Practice 10-Minute Consultation

Adult trigger finger

BMJ 2012; 345 doi: http://dx.doi.org/10.1136/bmj.e5743 (Published 12 October 2012) Cite this as: BMJ 2012;345:e5743
  1. John Henton, clinical research fellow, plastic surgery1,
  2. Abhilash Jain, clinical senior lecturer and consultant plastic surgeon12,
  3. Claire Medhurst, general practitioner3,
  4. Shehan Hettiaratchy, consultant plastic surgeon and lead clinician1
  1. 1Hand and Extremity Reconstruction Service, Department of Plastic and Reconstructive Surgery, Imperial College Healthcare NHS Trust, London W6 8RF, UK
  2. 2Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK
  3. 3Baddow Village Surgery, Chelmsford CM2 7EZ, UK
  1. Correspondence to: J Henton johnhenton{at}ymail.com
  • Accepted 2 August 2012

A 62 year old diabetic woman complains of pain in the palm of her hand at the base of her ring finger, which is held in flexion. Extension is painful, produces an audible click, and often requires the assistance of the other hand.

What you should cover

Trigger finger is caused by inflammation and constriction of the retinacular sheath through which the flexor tendons run as they pass from the palm of the hand into the finger. This causes irritation of the tendon, sometimes resulting in the formation of a nodule, which impinges on the pulley, causing pain and restricting movement.

The retinacular sheath is composed of five annular “pulleys” which hold the tendon close to the bone and are integral to the biomechanics of finger flexion (figure). The A1 pulley, at the level of the metacarpal head, is the first part of the sheath and is subject to the highest force. Consequently, triggering usually occurs at this level.

Figure1

Fig 1 Lateral view of a digit showing a simplified view the annular pulley system (A1-5), the flexor tendons with inflammatory nodule, and the passage of the needle for corticosteroid injection

The cause is often multifactorial. Trigger finger is most common in the sixth decade, women, people with diabetes, and the dominant hand.1

History

  • Symptom duration, frequency, and severity

  • Which digit(s) affected? Handedness?

  • Triggering is exacerbated by occupation, repetitive movements, and manual work

  • History of diabetes or arthritis? Trigger digit is often idiopathic, but more common in people with diabetes or arthritis

  • Has the digit ever locked in flexion? (Indicates severity).

What you should do

Examination

  • Look at both hands for swelling, arthropathy, or injury

  • Examine all digits in flexion and extension; triggering can affect multiple digits

  • Palpate palms over the metacarpal heads; you may feel a nodule

  • Examine for carpal tunnel syndrome: sensory changes in the distribution of the median nerve; positive Tinel sign (shooting pains into hand when percussing over median nerve at the wrist); Phalen’s sign (full wrist flexion produces numbness or pain, usually within 1 minute); or thenar muscle wasting. Trigger digit and carpal tunnel syndrome often occur concurrently.

Treatment options

  • Corticosteroid injection into the tendon sheath is usually the first line treatment. Up to 57% of cases resolve with one injection, and 86% with two.2 It has low complication rates and high patient satisfaction.3 4

  • Surgery—Usually indicated if two corticosteroid injections six weeks apart have failed, or the finger is irreversibly locked in flexion. Surgery to release the pulley is done as a day case through a palmar incision under local anaesthetic. Cure rates approach 100%. Complication rates are low, but these include a scar that can be painful for several weeks, and residual triggering and damage to the digital nerves resulting in a sensory deficit (rare). Some surgeons perform a percutaneous procedure.

    • Surgical intervention is different in cases of rheumatoid arthritis; A1 pulley release is not indicated (and it may require tenosynovectomy).

  • Splinting for six weeks can decrease inflammation. This is an option for those wishing to avoid injections or surgery. It has 47-70% success in cases of less than six months’ duration and can cause stiffness.5 6 7 8 9

  • Congenital triggering usually presents in the first year of life. The digit is locked in flexion or extension. Steroid injections have no role in management; instead, refer to a hand surgeon.

Management

  • Explain the nature of the condition and treatment

  • Encourage analgesia and rest until definitive treatment. Light household duties are unavoidable, but advise against heavy lifting, manual work, or gardening

  • It is reasonable to perform the first corticosteroid injection in primary care. Bring the patient back for another appointment and perform the injection yourself if you are confident (see box) or refer appropriately

  • You may be able to refer to a local general practitioner with a specialist interest in musculoskeletal disorders; some routinely manage trigger finger

  • In secondary care, hand surgery is covered by plastic surgeons or orthopaedic hand surgeons.

How to inject a trigger digit

Injection of corticosteroid into the flexor tendon sheath
  • Equipment: chlorhexidine wipe; 2 × 1 ml insulin syringes with attached needle or 1 ml syringes with 25 gauge (orange) needles for injection; 1 ml of 2% lidocaine; corticosteroid (betamethasone in aqueous solution 4 mg in 1 ml, or triamcinolone 10 mg in 1 ml). Betamethasone is preferred as it does not leave a chalky residue in the tissues, which can make subsequent surgery more difficult, and is less likely to cause atrophy of the palmar fat pad.

  • Warn patient of the risks of pain, failure of treatment, recurrence, and further injection. Infection and tendon rupture are exceptionally rare complications. Do not perform the procedure if the skin is obviously infected.

  • Draw up the lidocaine and corticosteroid in separate syringes. Prepare the site with chlorhexadine. Attach 25 gauge needles if using normal syringes.

  • The A1 pulley arises from the palmar aspect of the metacarpal head and metacarpophalangeal joint (figure). The distal palmar skin crease marks this site.

  • In the skin crease, at the midline of the digit, inject a bleb of local anaesthetic into the skin to anaesthetise the area. Leave for 2 minutes.

  • With the steroid syringe, advance the needle at 45° to the palm, over the tendon (midline of digit in palmar crease). Flex and extend the finger to confirm the needle is not intratendinous. If the needle is within the tendon substance, the resistance will be too great to infiltrate; therefore withdraw slightly.

  • When the resistance decreases, infiltrate into the flexor tendon sheath. Remove needle and place a small plaster over the puncture site.

  • Explain that the steroid will take at least 48 hours (up to five days) to work. Encourage movement of the hand to distribute the steroid, but warn against heavy manual work or lifting for 48 hours. Arrange to review patient in four to six weeks.

  • Refer to a plastic or orthopaedic hand surgeon if the first steroid injection is unsuccessful or if the finger is locked in flexion. The patient may require a trigger finger release.

Notes

Cite this as: BMJ 2012;345:e5743

Footnotes

  • This is part of a series of occasional articles on common problems in primary care. The BMJ welcomes contributions from GPs.

  • Contributors: JH researched, wrote, and prepared the manuscript in collaboration with the other authors. JH also prepared the figure. AJ assisted in preparing the manuscript and advised on content. CM advised on the general practice aspects of the article and edited accordingly. SH is senior author and guarantor.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

References