What is the recommended procedure for a trigger finger injection?

Trigger Finger Injection Procedure

The recommended procedure for trigger finger injection involves using 20 mg of triamcinolone acetonide without local anesthetic, injected into the flexor tendon sheath using strict aseptic technique, as this provides the most effective symptom relief with minimal injection pain. 1

Preparation and Materials

• Triamcinolone acetonide 40 mg/mL (use 0.5 mL = 20 mg dose) 1
• 25-27G needle
• Alcohol swabs for skin preparation
• Sterile gloves
• Bandage for post-procedure

Step-by-Step Injection Technique

1. Patient Positioning:

   • Position the patient with hand resting palm-up on a flat surface
   • The affected finger should be slightly flexed for better access to the A1 pulley

2. Skin Preparation:

   • Cleanse the injection site with alcohol or appropriate antiseptic solution 2
   • Allow the antiseptic to dry completely before proceeding

3. Medication Preparation:

   • Shake the triamcinolone vial to ensure uniform suspension 3
   • Inspect for clumping or granular appearance (discard if present) 3
   • Draw 0.5 mL (20 mg) of triamcinolone acetonide 1
   • Do not mix with local anesthetic as this increases injection pain 4

4. Injection Site Identification:

   • Locate the A1 pulley at the palmar digital crease (metacarpophalangeal joint)
   • The needle entry point should be at the level of the distal palmar crease

5. Injection Technique:

   • Insert the needle at a 45-90° angle to the skin surface
   • Advance the needle until it reaches the tendon sheath
   • If resistance is felt, withdraw slightly to ensure proper positioning
   • Inject the medication slowly into the tendon sheath, not into the tendon substance 3
   • A successful injection will create minimal resistance during delivery

6. Post-Injection Care:

   • Apply gentle pressure to the injection site
   • Apply a small adhesive bandage if needed
   • Advise limited use of the finger for 24 hours following injection 2
   • Complete immobilization is not necessary 2

Important Considerations

• Dosage: 20 mg of triamcinolone acetonide provides significantly better outcomes than lower doses (5 mg or 10 mg), with 79% effectiveness at 6 months compared to 52-62% with lower doses 1

• Anesthetic Use: Contrary to common practice, excluding local anesthetic results in less injection-associated pain and simplifies the procedure 4

• Diabetic Patients: Be aware that corticosteroid injections are less effective in diabetic patients, particularly those with nephropathy or neuropathy 5

• Potential Complications:

  • Subcutaneous atrophy may occur if the injection is not properly given 6
  • Transient hyperglycemia in diabetic patients (monitor glucose levels for 1-3 days post-injection) 2
  • Secondary infection (rare with proper technique)

• Follow-up:

  • Patients should be monitored for 6 months after treatment 1
  • If symptoms persist after initial injection, a second injection may be considered
  • Surgical release of the A1 pulley is indicated if injections fail 7

Contraindications

• Active infection at the injection site
• Known allergy to corticosteroids
• Caution in patients with poorly controlled diabetes

This procedure offers a high success rate with minimal complications when performed with proper technique, making it the preferred first-line treatment for trigger finger before considering surgical intervention.