Trigger finger, trigger thumb, or trigger digit, is a common disorder of later adulthood characterized by catching, snapping or locking of the involved finger flexor tendon, associated with dysfunction and pain. A disparity in size between the flexor tendon and the surrounding retinacular pulley system, most commonly at the level of the first annular (A1) pulley, results in difficulty flexing or extending the finger and the “triggering” phenomenon . The label of trigger finger is used because when the finger unlocks, it pops back suddenly, as if releasing a trigger on a gun.
Injection of the tendon sheath with a corticosteroid is effective over weeks to months in more than half of patients.
When corticosteroid injection fails, 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. Anecdotally, patients who respond at least transiently to corticosteroid injection are more likely to respond to surgical treatment.
One recent study in the Journal of Hand Surgery suggests that the most cost-effective treatment is two trials of corticosteroid injection, followed by open release of the first annular pulley.Choosing surgery immediately is the most expensive option and is often not necessary for resolution of symptoms.
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.