What is the procedure for a trigger point injection for trigger finger (stenosing tenosynovitis)?

From the Guidelines

To perform a trigger point injection for a trigger finger, it is essential to use a sterile, single-use, disposable needle and syringe for each injection given, as emphasized by the study on infection prevention and control 1. When performing the injection, several key steps must be followed to ensure safety and efficacy.

• Identify the painful nodule or thickened area in the flexor tendon, typically at the base of the finger near the palm.
• Clean the area with an antiseptic solution like chlorhexidine or alcohol.
• Use a 25-27 gauge needle attached to a syringe containing a mixture of 1 mL of a corticosteroid (such as methylprednisolone 40 mg/mL or triamcinolone 10-40 mg/mL) and 1 mL of lidocaine 1% or 2%.
• Insert the needle perpendicular to the skin at the site of maximum tenderness, advance it into the tendon sheath (not the tendon itself), and aspirate to ensure you're not in a blood vessel.
• Then inject the solution slowly, feeling for resistance. The patient may experience temporary discomfort during injection.
• Apply pressure for a minute after removing the needle, then cover with a small bandage.
• Advise the patient to rest the finger for 24-48 hours and watch for signs of infection, as preventing infection is a critical aspect of the procedure, highlighted by the importance of using sterile equipment 1. This procedure works by reducing inflammation in the tendon sheath, allowing smoother tendon movement through the pulley system.
• Most patients experience significant improvement within a week, though some may require a second injection after 4-6 weeks if symptoms persist.

From the Research

Trigger Point Injection for Trigger Finger

To perform a trigger point injection for a trigger finger, the following steps can be considered:

• The first-line treatment for trigger finger is a corticosteroid injection 2
• The injectable solution can be prepared with or without a local anesthetic, but studies suggest that excluding the anesthetic may decrease injection pain 2
• The choice of corticosteroid solution can affect clinical outcomes, with triamcinolone demonstrating a higher rate of additional injections compared to methylprednisolone and dexamethasone 3
• Different dosages of triamcinolone acetonide can be used, with a 20-mg dose showing a significantly higher rate of clinical effectiveness at 6-month follow-up 4, 5

Corticosteroid Injection Technique

The technique for injecting corticosteroid into a trigger finger can vary, but the following points can be considered:

• A retrospective review of 577 digits treated with steroid injections found that the recurrence rate was 20.3% and that injection therapy is safe and highly effective (79.7%) 6
• The use of a local anesthetic, such as lidocaine, can increase injection-associated pain, and its exclusion may be preferred 2
• The dosage of triamcinolone acetonide can range from 5 mg to 20 mg, with higher doses showing better clinical outcomes 4, 5

Clinical Outcomes and Follow-up

The clinical outcomes and follow-up for trigger finger injections can be summarized as follows:

• Patients receiving triamcinolone may require additional injections compared to those receiving methylprednisolone and dexamethasone 3
• The choice of corticosteroid can affect the need for surgical intervention, with methylprednisolone showing a higher rate of surgical release 3
• Follow-up appointments can be used to assess the clinical response to the steroid injection, with outcomes measured using Visual Analog Scale (VAS) pain scores and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores 5