By Ian D. Archibald, M.D., F.A.C.S., CIME
Carpal tunnel syndrome (CTS) is a common nerve disorder caused by compression of the median nerve as it passes across the wrist into the hand and through a region known as the carpal tunnel. Many factors contribute to the cause of this condition and symptoms may vary. Generally, it occurs in patients over the age of 30 years and is five times more likely to occur in women than in men. The most common symptom of carpal tunnel is night time awakening with pain and numbness in the wrist and fingers. The same symptoms will occur with driving and repetitive wrist activity. CTS can also be associated with other conditions including wrist fractures, obesity, diabetes, low thyroid state, pregnancy, and rheumatoid arthritis. Most commonly, there is no definite cause.
Certain types of employment have been implicated as a cause of CTS, creating controversy in the workplace. Certainly the use of vibrating machinery, prolonged typing and data entry, or any activity that constantly holds the wrists in a flexed position can result in CTS symptoms. Whether these activities actually cause CTS or the workers are predisposed to CTS due to heredity or body makeup is highly debated.
Diagnosis is based on a complete patient history and physical exam. It is important to rule out other conditions that mimic CTS including other nerve entrapments, especially in the neck. A nerve study is usually diagnostic although it can be an uncomfortable procedure for the patient.
Initial treatment involves activity modification, wrist splinting especially at night and appropriate pain medication. In my experience pain medication, especially narcotics do not help CTS symptoms. In severe pain situations, a cortisone injection into the carpal tunnel will usually relieve pain temporarily.
The need for surgical treatment is evident when symptoms have not responded to the above treatment measures. In patients who have a specific job that causes CTS symptoms, it is imperative that they change jobs. Returning to the same work following a carpal tunnel release will almost always result in the recurrence of symptoms. Delay in surgical treatment can result in loss of dexterity, loss of feeling in the hand and may become permanent in extreme cases.
A carpal tunnel release (CTR) can be accomplished three different ways. The traditional procedure includes an open incision in the palm and wrist area approximately two to three inches long. This directly exposes the compressing ligament and allows maximum protection to the nerve while the ligament is released. There can be considerable variation concerning the anatomy of this region including abnormal locations of blood vessels and or the median nerve and its branches. Direct exposure allows for a very safe carpal tunnel release. Recovery usually takes four to six weeks with the most common complaint being soreness in the region of the wound.
More recently scope procedures have been developed to release this ligament without direct exposure and studies show patient recovery may be quicker (i.e. two – three weeks.) However, there has been an increase in nerve injuries with these techniques.
Finally, a combination of the concepts of these two techniques has resulted in a limited or “mini open” technique. The incision is kept to less than one inch and allows for clear exposure of the median nerve followed by the use of specialized instruments that release the ligament under direct vision. There is minimal scarring and less soreness while still providing maximum protection to the nerve. After twenty years of treating CTS and more than 2,000 CTR procedures, I personally find this technique to be most effective.
CTR usually results in very happy patients. However, as with any medical condition or surgery, there are no guarantees. Over the years I have learned that older patients who do not have repetitive wrist activities do well universally. Workers who have repetitive physical work demands cannot expect long term improvement following CTR if they go back to the same job. Finally, those patients that have direct trauma to the nerve with or without wrist fracture or those who have severe diabetes do not do as well.
In summary, CTS is an extremely common condition. There are a variety of symptoms but the diagnosis is usually not difficult and treatment options help preserve hand function and relieve numbness and pain.