Trigger finger also known as stenosing tenosynovitis or stenosing tenovaginosis, affects the tendons in the hand. When the affected finger or thumb is bent towards the palm, the tendon gets stuck and the finger clicks or locks. Trigger finger can affect one or more fingers. The symptoms can include pain, stiffness, clicking and a small lump in the palm at the base of the affected finger or thumb (known as a nodule).
What causes trigger finger? Tendons are fibrous cords that join bone to muscle. They allow the bone to move when the muscle contracts. In the hand, tendons run along the front and back of the bones in the fingers and are attached to the muscles in the forearm. The tendons on the palm side of the hand (flexor tendons) are held in place by strong bands of tissue, known as ligaments, which are shaped in arches over the tendon. These ligaments form a tunnel on the surface of the bone, which the tendons slide through. This tunnel is known as a tendon sheath. Trigger finger occurs if there is a problem with the tendon or sheath, such as swelling, which means the tendon can no longer slide easily through the sheath and it can become bunched up to form a nodule which makes it harder to bend the affected finger or thumb. If the tendon gets caught in the opening of the sheath, the finger can click painfully as it is straightened.
The exact reason why these problems develop is not known, but several things may increase the likelihood of trigger finger developing. For example, it is more common in women, people who are over 40 years of age and people with certain medical conditions such as Dupuytren’s contracture. They may also include some long-term conditions, such as diabetes and rheumatoid arthritis.
In some people, trigger finger may get better without treatment however there is a chance the affected finger or thumb could become permanently bent if not treated, which will make performing everyday tasks difficult. If treatment is necessary, several different options are available, including:
- Rest and medication, avoiding certain activities and taking non-steroidal anti-inflammatory drugsmay help relieve pain.
- Splinting, this involves strapping the affected finger to a plastic splint to help ease your symptoms.
- Corticosteroid injections, steroids are medicines that may be used to reduce swelling.
- Surgery on the affected sheath, surgery involves releasing the affected sheath to allow the tendon to move freely again. This is a relatively minor procedure generally used when other treatments have failed. It can be up to 100% effective, although you may need to take two to four weeks off work to fully recover.