Sonographically guided percutaneous first annular pulley release: Cadaveric safety study of needle and knife techniques

Objective: The purpose of this study was to assess the safety of sonographically guided percutaneous finger and thumb first annular (A1) pulley releases performed using needle and hook knife techniques in an unembalmed cadaveric model. Methods: A single operator completed 50 (40 fingers and 10 thumbs) sonographically guided percutaneous A1 pulley releases in unembalmed cadavers using previously described needle and hook knife techniques and simulated local anesthesia. Half of the fingers and thumbs were completed with each technique. An experienced observer blinded to the technique dissected each specimen and assessed for neurovascular, flexor tendon, and A2 pulley injury. Completeness of release was also recorded as a secondary outcome. Results: No neurovascular or A2 pulley injury occurred in any digit, regardless of technique. No significant flexor tendon injury was seen in any digit, although minor surface scratches were visualized in 3 cases (6%; 2 knife and 1 needle). The hook knife technique was significantly more likely to result in a complete pulley release compared to the needle technique (22 of 25 [88%] versus 8 of 25 [32%]; P< .001). Conclusions: Sonographically guided percutaneous A1 pulley releases can be performed safely using previously described needle and hook knife techniques. The safety margin for thumb releases is less than that for finger releases, particularly with respect to the radial digital nerve. These cadaveric data support recently published clinical investigations recommending consideration of sonographically guided percutaneous A1 pulley release in the management of patients with a disabling trigger finger.