Trigger Finger

Patients describe a painful click or catch during finger flexion or extension. Symptoms are usually worst on waking, when the digit may be locked in flexion until passively extended. With progression, locking becomes more frequent and may eventually become fixed.

Examination:

• •Palpate the A1 pulley over the volar MCP joint - a tender nodule moves with active flexion
• •Active flexion and extension reproduces the catch (often felt rather than seen)
• •In late disease the digit may be fixed in flexion or extension
• •Co-examine for diabetes-related hand changes, rheumatoid synovitis, and CTS (Tinel's, Phalen's)

The Quinnell grading system stages disease: I (palpable tenderness with no triggering), II (active triggering, passively correctable), III (locking requiring passive correction), and IV (fixed deformity). Differentials include flexor tendon nodule without triggering, Dupuytren's nodule (palmar fascia, not tendon, no triggering), and locked MCP joint from osteoarthritis or trauma.

Trigger finger is a clinical diagnosis. No imaging is required for typical presentations.

Ultrasound is useful in selected cases:

• •Atypical presentations or examination uncertainty
• •Suspected co-existing tenosynovitis or alternative pathology
• •To guide A1-pulley corticosteroid injection (small RCT evidence that ultrasound guidance improves accuracy but not necessarily clinical outcome)

Ultrasound demonstrates thickening of the A1 pulley, a hypoechoic flexor tendon nodule, and dynamic catching as the patient flexes the digit. MRI and X-ray are not indicated for primary diagnosis. Consider HbA1c if not already documented, particularly in multiple-digit involvement or younger patients, and screen for rheumatoid disease where the picture suggests it.

Management follows a stepwise NICE CKS / BSSH pathway based on severity and chronicity.

First-line (Quinnell I or mild II, symptoms under 4-6 months):

• •Activity modification - reduce repetitive forceful gripping
• •Night splinting of the affected digit in extension (MCP blocked at 0 degrees) for 6-10 weeks
• •Simple analgesia; oral NSAIDs offer limited benefit but are reasonable short-term
• •Glycaemic optimisation in diabetics

Second-line: corticosteroid injection (typically methylprednisolone 20-40 mg with 1% lidocaine) into the flexor tendon sheath at the A1 pulley. Cure rate ~60-80% at 6 months; lower in diabetics (~50%) and multiple-digit disease. NICE supports up to two injections before surgical referral. Counsel patients about transient skin depigmentation and the small risk of flexor tendon rupture.

Third-line: surgical release of the A1 pulley.

• •Open release: gold standard, performed under local anaesthetic as a day case. Success rate >95%, low complication rate, durable
• •Percutaneous release: comparable success in single-digit involvement, faster recovery, slightly higher risk of digital nerve injury (especially in the thumb and index)
• •Recurrence is rare after open release

Referral pathway: refer for surgical opinion after two failed injections, locked digits unresponsive to manipulation, recurrent disease, or diabetic patients with multi-digit involvement.

Conservative pathway: extension splinting at the MCP for 6-10 weeks combined with tendon-gliding exercises (active fist, hook fist, table-top, straight fist) for 5 minutes 4-6 times a day reduces nodular thickening and restores smooth glide. Hand therapy referral is appropriate for severe or recurrent cases.

Post-injection: return to normal activity within 24-48 hours. Avoid heavy gripping for 1-2 weeks to optimise local response.

Post-operative (A1 pulley release):

• •Day 0-3: light dressing, immediate active range of motion encouraged. Elevation and oedema management
• •Day 3-14: gentle activities of daily living; suture removal at 10-14 days; scar massage commences
• •Week 2-6: progressive return to manual work and grip-loaded activity. Most patients return to office work within 1 week and manual work within 4-6 weeks
• •Week 6-12: full return to sport and unrestricted use

Persistent stiffness, pillar tenderness, or incomplete release symptoms beyond 3 months warrants hand-therapy reassessment.

• •NICE CKS Trigger Finger - Supports stepwise pathway with splinting and steroid injection before surgical referral. Up to two injections recommended before surgery.
• •BSSH Trigger Finger Patient Information - UK hand-surgery framework: open release remains the gold standard with >95% success and low recurrence.
• •Peters-Veluthamaningal Cochrane Review (2009) - Corticosteroid injection produced significantly better outcomes than placebo at 4 weeks (NNT 3); benefit lower in diabetic patients.
• •Quinnell classification (1980) - Four-tier severity grading used to stratify conservative vs surgical management; persists as the high-yield UK framework.
• •Bruijnzeel et al. (2012) - Systematic review showed comparable success of percutaneous vs open release in single-digit non-thumb disease, with marginally higher complication rate in percutaneous.

• •The A1 pulley is the commonest site of stenosis because the flexor tendon angles sharply over the metacarpal head during flexion. Surgical release targets A1; the remaining pulleys (A2-A5) must be preserved to prevent bow-stringing.
• •Diabetics have a three to four times population risk and respond less well to steroid injection (cure ~50% vs ~80% in non-diabetics). Multiple-digit disease should prompt diabetes screening.
• •Paediatric trigger thumb is a distinct entity with fixed IP-joint flexion and Notta's node. Adult and paediatric trigger digits should not be managed by the same pathway.
• •Quinnell grading drives management: I-II splinting and injection; III-IV surgical referral. Locked digits unresponsive to manipulation are surgical.
• •The differential for a palmar nodule is Dupuytren's nodule, which is palmar fascia, does not trigger, and does not move with tendon excursion. A trigger nodule moves with the tendon.
• •Up to two steroid injections are supported before surgical referral. Counsel about transient skin depigmentation and rare flexor tendon rupture.