Cadaveric Study of Sonographically Assisted Percutaneous Release of the A1 Pulley

Abstract

The purpose of this study was to assess the value of using intraoperative sonography to assist percutaneous release of the A1 pulley in cadavers. By detailed sonographic examination and anatomical exploration, the authors determined the correlation of the actual A1 and A2 pulleys (and adjacent neurovascular bundles not visualized by sonography) to the clearly visualized flexor tendons and the metacarpophalangeal joint. The authors also evaluated their effectiveness as landmarks and the effectiveness of real-time sonographic monitoring during percutaneous release. Experiments were performed on 80 fingers and 20 thumbs in 10 cadavers. All digits were sonographically examined. The clearly delineated bony landmarks of the metacarpophalangeal joint were measured and marked. The A1 and A2 pulleys and the neurovascular bundles were surgically exposed, and their relation to the markers made during sonographic examination was measured. Using these parameters, sonographically assisted percutaneous release of the A1 pulley with a custom-made hook knife was performed on the contralateral side. The completeness of the A1 release and the potential risk of injuries to the A2, flexor tendon, and neurovascular bundles in each digit were examined. Results showed good correlation between the actual length of the A1 pulleys and the sonographically determined distance between the bony prominences of the metacarpophalangeal joint in all digits. Release was complete in 48 of the 50 digits (96 percent) and partial in two, with no injuries to neurovascular bundles. Sonography can clearly delineate the flexor tendon and underlying bony boundary of the metacarpophalangeal joint, which is useful in directing the percutaneous release of the A1 pulley. Sonography can also provide real-time intraoperative monitoring. The results using this new release technique were adequate. The method is safe and its clinical application should be encouraged.

Ultrasound-guided percutaneous release of the annular pulley in trigger digit

“…Whilst the results of their study were encouraging with no reported complications, they used a customised hook knife to perform the release that is not readily available and would represent an added expense of the procedure ($15 per knife) [4]. In contrast, we used a modified 19-gauge (white) needle as the cutting device which is cheap, widely available and used for blind percutaneous release of the annular pulley [3,8,13,16,20,23,27,28].…”

Sonographically Assisted Percutaneous Release of the A1 Pulley: A New Surgical Technique for Treating Trigger Digit

“…All 107 digits were successfully treated, postoperative recovery was uneventful and there were no recurrences during an average 12.5 month follow-up. Sonography was able to show the several landmarks for the division procedure and depict the instruments and the target structures simultaneously during the operation for our cadaver study (Chern et al, 2005) and this clinical study. The safety of sonographically assisted, percutaneous release has been demonstrated by the absence of iatrogenic digital nerve injury in any of these digits.…”

The Value of High-Frequency Ultrasonographic Imaging for Quantifying Trigger Digits: A Correlative Study with Clinical Findings in Patients with Different Severity Grading

“…Although most trigger digits can be diagnosed straightforwardly by clinical presentation, the value of ultrasonographic imaging in determining pathologic structures remains encouraging. To date, there are limited data evaluating the clinical use of ultrasonography in trigger digit (Boutry et al 2005;Chern et al 2005;Gruber et al 2011;Guerini et al 2008;Kim and Lee 2010;Rajeswaran et al 2009;Serafini et al 1996;Tagliafico et al 2009), and the association between clinical presentation and severity grading has rarely been reported in the literature. Although severity grading is not universally used as a guide to plan treatment, a tool that could help physicians in correlating the clinical presentations is useful and welcome in the current context of patient-oriented and cost-effective medicine.…”

“…It has been an ideal imaging tool in the initial investigation of flexor digit tendons (Chern et al 2005;Khoury et al 2007;Klauser et al 2004;Lee et al 2000;Serafini et al 1996) and can be helpful in the evaluation of trigger digits. In trigger digit, ultrasonography can reveal effusion or abnormality of the flexor digit tendons and surrounding structures and impairment of tendon gliding.…”