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

Abstract

This study introduces a sonographically assisted percutaneous technique for releasing trigger digits which provides direct visualization of the release and avoids the risks of incomplete release and injury to adjacent neurovascular structures associated with other percutaneous release techniques. The "safe zone" and an estimate of the size of the A1 pulley were determined in a separate cadaver study. We then used these landmarks in a prospective clinical study of 107 digits in 83 consecutive patients treated by this technique. During the follow-ups of between 9 and 15 months, we evaluated 104 digits in 80 patients. Pain was absent in 101 digits (97%) and considerably improved in the other three (3%). All mechanical problems had been resolved and none recurred during follow-up. This technique allows the surgeon to see and monitor, precisely, the percutaneous division of the A1 pulley without open surgery and, therefore, to avoid the inherent risks of percutaneous and open surgical release.

Kinematical and functional improvements of trigger digits after sonographically assisted percutaneous release of the A1 pulley

“…Similar results were reported in previous studies using clinical observations or telephone interviews. 7,9,11,13,[28][29][30] Subsequently, each joint's ROM showed improvement. Although most studies reported that the majority of trigger digit patients had regained full or normal ROM after treatment, 1,7,9,11,13,[28][29][30][31][32] the recovery rate of the workspace and joint ROM in this study was 87-92% of the performances of the intact hand 12 weeks postoperatively.…”

“…7,9,11,13,[28][29][30] Subsequently, each joint's ROM showed improvement. Although most studies reported that the majority of trigger digit patients had regained full or normal ROM after treatment, 1,7,9,11,13,[28][29][30][31][32] the recovery rate of the workspace and joint ROM in this study was 87-92% of the performances of the intact hand 12 weeks postoperatively. This might be because ROM evaluations in previous studies were based on direct observations or the clients' self-reported outcomes, 1,7,11,13,[28][29][30][31][32] so the 10% difference in full or normal ROM might not have been detected visually.…”

“…However, clinicians may not describe this phenomenon quantitatively, so the literature generally presents the effectiveness of intervention using simple and convenient physical examinations, as well as patients' self-reported satisfaction questionnaires. 1,6,[7][8][9][10][11][12][13][14] Kinematics investigations may provide a new approach for quantifying the inappropriate movements of the trigger digit. For example, clinical experience is usually based on a four-or five-grade taxonomy.…”

“…A sonographically assisted percutaneous release technique, introduced in our previous reports, avoids the risks of incomplete release and damage to adjacent tissues via a direct guide by intraoperative sonography. 9,19 Although successful results with this technique have been reported in physicians' observations and clients' self-reported satisfaction questionnaires, a critical lack of empirical support exists regarding objective and scientific functional outcome reports to ascertain the effects of the operation.The use of precise measures to represent treatment outcomes is crucial. The kinematics properties of the underlying tendon and pulley systems of the trigger digit, whether in vitro or in vivo, have not been much explored.…”

“…In prior studies, researchers usually used simple physical examinations, such as clinical observations of range of motion (ROM) or movement abnormality and pain rating and selfreported satisfaction questionnaires to evaluate conditions before and after treatment. 1,[6][7][8][9][10][11][12][13][14] With these methods, clinicians can easily and conveniently assess treatment outcomes; however, little research has focused on objectively assessing the efficacy of surgical release based on quantifiable measures. To describe hand movements thoroughly, uses of three-dimensional and dynamic goniometric measures to represent thumb and finger ROM based on computer-aided motion analysis techniques were recently reported.…”