Percutaneous release of the A1 pulley: a cadaver study

Percutaneous release of the A1 pulley has been used for treatment of trigger fingers with success. However, lack of direct visualization raises concerns about the completeness of the release and about potential injury to the tendons or neurovascular structures. The purpose of this study was to assess the efficacy and safety of percutaneous release of the A1 pulley in a cadaveric model using a commonly available instrument, a #15 scalpel blade.

Fourteen fresh frozen cadaveric hands (54 fingers, thumbs excluded) were used. Landmarks were established for the A1 pulley based upon cutaneous features. Percutaneous release was performed using a #15 blade. The specimens were then dissected and examined for any tendon or neurovascular injury, and completeness of A1 pulley release was evaluated.

There were 39 (72%) complete releases of the A1 pulley with 14 partial and 1 missed (failed) release. There was a 22% incidence of release of the proximal edge of the A2 pulley. However, there was no case of release of more than 25% of the A2 pulley length, nor was bowstringing of flexor tendons seen in these specimens. Eleven digits showed longitudinal scoring of the flexor tendons and 3 had partial tendon lacerations. No neurovascular injuries were noted.

Percutaneous release of the A1 pulley using a #15 blade was associated with good efficacy and an acceptable margin of safety in this series.

Percutaneous release of trigger digits may assume a greater role in the treatment of patients with trigger finger because of cost containment pressures. The data from this study suggest that the technique used in this study is both safe and effective. With use of proper anatomical guidelines, risk to neurovascular structures is low, although longitudinal scoring of the tendon can occur.