Update on Carpal Tunnel Syndrome

In this article, orthopedic surgeons from Northwestern Memorial Hospital in Chicago give us an update on carpal tunnel syndrome (CTS). They review the diagnosis, causes, and treatment of this condition. Results of new surgical methods are compared to the standard operation.

CTS remains a fairly common problem. Anything that can put pressure on the median nerve as it passes through the bones of the wrist (carpal tunnel) can cause CTS. Symptoms commonly include wrist and hand pain, numbness, and tingling. Weakness and muscle atrophy (wasting) can also occur.

The authors provide drawings of the most common, as well as unlikely, patterns of symptoms associated with CTS. They review the anatomy of the wrist bones and soft tissues, including the median nerve.

Normal pressure within the carpal tunnel is around 2.5 mm Hg. Symptoms of CTS occur when the pressure rises to 20 mm Hg. Symptoms get much worse when the pressure is 30 mm Hg or more.

No one knows for sure yet why so many people develop CTS. Trauma, shape of the wrist, tumors, and some systemic conditions are listed. Repetitive use has always been blamed for many cases of CTS. But it’s also true that just as often, people doing the same job for the same amount of time don’t develop CTS. Why the difference? We still don’t know.

Treatment depends on many factors such as how long the CTS has been present. If the cause is identified, then treatment may be centered on the specific problem (for example, taking vitamin B supplements for CTS caused by vitamin B deficiency).

Conservative (nonsurgical) care is usually tried first. This might include physical therapy, splinting, and/or antiinflammatory drugs. Surgery is advised when all other forms of treatment have failed or in the case of trauma or infection.

Surgery is done to release the transverse carpal ligament (TCL). The TCL stretches across the median nerve. Cutting it takes the pressure off the nerve. This operation can be done with an open incision or with a closed approach using an endoscope.

Endoscopic carpal tunnel release uses a thin, narrow tool that slips under the skin and into the carpal tunnel. Then the TCL is cut in half. The tool can be slipped back out with less risk of soft tissue or nerve injury. Results are the same between these two methods when patients are examined three months later.

The author say that more studies are still needed to better understand CTS. The result could mean more effective, less invasive treatments. Understanding the causes of CTS may help us find ways to prevent it as well.