Carpal Tunnel Syndrome
DescriptionAn in-depth report on the causes, diagnosis, treatment, and prevention of Carpal Tunnel Syndrome.
Alternative NamesRepetitive Stress Injuries; Thoracic Outlet Syndrome
Every year over 200,000 people in the US undergo surgeries for carpal tunnel syndrome, rendering them among the most common surgical procedures performed on the hand. In various trials, 70% to 90% of patients who underwent surgery were free of nighttime pain afterward.
Candidates for Surgery
Although evidence strongly suggests that surgery is more effective than conservative approaches (at least in patients with moderate to severe CTS), the decision about whether and when to have surgery to correct CTS is a troubling one for patients. Electrodiagnostic and other tests used to confirm the presence of CTS are not very useful in determining the best candidates for surgery. For example, results suggesting severe CTS may not relate at all to surgical success or the lack of it.
In general, patients with the following findings are less likely to respond to conservative therapy and, therefore, might benefit from surgery:
According to a 2002 study, if none of these factors are present, conservative therapies (splinting and anti-inflammatory agents) are effective in two thirds of patients. However, the conservative approach was ineffective in 60% of patients if only one of these factors were present, in 83% with only two of them, and in virtually all patients who had three or more.
Surgery does not cure all patients, and because it permanently cuts the carpal ligament, some wrist strength is often lost. A number of experts believe that release surgery is performed too often. They recommend aggressive conservative treatment (e.g., splints, anti-inflammatory agents, and physical therapy) before choosing the more invasive option.
Nevertheless, other experts argue that CTS is often progressive and will worsen over time without surgery. Furthermore, evidence now strongly demonstrates that surgery is superior to splints and conservative measures for the relief of pain.
Factors that may increase the chances for favorable surgical results:
Factors that may reduce the chances for success:
Factors that make no difference in results:
Standard Release Surgical Procedures
Open Release Surgery. Traditionally, surgery for CTS entails an open surgical procedure performed in an outpatient facility. The surgery is straightforward:
Endoscopy. Endoscopy for carpal tunnel syndrome is a less invasive procedure than standard open release.
Briefly, the procedure is as follows:
Patients report less pain and return to normal activities earlier (about half the time) than those who had the open release procedure. Nevertheless, at this time the best evidence available does not show any significant long-term advantages of endoscopy over open release in terms of muscle or grip strength or dexterity. The endoscopic approach may even carry a slightly higher risk of pain afterward. This may be due to a more limited view of the hand with endoscopy. (In the open release procedure, the surgeon has a full view of the structures in the hand.)
The Mini-Open Approach. In recent years, more surgeons have adopted a mini open--also called short-incision--procedure. It uses only a one-inch incision, but it still allows a direct view of the area (unlike endoscopy, which is viewed on a monitor). The mini-open approach may allow for quicker recovery while avoiding some of the complications of endoscopy, although few well-connected studies have been conducted on its benefits and risks.
Timing for Recovery. Patients should expect the following course:
For some patients, release surgery relieves CTS symptoms of numbness and tingling immediately.
Physical Therapy. Physical therapy is very important to help rebuild wrist strength. While physical therapy does not reduce the recurrence of symptoms or improve the long-term benefits of surgery, it does accelerate postsurgical recovery. Hand exercises can help restore circulation, muscle strength, and joint flexibility in the hand and wrist. (Wearing a splint to immobilize the wrist after surgery confers no benefits.)
Complications and Long-Term Outcome
In spite of the success of carpal tunnel surgery, treatment failure and complication rates range in studies from 3% to 19%. Postsurgery complications may include the following:
If pain and symptoms recur, the release procedure may be repeated. Reasons for failure include:
Procedures for Surgical Failure or Recurring Symptoms
Neurolysis. In some severe cases or when scarring is extensive after surgery, surgeons may choose to sever the nerves that are responsible for the pain using a procedure called external or internal neurolysis. The procedure may extend recovery time substantially, and the need for repeat surgeries may be higher in those who undergo the procedure. One report indicated that neurolysis should be considered if there has not been any recovery three months after surgery, after which improvement is unlikely. Nevertheless, it is unclear if this approach offers any benefits beyond conservative measures to free the nerve from surrounding scar tissue.
Implants. In another procedure for recurrent carpal tunnel syndrome, physicians may take muscle flaps or even fatty tissue from other parts of the body and implant them at the site of the nerve injury. Such flaps enhance the development of new blood vessels, provide padding, and possibly serve as a bed for nerve regrowth. These implants may be used with or without nerve dissection. Another procedure called vein wrapping uses grafts taken from veins to help protect the scarred nerves.