common, not all of them can be attributed to Carpal Tunnel Syndrome. A careful examination by a qualified physician is essential. Following such an examination, your doctor will be able to better discuss the treatment options that best suit your needs. Although carpal tunnel surgery is common, it is not always necessary. Be sure to discuss all of your options thoroughly with your doctor including benefits, risks and possible outcomes.
This content is not intended as a substitute for professional medical care. Only your doctor can diagnose and treat a medical problem.