- Trigger finger
- For the Belgian band, see Triggerfinger. "Trigger finger" can also mean the finger which is used to operate the trigger of a gun or of a power tool.
Trigger finger Classification and external resources ICD-10 M65.3 ICD-9 727.03 eMedicine orthoped/570
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.
Diagnosis is made almost exclusively by history and physical examination alone. 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.
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. A regimen of physical therapy is generally prescribed after the procedure, which may extend for two to six months. 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.
The natural history of disease for trigger finger remains uncertain.
There is some evidence that idiopathic trigger finger behaves differently in people with diabetes.
The majority of the studies that have not found a link to workplace involvement are of questionable intent. This, along with many other MSI injuries such as Carpal Tunnel Syndrome are rather commonly misdiagnosed as a 'simple' or single injury. More often they are part of a compound injury due to overuse, repetitive stresses, workplace vibration, which when combined in particular, are particularly harmful and accelerate the progression of the injuries.
Recurrent triggering is unusual after successful injection and rare after successful surgery.
While difficulty extending the proximal interphalangeal joint may persist for months, it benefits from exercises to stretch the finger straighter.
More than one potential causes have been described but the etiology remains idiopathic. It has also been called stenosing tenosynovitis (specifically digital tenovaginitis stenosans), but this may be a misnomer, as inflammation is not a predominant feature.
It has been speculated that repetitive forceful use of a digit leads to narrowing of the fibrous digital sheath in which it runs, but there is little scientific data to support this theory. The relationship of trigger finger to work activities is debatable and scientific evidence for and against hand use as a cause exist, but the overwhelming majority of anecdotal evidence points to repetitive stressful manual motion as a primary underlying cause of this condition.
- ^ a b c Makkouk et al. (2008). "Trigger finger: etiology, evaluation, and treatment". Curr Rev Musculoskelet Med 1 (2): 92–6.
- ^ a b Baumgarten KM, Gerlach D, Boyer MI (2007 Dec). "Corticosteroid injection in diabetic patients with trigger finger. A prospective, randomized, controlled double-blinded study". Journal of Bone and Joint Surgery (American) 89 (12): 2604–2611. PMID 18056491.
- ^ a b Kerrigan CL, Stanwix MG (2009 Jul–Aug). "Using evidence to minimize the cost of trigger finger care". J Hand Surg Am 34 (6): 997–1005. PMID 19643287.
- ^ Gorsche R, Wiley JP, Renger R, Brant R, Gemer TY, Sasyniuk TM (1998 Jun). "Prevalence and incidence of stenosing flexor tenosynovitis (trigger finger) in a meat-packing plant". J Occup Environ Med 40 (6): 556–60. PMID 9636936.
- ^ Kasdan ML, Leis VM, Lewis K, Kasdan AS (1996 Nov). "Trigger finger: not always work related". J Ky Med Assoc 94 (11): 498–9. PMID 8973080.
- Video of Trigger Finger Release Surgery on YouTube
- 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
Soft tissue disorders / Rheumatism / Connective tissue arthropathy (M65–M79, 725–728) Capsular jointSynovitis/Tenosynovitis (Calcific tendinitis, Stenosing tenosynovitis, Trigger finger, DeQuervain's syndrome) · Transient synovitis · Ganglion cystvillonodular synovitis (Giant cell tumor of the tendon sheath)BursopathyBursitis (Olecranon, Prepatellar, Trochanteric, Subacromial) · Synovial cyst (Baker's cyst) · Calcific bursitis Noncapsular jointEnthesopathy/Enthesitis
(and general tendinopathy)upper limb (Adhesive capsulitis of shoulder, Impingement syndrome Rotator cuff tear, Golfer's elbow, Tennis elbow)lower limb (Iliotibial band syndrome, Patellar tendinitis, Achilles tendinitis, Calcaneal spur, Metatarsalgia) · Bone spurother/general: Tendinitis · Tendinosis
NonjointDupuytren's contracture · Plantar fibromatosis · Aggressive fibromatosis · Knuckle pads
anat(h/c, u, t, l)/phys
noco(arth/defr/back/soft)/cong, sysi/epon, injr
proc, drug(M01C, M4)Categories:
- Ailments of unknown etiology
- Disorders of synovium and tendon
Wikimedia Foundation. 2010.