Carpal tunnel

What is carpal tunnel syndrome?
The carpal tunnel syndrome is a compression of a large nerve located in the palm of your hand called the median nerve.
The median nerve provides the sensitivity of the thumb, index, middle and half of the ring finger. The nerve also provides muscle innervation at the base of the thumb.
The nerve is compressed when it passes through the carpal tunnel. This tunnel is inextensible between the bones of the wrist on one side and a thick ligament on the other (see diagram). In addition to the median nerve, 9 tendons of the fingers pass through the carpal tunnel.
The compression of the nerve results from the increase in volume of the tendons and their synovial envelopes, or a narrowing of the channel due to osteoarthritis or a fracture.

Who gets carpal tunnel syndrome ?
The carpal tunnel syndrome is very common in the general population, particularly among women in their fifties.
Manual workers performing repetitive activities are more often affected than the general population .
Finally, some diseases that increase the thickness of the sheath around the tendons are more often associated with carpal tunnel syndrome: hypothyroidism, rheumatoid arthritis , amyloidosis , diabetes.

What are the symptoms of carpal tunnel syndrome?
Carpal tunnel syndrome results in pain, tingling and numbness of the thumb, index, middle and sometimes the ring finger.
Usually, these sensory disturbances affect only the fingers, but the pain may spread to the whole hand and arm.
Most often, these symptoms appear at night, waking you up at 3am and are temporarily relieved by shaking the hands for a few minutes.
Bilateral symptoms is very common.
Severe compression leads to progressive loss of sensitivity of the fingers and paralysis with muscle atrophy .

Fig1
It is better to operate before this stage because recovery may not always be complete.

Are additional tests useful ?

– X-rays of the wrists and hands are not systematic.
They might detect bone channel narrowing secondary to an old injury or osteoarthritis.
– Electromyography (EMG) measures the ability of the median nerve to transmit electrical signals.
This examination can confirm the diagnosis, locate the level of compression and detect an anomaly of the other nerves of the arm.
This examination is not always necessary. It presents no danger, but it is sometimes a bit unpleasant.

What is the treatment of carpal tunnel syndrome ?
Rest and a splint may help the symptoms to disappear .
Steroid injection can be performed if the symptoms persist.
If conservative treatment is not enough, surgery is recommended to reduce the pressure in the carpal tunnel and release the median nerve. The procedure involves opening the thick ligament that closes the channel .

 


Synovium surrounding the tendons can be removed when it is thickened.
This procedure is done under regional anaesthesia of the upper limb.
The size of the scar varies and depends on whether the operation is performed open or endoscopically.
Endoscopic technique reduces the scar in the palm of the hand, and allows faster recovery .
Fig2Fig3

It is not feasible in all cases. An experienced surgeon is required to avoid potential complications.

After surgery
Symptoms usually disappear after the first night.
Moving your fingers as normally as possible is recommended even if you have a splint .

Do not keep the arm sling continuously; moving the elbow and the shoulder is recommended.
You will see your surgeon between the 5th and 8th postoperative day.
Usual activities can be resumed within 2 to 3 weeks.
For manual workers, a 2 to 6 week work leave is usual.
Complete ligament healing is usually achieved within 6 weeks. Grip strength without pain is gradually restored within 3 to 6 months.
The palmar region may be sensitive to pressure for 3 to 6 months.

In summary
Carpal tunnel syndrome is very common. It provides tingling fingers particularly troublesome at night. When discomfort persists despite steroid injection, endoscopic carpal tunnel release provides immediate and permanent relief.
An informed consent form will be explained and given to you before the surgery.
I hope this presentation gave you as objective information as possible about the principles of the surgery, but also about the risks of complications.
If you are operated you will also be informed about the symptoms to detect potential complications early on.