Carpal tunnel syndrome
Pain or numbness caused by nerve compression at the wrist
About Carpal Tunnel Syndrome
Carpal tunnel syndrome (CTS) is usually described by patients as ‘pins and needles’ in the fingers, numbness or tingling or sometimes pain in the hand and wrist. It often wakes people at night and they have to wake and move their hands for relief. It tends to be worse when using the hands repetitively or sustained grip.
The symptoms are due to compression of the median nerve. This is a major nerve that provides feeling to most of the fingers, but usually not the little finger. It also controls some of the hand and thumb muscles. When patients have severe symptoms the hand may lose grip strength, and become less able to use the hand for delicate tasks like buttons, writing or keys.
What causes carpal tunnel syndrome?
The cause of CTS is compression of the median nerve at the wrist. The tunnel is the arch of the carpal bones covered by the tight flexor retinaculum. This is also known as the transverse carpal ligament.
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The tunnel contains 9 tendons that are usually not affected, however the median nerve is much softer and more sensitive to compression. When this nerve is compressed it functions poorly and symptoms are caused by this loss of normal nerve function.
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Anything that makes the tunnel smaller can bring on CTS. Fluid retention in menopause or pregnancy; tendon sheath swelling in inflammatory conditions; deformity caused by fractures and joint disease; hormonal conditions such as diabetes, thyroid dysfunction also may be causes. In many cases however there is no obvious cause identified.
Diagnosis of CTS
Carpal tunnel syndrome is normally diagnosed by your doctor by a combination of your symptoms, history and physical examination. Often the diagnosis is quite clear, but sometimes further tests may be required.
Tests look at other contributing problems such as: scans of your neck; inflammatory blood markers; and wrist x-rays may be required. Sometimes more than one thing may be contributing to your symptoms.
Nerve conduction studies are one of the most useful tests. They can help define the site of nerve compression but also help distinguish between similar nerve compression problems in neck and elbow.
Should I have surgery?
Although carpal tunnel surgery is considered minor many patients do not require surgery. Sometimes simple activity modification is enough to avoid symptoms - such as more ergonomic desk tasks or lighter tools. Some patients may only have temporary CTS due to swelling after surgery or pregnancy.
Some patients who have mostly nocturnal symptoms can use a night splint on their wrist for relief. Patients with underlying conditions may get better once these causes are treated.
When compression becomes severe however there is a risk of permanent nerve damage. This can lead to permanent loss of feeling or weakness that doesn't recover. Signs of severe compression is numbness that doesn't go away or is there all the time. Also any weakness, particularly if the hand muscles are getting smaller is a great concern and you should see a surgeon.
Frequently nerve compression may be a combined problem at the carpal tunnel but also the neck or elbow. It is often worthwhile to release the carpal tunnel first to see if this simple procedure is sufficient to avoid more major surgery.
Carpal Tunnel Release Surgery
Surgery for carpal tunnel syndrome is known as a carpal tunnel release. It involves a small cut in the palm and splitting the ligament to relieve the pressure on the nerve. it is a delicate procedure that cuts directly next to the median nerve and takes special care. Many patients will have immediate relief of symptoms if treated early.
The surgery can be done in hospital asleep (under general anaesthetic), or awake in clinic (after injection of local anaesthetic). If you are older or have other risk factors local anaesthetic is safer. If however you have more complex surgery, don't tolerate needles or having both sides you may prefer a general anaesthetic.
Both hands can be done together without too much inconvenience, or one at a time. It may be more difficult having both done together but most patients manage well and you require less time off work. You should talk to your surgeon about these options.
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Release can be performed open or endoscopically which is more expensive due to additional equipment. At QJC we prefer open surgery due to the lower risk of irreversible nerve injury under direct vision.
What are the risks of surgery?
Carpal tunnel release is a comparatively safe minor procedure, however all surgery carries some risks. A general anaesthetic has intrinsic risks you can speak to our anaesthetists about this. Local anaesthetic requires injection in the palm that may be painful and some sensation may be felt during surgery.
Wound infection can occur especially if the dressings are disturbed. This normally only requires antibiotics but can require surgical drainage. Wounds can have delayed healing and can split open if stitches are removed too early. This is increased in patients who smoke, have diabetes or steroid/immunotherapy treatment.
Pain or tenderness in the palm is common especially for the first 2 weeks. This is similar to any deep cuts in the palmar hand skin. Deeper pain along the cut ends of the tendon can occur for longer until the ligament heals over. This can be helped with de-sensitisation therapy.
After all hand surgery there is a risk of CRPS. This is persistent pain and stiffness, heat and swelling after surgery. This is treated and avoided by early active mobilisation. vitamen C is also a helpful treatment. This risk of this is about 1:200.
Nerve injury is possible as the surgery is directly over the median nerve and right next to the ulnar nerve. This is why we recommend having surgery with a specialist surgeon to reduce risk. recurrence after surgery is possible but very rare and usually due to scarring or blood clot if properly released. Finger stiffness may occur due to scarring and adhesions within the carpal tunnel. As the skin edges stick together the tendons within the tunnel may also become stuck if the are not encouraged to move post-operatively.
Complete recovery is not always possible. If you already have muscle loss this may not recover completely, but surgery will prevent it from getting worse. Similarly if you have had compression for a very long time, full sensory recovery may not occur or take up to a year. Where there are multiple sites of nerve compression carpal tunnel surgery will only partially relieve symptoms which are due to compression at the wrist.
Most of the risks described are infrequent or minor, and most patients are happy with carpal tunnel release and make a quick recovery without any problems.
Recovery from Surgery
The surgical cut is closed with 5 or 6 stitches which need to be removed in about 10-14 days. After surgery you will have bandages and a light breathable dressing. The bandages may be removed after 48 hours and a waterproof film applied to keep it dry.
It can be hard to keep hand wounds clean and dry but it is important to prevent infection. If your dressing becomes wet you should have it re-dressed by the clinic nurse or your GP. The stitches need to be kept covered until they are removed.
After surgery keep moving the fingers gently to avoid stiffness from scarring around the tendons in the carpal tunnel. It is also important however to rest enough to let the wound heal so not do heavy work or sport during this time.
Until the cut ligament heals over it may be tender, as might the cut in the palm. You may use scar massage with moisturising cream to de-sensitise this. When doing work on the palms you might want to use padded cycling/weight-lifting gloves for comfort.
You can return to driving soon after surgery - usually 1-2 weeks. Before you can drive you must be able to control the wheel comfortably and perform an emergency stop. This varies between different patients.
General advice regarding Carpal tunnel surgery
The information here is general and varies depending on individual factors such as: time to treatment, occupation, age and sporting demands.
Do I need surgery
You should have surgery if you have frequent numbess or any weakness
Immobilisation
bandages for 2 days
stitches for 2 weeks
Driving
1-2 weeks
Aim of surgery
release of ligament compressing the median nerve
Hospital stay
Day surgery only
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Return to Work
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1 handed duties for 2 weeks
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Full duties whenever comfortable
Investigations
Clinical examination and sometimes nerve conduction studies
Therapy
many patients can do
exercises without therapy
Return to Sport
as soon as comfortable after wound healed. 2-4 weeks