Trigger finger

From Wikipedia, the free encyclopedia

Trigger finger, or trigger thumb, is a type of stenosing tenosynovitis (specifically digital tenovaginitis stenosans) in which the sheath around a tendon in a thumb or finger becomes swollen, or a nodule forms on the tendon. Affected digits may become painful to straighten once bent, and may make a soft crackling sound when moved. The label of trigger finger is used because when the finger unlocks, it pops back suddenly, as if releasing a trigger on a gun.

More than one finger may be affected at a time, though it usually affects the thumb, middle, or ring finger. The triggering is usually more pronounced in the morning, or while gripping an object firmly.

Trigger finger is usually idiopathic, meaning that the cause is unknown. Some speculate that repetitive forceful use of a digit leads to narrowing of the fibrous digital sheath in which it runs, but there is no data to support this theory and it may unfairly stigmatize hand use. The relationship of trigger finger to work activities is debatable and scientific evidence for^[1] and against^[2] hand use as an etiological factor are sparse and of low quality.

There is some evidence that idiopathic trigger finger behaves differently in patients with diabetes.[1]

[edit] Treatment

The natural history of disease for trigger finger remains uncertain.

Injection of the tendon sheath with a corticosteroid is effective over weeks to months in more than half of patients. [2]

The problem is predictably resolved by a relatively simple surgical procedure (usually outpatient, under local anesthesia). The surgeon will cut the sheath that is restricting the tendon.

Investigative treatment options with limited scientific support include: non-steroidal anti-inflammatory drugs, occupational or physical therapy, steroid iontophoresis treatment, splinting, therapeutic ultrasound, phonophoresis (ultrasound with an anti-inflammatory dexamethasone cream), and Acupuncture.

[edit] Recovery

Recurrent triggering is unusual after successful injection and rare after successful surgery.

Difficulty extending the proximal interphalangeal joint may persist for months and benefits from exercises to stretch the finger straighter.

[edit] External links

• Hand World Trigger Finger Page
• American Academy of Orthopaedic Surgeons information on trigger finger
• Overview page from a UK surgeon
• Information from the Mayo Clinic
• Information from eMedicine