Carpal Tunnel Syndrome

Carpal tunnel syndrome is caused by compression of the median nerve within a tunnel comprising a "U" shaped collection of bones with a tight carpal ligament at the top. The most common cause is tenosynovitis. The nerve can gradually wither if the condition is not treated. This causes loss of sensation and wasting of thumb muscles, which may not always be completely relieved by surgery. There are a number of ways of treating the condition including activity modification, splinting, anti-inflammatory drugs, steroid injections and surgery. Additional nerve testing may be required. Surgery is recommended if you have had the problem for a long time, your symptoms are severe, non-surgical treatments have failed or if the doctor detects wasting of muscles or loss of sensation in the hand. Surgery involves cutting the ligament over the tunnel to relieve the pressure on the nerve. This can be achieved in two ways.

Open technique: This is the most common type. Under local anesthetic a cut is made in the palm and the carpal ligament is reached by cutting through the underlying tissues and muscle. The ligament is then cut under direct vision

Endoscopic technique: This is suitable in 25% of cases. The carpal ligament is reached from a small cut at the wrist and divided from underneath. The ligament is seen using a small telescope, which provides a magnified image on a television screen that the surgeon watches whilst performing the surgery. There is no scar in the palm. Technical difficulties can occur necessitating conversion to the open technique (6%).

View the video of the Carpal Tunnel Syndrome procedure below.

Postoperative care

Either procedure is done as a day case. Local anaesthetic is injected around the site of operation in the open procedure and therefore this area and the nearby fingers will remain numb for up to ten hours after surgery. As this effect wears off it may well be worth taking some pain-killers. Your CT symptoms at night should settle immediately. Any tingling in the fingers may take some weeks to disappear.

Hand elevation is important to prevent swelling and stiffness of the fingers. Please remember not to walk with your hand dangling, or to sit with your hand held in your lap. It is fine, however, to lower your hand for light use and you should get back to normal light activities as soon as possible as guided by common sense. There are a number of exercises you should do to prevent stiffness.

You have been discharged with a supportive dressing, consisting of gauze, wool and a crepe bandage. You may be requested to return within 48 hours if you have had keyhole surgery, in order to reduce the dressings. In the open procedure, the dressings will be left on for about 10 days. There obviously will be some swelling and bruising. Look out for any redness or tenderness in the area round the wound that might indicate an infection. Do not apply antiseptic but contact the ward if you have any worries. It is quite safe to leave the wound open.

At this stage it is safe to get the hand wet in a bath or shower. The wound and the surrounding skin often become very dry and will be more comfortable if a moisturiser is applied. An easy way of doing this is to immerse your hand briefly in some warm water to which some Johnson's baby oil has been added.

Alternatively, apply an unscented moisturising cream such as E45 or Nivea to the skin. You can drive if you are comfortable and have regained full finger movements and if you have sufficient power to control the vehicle. Timing of your return to work is variable according to your occupation and you should discuss this. Your stitches will be removed at about two weeks after the operation. Following this the scar will be somewhat lumpy, firm and tender. The scar will settle after about three months but this can be helped by massaging the area firmly with the moisturising cream.

Complications

• Nerve damage: Nerves running in the region can be bruised or damaged during the surgery and form a painful spot in the scar (neuroma) or numbness. The most commonly involved areas are the heel of the hand or the space between the middle and ring fingers. This complication is rare (2%) but may require a further operation to correct.
• Recurrence: If you continue to have attacks of tingling and numbness, it might mean that not all the ligament has been cut. This is rare (1%) but the operation would need to be repeated to correct this.
• Infection: Any operation can be followed by infection and this would be treated with antibiotics.
• Scar: You will have a scar with either technique which will be somewhat firm to touch and tender for 6-8 weeks. This can be helped by massaging the area firmly with moisturising cream.
• Grip: You will find that your grip is weaker than previously and slightly painful, causing discomfort in the heel of the hand. This will gradually improve over six months.
• Stiffness: About 5% (1 in 20) of people are sensitive to hand surgery and their hand may become swollen, painful and stiff after any operation (algodystrophy). This problem cannot be predicted but will be watched for afterwards and treated with physiotherapy.
• Recovery: Patients who had very numb fingers or wasting of the thumb muscles before surgery will probably never regain full nerve function. Recovery can be very slow (6-12 months). As the nerves grow back, the fingers can actually feel tingly or even unpleasant.