Clinical Applications of Ultrasonography in Carpal Tunnel Syndrome and Trigger Finger

Abstract

Carpal tunnel syndrome (CTS) and trigger digit (TD) both are common hand disorder with a significant co-incidence The elevated carpal tunnel pressure (CTP) within the carpal tunnel is a possible mechanism to result in the CTS Carpal tunnel release is one of the treatments for CTS by transecting the transverse carpal ligament (TCL) to relieve the symptoms of CTS The patients with TD usually present pain at the metacarpophalangeal(MCP) joint and locking catching or snapping sensation at the proximal portion of first annular (A1) pulley of the affected finger during flexion and extension The mismatch of the A1 pulley-tendon sheath system is a possible mechanism to cause the triggering phenomenon In this thesis study designs were divided into three parts The concept of these studies is to solve the clinical scenario using ultrasonography We treated CTS and TD using ultrasonography-assisted percutaneous release in our daily practice and furthermore measured the CTP using the unique technique Finally we evaluated the mismatch of the A1 pulley-tendon sheath system using ultrasonography The three parts were described as follows:US-assisted PCTR:The purpose of this part of the study is to present the technique and the results of an ultrasonographically guided percutaneous carpal tunnel release (PCTR) in a consecutive series of patients with carpal tunnel syndrome Methods: We used previously defined landmarks with the "safe zones" localization estimated size and extent of the transverse carpal ligament for this prospective clinical study of 91 consecutive cases of carpal tunnel release treated with this technique The follow-up consisted of four time points(1 week and 2 6 and 12 months) and a final evaluation in an average 22 5 months Results: The sensory disturbances disappeared in 76 8 93 4 100 and 100% of the patients in 1 week and 2 6 and 12 months postoperatively and 24 2% experienced moderate pain within 1 week 6 6% within 2 months and 1 1% within 12 months after the operation In the final evaluation two hands were graded as unsatisfactory: one had moderate wrist pain without sensory disturbance and one had a recurrence 14 months after the operation There was no intra- or postoperative complication Conclusions: Ultrasonographically assisted PCTR is a safe and effective procedure but it is technically demanding and requires substantial training to be proficient in its use CTP-outcomes correlation: Since there were no studies to investigate the effect of ultrasonographically guided percutaneous carpal tunnel release (UCTR) on CTP by percutaneous ultrasound-guided needle puncture method and establish the relationship between CTP and clinical outcomes The aim of this part of the study is to evaluate the correlation of carpal tunnel pressure (CTP) with clinical outcomes and cross-sectional area of median nerve (CSAMN) following ultrasonographically guided percutaneous carpal tunnel release (UCTR) Methods: Serial patients with idiopathic CTS were enrolled CSAMN under ultrasound examination and Boston Carpal Tunnel Questionnaire (BCTQ) were evaluated until twelve months postoperatively Results: The CTP in 37 hands of 36 patients significantly decreased after UCTR There were the lower post-operative CTP and the higher decrease ration of CTP in patients with the mild and moderate electrodiagnostic grades After surgery BCTQ score significantly improved at one-month follow-up and CSAMN did not significantly improve until three-month follow-up The pre-operative CTP was significantly positively correlated with pre-operative BCTQ score and CSAMN The immediately post-operative CTP was still significantly positively correlated with CSAMN until twelve months after surgery but only with post-operative BCTQ at one-month followup Conclusions: Therefore the immediate postoperative CTP might predict the short-term postoperative functional outcomes and CSAMN Tendon-A1 pulley mismatch: The aim of this study was to evaluate and to compare the cross-sectional area (CSA) of flexor digitorum tendons and the thickness of A1 pulleys between contralateral normal digits and trigger digits at positions of finger flexion and extension using a noninvasive ultrasound system Methods: Seventeen affected fingers of seventeen trigger finger patients who involved the trigger finger in one hand were examined in this study Seventeen contralateral normal digits without symptoms of trigger finger were examined The sonographic appearances of flexor digitorum tendons and A1 pulley were observed at two positions of 0? and 60? metacarpophalangeal (MCP) joint flexion Results: The findings of this study indicate that CSA of flexor digitorum tendons and A1 pulley thickness were significantly larger in both positions of 0° and 60° flexion of MCP joint compared to contralateral normal digits (p< 0 01) In trigger digits there was a significantly thicker A1 pulley at 60° flexion of MCP joint than that at 0° flexion (p< 0 01) but no significant change on CSA of flexor tendons Conclusions: Our results suggested that trigger digits lead to the thicker A1 pulley and larger CSA of the flexor digitorum tendons The mismatch in volume change between CSA of flexor digitorum tendons and A1 pulley thickness during MCP flexion may lead to the trigger phenomenon

Date of Award	2019
Original language	English
Supervisor	Fong-chin Su (Supervisor)