Trigger Finger Injection

About this injection

Trigger finger (stenosing tenosynovitis) occurs when the flexor tendon sheath becomes thickened and inflamed, causing the tendon to catch, click, or lock as it passes through the A1 pulley at the base of the finger. The affected finger may snap or trigger on flexion and extension, and in severe cases become locked in a bent position.

Corticosteroid injection into the tendon sheath at the A1 pulley is the most effective non-surgical treatment for trigger finger, with success rates of 60–90% in appropriately selected patients. It works by reducing the inflammation and thickening that causes the tendon to catch.

Dr Hasham performs trigger finger injections with precision using anatomical landmark technique. The procedure is straightforward, takes under 20 minutes, and most patients notice improvement within 1–2 weeks.

Conditions treated

• ✓Trigger finger (stenosing tenosynovitis) — any digit including the thumb
• ✓Trigger thumb — particularly common in adults and may present differently to trigger finger
• ✓Diabetic cheiroarthropathy — patients with diabetes have a higher incidence of trigger finger
• ✓Post-inflammatory flexor tendon sheath thickening

Symptoms

• —Clicking or snapping of a finger on flexion or extension
• —A palpable or visible nodule at the base of the affected finger in the palm
• —Finger that locks in a bent position and requires the other hand to straighten
• —Pain and tenderness at the base of the finger in the palm (A1 pulley)
• —Stiffness in the morning that eases with movement
• —Progressive locking with inability to fully extend the finger

Assessment & diagnosis

Diagnosis is clinical. Tenderness is maximal over the A1 pulley at the metacarpophalangeal (MCP) joint in the palm. A palpable nodule on the flexor tendon is often present. Triggering or locking can usually be demonstrated during examination.

Treatment options

What happens on the day

1. Palpation of A1 pulley at the base of the finger in the palm
2. Tendon nodule identified where present
3. Palm cleaned with antiseptic
4. Small gauge needle (25G) positioned at the A1 pulley
5. Needle angled 45° distally along the tendon
6. Corticosteroid and local anaesthetic injected into the tendon sheath
7. Correct placement confirmed — injection flows freely without resistance
8. Needle withdrawn, pressure applied
9. Patient asked to flex and extend finger post-injection

Injection technique

The A1 pulley is located at the level of the distal palmar crease, over the MCP joint. The needle is inserted at 45° to the skin, directed distally along the flexor tendon. Correct placement within the tendon sheath produces free flow of medication — resistance suggests the needle is in the tendon substance and should be repositioned. Triamcinolone 10–20mg or methylprednisolone 20mg in 0.5–1ml local anaesthetic is used.

Risks & side effects

• —Post-injection flare — temporary increase in palm pain for 24–48 hours
• —Tendon rupture — rare but serious; avoid injecting directly into the tendon
• —Skin depigmentation and fat atrophy at the injection site in the palm
• —Infection — rare with sterile technique
• —Incomplete relief requiring a second injection

Aftercare

• ✓Normal use of the hand is possible from the next day
• ✓Avoid heavy gripping for 48 hours
• ✓Triggering may persist for 1–2 weeks as the steroid takes effect
• ✓A second injection 6–8 weeks later is appropriate if partial response
• ✓If two injections fail to resolve triggering, surgical release is recommended

Frequently asked questions