Trigger finger is a common reason for a finger or thumb that catches, clicks or locks when you bend it. This guide explains what happens inside the finger, who gets it and how it is treated — with splints, injections or a small operation. It also covers recovery, risks and when to seek help.

What is trigger finger?

Each finger bends by a tendon that runs through a tunnel of small bands, called pulleys. The first band, at the base of the finger, is the . In , this band thickens and the tendon no longer glides freely through it1. The tendon may swell into a small lump. When you bend the finger, the lump has to squeeze through the narrow band. It may catch, click or lock. Sometimes you need the other hand to straighten it.
The medical name is . Despite the name, there is little true inflammation. The band changes into a firmer, cartilage-like tissue2.

Who gets it?

About 2 in every 100 people develop trigger finger at some point in their lives13. It is most common between the ages of about 50 and 70, and women are affected more often than men3. The thumb, ring finger and middle finger are involved most often3. In most cases there is no single cause.
People with diabetes are about four times as likely to get trigger finger, and more likely to have several fingers involved4. It also often goes together with 5.
Young children can develop a trigger thumb. It is not present at birth, and it usually shows as a thumb that stays bent rather than one that clicks67. More than half settle on their own over a few years. The rest are treated with a small operation7. This is usually offered from about three to four years of age, if the thumb still stays bent.

Symptoms

  • A catching, clicking or locking feeling when you bend or straighten the finger.
  • A tender lump in the palm at the base of the finger.
  • Pain at the base of the finger, sometimes spreading into the finger.
  • Stiffness, often worst first thing in the morning.
  • In severe cases, a finger that locks bent and needs the other hand to straighten it.

How it is diagnosed

Trigger finger is diagnosed from your story and by examining your hand. Your doctor will feel for the lump and watch the finger catch as it moves. Scans and X-rays are not usually needed. An ultrasound scan is sometimes used when the picture is unclear.

Treatment without surgery

Trigger finger does not always need surgery. Mild cases may settle with rest and by avoiding the activities that set it off. Two treatments are well studied.
A splint holds the finger straight, usually at night, for six to ten weeks8. In one study, splinting helped about two in three people9. It is a fair choice if you would rather avoid an injection.
A into the tendon tunnel is the usual first treatment10. It works better than local anaesthetic alone11. Roughly six in ten people are free of triggering after one injection, and more after a second1213. The relief does not always last. About half of people have symptoms again within a year14. Five years after a single injection, about 45 in 100 are still free of trouble15. A second or third injection gives about four in ten people a year or more of relief16.
If you have diabetes, injections work less well17. Your blood sugar may also rise for a few days afterwards1.

When surgery is considered

Surgery is considered when an injection has not worked, when the triggering comes back, or when the finger is locked10. Surgery can also be a reasonable first choice, for example if you have diabetes or several fingers are affected18. It is the most reliable way to stop the triggering for good. In trials, almost everyone treated with surgery was free of triggering, and it came back far less often than after an injection1312.
In practice, one steroid injection is usually tried first. Surgery is offered if the injection fails or the triggering returns. It is also a reasonable first choice if the finger is locked, if you have insulin-dependent diabetes or several affected fingers, or if you would rather have the problem fixed for good.

What happens during surgery

The operation is called a trigger finger release, or A1 pulley release. It is done as a day case under local anaesthetic and takes about ten to twenty minutes19. The finger is numbed with a small injection of local anaesthetic: 0.4 per cent lignocaine with adrenaline (1 in 250,000), about 5 mL for each finger. A cuff on the upper arm keeps the area free of blood while the surgeon works. Some surgeons use a stronger anaesthetic mix and no cuff, a method called WALANT. A short cut, about 1 to 1.5 cm long, is made across the crease in the palm at the base of the finger. For a thumb, the cut is made in the crease at the base of the thumb. The small nerves on either side are found and protected. The thickened band is divided so that the tendon can glide freely again. The surgeon checks that the tendon now runs freely, and because you are awake you may be asked to bend and straighten the finger to confirm it19. The wound is closed with a few stitches and covered with a soft, bulky dressing.
Some surgeons divide the band with a needle through the skin, without a cut; the open operation, in which the small nerves are seen and protected, is the approach described here1.

Recovery

You can move the finger straight away. Gentle bending and straightening from the first day helps prevent stiffness. You go home with a soft, bulky dressing on the hand and no splint. After two to three days it is changed to a light, dry dressing by your GP or the dressings clinic. Keep the dressing dry until the wound is checked. Stitches are removed after 10 to 14 days.
Most people are back to their usual activities within about two to three weeks20. Heavy gripping may take a little longer. The scar in the palm can feel firm and tender for a few weeks; massage helps once the wound has healed. A hand therapist sees everyone once, early on. They check movement and swelling, and advise on scar care and getting back to work. Only a few people need more sessions, if the finger stays stiff21.

Risks

Trigger finger release is a safe and reliable operation, but no operation is free of risk. In a series of about 1,600 releases, one person in fifteen had a minor problem, most often a slow recovery or a wound that took time to settle. Fewer than one in a hundred needed further surgery21. Possible problems include:
  • Infection of the wound, in about 2 in 100 cases22.
  • A tender or thickened scar in the palm.
  • Stiffness of the finger, which usually improves with movement.
  • Triggering that persists or comes back, in fewer than 3 in 100 cases211.
  • Numbness on one side of the finger from injury to a small nerve. This is rare with open surgery21.
  • Very rarely, , a prolonged pain and stiffness reaction1.
The risk of infection is higher when a steroid injection was given within the previous three months, so surgery is usually timed at least three months after an injection22. People with diabetes have a somewhat higher risk of wound problems and slow recovery21.

When to seek help

Seek advice if:
  • the finger is locked and cannot be straightened, even with the other hand;
  • pain, redness or swelling of the wound increases after surgery, or you develop a fever;
  • you notice new numbness in the finger;
  • the finger has not regained its movement several weeks after surgery;
  • symptoms interfere with work or daily life despite treatment.
Your GP can refer you to a hand surgeon.