Trigger Finger Injections
- Common digital nerves.
- Flexor tendons.
- Safer than digital blocks because they cause less disruption to venous outflow.
- 2 - 3mls of plain 2% Lignocaine for each finger - then get patient to massage the area.
- Only 1 injection is required per finger.
- Note relative safe zone over flexor sheath.
- Nerves are largely Volar.
- The dorsal cutaneous nerves supply up to and just beyond the PIP joint.
- Palpate the flexor sheath and mark the line with your thumb nail.
- Get the patient to flex their fingers in and out if you are having trouble.
- Clean with alcohol swab then no touch technique.
- If the needle goes too deep it will hit the flexor tendon.
- Not the N/V bundle.
- Never inject against resistance.
- Aim to inject superficial to flexor sheath.
- The local anaesthetic will leak around the adjacent common digital nerves.
- Ask patient to gently move their fingers while injecting.
If the needle moves with finger ROM it is in the tendon!!!
The finger will be numb for an hour. Sometimes the triggering increases due to the volume of fluid but this rapidly resolves.
For further information, refer to Hand Injections - General.