Trigger finger (stenosing flexor tenosynovitis)
Trigger finger is stenosing tenosynovitis of a digital flexor tendon, in which a thickened, constricted A1 pulley at the metacarpophalangeal joint blocks tendon gliding and causes painful catching, snapping, or locking of the finger. It is a clinical diagnosis made on examination, and corticosteroid injection into the flexor tendon sheath is the best initial treatment, with surgical release when injections fail.
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What this article covers
- Overview
Trigger finger is a stenosing tenosynovitis of a digital flexor tendon: thickening or constriction of the A1 pulley over the flexor tendon sheath at the metacarpophalangeal (MCP) joint impedes tendon gliding.
- Epidemiology
Trigger finger is one of the core overuse disorders of the hand, grouped with ganglion cyst, Dupuytren contracture, de Quervain tenosynovitis, and the nerve entrapments as a core wrist and hand disorder.
- Risk factors
Repetitive hand use (overuse) is the main mechanical risk factor.
- Pathophysiology
The digital pulley system holds the flexor tendons against the phalanges: five annular (A1-A5) and three cruciform pulleys keep the tendons from bowstringing during flexion.
- Clinical features
The defining feature is painful catching or snapping of a digit as it moves from flexion into extension, episodic rather than constant.
- Differential diagnosis
Infectious flexor tenosynovitis: rapidly progressive pain, swelling, and erythema of the digit after a puncture or bite with the Kanavel signs (fusiform sausage-digit swelling, finger held in slight…
- Diagnosis
Trigger finger is a clinical diagnosis: painful catching or locking of a digit on extension, plus a palpable catch or nodule along the flexor tendon at the A1 pulley on active flexion, confirms it; no blood test or imaging is required.
- Management
First, exclude infection: never inject a digit with Kanavel signs, since infectious flexor tenosynovitis requires urgent intravenous antibiotics and surgical irrigation and debridement.
- Complications
Tendon rupture can follow persistent tenosynovitis or an injection placed into the tendon substance rather than the sheath.
- Prognosis
Corticosteroid injection is the best initial therapy, with a single repeat injection for partial responders.
- Prevention
Reduce repetitive forceful gripping, the overuse exposure that drives the disease, and splint the digit during periods of heavy hand use.
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Related articles
- Dupuytren contracture
Dupuytren contracture is fibroblastic proliferation and collagen deposition in the palmar fascia that produces painless nodules, then palmar cords, then a fixed flexion contracture of the ring and little fingers, typically after the fifth decade in White men. It is a clinical diagnosis on palpation and inspection, treated with intralesional collagenase or surgical fasciectomy once a joint contracture limits extension.
- De Quervain tendinopathy
De Quervain tendinopathy is noninflammatory thickening of the abductor pollicis longus and extensor pollicis brevis tendons at the first dorsal wrist compartment, diagnosed clinically by radial wrist pain reproduced on the Finkelstein test. First-line care is rest, NSAIDs, and thumb spica splinting, escalating to corticosteroid injection and then surgical release for refractory cases.
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Hand infections range from paronychia and purulent abscess to limb-threatening necrotizing fasciitis, are diagnosed by anatomic pattern and bite or wound history, and are managed by prompt incision and drainage or debridement plus empiric antibiotics targeting staphylococci, streptococci, and bite-specific organisms.
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Ulnar neuropathy is compression of the ulnar nerve (C8-T1), most often at the elbow in the cubital tunnel and less often at the wrist in Guyon canal, causing numbness of the fourth and fifth fingers and, when severe, intrinsic hand weakness, hypothenar atrophy, and an ulnar claw. Diagnosis is clinical with nerve conduction studies and EMG for confirmation, and treatment is avoidance of pressure, splinting, and short-term NSAIDs, with surgical decompression for progressive weakness or persistent symptoms.
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