First, the facts: carpal tunnel syndrome surgery is the second-most common type of operation, with more than 230,000 procedures performed annually.
The Bureau of Labor and Statistics says U.S. employers spend more than $7.4 billion on workers' compensation costs because of carpal tunnel.
The condition is often thought to be a work-related disability, but according to some local experts, that may be a myth.
Dr. Kelley Crozier, chairwoman of the department of physical medicine and rehabilitation and medical director, Reading Hospital Rehabilitation at Wyomissing, explained what carpal tunnel syndrome, or CTS, is.
“CTS is caused by compression of the median nerve as it passes through the carpal tunnel in the wrist,” Crozier said. “The carpal tunnel is formed by a ligament on top and the wrist bones on the bottom, which are the carpal bones. The median nerve supplies sensation to the thumb and the first two-and-a-half to three fingers, and muscle strength in the hand to the thumb muscles.”
Crozier said CTS occurs when inflammation causes increased pressure on the median nerve as it goes through the narrow carpal tunnel.
Dr. Leonard L. D’Addesi, an orthopaedic surgeon with Orthopaedic Associates of Reading Ltd., Wyomissing, said CTS is commonly referred to as idiopathic, a condition which can arise spontaneously and for which the cause is unknown.
“The truth is, we are not sure why people get it,” D’Addesi said. “The carpal tunnel is almost like a hard pipe, in that it doesn’t expand. If the volume is suddenly limited, then the only thing that can get injured is the nerve.”
Dr. Brian A. Tinsley, an orthopaedic surgeon with Orthopaedic Associates of Reading, said anything that inflames the tendons can reduce space for the nerve.
“A misconception is that typing causes carpal tunnel syndrome,” Tinsley said. “It has definitely been proven that is not the case. But some of the symptoms can flare up with overuse.”
Crozier said some occupational factors can increase or aggravate CTS, especially if the work requires repetitive or forceful hand use.
“Other causes can include inflammation of the tendons, which can be caused by cysts or illnesses such as rheumatoid arthritis,” Crozier said. “People with diabetes, arthritis, obesity, with connective tissue diseases or who are pregnant are most at risk. Certain people are born naturally with small carpal tunnel canals.”
Tinsley said people should be aware that numbness and a tingling sensation in the thumb, index and middle fingers can signal CTS.
“Most patients start noticing when waking up in the middle of the night and feel numbness,” Tinsley said.
Crozier said that in severe cases, the compression of the median nerve goes beyond the sensory fibers into the motor fibers, causing weakness in the hands that can lead to difficulty in performing everyday tasks.
“In very advanced cases, persons with CTS may have trouble holding onto things,” Crozier said.
D’Addesi said it can be dangerous for people to shrug off the symptoms and allow the condition to go on untreated.
“If you come in too late, there can be nerve damage that is beyond repair,” D’Addesi said. “We want to get to the carpal tunnel before there is nerve damage. Numbness and tingling are not normal and can be straight-up CTS, but we also want to rule out other nerves being pinched or a problem with the neck.”
Crozier agrees that early intervention is best to avoid developing weakness in the hand.
“The first line of defense is to maintain good posture while doing tasks requiring repetitive actions and keeping your wrist in a neutral position,” Crozier said. “Wearing an over-the-counter splint or wrist support can help keep the wrist in a neutral position, which is especially helpful when sleeping.”
All three doctors warn that without treatment, the median nerve can become damaged, resulting in hand weakness and atrophy of the thick part of the hand.
CTS is first diagnosed through a clinical evaluation and exam.
“I usually take the patient’s history and do a physical exam to test the nerve,” Tinsley said. “I do a couple of tests to push on the nerve where it is compressed to try and reproduce the symptoms. When the symptoms have gotten sever, a patient is sent for a nerve test to test how well the nerve is sending signals and for muscle weakness.”
Crozier said a diagnosis can also be made through electrophysiological testing.
“This consists of examining how quickly the nerves conduct through the carpal tunnel by administering small static electric zaps.” Crozier said. “If these conduction speeds are below normal. That could indicate CTS. Damage to the muscle is diagnosed by sticking a thin wire into the muscle and reading the electrical conduction activity on an electromyography machine.”
Many patients believe surgery is inevitable, but that is another myth.
“I don’t want to rush a patient into an operation,” D’Addesi said. “If the nerve test shows the condition is mild, that is a nonoperative case and is treated with bracing, therapy, ant-inflammatory medicines and cortisone injections. Surgery is for a small percentage of patients and is not the normal treatment.”
For severe cases where surgery is needed, an endoscopic carpal tunnel release is performed where pressure on the median nerve is released.
Tinsley said the endoscopic release has been done for about 20 years.
D’Addesi said the patients usually do really well with the release operation, because it requires only a small incision and generally a fast recovery.
Crozier said there are some alternative treatments which have provided relief for some patients, but have not been supported by sufficient research.
“These include yoga, acupuncture, relaxation exercises and vitamin B6 supplements,” she said.
D’Addesi said there really isn’t much anyone can do to prevent CTS.
“It’s a problem with volume of space, and if the tendons swell, you can’t really prevent that from happening,” he said. “As people get older, the tissue gets thicker, which can put pressure on the nerve.”
Tinsley agreed saying the condition is a combination of a lot of factors.
“We don’t know why some people get it, and there is no real way to prevent it,” he said. "It’s just something to be aware of because it can cause permanent problems."