Information
Editors
Trigger Finger
Definition and aetiology
- 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.
Symptoms and diagnosis
- 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.
Treatment
- 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% 17. 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.
References
- 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.