What is trigger thumb?
Trigger finger is a common condition in which the tendons in the thumb develop swellings. ‘Triggering’ occurs when the swelling catches on the entrance to the tunnel that the tendon runs in at the base of the thumb, stopping it moving the thumb effectively. You may have noticed that your thumb appears stiffer and may lock down or jam in the palm of your hand, particularly first thing in the morning. When you try and straighten the thumb it may be painful and move suddenly with a click. You may also have noticed a swelling or nodule at the base of the thumb that moves when you move your thumb. In some cases the thumb is swollen and painful.
What is the cause?
The cause of trigger thumb is unknown. It can occur at any age and in both sexes. It may occur in children and may be present at birth or develop during the first few years of life. Some conditions are associated with an increased likelihood of developing it, such as diabetes and rheumatoid arthritis.
Diagnosis can often be made from the clinical history (the account of events and symptoms from the patient) and the clinical examination.
Some people with trigger thumb manage without treatment as the locking or jamming can resolve spontaneously. Treatment is usually offered if there are significant problems with hand function because of locking, the thumb end joint has become stuck and no longer straightens, or the thumb has become very painful.
1.Cortisone injection 50-60 % of patients can successfully be treated with an injection of steroid (cortisone) into the tunnel around the tendon. Studies have shown long term improvement of pain and locking with injection treatment. Some patients find that the effect of the injection wears off. In this case a further injection may be recommended or alternatively your surgeon may recommend surgical release.
3.Surgery : Surgery (‘trigger thumb release’) involves dividing part of the tunnel around the tendon in the base of the thumb, through a small incision, allowing the tendon to move more freely. This is usually performed under a local anaesthetic by “freezing the skin” with an injection. A tourniquet (similar to a blood pressure cuff) is applied to the arm to provide the surgeon with a blood-free field for surgery. An incision approximately 1-2cm long is then made at the base of the thumb on the palmar surface. The surgeon divides the entrance to the tunnel in which the tendon runs. This stops the triggering and allows the inflammation to improve. The nodule is not removed. At the end of the procedure the incision is stitched with fine sutures and the hand put in a large bandage. This is usually removed after 48-72 hours.
In patients with rheumatoid arthritis the tunnel is released less frequently. Instead, if surgery is required the inflamed tissue (synovitis) around the tendon is removed and this often improves the pain and triggering. This is a more involved procedure and may be performed under general/regional anaesthesia.
In babies/children we do not recommend steroid injections and a general anaesthetic is required for surgery.
You should be fit to go home soon after the operation. The local anaesthetic will wear off after approximately 6 (6-36 hours) hours . Simple analgesia usually controls the pain and should be started before the anaesthetic has worn off. The bandage you will have on initially may make it difficult for you to eat and wash yourself, so you may need to arrange assistance.
You should keep your hand/arm elevated whenever possible over the first 48 hours after surgery. While sitting this is best achieved by placing your arm on pillows above the level of your heart. Light use of the hand is encouraged to maintain thumb mobility.
You will have a bandage or dressing on for about 2 weeks after the operation. Some wounds are closed with dissolvable stitches, which can take up to a month to disappear. Any non-dissolving stitches will need to be removed at 10-14 days following the operation. Until this time you should keep the wound clean and dry, your fingers and thumb moving, and the hand elevated when possible to reduce swelling and throbbing.
Once the wound is well healed the scar and surrounding tissues should be massaged using small circular movements to reduce the sensitivity. You can rub simple hand cream or pure vegetable oil into the scar to soften it, for five minutes several times a day. There is usually no need for physiotherapy.
Returning to work will depend on your circumstances and type of work. If your job is light you may return after 2-3 weeks, but if it is heavy/manual you may require 6 weeks or more off work.
You should not drive for at least 2 weeks following your operation. You need to be able to perform an emergency stop safely and use the gear stick, steering wheel and hand brake without difficulty.
What are the potential complications?
The majority of patients are very satisfied with the outcome of surgery. Whilst uncommon, all surgical procedures are associated with some risks. Every effort is made to minimize these to ensure the best possible outcome from your surgery.
Infection - Uncommon occurs in approximately 1% of operations and usually treated very successfully with antibiotics. Very rarely would require further surgery
Delayed healing - Smokers and those with diabetes are more prone to this
Painful/Tender/thickened Scars - the vast majority of patients complain of some discomfort around the scar but it generally resolves with time. Wound care and desensitization as directed by your physiotherapist/hand therapist will improve this.
Nerve injury – small nerves that supply the skin around the scar may be injured giving a numb patch or unpleasant sensation round the scar. The use of magnification glasses ( Loupes) by your surgeon and very careful dissection will be used to minimise this complication
Stiffness - Operations to the thumb may cause stiffness, this can be minimized by getting your hand moving as early as possible and working closely with your hand therapist if necessary.
Incomplete resolution of your symptoms
CRPS – complex regional pain syndrome, this is an uncommon but serious complication. It can on rare occasions leave you with a less function hand with on-going pain stiffness and swelling. See section on CRPS. The exact incidence or rate of CRPS after surgery is unknown. It probably occurs in a significant form in approximately 1-2% of cases
See also BSSH guidelines. www.bssh.ac.uk/education/guidelines/trigger.pdf