As the tendons that bend your fingers and thumb move through into your hand towards the tips of the digits, they travel through a tunnel of bony and fibrous tissue (called the flexor pulley system). There are 8 pulleys in your hand and three in your thumb. The pulleys bind the tendons against the finger bones and improve the mechanical advantage of the tendons. The pulleys and tendons are covered with tenosynovium, a thin slippery layer that helps the tendons glide easily through the tunnel.
For various reasons the tendons can swell and then become stuck as they move through the pulleys. The A1 pulley, located in your palm towards the fingers, is narrow and frequently the site of obstruction.
Age is often a factor in the swelling of the tendon. Other diseases can also be responsible for causing swelling of the tendon such as diabetes, rheumatoid arthritis or kidney disease. Sometimes the pulleys or tendons swell because of local trauma.
Trigger finger and thumb is common and occurs in 2% of the population and 20% of diabetics.
In the early stages, you may experience swelling, stiffness and pain with your grasp. You may have difficulty making a complete fist.
As the triggering becomes worse, your finger or thumb becomes stuck in a bent position. It may take some force to straighten the digit, or you may even need to use your other hand to bring the finger straight. You will feel a snapping sensation as the swollen tendon is forced through the pulley.
Some patients have some mild tenderness over the palm.
A steroid injection improves the vast majority of trigger digits. A single injection is all that is required in 50% of patients. Steroid reduces the inflammation around the tendon and allows the tendon to glide easily through the pulley.
Depending on how your finger or thumb responds to the first injection, we may look at administering another steroid injection. If your digit does not respond to two injections (or one injection if you are diabetic), you may require surgical correction. This is the case for about 25% of patients.
Side effects of steroid injections you may experience include: thinning and discolouration of skin, development of fine blood vessels (telangiectasia) and infection (redness, swelling, throbbing discomfort). Two injections is the maximum I will administer, within a short period of time (6 -12 months or so), as side effects become more frequent with increasing injections.
If you are a diabetic patient, your blood glucose may be more variable and difficult to control for the next few weeks.
If you require surgery, I will release the A1 pulley under local or general anaesthetic. I make a small incision in your palm, and then I divide the A1 pulley. This division allows the tendon to glide freely. In severe cases or rheumatoid arthritis, I may also need to cut out a slip of tendon.
After the surgery, the wound is sutured. I apply a light dressing and you will be provided with an information sheet about wound care.
Please read Post Hand Surgery Advice and Exercises.
You can drive a car after about a week, provided your hand is comfortable and able to control a motor vehicle safely. Your return to work depends on your level of occupation: Office workers may need a few days away from work, heavy manual labourers, who need to grip strongly, 4-8 weeks.
Possible problems include swelling, bruising, bleeding, blood collecting under the wound (haematoma), infection and splitting open of the wound (dehiscence).
The scar may become a little thickened and red as it heals, but this will settle with time. The scar will be tender, and this will also resolve. It is possible that your scar remains unsightly.
Your finger may be stiff after surgery, but exercises from your hand therapist should resolve this.
Fortunately, this is a very rare complication. If it does occur however, a second operation is required to repair this.
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 we cannot predict whom it will happen to. I will monitor you for this after the operation, and the treatment involves special forms of pain relief and physiotherapy. Read more about Complex regional pain syndrome.
Please read Complications after Hand Surgery