para />
The thumb is more commonly involved in children.
Surgery is often more complicated for children with a trigger finger (as opposed to a trigger thumb).
Release of the A1 pulley alone is often insufficient, other procedures may be necessary.
ETIOLOGY AND PATHOPHYSIOLOGY
- Narrowing around the A1 pulley from inflammation, protein deposition, or thickening of the tendon itself. Prolonged inflammation leads to fibrocartilaginous metaplasia of the tendon sheath.
- If the flexor tendon become nodular, the triggering phenomenon is worse because the nodule has difficulty passing under the A1 pulley.
- Because intrinsic flexor muscles are stronger than extensors, the finger can stick in the flexed position.
- No clear association with repetitive movements
RISK FACTORS
- Diabetes mellitus
- Rheumatoid arthritis
- Hypothyroidism
- Mucopolysaccharide disorders
- Amyloidosis
GENERAL PREVENTION
Most cases are idiopathic, and no known prevention exists. No clear association with repetitive movements
COMMONLY ASSOCIATED CONDITIONS
- De Quervain tenosynovitis
- Carpal tunnel syndrome
- Dupuytren contracture
- Diabetes mellitus
- Rheumatoid arthritis
- Hypothyroidism
- Amyloidosis
DIAGNOSIS
Diagnosis is based on clinical presentation.
HISTORY
Clicking, snapping, or locking of a digit while attempting to extend; with or without associated pain
PHYSICAL EXAM
- A palpable nodule may be present.
- Snapping/locking may be present but neither is necessary for the diagnosis.
- Tenderness to palpation is variable.
DIAGNOSTIC TESTS & INTERPRETATION
Test Interpretation
- Thickening of the A1 pulley with fibrocartilaginous metaplasia
- Thickening/nodule formation of flexor tendon
TREATMENT
- Splinting the metacarpophalangeal (MCP) joint at 10 to 15 degrees of flexion for 6 weeks with the distal joints free to move:
- Splinting is more effective for fingers than thumbs (70% vs. 50%).
- Splinting is less effective with severe symptoms, symptoms >6 months, or if multiple digits are involved (1)[B].
- Injection of long-acting corticosteroid may provide symptom relief. Subsequent injections are less likely to help.
- Surgery often successful for patients unresponsive to splinting/corticosteroid injections.
GENERAL MEASURES
Attempt splinting/steroid injection prior to surgery. Splinting may be more effective for preventing recurrence than as initial treatment (2)[B].
MEDICATION
First Line
- Steroid injection of the tendon sheath/surrounding SC tissue has 57 " 90% success rate.
- Injection in surrounding tissues is as efficacious as injecting into the tendon sheath (1,3)[B]. Injection into the palmar surface at the midproximal phalanx is associated with less pain than injection of tendon sheath at MCP joint (4)[B].
- Injection using ultrasound guidance does not improve success rate compared to standard injection technique (5)[A]. Corticosteroid injection has higher success rate than splinting (2)[B].
Second Line
- Oral NSAIDs may reduce pain and discomfort but have not been shown to alter underlying disease. NSAIDs do not reduce symptoms of snapping/locking.
- Injection with diclofenac may be an alternative to corticosteroid for patients with diabetes mellitus if increase in blood sugar is a concern (6)[A].
- Corticosteroids are more effective than diclofenac during the first 3 weeks postinjection. Efficacy is similar to other modalities by 3 months postinjection (6)[B].
- In one randomized trial, hyaluronic acid (HA) injections were as effective as corticosteroid injections. The optimal frequency, dosage, and molecular weight of HA injections has yet to be adequately studied.
ISSUES FOR REFERRAL
Refer to a hand surgeon for release if the patient is not responding to splinting and/or steroid injections.
ADDITIONAL THERAPIES
Physiotherapy is helpful, particularly in children.
SURGERY/OTHER PROCEDURES
- Surgical release can be done as an open procedure or percutaneously.
- No apparent differences in success or rates of complications between surgical approaches (6)[A].
- Surgery has a lower rate of recurrence than corticosteroid injection (6)[A].
- Most hand surgeons prefer open release because of concern about nerve injury.
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
Day surgery for trigger finger release
Discharge Criteria
Absence of complications
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- Follow up is needed only if symptoms persist or if complications develop after surgery.
- Splinting of the affected digit to minimize flexion/extension of the MCP joint helps symptom resolution (1)[B],(7)[C].
PROGNOSIS
Prognosis is excellent with conservative treatment or surgical intervention. Recurrence following corticosteroid injection is more likely for patients with type 1 diabetes mellitus, younger patients, involvement of multiple digits, and patients with a history of other upper extremity tendinopathies (8)[B].
COMPLICATIONS
- Complications from surgery include infection, bleeding, digital nerve injury, persistent pain, and loss of range of motion of the affected finger. The rate of major complications is low (3%). The rate of minor complications (including loss of range of motion) is higher (up to 28%).
- Injury to the A2 pulley may result in bowstringing, (bulging of the flexor tendon in the palm with flexion). This can be painful.
- Diabetic patients may have increased blood sugar levels for up to 5 days following steroid injection.
REFERENCES
11 Akhtar S, Bradley MJ, Quinton DN, et al. Management and referral for trigger finger/thumb. BMJ. 2005;331(7507):30 " 33.22 Salim N, Abdullah S, Sapuan J, et al. Outcome of corticosteroid injection versus physiotherapy in the treatment of mild trigger fingers. J Hand Surg Eur Vol. 2012;37(1):27 " 34.33 Kazuki K, Egi T, Okada M, et al. Clinical outcome of extrasynovial steroid injection for trigger finger. Hand Surg. 2006;11(1 " 2):1 " 4.44 Pataradool K, Buranapuntaruk T. Proximal phalanx injection for trigger finger: randomized controlled trial. Hand Surg. 2011;16(3):313 " 317.55 Cecen GS, Gulabi D, Saglam F, et al. Corticosteroid injection for trigger finger: blinded or ultrasound-guided injection? Arch Orthop Trauma Surg. 2015;135(1):125 " 131.66 Shakeel H, Ahmad TS. Steroid injection versus NSAID injection for trigger finger: a comparative study of early outcomes. J Hand Surg Am. 2012;37(7):1319 " 1323.77 Ryzewicz M, Wolf JM. Trigger digits: principles, management, and complications. J Hand Surg Am. 2006;31(1):135 " 146.88 Rozental TD, Zurakowski D, Blazar PE. Trigger finger: prognostic indicators of recurrence following corticosteroid injection. J Bone Joint Surg Am. 2008;90(8):1665 " 1672.
ADDITIONAL READING
- Fleisch SB, Spindler KP, Lee DH. Corticosteroid injections in the treatment of trigger finger: a level I and II systematic review. J Am Acad Orthop Surg. 2007;15(3):166 " 171.
- Guler F, Kose O, Ercan EC, et al. Open versus percutaneous release for the treatment of trigger thumb. Orthopedics. 2013;36(10):e1290 " e1294.
- Huisstede BM, Hoogvliet P, Coert JH, et al. Multidisciplinary consensus guidelines for managing trigger finger: results from the European HANDGUIDE Study. Phys Ther. 2014;94(10):1421 " 1433.
- Wang J, Zhao JG, Liang CC. Percutaneous release, open surgery, or corticosteroid injection, which is the best treatment method for trigger digits? Clin Orthop Relat Res. 2013;471(6):1879 " 1886.
- Will R, Lubahn J. Complications of open trigger finger release. J Hand Surg Am. 2010;35(4):594 " 596.
CODES
ICD10
- M65.30 Trigger finger, unspecified finger
- M65.319 Trigger thumb, unspecified thumb
- M65.329 Trigger finger, unspecified index finger
- M65.339 Trigger finger, unspecified middle finger
- M65.322 Trigger finger, left index finger
- M65.359 Trigger finger, unspecified little finger
- M65.349 Trigger finger, unspecified ring finger
- M65.351 Trigger finger, right little finger
- M65.311 Trigger thumb, right thumb
- M65.342 Trigger finger, left ring finger
- M65.312 Trigger thumb, left thumb
- M65.332 Trigger finger, left middle finger
- M65.331 Trigger finger, right middle finger
- M65.341 Trigger finger, right ring finger
- M65.321 Trigger finger, right index finger
- M65.352 Trigger finger, left little finger
ICD9
727.03 Trigger finger (acquired)
SNOMED
- 1539003 acquired trigger finger (disorder)
- 239987006 Triggering of digit (disorder)
- 42786005 Snapping thumb syndrome (disorder)
CLINICAL PEARLS
- Trigger finger is caused by narrowing of the A1 flexor tendon pulley.
- Splinting the MCP joint at 10 to 15 degrees flexion for 6 weeks is the preferred initial conservative treatment.
- Splinting is more effective for fingers as opposed to thumbs (70% vs. 50%). Splinting is less effective with severe symptoms, longstanding symptoms (>6 months), or if multiple digits are involved.
- Long-acting corticosteroid injections are effective for treatment of trigger finger.
- Open and percutaneous surgical release has high success rates for patients not responsive to splinting or injections.