Carpal Tunnel Decompression

The median nerve is compressed at the base of the palm. A common condition, particularly in women, and often in both hands.

Tingling in the thumb and neighbouring fingers, sometimes progressing to numbness, with pain that can be felt in the arm. Sleep is often disturbed, and during the day symptoms may occur particularly when the hand is relatively still (driving, holding the phone).

In severe cases the symptoms are constant, pain can be a major problem, and muscle weakness can ensue.

Often made on the history alone, assisted by clinical examination. Sometimes specific electrophysiology tests are advised.

Wearing a night splint, steroid injections (usually temporary relief). Surgery.

The operation fails in a small proportion (2%) and may need to be repeated with a more extensive release. Following successful surgery late recurrence is unusual.

Injury to the nerve during the operation can occur, resulting in permanent numbness of part of the hand or weakness of the thumb, possibly pain, and the need for further surgery. In my experience significant problems of this nature are very rare.

Pain at the base of the palm in the muscles on either side (pillar pain) occasionally persists and causes difficulty in people who have heavy manual jobs.

With planned operations complications are unusual, overall, probably about 5% of patients have a post-operative problem, of which the vast majority are temporary and do not affect the final result.

• Infection – the signs may develop after a few days, with increasing pain, swelling and redness. Treatment with antibiotics is usually sufficient. Very occasionally an infection can be severe and cause major problems.
• Wound healing problems – for instance excessive bleeding, causing a painful swollen wound (haematoma) or delayed healing may slow down the recovery.
• Swelling and stiffness – these always occur to a certain extent, and it is very important to elevate and exercise the hand after an operation or injury. Occasionally the swelling is severe, prolonged and associated with pain, due to the development of the poorly understood condition of reflex sympathetic dystrophy. This occurs unpredictably and is treated by physiotherapy and pain medication. Very rarely it leads to long-term stiffness and disability, compromising the function of the hand permanently.
• Scar tenderness – all scars are tender for at least two months, and often longer. In about 10% of people the scar, after healing well initially, thickens and becomes itchy, red and more painful after the first month. If this happens the full process of maturation of the scar (settling down to normal, thin, mobile skin) can take more than a year. Occasionally nerves running in or just under the skin at the site of an incision are damaged, resulting in persistent tenderness of the scar.

Usually done under local anaesthetic as a day case. The incision is at the base of the palm, a ligament running over the nerve is cut, releasing the pressure on the nerve. Dissolving stitches are routinely used to close the skin.

The dressings leave the fingers and thumb free to move normally. If both hands are symptomatic, both can be done at once – because you can use and move the hands it is possible to look after yourself.

Even though it is possible, I do not recommend that the operation should be done by keyhole surgery. The benefit of a somewhat shorter time off work does not outweigh the increased risk of nerve injury.

Normally the symptoms are immediately improved. The hand must be elevated for 48 hours, particularly when still, to minimize swelling, which causes pain and stiffness, but should also be moved and used as normally as possible. The dressings can come off after about 5 days, following which you can get the wound wet. Any knots from the dissolving stitches should be picked off after two weeks.

Any pain after the operation usually settles if the hand is kept elevated. Painkillers may be needed for the first few days. Physiotherapy is not usually needed.

Ability to drive post-operatively varies from person to person – it is up to you to decide when you can do so. About a week later is normal for most people. If the left hand is operated on it may be longer because of the need to use the gear lever.

If the symptoms are severe and constant before the operation, particularly in the elderly, recovery can occur very slowly – over a year or more. Sometimes the symptoms seem to get worse initially, because the first sensations to recover are pain and tickle. In a small proportion of people the nerve is too badly injured to be able to recover, and the symptoms persist.

The scar remains tender for at least two months – this can be frustrating. It should be massaged with cream (lanolin, E 45, DoubleBase). Manual workers normally need about 6 weeks off work; office workers can get back sooner.