The median nerve supplies sensation to your thumb, as well as the index, middle and half of the ring fingers. It also supplies power to the muscles at the base of the thumb. Below your wrist, the median nerve runs through the carpal tunnel, which consists of a u-shaped collection of bones with a ligament (the transverse carpal ligament) over the top; any increase in the volume of structures within the tunnel results in a pressure increase within the carpal tunnel. The nerve is vulnerable to pressure and increased pressure slows transmission of nerve impulses. Prolonged pressure (often described as compression of the nerve) may cause the nerve to wither.
As a result of your median nerve compression, you feel pain and tingling; as the nerve withers, numbness and weakness occur. While I can effectively treat your pain and tingling with surgery, the permanent symptoms of numbness and weakness may not recover completely. In these cases, surgery prevents further deterioration.
Commonly people experience some or all of the following: pain, tingling, pins and needles and numbness. The symptoms are most prevalent in the thumb, index and middle fingers, but may radiate up into the arm. Initially the symptoms are intermittent and frequently occur at night or when the hand is positioned in a particular way, for example driving, writing and talking on phone. The night waking can be very troublesome for both patients and their partners.
As the compression becomes more significant and the nerve dies back, the symptoms may become permanent. At this stage people notice that the permanent numbness causes difficulty with tasks that require fine manual dexterity, for example sewing or doing up little buttons. Poor sensation may also cause people to drop objects. Pinch grip and grasp may become weaker.
Carpal tunnel surgery is usually performed under local anaesthetic. I make a cut of 3-5 cm down the base of your palm. Then I divide the transverse carpal ligament (the fibrous band on the palm side of your hand, close to the wrist) so it springs open. This allows more room within the carpal tunnel and reduces pressure on the nerve. During the procedure, I inspect the nerve, and then the wound is closed with dissolving sutures. A bulky dressing is applied to support the wrist.
The pain and tingling you felt before the surgery should resolve in the first 48-72 hours as the pressure on the nerve is relieved.
If you experienced permanent numbness or severe nerve damage before the operation then the nerve will need to grow back for your symptoms to resolve. Your recovery time may be 6-12 months. As the nerves grow back, your fingers can feel tingly and occasionally unpleasant. Sometimes your nerve will not recover fully. If your thumb muscles have been without nerve supply for more than 12 months, they are unlikely to regenerate at all.
Your grip will be temporarily weaker than usual following carpal tunnel surgery. Performing heavy work or significant activities will feel uncomfortable for quite some time. Your discomfort is due to the division of the ligament that helps stabilise your wrist. This phenomenon is called “pillar pain” and resolves over 3-4 months following the procedure. I recommend you don’t try to make the “pillar pain” go away faster with excessive strengthening exercises; time alone settles it.
You can drive a car when your hand feels comfortable and strong enough to control a motorcar.
As a minimum, I recommend not driving for two weeks if you have had one side released and four weeks if both sides have been released.
It is very important to elevate your hand as often as possible, following your operation. This reduces swelling which makes your hand more comfortable and makes moving your fingers easier.
I encourage you to perform light activities, as guided by comfort, from the first day following your operation.
Perform hand exercises every four hours or as often as possible. Please read Post Hand Surgery Advice and Exercises.
Please don’t try to rush your recovery – if you find that your wrist is achy following activity, then you have probably done a bit too much. Elevate your hand, take some pain relief and then lighten your activities for the next few days. If you attempt heavy activity too soon, you may delay your overall recovery.
This depends on your occupation, but as general guidance:
This may be longer if you have both sides operated on at the same time. As with all other aspects of your treatment, we will talk about your recovery and return to work during our consultations.
Possible problems include swelling, bruising, bleeding, blood collecting under the wound (haematoma), infection and splitting open of the wound (dehiscence).
Depending on the size of your hands, you will have a scar between 3-5 cm in length over the base of your palm. The scar may become a little thickened and red as it heals, but this will settle with time. Your scar will be tender, and this will also resolve. Firm massage with a plain cream or oil will help the scar heal.
I am acutely aware of the median nerve at all times during your carpal tunnel surgery, however occasionally the nerve or its branches can be vulnerable to damage. This includes small branches that supply the palm, a variant branch that supplies the 3rd web space between your middle and ring fingers, and the branch that supplies the base of thumb if it has variant (unusual) anatomy. Nerve damage that causes problems may require further surgery. Significant nerve damage is extremely rare.
If your symptoms do not resolve, it may mean that not all the ligament has been cut. This is rare (2%), but may mean the operation would need to be repeated.
Sometimes the compression will have caused permanent damage of the median nerve, and recovery will be incomplete. Incomplete recovery becomes increasingly likely the longer your thumb muscles have been without nerve supply.
If you have a tendency to triggering or thumb base arthritis then a carpal tunnel release, with division of the ligament that provides stability across the wrist, may cause a temporary exacerbation of these problems.
This is a syndrome of pain, stiffness and swelling that occurs in about 5% of people following surgery. The symptoms are out of proportion to the nature of the operation. At the moment we are not sure why it happens, and it cannot be predicted whom it will happen to. I will monitor you for this after the operation. The treatment involves special forms of pain relief and physiotherapy. Read more about Complex regional pain syndrome.
Please also read Complications after Hand Surgery.