Carpal Tunnel Syndrome

By Dr. Kumar K K

Hand, Shoulder and Micro-Vascular Specialist

 

Who gets it?

It can occur in any patient but is more common in females over the age of 50 years.

Cause – In the majority of patients, the cause is still unknown. However there are a number of medical conditions that predispose patients to Carpal Tunnel syndrome. These include pregnancy, thyroid disease, rheumatoid arthritis and wrist injuries.

Carpal tunnel syndrome occurs when the median nerve is compressed at the level of the wrist. The nerve and tendons that bend the fingers pass from the forearm into the hand through a narrow tunnel called the carpal tunnel. When there is a build up of pressure in this tunnel the nerve becomes squashed and causes symptoms of carpal tunnel syndrome.

Symptoms

Pins and needles in the thumb, index and middle fingers. This commonly occurs at night and the patient is often awakened from sleep and has to shake their hands to gain relief from these symptoms. Occasionally in severe cases, the muscles on the front of the palm next to the thumb can waste, causing hollowing. In such severe cases the thumb may become weak or clumsy.

Clinical Examination

Modified Phalen’s test – Direct pressure over the carpal tunnel especially whilst bending the wrist forward, may reproduce the pins and needles in the thumb, index and middle fingers.

Tinel’s test – Tapping the nerve in the carpal tunnel may cause tingling in these fingers.

Investigations

Nerve conduction studies are used to record the speed of the nerve across the wrist joint. This can be compared to the other hand, or in cases where both hands are affected, compared to normal population data. The test takes about 20 minutes and is slightly uncomfortable.

Non-operative treatment

Simple painkillers and resting splints can offer help. Occasionally a steroid injection into the carpal tunnel will improve symptoms. However the majority of patients who have troublesome symptoms have surgery.

Operative treatment

Most patients who have troublesome carpal tunnel syndrome have surgery. The surgery is a day case procedure usually under regional anaesthesia and takes about 10 minutes.

The surgery can be performed open (through a 4cm incision) or endoscopic
(Keyhole, through one or two 1cm incisions). The results are the same for both technique.

Open technique

Local anaesthetic is infiltrated under the skin in line with the incision. Once numb, the skin is incised and then the underlying fat is retracted.

Care is taken not to injure sensory nerves to the palm. At the base of the wound is a thick band of tissue called the transverse carpal ligament. This structure needs to be released to allow the contents of the carpal tunnel to be decompressed.

Having released this ligament the contents of the carpal tunnel are inspected to ensure adequate release and no other conditions are present.
The skin is sutured with fine absorbable sutures and a bulky dressing is applied.

Post-operative rehabilitation

The hand should be elevated as much as possible for the first 5 days to prevent the hand and fingers swelling. Gently bend and straighten the fingers from day 1. My preference is to remove the dressing at 2 days. The wound is cleaned and redressed with a simple dressing. Avoid forced gripping or lifting heavy objects for 2-3 weeks. The sutures dissolve at about 10 days. You should notice an improvement in symptoms within a week but the final result may be realized at about 3 months.