Editors

NoraSuojärvi

Trigger Finger

Tenosynovitis of the flexor tendon of a finger, leading to narrowing of the tendon sheath
Often caused by repetitive use (work or hobbies)
Tendon movement beneath the edge of the inflamed and hence constricted tendon sheath causes snapping.
Secondary trigger finger is often encountered in patients with diabetes, gout or rheumatoid disease.

The extension and flexion of an affected finger causes painful snapping or locking.
The symptoms are at their worst in the morning and alleviate as the hand is used. In the morning, the finger may be locked in a flexed position.
The tendon sheath is most constricted at the so-called A1 pulley area (where the digit meets the palm) which is often tender on palpation on the volar (palmar) side of the metacarpophalangeal joint.
The most commonly involved digit is the thumb, but other fingers may also be affected and more than one finger may be affected at a time.
A locked trigger finger may be confused with, for example, post-traumatic or degenerative proximal interphalangeal joint contracture or Dupuytren's disease Dupuytren's Contracture.

The majority of cases can be managed conservatively if only local tenderness is present or the patient is able to straighten the finger without aid.
- Rest, avoidance of strain
- Anti-inflammatory analgesics
- A combination injection of glucocorticoid and local anaesthetic (video Injection for Trigger Finger).
  - There are several injection techniques. A glucocorticoid injection seems to alleviate trigger finger symptoms more effectively when given around the tendon sheath instead of inside of it 6.
  - The efficacy of glucocorticoid is good, 45-69% 1 7. Repeating the injection increases the success to up to 86% 5.
  - Younger age, insulin-dependent diabetes mellitus, involvement of multiple digits, and earlier other tendinopathy are associated with a higher treatment failure rate.
If the condition recurs after a glucocorticoid injection or if the finger is completely locked in a flexed position, surgical repair is warranted. It involves release of the A1 pulley.

Taras JS, Raphael JS, Pan WT et al. Corticosteroid injections for trigger digits: is intrasheath injection necessary? J Hand Surg Am 1998;23(4):717-22. [PubMed]
Castellanos J, Muñoz-Mahamud E, Domínguez E et al. Long-term effectiveness of corticosteroid injections for trigger finger and thumb. J Hand Surg Am 2015;40(1):121-6. [PubMed]
Wojahn RD, Foeger NC, Gelberman RH et al. Long-term outcomes following a single corticosteroid injection for trigger finger. J Bone Joint Surg Am 2014;96(22):1849-54. [PubMed]
Sato ES, Gomes Dos Santos JB, Belloti JC et al. Treatment of trigger finger: randomized clinical trial comparing the methods of corticosteroid injection, percutaneous release and open surgery. Rheumatology (Oxford) 2012;51(1):93-9. [PubMed]
Rozental TD, Zurakowski D, Blazar PE. Trigger finger: prognostic indicators of recurrence following corticosteroid injection. J Bone Joint Surg Am 2008;90(8):1665-72. [PubMed]
Repetitive strain injuries of the hand and elbow. A Current Care Guideline. Working group appointed by the Finnish Medical Society Duodecim and the Finnish Association of Occupational Health Physicians. Helsinki: Finnish Medical Society Duodecim, 2013 (referenced 8.4.2022). Available in Finnish only http://www.kaypahoito.fi/hoi50055?tab=suositus#s21.