Ultrasound-Guided Surgery for Carpal Tunnel Syndrome: A New Interventional Procedure

Prospective evaluation of a novel device for ultrasound-guided percutaneous treatment of carpal tunnel and trigger finger disease. Efficacy and safety of sono-instruments®

PURPOSE

To evaluate the safety and effectiveness of percutaneous release procedures under sonography using Sono-Instruments® in the treatment of carpal tunnel syndrome (CTS) and trigger finger (TF).

METHODS

Prospective study involving 30 patients, divided into two groups (15 CTS, and 15 TF). The primary outcomes were surgical performance-related outcomes (visibility, ease of use, satisfaction, duration) using Sono-Instruments® and patient-related outcomes (pain, activity limitations, time to return to work, functional scores). Secondary outcomes included complications. Patients were followed for two months post-operatively.

RESULTS

In the CTS group, the average age of the patients was 58.7 years. The percutaneous release of the transverse carpal ligament was effectively completed in all cases, with excellent device performance and no adverse events. At one week, all patients could wash their hands, 80% could perform activities of daily living, and 80% of those working had returned to their activities. At two months, all patients had resumed all activities. Pillar pain was still present in 53.3%. In the TF group, the patients had an average age of 57.9 years. The percutaneous release of the A1 annular pulley was successful in all cases, with excellent device performance and no adverse events. At one week, all patients could wash their hands, 93.3% could do all activities of daily living, and 75% of those working were back to their professional activities. At two months, all patients were back to all activities of daily living and work. The DASH score was significantly improved at two months, compared to preoperative, for both groups (p < 0.001).

CONCLUSION

Percutaneous sono-guided release using Sono-Instruments® is safe and efficient, and associated with quick functional recovery.

LEVEL OF EVIDENCE

II.

Long-Term Clinical Results of Carpal Tunnel Release Using Ultrasound Guidance: A Multicenter Pragmatic Study

Purpose

The purpose of this study was to report the 1-year clinical outcomes of carpal tunnel release using ultrasound guidance (CTR-US) performed in a large, real-world population of patients enrolled in a multicenter registry.

Methods

All patients who participated in a postmarket registry study of CTR-US outcomes and provided both preoperative and 1-year postoperative data were included. Main outcomes were the Quick Disabilities of the Arm, Shoulder, and Hand Questionnaire (QDASH), Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ-SSS), and Boston Carpal Tunnel Functional Status Scale (BCTQ-FSS) scores at 1 year. Subgroup analysis was performed to assess the effect of patient and procedural factors on 1-year outcomes.

Results

A total of 300 patients (341 hands) were treated by 25 different physicians, including 41 (13.7%) treated with simultaneous bilateral procedures. Mean patient age was 54.2 years, 63% were women, 24% had ≥2 comorbidities, and 54% had symptoms for >2 years. Mean QDASH scores decreased from 40.6 ± 20.6 to 12.2 ± 18.3 at 1 year, BCTQ-SSS scores decreased from 3.0 ± 0.7 to 1.5 ± 0.7 at 1 year, and BCTQ-FSS scores decreased from 2.4 ± 0.8 to 1.4 ± 0.6 at 1 year. Women improved more than men at 1 year for QDASH, BCTQ-SSS, and BCTQ-FSS. Patients treated with simultaneous bilateral procedures had similar 1-year outcomes to those treated with unilateral procedures. Multiple other factors including high body mass index, diabetes status, current tobacco use, rheumatoid/inflammatory arthritis, operation in the dominant hand, higher comorbidity burden, and concurrent ipsilateral procedures did not significantly affect 1-year outcomes. Two patients had revision surgeries in addition to one patient with an infection, and one with a suspected small finger tendon injury.

Conclusions

Patients treated with CTR-US in real-world conditions report significant and clinically meaningful improvements in symptoms and function that are maintained at 1 year. The results are consistent across broad patient demographics and are not affected by performing simultaneous bilateral procedures.

Type of study/level of evidence

Therapeutic IV.

Variations of the Median Nerve and Carpal Tunnel Syndrome: a Systematic Review of the Literature

Objectives:The purpose of this systematic review is to examine the different variations of the median nerve (MN) and the diagnostic methods used to identify carpal tunnel syndrome (CTS), a common neuropathy resulting from the entrapment of the MN within the carpal tunnel. Understanding the different variations of the MN is crucial in order to prevent injuries during surgical treatment of the syndrome. Materials and methods:Data were extracted from studies published in PubMed. A detailed search in PubMed was performed for studies that reviewed the variations of the MN and CTS. Results:There are two main classifications of the MN, known as the Lanz and Amadio categories. Lanz's classification is the one being mostly used in the surgical literature, with group 3 (Bifid MN) being the main cause of the CTS. Additionally, there are branches and anastomosis of the MN that do not fit into either category, with the third common digital branch being the most injured nerve during carpal tunnel release surgery. Diagnostic techniques for CTS include physical examination combined with NCS tests, magnetic resonance imaging (MRI), ultrasound, or elastography. While NCS has been previously the most commonly used diagnostic method, the recent literature suggests that ultrasound and elastography are the most accurate techniques. Conclusions:In order to minimize injuries during carpal tunnel release surgery, it is crucial to have knowledge on the different variations of the MN that cause CTS. Additionally, this review emphasizes the significance of the current diagnostic methods, which not only make CTS more affordable but also facilitate easier recognition of the condition.

Carpal Tunnel Release With Ultrasound Guidance: Intermediate-Term Clinical Outcomes and Magnetic Resonance Imaging Findings

Purpose

The purpose of this study was to report intermediate-term outcomes following carpal tunnel release using ultrasound guidance and wide-awake local anesthesia no tourniquet, including a subset of patients with preoperative and postoperative magnetic resonance imaging (MRI).

Methods

In this observational study, patients with carpal tunnel syndrome were treated with carpal tunnel release using ultrasound guidance and wide-awake local anesthesia no tourniquet in a procedure room at a single center. Main outcomes were complications; return to activity and work at 2 weeks; Quick Disabilities of the Arm, Shoulder, and Hand and Boston Carpal Tunnel Questionnaire scores through 6 months; and postoperative morphological changes of the transverse carpal ligament, median nerve, and carpal tunnel evaluated using MRI.

Results

No complications were reported among 65 patients (68% women, 96 wrists). By 2 weeks, 97% of patients returned to normal activity and 100% returned to work. Statistically significant improvements in Boston Carpal Tunnel Questionnaire symptom severity scale, Boston Carpal Tunnel Questionnaire functional status scale, and Quick Disabilities of the Arm, Shoulder, and Hand scores occurred by the 2-week follow-up interval and persisted at 6 months (all P < .001). Pre- and postoperative MRI scans were available for 13 patients (17 wrists) at the 3-month mean follow-up. Complete transverse carpal ligament transection was documented in all wrists. Key MRI findings included a 22% increase in carpal tunnel cross-sectional area at the hamate (P < .001), a 52% increase in median nerve cross-sectional area at the hamate (P < .001), an 18% reduction in median nerve signal intensity (P = .002), a 38% reduction in the flattening ratio of the median nerve at the hamate (P < .001), a 33% reduction in the flattening ratio of the median nerve at the pisiform (P < .001), a 20% reduction in the flattening ratio of the carpal tunnel at the hamate (P < .001), and a palmar shift of the median nerve relative to the hamate in all cases.

Conclusions

Carpal tunnel release using ultrasound guidance using wide-awake local anesthesia no tourniquet in a procedure room setting was safe, effective, and resulted in morphological changes that were consistent with carpal tunnel decompression as demonstrated by MRI.

Type of study/level of evidence

Therapeutic IV.

Anatomical considerations of US-guided carpal tunnel release in daily clinical practice

Carpal tunnel syndrome is the most frequent compression neuropathy with an incidence of one to three subjects per thousand. As specific anatomical variations might lead to unintended damage during surgical interventions, we present a review to elucidate the anatomical variability of the carpal tunnel region with important considerations for daily clinical practice: several variants of the median nerve branches in and around the transverse carpal ligament are typical and must - similarly to the variant courses of the median artery, which may be found eccentric ulnar to the median nerve - be taken into account in any interventional therapy at the carpal tunnel. Unintended interference in these structures might lead to heavy arterial bleeding and, in consequence, even underperfusion of segments of the median nerve or, if neural structures such as variant nerve branches are impaired or even cut, severe pain-syndromes with a profound impact on the quality of life. This knowledge is thus crucial for outcome- and safety-optimization of different surgical procedures at the volar aspect of the wrist and surgical therapy of the carpal tunnel syndrome e.g., US-guided carpal tunnel release, as injury might result in dysfunction and/or pain on wrist motion or direct impact in the region concerned. For most variations, anatomical and surgical descriptions vary, as official classifications are still lacking.

Ultrasound-Guided Interventions for Carpal Tunnel Syndrome: A Systematic Review and Meta-Analyses

Carpal tunnel syndrome (CTS) is the most common peripheral entrapment, and recently, ultrasound-guided perineural injection (UPIT) and percutaneous flexor retinaculum release (UPCTR) have been utilized to treat CTS. However, no systematic review or meta-analysis has included both intervention types of ultrasound-guided interventions for CTS. Therefore, we performed this review using four databases (i.e., PubMed, EMBASE, Scopus, and Cochrane) to evaluate the quality of evidence, effectiveness, and safety of the published studies on ultrasound-guided interventions in CTS. Among sixty studies selected for systemic review, 20 randomized treatment comparison or controlled studies were included in six meta-analyses. Steroid UPIT with ultrasound guidance outperformed that with landmark guidance. UPIT with higher-dose steroids outperformed that with lower-dose steroids. UPIT with 5% dextrose in water (D5W) outperformed control injection and hydrodissection with high-volume D5W was superior to that with low-volume D5W. UPIT with platelet-rich plasma outperformed various control treatments. UPCTR outperformed open surgery in terms of symptom improvement but not functional improvement. No serious adverse events were reported in the studies reviewed. The findings suggest that both UPIT and UPCTR may provide clinically important benefits and appear safe. Further treatment comparison studies are required to determine comparative therapeutic efficacy.

Carpal tunnel syndrome: updated evidence and new questions

Carpal tunnel syndrome is the most common entrapment neuropathy, affecting quality of life for many people. Although it is a well recognised condition, new insights into epidemiology, diagnosis, and treatment have emerged in the past 6 years. The availability of disease-modifying treatments for rare systemic disorders associated with carpal tunnel syndrome (eg, amyloidosis) should alert clinicians to these diagnostic possibilities. Besides clinical evaluation and electrophysiology, the role of ultrasonography as a diagnostic tool has been confirmed and new ultrasound techniques have been applied, the clinical use and feasibility of which require further investigation. Surgical and non-surgical interventions are beneficial for the treatment of carpal tunnel syndrome and several treatment options are now available, giving clinicians the possibility to choose the best approach for every patient. New diagnostic and therapeutic techniques require further validation.

Dynamic ultrasound for evaluating the adequacy of median nerve decompression following minimally invasive carpal tunnel release: technical innovation and case study

Background

Minimally invasive carpal tunnel release has recently emerged as the primary surgical approach for recalcitrant carpal tunnel syndrome. A major concern related to surgical failure with this technique is the incomplete release of the flexor retinaculum.

Case presentation

We developed a technique using dynamic ultrasound for evaluating the adequacy of median nerve decompression following minimally invasive carpal tunnel release. This novel imaging method was applied to two patients who showed significant symptom relief after the intervention. This case study also provides details of the dynamic ultrasound protocol and highlights the advantages of this technique.

Conclusion

Dynamic ultrasound imaging can be used to confirm the completeness of carpal tunnel decompression. A large-scale prospective trial should be conducted to validate whether additional dynamic ultrasound examination can improve the outcome of minimally invasive carpal tunnel release.

Multicenter Pragmatic Study of Carpal Tunnel Release with Ultrasound Guidance

OBJECTIVES

To report outcomes of patients who underwent carpal tunnel release with ultrasound guidance (CTR-US) in routine clinical practice.

METHODS

This was a multicenter post-market registry of patients treated with CTR-US. Main outcomes included the Quick Disabilities of Arm, Shoulder, and Hand Questionnaire (QDASH), Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ-SSS) and Functional Status Scale (BCTQ-FSS), return to normal activities, return to work, and complications.

RESULTS

Of 535 patients who provided follow-up data, 373 (70%) were followed for 6 months post-treatment. Among these 373 patients (427 hands, mean age 55 years, 71% female), QDASH scores decreased by 30.8 points, BCTQ-SSS scores decreased by 1.6 points, and BCTQ-FSS scores decreased by 1.0 points at 6 months (all p<0.001). The median time to return to normal activities was 3 days and time to return to work was 5 days. Subgroup analysis revealed consistent outcomes regardless of age group, sex, body mass index, diabetes, tobacco use, worker compensation status, or procedure type (unilateral/bilateral simultaneous). No major neurovascular complications were reported.

CONCLUSION

Patients treated with CTR-US reported clinically meaningful improvements in symptoms and function, rapid return to normal activities, and minimal work absenteeism, with an excellent safety profile.

The radiological approach to the carpal tunnel release - An anatomical pilot study

Different techniques are available for carpal tunnel release such as classical surgical operations or minimally invasive procedures. A minimally invasive approach and the relevant regional anatomy are reported in this pilot study which was conducted with bodies from a body donation program. The method described here uses a hook knife to cut through the transverse carpal ligament or flexor retinaculum under ultrasound guidance. The results are documented by means of magnetic resonance and ultrasound imaging as well as by anatomical dissection.

Carpal tunnel ultrasound: is the "safe zone" on the ulnar side of the median nerve really avascular?

INTRODUCTION

Numerous publications have studied the regional anatomy of the carpal tunnel to define a "safe zone" to reduce the risk of perioperative neurovascular complications. This zone, located between the ulnar neurovascular bundle and the median nerve, is considered to be safe mainly because of the absence of vascular structures. This study aims to assess the presence of arterioles within this area using superb microvascular imaging (SMI).

MATERIALS AND METHODS

The images from patients who underwent a bilateral routine wrist ultrasound with SMI, between January 28 and February 28, 2019, were retrospectively reviewed by two radiologists to evaluate the presence and location of arterioles in the safe zone. In addition, cadaveric wrists injected with intra-arterial red latex underwent dissection of the carpal tunnel.

RESULTS

The images from 27 patients (54 wrists) were reviewed. In the safe zone, arterioles were seen superficial to the retinaculum in 36 wrists (36/54; 66.7%) and deep to the retinaculum in 21 wrists (21/54; 38.9%). The arterioles located deep to the retinaculum were more frequently found close to the median nerve (21/54; 38.9%) than to the ulnar artery (9/54; 16.7%). In five cadaveric wrists, arterioles were detected superficial to the retinaculum in 3 wrists (3/5; 60%) and deep to the retinaculum in 2 wrists (2/5; 40%).

CONCLUSION

Arterioles can be seen in the safe zone both superficial and deep to the flexor retinaculum. Deep to the retinaculum, they are mainly observed in the proximal aspect of the carpal tunnel and more frequently close to the median nerve.

KEY POINTS

• Superb microvascular imaging (SMI) enables the visualization of arterioles within the "safe zone" of the carpal tunnel (visible both superficial and deep to the flexor retinaculum). • Arterioles were more frequently observed in the proximal aspect of the carpal tunnel. • Deep to the retinaculum, arterioles were more frequently seen in proximity to the median nerve.