Trigger finger is a common hand condition that causes pain or reduced movement of a finger that tends to catch, snap or lock. It can be hard to bend (flex) or fully straighten (extend) the finger.
- This condition is called trigger finger because when your finger unlocks, it pops back suddenly, as if releasing a trigger on a gun.
- The cause is not totally clear. It can be more common in people with other conditions such as diabetes or rheumatoid arthritis.
- Trigger finger is more common in the right hand and most often affects your thumb, ring finger or little finger.
- Trigger finger is usually treated at first with rest, pain relief and a splint. If these do not work, your doctor may recommend steroid injections or, if these don't work, surgery.
Image source: 123rf
What are the causes of trigger finger?
Tendons are tough fibrous cords that connect your muscles to your bones. They are covered by protective sheaths. These lubricate and allow the tendons to move freely during movement of your body. Trigger finger can occur if there is a problem with the tendons or the sheaths, such as swelling or inflammation.
The cause of trigger finger is not totally clear. However, there are several factors that can increase your risk of getting a trigger finger. These include:
- rheumatoid arthritis
- carpal tunnel syndrome
- underactive thyroid
- Dupuytren disease
- De Quervain’s tenosynovitis
- people on renal dialysis
- using your hand a lot at work, such as for screwdriving or using tools that press on your palm
- previous hand injuries.
What are the symptoms of trigger finger?
Common symptoms of trigger finger include:
- a lump or nodule appearing in your palm
- pain when you move your finger or press on it
- catching or popping on bending or straightening your finger.
The triggering may be more obvious at night and in the morning, or while gripping an object firmly. It usually affects your thumb, little finger or ring finger, although more than one finger may be affected at a time.
How is trigger finger diagnosed?
Your doctor will usually be able to diagnose trigger finger by taking a history and doing a physical examination. A history might include asking questions about any other health conditions and your work, as well as your symptoms, when they started and when the triggering happens.
Video source: The American Society for Surgery of the Hand.
How is trigger finger treated?
Usually the initial treatment includes the following:
- avoiding activities that make the pain worse
- pain relief
- anti-inflammatory medication, such as NSAIDs
- use of a splint to keep the finger in a neutral, resting position.
If those measures have been tried and haven't not been successful, treatment such as steroid injections or surgery may be recommended.
Steroid injections involve the injection of cortisone medications such as triamcinolone, dexamethasone or methylprednisolone directly into the tendon sheath to reduce inflammation (swelling) and pain. You may need to use a finger splint to help rest the finger for a few days after the injection. Steroid injections are usually effective. However, it will take a few days to a few weeks for the steroids to work.
Read more about steroid injections.
Surgery will only be recommended after 2 unsuccessful steroid injections or for people with severe symptoms. You will be referred to a plastic or orthopaedic surgeon. Surgery for trigger finger is done under local anaesthesia. A cut is made through the tendon sheath to widen it so that your finger can move freely again.
Talk to your doctor to find out which treatment is the best for you.
What is the outlook for someone with trigger finger?
Some people may recover by themselves without needing treatment. However, there is a possibility that your finger will become permanently bent if it is not treated.
Steroid injections have been shown to be effective in up to 75% of people with trigger finger. Sometimes, the condition can return after the injection and you may need a second injection.
Surgery has been shown to be effective and it is rare for the condition to come back. However, surgery is only needed if other treatments do not work.
Trigger finger overview NHS Choices, UK
Trigger finger American Academy of Orthopaedic Surgeons
Steroid injections HealthInfo Canterbury, NZ
Trigger finger HealthInfo Canterbury, NZ
Trigger finger Patient Info, UK