Trigger finger – also known as stenosing tenosynovitis – is a condition that causes one of your fingers to get stuck in a bent condition. It is caused by inflammation, which narrows the space in the sheath surrounding the tendon. Your finger may bend or straighten with a snap or may become completely locked in a bent position. The condition is more common in women and people whose jobs or leisure pursuits require them to make repeated gripping motions.
The sheath that surrounds the tendon in the affected finger becomes irritated or inflamed which prevents the tendon from sliding smoothly through the sheath and causes it to stick. If the irritation is prolonged it can produce thickening, scarring and the formation of nodules on the tendon which makes it even more difficult for the tendon to move smoothly. Certain factors can increase the risk of developing the condition, including:
- Activities that involve prolonged gripping and repetitive hand use
- Health conditions such as diabetes or rheumatoid arthritis
The symptoms, which may start relatively mild and become more severe over time, include:
- A clicking or popping sensation when you move your finger
- Stiffness in your finger, particularly in the morning
- A lump or pain in the palm at the base of the affected finger
- Your finger locking in a bent position before popping straight
- Being unable to straighten your finger
A physical examination will be used to diagnose trigger finger. Your consultant will ask you to open and close your hand and will check for evidence of locking and pain as well as examining your palm for lumps.
A range of treatments are available depending on the condition’s severity and how long you have had it. Anti-inflammatories may help to relieve the pain but will not make a significant difference to the swelling that is trapping the tendon. It is important to rest the affected hand to allow the symptoms to subside. Wearing a splint at night for up to six weeks can keep the affected finger in an extended position, which allows the tendon to rest. Your consultant may be able to show you some simple exercises to improve mobility in your finger.
An injection of corticosteroids into the tendon sheath may help to reduce inflammation so the tendon can move smoothly again. You may also be offered a percutaneous release treatment which entails inserting a needle into the tissue around the affected tendon and moving it, along with your finger, to break up anything that is constricting the tendon sheath. This is normally done under local anaesthetic and using ultrasound to guide the needle.
In more severe cases, you may be offered surgery to release the affected tendon. A small incision will be made near to the base of your affected finger and the surgeon will cut open the constricted sections of tendon sheath. The incision will be closed with sutures.