Comparing Steroid Injections for Trigger Finger
Trigger finger can be successfully treated with a steroid injection. Hand surgeons differ in which type of steroid should be used. This is the first study to provide evidence that one type may be better than another.

Trigger finger (or thumb) occurs when swelling of the lining around a tendon causes narrowing of the tunnel through which the tendon moves. The person with a trigger finger is unable to extend the affected finger. When attempting to straighten the finger, pain and cracking occurs. If the finger can unlock, it pops back suddenly, as if releasing a trigger on a gun.

Steroid combined with a numbing agent such as lidocaine can be injected into and around the flexor sheath. The goal is to reduce inflammation and resolve the symptoms of trigger finger. Two types of steroid are commonly used: dexamethasone and triamcinolone.

Dexamethasone is much stronger than triamcinolone and the effects last twice as long. Triamcinolone may leave a deposit in the flexor tendon sheath that can prevent smooth tendon gliding.

In this study, patients with trigger finger received a single injection of either dexamethasone or triamcinolone. They were evaluated at six weeks and three months after the injection. Measures used to assess the outcome included function, patient satisfaction, and improvement of the trigger finger.

Improvement was measured using the Quinnell system of grading the finger. The Quinnell system grades trigger fingers as:
  • 0 - normal movement
  • 1 - uneven movement
  • 2 - locking can be corrected with active motion
  • 3 - locking corrected with passive motion
  • 4 - unable to correct deformity

    Results showed no difference in function at six weeks between the two groups. There were fewer triggering fingers in the triamcinolone group at six weeks. But there were more recurrences of trigger finger at three months in the triamcinolone group.

    Overall, the triamacinolone had a faster result but the benefits didn't always last. Recurrence rate was higher for triamacinolone. Dexamethasone may be the preferred steroid injection, but the authors suggest further study to confirm this finding.
    References
    David Ring, MD, PhD, et al. A Prospective Randomized Trial of Injection of Dexamethasone Versus Triamcinolone for Idiopathic Trigger Finger. In The Journal of Hand Surgery. April 2008. Vol. 33A. No. 4. Pp. 516-522.