Trigger finger release: the percutaneous needle technique

Trigger finger happens when a flexor tendon can no longer glide smoothly through its pulley system. Usually, the A1 pulley — a band of tissue at the base of the finger — has thickened. The finger catches, locks, or snaps as it bends and straightens. In more advanced cases, it can lock in a bent position altogether.

From open surgery to a needle in clinic

Mild cases often respond to splinting, activity changes, or a corticosteroid injection into the tendon sheath. When the pulley genuinely needs to be released, the traditional option is a small open surgical incision.

Over the past two decades, ultrasound-guided percutaneous release has become a well-studied alternative. Instead of an incision, a clinician divides the tight pulley through a single puncture point — watching the tendon, pulley, and nearby nerves and blood vessels on ultrasound the entire time.

Several instruments have been used for this: plain hypodermic needles, specially designed needle-knives, and blade-tipped needles. A commonly used option is a Nokor needle — an 18-gauge needle with a small triangular blade at its tip, originally designed for other uses in medicine and adapted for this purpose.

Under continuous ultrasound guidance, the clinician positions the needle-knife along the pulley. Controlled, direct cutting movements divide it, with tendon gliding checked along the way. The nearby digital nerves and vessels stay clearly in view and out of the way throughout.

Why ultrasound guidance matters here

The A1 pulley sits very close to the digital nerves that supply feeling to the finger. That’s exactly why this procedure is done under direct ultrasound vision rather than by feel alone. Studies comparing ultrasound-guided release to the older “blind” needle technique have found more complete pulley release and fewer complications — ultrasound lets the clinician confirm exactly where the needle tip is at every step.

What to expect

The procedure is done in clinic under local anesthetic. It usually takes well under 30 minutes and needs only a small bandage afterward — no stitches.

Published outcomes generally report high patient satisfaction, resolution of catching or locking, and a fast return to normal hand use, with a low rate of complications under ultrasound guidance. Whether percutaneous release is the right next step depends on the grade of triggering and your individual anatomy — best assessed with an in-person evaluation.

This page is educational and general in nature, and describes a procedure performed by trained clinicians under ultrasound guidance. It is not a guide to performing this procedure, and does not replace an individualized evaluation — see our medical disclaimer.