Wrist
Trigger Finger (Stenosing Tenosynovitis)
방아쇠수지 (협착성 건초염)
Stenosing tenosynovitis where the flexor tendon catches at the A1 pulley, causing triggering
- How common
- Very common (2–3% of adults)
- Typical age
- Women 40–60, diabetics
What is it?
A1 pulley thickens and the flexor tendon forms a nodule; passage through the narrowed pulley causes triggering.
Commonly affected: A1 pulley of thumb, ring, and middle fingers most common
How it develops
- Normal Tendon GlideFlexor tendon glides smoothly under A1 pulley
- Repetitive FrictionRepetitive gripping causes pulley friction
- Pulley Thickening / Tendon NoduleA1 pulley thickens, tendon develops nodule
- TriggeringNodule catches at pulley, then snaps through
- LockingSevere cases lock in flexion
Symptoms
- Catching/TriggeringAudible/palpable snap during extension
- A1 Pulley PainTenderness at MCP joint base
- Morning StiffnessFinger locked in morning
- LockingSevere cases lock finger in flexion
How it is examined
- A1 Pulley TendernessTenderness at MCP base volar surface
- Palpable NodulePalpable tendon nodule at A1 pulley
- Active ROM ReproductionActive flex/extend reproduces triggering
Imaging
X-ray usually not needed — only if concurrent arthritis suspected.
- Normal or MCP arthritis
- Often unnecessary
US is most useful; MRI rarely needed.
- A1 pulley thickening
- Tendon nodule
- Dynamic triggering on US
Non-surgical care
- Activity Mod + SplintNighttime MCP extension splint 4–6 weeks
- NSAIDsNSAIDs
- A1 Pulley Steroid InjectionSingle injection resolves 60–80%
- Stretching ExercisesFlexor stretching, towel curls
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Failure of 2 steroid injections, persistent locking
Procedures that may be discussed
- A1 pulley release (open or percutaneous)
Outlook
60–80% cured by steroid injection; surgical success >98%.