Ultrasound-Guided Percutaneous A1 Pulley Release by Acupotomy (Needle-Knife): A Cadaveric Study of Safety and Efficacy

Abstract

Purpose: This study was to assess the safety and effectiveness of ultrasound-guided percutaneous A1 pulley release by acupotomy on unembalmed cadavers. Materials and Methods: Sixty digits (from six cadavers, three male and three female) were split into two groups using stratified randomization. All procedures were completed by a single doctor with rich experience in ultrasound-guided treatment. In the acupotomy group, the A1 pulley was released under ultrasound-guided by a needle-knife; while in the needle group, the A1 pulley was released under ultrasound-guided by a 21-gauge needle. Two groups completed six thumbs and 24 fingers, respectively. Another anatomist, blinded to the two techniques, assessed the safety, including the minimum distance between the incision and the neurovascular; flexor tendon, neurovascular and A2 pulley injury or not. Completeness release of the A1 pulley was recorded as effectiveness. Results: No neurovascular or A2 pulley injuries were recorded. However, the incision of the thumb in both groups biased to the radial side (P <0.05), while the incision of the finger biased to the ulnar side (P <0.05). No significant flexor tendon injury was found, and only five cases (16.7%) had minor scratches in the acupotomy group; while in the needle group, 15 cases had minor scratches and lacerations occurred in three cases. The flexor tendon injury rate was 60%. Compared with the needle, ultrasound-guided acupotomy release is safer (P <0.05). The ultrasound-guided acupotomy technique was significantly more likely to result in a complete A1 pulley release compared to the needle technique (28 of 30 [93.3%] versus 11 of 30 [36.7%]; P <0.05). Conclusion: Ultrasound-guided percutaneous A1 pulley release by acupotomy is a safe and effective technique. When releasing the thumb by ultrasound-guided, be careful not to bias to the radial side to avoid neurovascular injury, while when releasing a finger, be careful not to bias to the ulnar side.