What Is Trigger Finger—and Why the A1 Pulley Matters?

Trigger finger, known as A1 pulley stenosing tenosynovitis, is a common and painful condition that causes your finger or thumb to catch or lock. It happens when the A1 pulley, a fibrous band that helps guide tendons, becomes thickened or inflamed, disrupting smooth movement.

Treatment starts conservatively with splinting, rest, and steroid injections, but when these treatments fail, surgery is often required. Traditionally, that means open surgery or a “blind” percutaneous release. But ultrasound-guided A1 pulley release (USGAR) is a new minimally invasive procedure that uses real-time ultrasound imaging to precisely guide a needle or blade through the A1 pulley to release the constricted tendon.

What Is Ultrasound-Guided A1 Pulley Release?

Ultrasound-guided A1 pulley release is a minimally invasive procedure that uses real-time ultrasound imaging to precisely guide a small instrument—like a needle or custom knife—to release the tight A1 pulley. Unlike blind techniques, ultrasound guidance lets the doctor see exactly where nerves and tendons are, making the procedure safer and more effective.

What does the data say?

A recent systematic review by Nakagawa et al. that was published in the Journal of Ultrasound Medicine analyzed 17 studies involving 749 procedures of ultrasound-guided A1 pulley release. The overall success rate for this method was found to be 97%, with very few complications reported. Minor complications such as hematomas, transient numbness, and persistent pain occurred in a small percentage of cases, but there were no major complications or permanent nerve damage observed.

Key Findings: The results? Impressive across the board.

• Success Rate: 97%
  • Defined as symptom resolution or significant improvement without needing a second procedure.

  • Success rates in individual studies ranged from 76% to 100%.

• Safety Profile
  • Zero major complications.

  • Only 23 minor complications:

    • 15 cases of persistent pain

    • 4 hematomas

    • 4 transient numbness (all resolved on their own)

• Recovery Time

  • Return to daily activities ranged from 1 to 6.6 days—far faster than traditional surgery.

Real-World Benefits: What This Means for Patients?

• Minimally invasive: Small puncture site, not a surgical incision.
• No stitches: Usually just a bandage.
• Immediate mobility: Most patients resume finger movement the same day.
• Cosmetically superior: Less scarring, especially important for the hands

Why Ultrasound Guidance Makes the Difference?

• Traditional "blind" percutaneous releases rely on anatomical landmarks, which can vary person-to-person.
  
  • This increases the risk of incomplete release or nerve damage, especially in thumbs and pinky fingers where nerves run closer to the pulley.
• Ultrasound:
  
  • Allows live visualization of nerves and tendons.
    
  • Guides the tool precisely to the pulley.
    
  • Reduces the likelihood of cutting the wrong structure.
    
• Several studies directly comparing ultrasound-guided and non-guided techniques found statistically better outcomes for the ultrasound group—with fewer complications and faster returns to normal life.

Reference:

Nakagawa H, Redmond T, Colberg R, Latzka E, White MS, Bowers RL, Sussman WI. Ultrasound-Guided A1 Pulley Release: A Systematic Review. J Ultrasound Med. 2023 Nov;42(11):2491-2499.