A trigger finger is a finger which can only be stretched with difficulty and then with a (little) shock pops back again. There is a swelling caused by inflammation in one of the flexor tendons of the fingers. The most affected fingers are the ring finger and the thumb; the index finger and the little finger are almost never affected. It frequently occurs in both hands.
Trigger finger is caused by an inflammatory response of the flexor tendon of one of the fingers and sometimes also of the tendon sheath (the sheath the tendon is sliding through). Thereby creating a thickening of the tendon, allowing it no longer to slide properly through the tendon sheath. This occurs at the level of the joint of the finger or thumb to the palm of the hand, at the inside of the hand. At a given moment, the tendon can even get stuck, so the finger has to be helped stretching. The cause of the inflammatory response is usually not clear. Sometimes there has been overload.
While bending, the finger freezes and hurts. This situation looks like a finger that pulls the trigger of a gun, hence the name ‘trigger finger’. Often there will first be a strange feeling at the base of the finger. Bending is painful and clearly can be seen that the finger makes a strange movement. After some time, stretching can also be painful. Sometimes there is a painful thickening in the palm or at the thumb base. In severe cases, it’s no longer possible to stretch the finger by itself and the finger has to be helped. Then the tendon is stalled.
The diagnosis of trigger finger is made on the basis of the consult conversation and physical examination. The finger is ‘locked’. When the patient is asked to open and close the hand, this cannot be done. The easy and painless movement of the affected finger is no longer possible. Furthermore, the doctor feels the flexor tendons and looks whether there is pain and swelling.
Rest of the finger is often prescribed, sometimes in combination with anti-inflammatories. Sometimes, an anti-inflammatory injection is administered. The tendon can thus recover. Unfortunately, this is no permanent remedy and the inflammation can come back again. A splint can also help. In doing so, a splint is applied, so that the finger cannot bend properly. This way, the tendon gets sufficient rest to recover. When this doesn’t help enough, the doctor will make an opening in the tendon sheath, on the route where the tendon nodule runs. This will prevent swelling to reappear. Then the thickened tendon has room again and the hand can fairly quickly be used normally again.
After the operation, the hand needs to be practised as much as possible. This prevents adhesions. The healing lasts approximately six to eight weeks. Sometimes, hand therapy is needed. This is aimed at rehabilitating the hand after the operation.
The prognosis is usually very good. Some people recover spontaneously, most of them after injection of corticosteroids with or without associated splints. Surgery usually has a very good result, although recovery may take several weeks. Chronic or frequently recurring problems may arise if the condition and the associated inflammation are caused by an underlying disease. Sometimes, the condition can return spontaneously with no apparent cause.
- Avoid activities, in which it is necessary to grab and in which the hand and wrist are excessively loaded.
- A wrist splint can provide support in preventing overuse of the hand.
- Put the keyboard flat and type with straight wrists.
- Try to use the computer mouse with the other hand, so that the load for the hand with the trigger finger is minimal.
- Keep surrounding joints, such as elbow and shoulder, well supple.
- The prevalence of trigger finger is 2.5%.
- Trigger finger occurs mainly in women aged 45 to 65 years.
- The condition often occurs in combination with carpal tunnel syndrome and vice versa.