Treatment of carpal tunnel syndrome : from ultrasonography to ultrasound guided carpal tunnel release

Carpal Tunnel Anthropometrics Using Acrylic Casts: A Cadaveric Study With Implications for Carpal Tunnel Release

BACKGROUND

Abundant literature exists on the morphology of the carpal tunnel. Despite this, the shape of the carpal tunnel has been reported erratically, and most studies did not attempt to correlate findings with measurements taken from cadavers. The objective of this study was to perform a morphological analysis, determine the shape and mean dimensions of the carpal tunnel, determine the level of the narrowest area of the tunnel, and establish a set of values capable of serving as a reference for carpal tunnel release.

METHODS

The carpal tunnels of 20 fresh cadaveric hands were dissected, and acrylic casts were created and measured using industrial computed tomography.

RESULTS

Of the 20 casts, 19 were shaped like elliptic cylinders, with little variation in their measurements along the length. The location of the narrowest section of the carpal tunnel is very different among casts, and the length of the roof of the carpal tunnel ranged from 21.26 to 29.86 mm.

CONCLUSIONS

The most common shape of the carpal tunnel is an elliptic cylinder. Because of the unpredictability of the location of the narrowest area of the carpal tunnel, carpal tunnel release must continue through all extension of its roof. We advise that the release should rarely be extended distally more than 30 mm from the distal palmar wrist crease, which corresponds, in most cases, to the middle of the pisiform.

Challenges of Imaging the Greater Occipital Nerve Using Magnetic Resonance Imaging

ABSTRACT

Migraine headaches are a significant global health concern, frequently managed with varying levels of success. Compression of the greater occipital nerve (GON) is hypothesized to contribute to pathology in some migraine patients, making extracranial nerve decompression surgery a potential intervention for refractory cases. However, accurate methods to image the GON along its tortuous course still need to be explored. Our group has developed magnetic resonance imaging sequences to track the GON. Yet, many challenges were met, which included navigating the GON's complex anatomy, understanding anatomical variants, and designing advanced magnetic resonance imaging sequences and coils to image the posterior scalp. Addressing these hurdles is vital to capture and understand GON pathology and guide potential interventions.

Preoperative visualization of the greater occipital nerve with magnetic resonance imaging in candidates for occipital nerve decompression for headaches

Occipital nerve decompression is effective in reducing headache symptoms in select patients with migraine and occipital neuralgia. Eligibility for surgery relies on subjective symptoms and responses to nerve blocks and Onabotulinum toxin A (Botox) injections. No validated objective method exists for detecting occipital headache pathologies. The purpose of the study is to explore the potential of high-resolution Magnetic Resolution Imaging (MRI) in identifying greater occipital nerve (GON) pathologies in chronic headache patients. The MRI protocol included three sequences targeting fat-suppressed fluid-sensitive T2-weighted signals. Visualization of the GON involved generating 2-D image slices with sequential rotation to track the nerve course. Twelve patients underwent pre-surgical MRI assessment. MRI identified four main pathologies that were validated against intra-operative examination: GON entanglement by the occipital artery, increased nerve thickness and hyperintensity suggesting inflammation compared to the non-symptomatic contralateral side, early GON branching with rejoining at a distal point, and a connection between the GON and the lesser occipital nerve. MRI possesses the ability to visualize the GON and identify suspected trigger points associated with headache symptoms. This case series highlights MRI's potential to provide objective evidence of nerve pathology. Further research is warranted to establish MRI as a gold standard for diagnosing extracranial contributors in headaches.

Trends in Open Versus Endoscopic Carpal Tunnel Release From 2010 to 2021

BACKGROUND

This study compared trends in use, predictive factors, and reimbursement of endoscopic carpal tunnel release (ECTR) withthose of open carpal tunnel release (OCTR) from 2010 to 2021 using a national administrative database.

METHODS

ECTR and OCTR patients were identified in the PearlDiver M151Ortho data set. Numeric and proportional utilization of these procedures was characterized for each year of study. Multivariate analysis was conducted to identify predictive factors for having ECTR performed. The average 90-day reimbursement of ECTR and OCTR was determined.

RESULTS

From 2010 through 2021, 441,023 ECTR and 1,767,820 OCTR procedures were identified. The proportional use of ECTR compared with OCTR rose from 2010 (15.7% of procedures) to 2021 (26.1%). Independent predictors of having ECTR performed rather than OCTR included geographic variation (compared with having surgery in the Midwest, Northeast odds ratio [OR], 1.53; West OR, 1.62; and South OR, 1.66), having Medicare or commercial insurance (compared with commercial, Medicare OR, 0.94, and Medicaid OR, 0.69), female sex, and fewer comorbidities. The average 90-day reimbursement for ECTR was $3,114.82, compared with $3,087.62 for OCTR.

DISCUSSION

As of 2021, over one-fourth of carpal tunnel releases are done endoscopically. Several factors independently predict whether patients receive ECTR or OCTR.

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.

Acroparesthesias: An Overview

Acroparesthesia is a symptom characterized by a subjective sensation, such as numbness, tingling, prickling, and reduced sensation, affecting the extremities (fingers and toes). Despite its frequency, data regarding its diagnostic approach and management are scarce. The etiological diagnosis of acroparesthesia is sometimes challenging since it can be due to abnormality anywhere along the sensory pathway from the peripheral nervous system to the cerebral cortex. Acroparesthesia can reveal several diseases. It can be associated with rheumatic complaints such as arthritis or myalgia. Further cautions are required when paresthesia is acute (within days) in onset, rapidly progressive, severe, asymmetric, proximal, multifocal, or associated with predominant motor signs (limb weakness) or severe dysautonomia. Acroparesthesia may reveal Guillain-Barré syndrome or vasculitis, requiring rapid management. Acroparesthesia is a predominant symptom of polyneuropathy, typically distal and symmetric, often due to diabetes. However, it can occur in other diseases such as vitamin B12 deficiency, monoclonal gammopathy of undetermined significance, or Fabry's disease. Mononeuropathy, mainly carpal tunnel syndrome, remains the most common cause of acroparesthesia. Ultrasonography contributes to the diagnosis of nerve entrapment neuropathy by showing nerve enlargement, hypoechogenic nerve, and intraneural vascularity. Besides, it can reveal its cause, such as space-occupying lesions, anatomical nerve variations, or anomalous muscle. Ultrasonography is also helpful for entrapment neuropathy treatment, such as ultrasound-guided steroid injection or carpal tunnel release. The management of acroparesthesia depends on its causes. This article aimed to review and summarize current knowledge on acroparesthesia and its causes. We also propose an algorithm for the management of acroparesthesia.

Ultrasound-guided interventions in primary carpal tunnel syndrome: perineural injection to thread carpal tunnel release

Carpal tunnel syndrome (CTS), the most common entrapment neuropathy, is compression of the median nerve deep to transverse carpal ligament at wrist. Ultrasonography and electrophysiological study are complementary in the diagnosis and grading of CTS in appropriate clinical settings. The initial management of patients with CTS is conservative with medical therapy and splinting. However, surgical interventions are indicated in patients in whom medical management has failed. With evolution of the concept of safe zone on ultrasonography and identification of the sonoanatomical landmarks of carpal tunnel in greater detail, Ultrasonography-guided interventions are safer and preferred over surgical management in CTS. The primary ultrasonography-guided interventions include perineural injection, perineural hydrodissection and ultrasonography-guided release of transverse carpal ligament. This review article presents the principles of ultrasonography-guided perineural injection, perineural hydrodissection in CTS, the merits and demerits of injectant used in perineural injection/ hydrodissection, and percutaneous ultrasonography-guided thread release of transverse carpal ligament utilizing the concept of safe zone of the ultrasonography-guided interventions for CTS.

Role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of peripheral nerves in the upper extremity

Upper extremity entrapment neuropathies are common conditions in which peripheral nerves are prone to injury at specific anatomical locations, particularly superficial regions or within fibro-osseous tunnels, resulting in pain and potential disability. Although neuropathy is primarily diagnosed clinically by physical examination and electrophysiology, imaging evaluation with ultrasound and magnetic resonance neurography are valuable complementary non-invasive and accurate tools for evaluation and can help define the site and cause of nerve dysfunction which ultimately leads to precise and timely treatment. Ultrasound, which has higher spatial resolution, can quickly and comfortably characterize the peripheral nerves in real time and can evaluate for denervation related muscle atrophy. Magnetic resonance imaging on the other hand provides excellent contrast resolution between the nerves and adjacent tissues, also between pathologic and normal segments of peripheral nerves. It can also assess the degree of muscle denervation and atrophy. As a prerequisite for nerve imaging, radiologists and sonographers should have a thorough knowledge of anatomy of the peripheral nerves and their superficial and deep branches, including variant anatomy, and the motor and sensory territories innervated by each nerve. The purpose of this illustrative article is to review the common neuropathy and nerve entrapment syndromes in the upper extremities focusing on ultrasound and magnetic resonance neurography imaging.

Delayed Surgical Treatment in Patients with Chronic Carpal Tunnel Syndrome Is Still Effective in the Improvement of Hand Function

Background and Objectives: Severe carpal tunnel syndrome (CTS) is the most common compression neuropathy in the upper extremities treated conservatively; later, when advanced, CTS is treated mostly surgically. The most prevalent symptoms comprise numbness, as well as sensation loss in the thumb, index, and middle finger, and thenar muscle strength loss, resulting in impaired daily functioning for patients. Data on the results of CTS treatment in patients with delayed surgical intervention are scarce. The aim of this study was to determine the postoperative results of chronic carpal tunnel syndrome treatment in patients with symptoms lasting for at least 5 years. Materials and Methods: A total of 86 patients (69 females, 17 males) with a mean age of 58 years reporting symptoms of CTS for at least 5 years (mean: 8.5 years) were prospectively studied. The average follow-up time was 33 months. All patients underwent the surgical open decompression of the median nerve at the wrist. A preoperative observation was composed of an interview and a clinical examination. The subjects completed the DASH (the Disabilities of the Arm, Shoulder, and Hand), PRWE (Patient-Rated Wrist Evaluation), and self-report questionnaires. Global grip strength, sensory discrimination, characteristic symptoms of CTS, and thenar muscle atrophy were examined. Postoperatively, clinical and functional examinations were repeated, and patients expressed their opinions by completing a BCTQ (Boston Carpal Tunnel Syndrome Questionnaire). Results: We found improvements in daily activities and hand function postoperatively. Overall, 88% of patients were satisfied with the outcome of surgery. DASH scores decreased after surgery from 44.82 to 14.12 at p < 0.001. PRWE questionnaire scores decreased from 53.34 to 15.19 at p < 0.001. The mean score of the BCTQ on the scale regarding the severity of symptoms was 1.48 and 1.62 on the scale regarding function after surgery. No significant differences were found in the scores between the male and female groups or between age groups (p > 0.05). A significant increase in global grip strength from 16.61 kg to 21.91 kg was observed postoperatively at p < 0.001. No significant difference was detected in the measurement of sensory discrimination (6.02 vs. 5.44). In most of the examined patients, night numbness and wrist pain subsided after surgery at p < 0.001. Thenar muscle atrophy diminished after surgery at p < 0.001. Conclusions: Most patients were satisfied with the results of CTS surgery regarding the open decompression of the median nerve even after 5 years of ineffective conservative treatment. Significant improvement of the hand function was confirmed in the functional studies.

Median Nerve Recovery and Morphological Change on MRI at 24 Months after Open Carpal Tunnel Release

Background: This study aimed to investigate the relationship between postoperative clinical results and long-term morphological changes in patients with carpal tunnel syndrome (CTS) as observed on magnetic resonance imaging (MRI) before and after open carpal tunnel release (OCTR). Methods: We retrospectively analysed data for 28 hands that had undergone OCTR with at least 24 months of follow-up data. Two-point discrimination (2PD) test results were examined for the first three fingers, as were the distal motor latency (DML) and sensory conduction velocity (SCV) of the median nerve. We also calculated the cross-sectional area (CSA) of the carpal tunnel and the distance from the median nerve to the volar carpal bone at the hamate and the pisiform levels using MRI images. Variables were compared before and 24 months after OCTR. Results: Significant improvements in all variables were observed, including average 2PD scores (Finger I: 13.1 ± 6.2 vs. 7.7 ± 4.3, p < 0.01, Finger II: 11.9 ± 6.6 vs. 7.0 ± 3.5, p < 0.01, Finger III: 13.6 ± 6.1 vs. 7.8 ± 4.5, p < 0.01), average DML (8.3 ± 3.3 vs. 4.3 ± 0.6 m/s, p < 0.01), average SCV (30.8 ± 11.0 vs. 41.3 ± 5.3 m/s, p < 0.01), CSA of the carpal tunnel (hamate level: 194.9 ± 30.6 vs. 254.2 ± 47.6 mm2, p < 0.01, pisiform level: 244.2 ± 46.5 vs. 274.7 ± 75.1 mm2, p = 0.01) and the distance between the median nerve and volar carpal bone (hamate level: 8.7 ± 1.4 vs. 11.2 ± 1.6 mm, p < 0.01, pisiform level: 11.8 ± 1.7 vs. 13.8 ± 2.5 mm, p < 0.01). Conclusions: Our results demonstrate that OCTR is successful in achieving long-term decompression and recovery of the median nerve in patients with CTS. Level of Evidence: Level III (Therapeutic).

Minimally Invasive Carpal Tunnel Release Using a Hook Knife through a Small Transverse Carpal Incision: Technique and Outcome

Background

Compared to the classic open technique, limited exposure techniques have the advantages of less scar pain, more grip and pinch strength, and earlier return to daily life. We evaluated the effectiveness and safety of our novel method of minimally invasive carpal tunnel release using a hook knife through a small transverse carpal incision.

Methods

This study included 111 carpal tunnel decompressions in 78 patients who underwent carpal tunnel release from January 2017 to December 2018. We performed carpal tunnel release using a hook knife through a small transverse incision just proximal to the wrist crease under local infiltration of lidocaine with tourniquet inflation in the upper arm. All patients were tolerable during the procedure and discharged following the procedure on the same day.

Results

At an average of 29.4 months of follow-up (range, 12-51 months), all but one patient (99%) revealed complete or near complete symptomatic recovery. The average of the symptom severity score on the Boston questionnaire was 1.31 ± 0.30 and the average of the functional status score was 1.19 ± 0.26. The final mean Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH) score was 8.66 (range, 2-39). There was no superficial palmar arch injury or nerve injury of the palmar cutaneous branch, recurrent motor branch, or median nerve itself as a complication of the procedure. No patient showed any wound infection or wound dehiscence.

Conclusions

Our carpal tunnel release using a hook knife through a small transverse carpal incision performed by an experienced surgeon is a safe and reliable method that is expected to have the benefits of simplicity and minimal invasiveness.

Early Postoperative Recovery after Modified Ultra-Minimally Invasive Sonography-Guided Thread Carpal Tunnel Release

Thread carpal tunnel release (TCTR) has been reported to be safe and effective for the treatment of carpal tunnel syndrome. The aim of this study is to evaluate the modified TCTR for safety, efficacy, and postoperative recovery. Seventy-six extremities in 67 patients undergoing TCTR were analyzed pre- and postoperatively using clinical parameters and patient-reported outcome measures. Twenty-nine men and 38 women with a mean age of 59.9 ± 18.9 years underwent TCTR. The mean postoperative time to resume activities of daily living was 5.5 ± 5.5 days, analgesia was completed after 3.7 ± 4.6 days, and return to work was achieved after a mean of 32.6 ± 15.6 days for blue-collar workers and 4.6 ± 4.3 days for white-collar workers. The Boston Carpal Tunnel Questionnaire (BCTQ) and Disability of Arm, Shoulder, and Hand (DASH) scores were comparable with previous studies. Overall, two persistent compressions and one recurrence required open reoperation (3.9%). All three had been operated in the initial phase, and none required reoperation after an additional safety step was introduced. No other complications occurred. TCTR surgery appears to be a safe and reliable technique with almost no wound and scarring and a potentially faster recovery time than open techniques. Although our technical modifications may reduce the risk of incomplete release, TCTR requires both ultrasound and surgical skills and has a considerable learning curve.

Comparison efficacy of ultrasound-guided needle release plus corticosteroid injection and mini-open surgery in patients with carpal tunnel syndrome

This retrospective study was to compare clinical outcomes of ultrasound-guided needle release with corticosteroid injection vs. mini-open surgery in patients with carpal tunnel syndrome (CTS). From January 2021 to December 2021, 40 patients (40 wrists) with CTS were analyzed in this study. The diagnosis was based on clinical symptoms, electrophysiological imaging, and ultrasound imaging. A total of 20 wrists were treated with ultrasound-guided needle release plus corticosteroid injection (Group A), and the other 20 wrists were treated with mini-open surgery (Group B). We evaluated the Boston carpal tunnel questionnaire, electrophysiological parameters (distal motor latency, sensory conduction velocity, and sensory nerve action potential of the median nerve), and ultrasound parameters (cross-sectional area, flattening ratio, and the thicknesses of transverse carpal ligament) both before and 3 months after treatment. Total treatment cost, duration of treatment, healing time, and complications were also recorded for the two groups. The Boston carpal tunnel questionnaire and electrophysiological and ultrasound outcomes at preoperatively and 3 months postoperatively had a significant difference for each group (each with P &lt; 0.05). There were no complications such as infection, hemorrhage, vascular, nerve, or tendon injuries in both groups. Ultrasound-guided needle release and mini-open surgery are both effective measures in treating CTS patients. Ultrasound-guided needle release plus corticosteroid injection provides smaller incision, less cost, less time of treatment, and faster recovery compared with mini-open surgery. Ultrasound-guided needle release plus corticosteroid injection is better for clinical application.

Ultrasonographic anatomy of the palmar region of the carpus of the dog

The palmar region of the canine carpus may be injured by traumatic, inflammatory, infectious, neoplastic, and degenerative disorders. The normal ultrasonographic anatomic features of the dorsal region of the canine carpus have been published, however information regarding the palmar region is currently lacking. The aims of this prospective, descriptive, anatomic study were (1) to describe the normal ultrasonographic characteristics of the palmar carpal structures in medium to large-breed dogs, and (2) to establish a standardized ultrasonographic protocol for evaluating them. As in the previously published study, the current study consisted of two phases: (1) identification phase, in which the palmar structures of the carpus were identified ultrasonographically in fifty-four cadaveric specimens and an ultrasonographic protocol to examine them was developed; and (2) descriptive phase, in which the ultrasonographic characteristics of the main palmar structures in twenty-five carpi of thirteen living healthy adult dogs were documented. The tendons of the flexor muscles of the carpus and digits, the superficial and deep parts of the retinaculum flexorum, the carpal canal and the median and ulnar neurovascular structures were ultrasonographically identified and described. Findings from the current study can serve as a reference for evaluating dogs with suspected injury involving the palmar carpal region using ultrasonography.

Comparison of acupotomy release combined with glucocorticoid intrathecal injection versus isolated glucocorticoid intrathecal injection for carpal tunnel syndrome: A protocol for a meta-analysis of comparative studies

BACKGROUND

Carpal tunnel syndrome (CTS) is more common in people who need to engage in repetitive wrist work. Once it has occurred, localized pain and numbness of the fingers will develop, in severe cases, muscle atrophy will even arise, and after rest and physical therapy, many patients will still be unable to relieve or recur. In this case, the patient can receive intrathecal glucocorticoid injections, but the hormone injections alone can only provide short-term relief, and because the mechanical factors of median nerve compression are not fundamentally removed. Therefore, combined acupotomy release can help to release the compression of the transverse carpal ligament on the nerve and increase the volume within the carpal tunnel to achieve more satisfactory long-term results. Hence, a meta-analysis is necessary to provide evidence whether there is a significant difference in the treatment of CTS with acupotomy release combined with glucocorticoid intrathecal injection (ARGI) compared with isolated glucocorticoid intrathecal injection (GI).

METHODS

We will search, with no time restriction, without any restriction of language and status, the time from the establishment of the database to October 2022, on the following databases: PubMed, Cochrane central register of controlled trials, Web of Science, Chinese national knowledge infrastructure, Wanfang data, Chinese scientific journals database, Chinese databases SinoMed, and electronic databases. The electronic database search will be supplemented by a manual search of the reference lists of included articles. We will apply the risk-of-bias tool of the Cochrane collaboration for randomized controlled trials to assess the methodological quality. Risk-of-Bias Assessment Tool for nonrandomized studies was used to evaluate the quality of comparative studies. Statistical analysis will be conducted using RevMan 5.4 software.

RESULTS

This systematic review will evaluate the difference in efficacy of ARGI versus isolated GI in the treatment of CTS.

CONCLUSION

The conclusion of this study will provide evidence for judging whether ARGI is superior to GI for treatment of CTS.

Infrared thermographic changes after decompression surgery in patients with carpal tunnel syndrome

BACKGROUND

Digital infrared thermal imaging (DITI), which detects infrared rays emitted from body surface to create a body heat map, has been utilized at various musculocutaneous conditions. Notably, DITI can demonstrate autonomic vasomotor activity in the nerve-innervated area, and thus may be of use in carpal tunnel syndrome (CTS). In this study, we compared DITI findings before and after carpal tunnel release (CTR) surgery in patients with unilateral CTS to investigate the corresponding neurophysiological changes.

METHODS

In this retrospective cohort study, DITI parameters such as the temperature differences between the median and ulnar nerve territories and median nerve-innervated digital anisometry were measured. Subjective symptom duration, pain scale, and ultrasonographic findings were also compared before and after CTR. Patients were evaluated before and 6 weeks after CTR, respectively.

RESULTS

A total of 27 patients aged 59.0 ± 11.2 years were finally included. After CTR, median nerve-innervated thermal anisometry was improved (2.55 ± 0.96 °C to 1.64 ± 1.34 °C; p = 0.003). The temperature differences between the median and ulnar nerve territories were not significantly changed. Subjective pain, the Simovic Weinberg Clinical Scale, and palmar bowing of the flexor retinaculum were also significantly improved (p <  0.001 for all comparisons).

CONCLUSIONS

Our results demonstrated that DITI findings could reflect an improvement in autonomic function after CTR. Therefore, DITI can be an objective method to assess pre- and post-operative neurophysiologic changes in CTS.

A Hybrid Musculoskeletal Ultrasound Curriculum for Physical Medicine and Rehabilitation Residents-a Multi-center Pilot Program

Purpose of Review

The increased use of musculoskeletal ultrasound (MSKUS) in clinical practice warrants achieving competency earlier in physiatrists' careers. Physical Medicine and Rehabilitation (PM&R) residency programs have started incorporating formal MSKUS training in their curricula; however, significant heterogeneity remains in MSKUS education.

Recent Findings

Numerous barriers contribute to the lack of consensus for MSKUS training during residency, but the COVID-19 pandemic severely disrupted in-person learning. As an adjunct or alternative to in-person learning, teleguided technology is being utilized.

Summary

This curriculum demonstrates the role of a hybrid MSKUS training with interinstitutional collaboration. Twenty PM&R learners, from two institutions, were divided into a fundamental or advanced track. Virtual didactic sessions alternated weekly with hands-on ultrasonographic scanning sessions. Following a 12-month longitudinal curriculum, an end-of-year practical examination was used for competency assessment, in addition to a survey assessing resident perceptions and feedback. To our knowledge, this is the first collaborative and hybrid MSKUS curriculum for PM&R learners that can be easily reproduced at most training institutions and circumvent some of the barriers amplified by the COVID-19 pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40141-023-00380-z.

Longitudinal Median Nerve Ultrasound Changes in Individuals With Spinal Cord Injury and an Age- and Sex-Matched Nondisabled Cohort

Objectives

To assess the natural history for development of carpal tunnel syndrome (CTS) in persons with acute spinal cord injury (SCI) at 1 year postdischarge from initial rehabilitation and to assess baseline median nerve (MN) cross-sectional area (CSA) above/below 10 mm2 correlates with any longitudinal changes in quantitative ultrasound (US) of the MN.

Design

A prospective cohort study of persons with acute SCI evaluated for CTS using quantitative US and compared to a group without SCI (non-SCI).

Setting

Academic medical center.

Participants

N=69 total (N=34 SCI, N=35 non-SCI). The average age in both groups was 28 and the SCI group included 30 males and 2 females and the non-SCI group included 30 males and 3 females.

Interventions

Not applicable.

Main Outcome Measures

The primary outcome was the change in quantitative US parameters of the MN, including CSA and grayscale, from baseline to 1-year follow-up in those with SCI and those without SCI. CTS symptomatology and physical exam sum score and US measures for dominant and nondominant arms were considered secondary outcomes.

Results

The SCI had darker nerves at baseline (P=.036, nondominant), greater CTS symptoms at follow-up (P≤.036, bilateral), and no differences in all change scores (all P≥.056). Individuals with smaller nerves at baseline had larger increases in nerve size (P=.029, nondominant) vs those with larger nerves. Change in CTS symptoms CSA (nondominant) and nerve echogenicity (dominant) were inversely associated with their respective baseline values (all P≤.045).

Conclusions

We observed few differences between the SCI group and the non-SCI control group and between those with smaller vs larger MN. In general, MN pathology changes (CTS symptoms and US variables) over 1 year were more common in the nondominant arm and appear to be a function of MN pathology at enrollment. Individuals with SCI may experience increased CTS symptoms as soon as 1 year after injury.

Percutaneous ultrasound-guided ulnar nerve release technique compared to open technique: A cadaveric study

OBJECTIVES

To evaluate the outcomes of a novel percutaneous ultrasound-guided technique for release of ulnar nerve entrapment at the elbow when compared to standard open release Methods: One single surgeon performed an ultrasound-guided percutaneous release of the cubital tunnel on a group of five cadaveric elbows and open release on five others. All procedures were timed, and incision lengths were recorded. Meticulous anatomic dissection was then performed to assess the complete release of the carpal tunnel and iatrogenic injuries.

RESULTS

No significant difference was found between the two groups in terms of complete release and iatrogenic injury, whereas Operative time was significantly shorter for the US-guided technique. Incomplete releases of the nerve were found only during the first two trials in each group, while the third, fourth, and fifth trials showed a complete ulnar nerve release in both series, highlighting a fast learning curve for both techniques. All of this through a significantly smaller incision in the US-guided technique.

CONCLUSIONS

This study highlights the similar effects of these two techniques in terms of complete release of the ulnar nerve, with no clear superiority of one over the other in terms of morbidity rate. Both have a fast learning curve for an ultrasound-trained surgeon, with the US-guided technique being a less traumatic and quicker alternative procedure.

The Correlation of Carpal Tunnel Pressure with Clinical Outcomes following Ultrasonographically-Guided Percutaneous Carpal Tunnel Release

Background: To evaluate the correlation between carpal tunnel pressure (CTP) and the clinical presentations, and to explore the possible predictors for the postoperative recovery pattern in patients with carpal tunnel syndrome (CTS). Materials and Methods: Consecutive patients with idiopathic CTS following percutaneous ultrasound-guided carpal tunnel release (UCTR) were enrolled. CTP was measured preoperatively and immediately after operation. The Boston Carpal Tunnel Questionnaire (BCTQ) and the cross-sectional area (CSA) of median nerve were recorded preoperatively and at 1, 3, and 12 months postoperatively. Results: 37 patients (37 hands; 8 men and 29 females; median age, 59.0 years) were enrolled. CTP significantly decreased immediately from 40.0 (28.0−58.0) to 13.0 (8.0−20.0) mmHg after UCTR. BCTQ scores significantly improved at 1 month postoperatively, and the improvement trend persisted until 12 months postoperatively (p < 0.001). Preoperative CTP was positively correlated with preoperative CSA and preoperative BCTQ scores (p < 0.05, all). Using group-based trajectory modeling, all patients were categorized into the “gradual recovery” or “fast recovery” group. Higher preoperative CTP was significantly associated with a faster recovery pattern (odds ratio: 1.32). Conclusions: Preoperative CTP was well correlated with the clinical presentations and might be a useful predictor for the postoperative clinical recovery pattern.

Clinical Value Analysis of High-Frequency Ultrasound Combined with Carpal Dorsiflexion Electrophysiological Detection in the Diagnosis of Early Carpal Tunnel Syndrome

Objective

To investigate the clinical value of ultrasound combined with electrophysiological examination in the diagnosis of early carpal tunnel syndrome, we aimed to provide a new EMG (electromyography) method for detecting early carpal tunnel syndrome by exploring the wrist back stretch position and electrophysiological examination.

Methods

For the 82-lateral wrist (case group) of 62 patients with clinical symptoms or confirmed carpal tunnel syndrome and 40 normal healthy patients, neuroelectrophysiological measurements were performed using a Keypoint6.0 EMG evoked potentiometer, measuring each group twice: conventional position (before compression) and dorsal wrist extension position. The measures for each measurement included DSL, DML, and CAMP. Measure sensory conduction first and then measure motor conduction. The measurements were analyzed in a comprehensive comparative analysis. Combined ultrasound examination, the positive rate of combined ultrasound examination and electrophysiological examination was compared, respectively.

Results

In the carpal tunnel syndrome (CTS) group, the anterior and posterior median nerve DSL was (4.27 ± 0.73) ms and (4.82 ± 0.65) ms, and SNAP was (13.32 ± 13.68) UV and (12.19 ± 11.04) UV; the median nerve (wrist-bunions) DML was (5.29 ± 1.26) ms and (5.54 ± 1.29) ms, and CMAP was (6.44 ± 2.40) mV and (6.21 ± 2.46) mV. Mid-median DSL and DM in the CTS group L were significantly longer than before compression; median nerve SNAP and CMAP were significantly reduced compared with before compression.

Conclusion

Electrophysiological testing at the dorsal carpal extension position has high diagnostic value in the diagnosis of mild carpal tunnel syndrome. It helps to improve the diagnostic rate of early carpal tunnel syndrome, while providing a more accurate and effective EMG detection of early carpal tunnel syndrome, and combination examination of neuroelectrophysiology and ultrasound can improve the diagnosis rate of compression peripheral nerve diseases and clarify the site, nature, and scope of compression lesions, which is worthy of clinical application.

Ultrasound-guided carpal tunnel injections

Background

Carpal tunnel syndrome (CTS), one of the most common entrapment neuropathies, can, in fact, be considered as a socio-economic issue that reduces work productivity, increases disability, and requires prolonged rehabilitation. The imaging modality of choice in CTS imaging is the ultrasound (US), as several morphological parameters can be used in CTS diagnosis and follow-up. In recent years, US-guided CTS injection therapy has become an established treatment option for mild to moderate CTS. The authors of this review performed a literature search that revealed several differences in US-guided carpal tunnel injection in an attempt to unify individual stages of CTS injections protocol for future guidance: patient preparation, injection approach, needle positioning, injected medications, and injectate volume. The three approaches to carpal tunnel injections described in the literature, that is, the ulnar, radial, and longitudinal, can be implemented with single or multiple deposits and different injection volumes. Medications used for injections are corticosteroids, local anaesthetics, dextrose, saline, platelet-rich plasma, and progesterone.

Conclusions

Although no consensus has yet been reached as to which protocol should be used, the ulnar approach with a single deposit injected in large volumes should be considered as the first choice, while dextrose should be the first-line medication option. Furthermore, as terminological differences make it difficult to draw a uniform comparison the presented steps for US-guided carpal tunnel injection might serve as a guideline for future studies.

Cost-Effectiveness of Sonography-Guided Surgery

Percutaneous carpal tunnel release (CTR) is a new surgical technique allowing to cut the transverse carpal ligament under sonography, without skin incision. The technique is safe, offers good functional results and early return to daily activities. This study investigates if percutaneous CTR is also cost-effective. Percutaneous CTR presents many advantages and may be safer than open and endoscopic CTR. This study could not demonstrate that it allows also cheaper surgery, at least as compared to open CTR. However, if it allows earlier return to work, percutaneous CTR could offer a major economic advantage over other techniques, particularly open surgery.

Safe Zones for Percutaneous Carpal Tunnel Release

Carpal tunnel release (CTR) is an effective procedure used in open, endoscopic, or ultrasound-guided methods. The complications are rare but potentially devasting. Most complications come from errors related to intraoperative technique, especially in the minimally invasive approach. An understanding of the "safe zones" is essential to perform percutaneous CTR safely. This article reviews the anatomy of safe zones and the ultrasound-guided CTR (UCTR) techniques in an attempt to prevent intraoperative complications. In strict accordance with the concepts of safe zones, UCTR is an effective and reliable procedure. Substantial experience for ultrasound-guided injection and surgery is required.

Five Wrist Operations That Give the Best Results

LEARNING OBJECTIVES

After reading this article and viewing the videos, the participant should be able to: 1. Recognize the following five wrist operations as consistent options for different wrist injuries: carpal tunnel release, medial femoral condyle bone flap for scaphoid nonunion associated with carpal collapse and avascular necrosis, scaphocapitate arthrodesis for Kienböck disease, percutaneous screw fixation of nondisplaced scaphoid fracture, and four-corner arthrodesis. 2. Know the state-of-the-art of these five procedures. 3. State the indications of each operation. 4. List the surgical steps of these five procedures.

SUMMARY

The wrist is a complex joint that concentrates different types of tissues (e.g., bone, cartilage, ligaments, nerves, vessels) and a broad different spectrum of diseases. Treatment of wrist injuries has improved during recent years, mainly because of improvement in strategy, techniques, microsurgical equipment, understanding anatomy and improvements in technology. In this article, we present the five operations (i.e., carpal tunnel release, medial femoral condyle bone flap for scaphoid nonunion associated with carpal collapse and avascular necrosis, scaphocapitate arthrodesis for Kienböck disease, percutaneous screw fixation of nondisplaced scaphoid fracture, and four-corner arthrodesis) that have consistently given good outcomes in patients suffering from different wrist injuries/maladies.

Microinvasive Carpal Tunnel Release Using a Retractable Needle-Mounted Blade

We report 166 microinvasive ultrasound-guided carpal tunnel releases using the MICROi-Blade (Summit Medical Products, Inc, Sandy, UT), a needle-based tool for cutting under ultrasound guidance. The 6-month follow-up of the first 21 cases, including 5 bilateral releases, showed a progressive reduction in median pain scores, Boston Carpal Tunnel Questionnaire (BCTQ) Symptom Severity Scale scores, and BCTQ Functional Status Scale scores. The median return to work was 7 days. The 3-month follow-up of 62 subsequent cases showed similar improvement in the BCTQ scores and return to work. There were no complications. This report supports the effectiveness of the technique.

Transthyretin Gene Mutation Associated with Familial Carpal Tunnel Syndrome in Sample of Iraqi Patients

BACKGROUND

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy in upper limbs. It affects women more frequently than men. CTS can be caused by many different systemic diseases and local mechanical conditions and it had signs and symptoms due to compression of median nerve at the carpal tunnel in wrist.

OBJECTIVE

The present study aims to study whether Transthyretin (TTR) gene polymorphisms have association with the development of FCTS.

METHODS

Sixty-four patients suffering from CTS were enrolled in this controlled cross sectional study. For all, nerve conduction study was performed to prove the diagnosis of CTS and to classify its severity. The mean age of all patients was 44.9±7.8 years, 89.1 % were female, 37.5 % had mild type CTS and 40.7 % had right side CTS. 3 mL of peripheral blood was collected from all patients which is a labeled (EDTA) tube at -20 C° for DNA extraction to identify a particular SNP (rs28933979; 148G/A; V50M) that locates at position chr18:31592974 on the exon-2 region which is reported to be associated to the Carpal Tunnel Syndrome. Exon-2 of TTR gene was amplified using the PCR technique and subjected to be tested for presence of SNP by Restriction Fragment Length Polymorphism (RFLP) assay.

RESULTS AND CONCLUSION

According to genetic variation, the study cannot discover any TTR gene polymorphism that back to FCTS.

Percutaneous Needle Electrolysis Reverses Neurographic Signs of Nerve Entrapment by Induced Fibrosis in Mice

Nerve entrapments such as carpal tunnel syndrome are the most common mononeuropathies. The lesional mechanism includes a scarring reaction that causes a vascular compromise. The most effective treatment is surgery, which consists of removing the scarred area, thus reverting the vascular impairment. In the present study, a more conservative therapeutic approach has been undertaken to release the nerve by means of galvanic current (GC) applied with a needle: percutaneous needle electrolysis (PNE). For this purpose, a mouse model of sciatic nerve entrapment has been created using albumin coagulated by glutaraldehyde (albumin 35% and glutaraldehyde 2% volume applied, 10 μl). After two weeks, a fibrous reaction was obtained which entrapped the nerve to the extent of causing atrophy of the leg musculature (14.7%, P < 0.05 compared to the control leg). Ultrasound imaging confirmed that the model's image was compatible with that of nerve entrapment in patients. To quantify the degree of entrapment, nerve conduction recordings were made. The amplitude (peak-to-peak) of the compound muscle action potential (CMAPs) decreased by 32.2% (P < 0.05), and the proximal latency increases by 17.7% (P < 0.05, in both cases). In order to release the sciatic nerve, PNE was applied (1.5 mA for 3 seconds and 3 repetitions; 1.5/3/3) by means of a solid needle in the immediacy of perineural fibrosis before and 5 minutes after the application of GC, and the proximal latency shows a decrease of 16% (P < 0.05). The recovery of CMAPs amplitude was about 48.7% (P < 0.05). Three weeks later, the CMAPs amplitude was almost completely recovered (94.64%). Therefore, with the application of GC by means of a solid needle, the sciatic nerve was definitively released from its fibrous entrapment.

Translation and Validation of the Bulgarian Version of the Boston Carpal Tunnel Questionnaire

Background and Objective: Carpal tunnel syndrome (CTS) is the most common mononeuropathy in humans. Despite the continuous improvement of diagnostic and treatment methods, difficulties remain in the evaluation and quantification of such symptoms as pain, paresthesias, hypesthesia, and hyperesthesia. Numerous tests and questionnaires have been developed for patients with upper limb disease, but the most specific for CTS and the most commonly used is the Boston Carpal Tunnel Questionnaire (BCTQ). BCTQ has been translated and validated for use in many languages, but there is no valid version in Bulgarian yet. The purpose of this work is to create and validate a Bulgarian version of BCTQ, with a recommendation for its use in Bulgarian patients.

Methods: The process was divided into two parts. The first part included a translation and a cultural-linguistic adaptation of the Bulgarian version of BCTQ. In the second part, verification of the psychometric properties of the Bulgarian BCTQ, we investigated the reliability, validity and responsiveness of the Bulgarian version of BCTQ. We evaluated BCTQ's construct validity by comparing its results with the score of the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. The study was performed on a group of 64 patients with a confirmed diagnosis of CTS. All patients were evaluated using the BCTQ and DASH questionnaires. A subgroup of 26 patients underwent open surgical decompression of the carpal canal using a mini-incision technique. The subgroup was evaluated through BCTQ and DASH questionnaires preoperatively and through BCTQ postoperatively at the third month after the intervention.

Results: In the first part of the study, the final version of the questionnaire was presented. Cronbach’s alpha coefficient was 0.88 for the Symptom Severity Scale (SSS) and 0.87 for the Functional Status Scale (FSS). The reproducibility of scores showed an extremely high degree of correlation between the two consecutive BCTQ scores at one-week interval (SSS r=0.99, p<0.0001; FSS r=1, p<0.0001). The criterion validity of the Bulgarian version of BCTQ revealed a strong correlation between the results of the BCTQ and the DASH questionnaires. (SSS r(62)=0.569, p<0.00001; FSS r(62)=0.605, p<0.00001). There was a statistically significant decrease in BCTQ results after surgery for both the SSS (t=-9.43, p<0.00001) and the FSS (t=-9.82, p<0.00001).

Conclusion: Our study created a translated and culturally adapted version of BCTQ. The Bulgarian version of BCTQ is reliable, valid, and responsive for measuring symptoms and functional deficits in patients with CTS.

Ultrasound assessment of carpal tunnel in rheumatoid arthritis and idiopathic carpal tunnel syndrome

Objectives

To comparatively assess the sonographic spectrum of carpal tunnel syndrome (CTS) in patients with rheumatoid arthritis (RA) and in patients with idiopathic CTS.

Methods

Fifty-seven RA patients and 25 idiopathic CTS patients were consecutively enrolled. The diagnosis of CTS in RA patients was made according to clinical history and examination. The following sonographic findings were assessed at carpal tunnel level: median nerve cross-sectional area (CSA) at the carpal tunnel proximal inlet, finger flexor tendons tenosynovitis, radio-carpal synovitis and intraneural power Doppler (PD) signal.

Results

CTS was diagnosed in 15/57 RA patients (26.3%). Twenty-three RA wrists with CTS, 84 RA wrists without CTS and 34 idiopathic CTS wrists were evaluated. The average CSA of the median nerve was higher in idiopathic CTS than in RA wrists with CTS (17.7 mm² vs 10.6 mm², p < 0.01). A higher rate of inflammation of synovial structures (flexor tendons sheath and/or radio-carpal joint) was found in RA wrists with CTS compared with those without CTS (p = 0.04) and idiopathic CTS (p = 0.02). Intraneural PD signal was more common in CTS (in both RA and idiopathic CTS) wrists compared with wrists without CTS (p < 0.01).

Conclusion

The sonographic spectrum of CTS in RA patients is characterized by an inflammatory pattern, defined by the presence of finger flexor tendons tenosynovitis and/or radio-carpal joint synovitis. Conversely, a marked median nerve swelling is the dominant feature in idiopathic CTS. Intraneural PD signal is a frequent finding in both conditions.

Key Points • Carpal tunnel syndrome (CTS) associated with rheumatoid arthritis (RA) and idiopathic CTS have distinct ultrasound patterns. • The most characteristic sonographic features of CTS in RA patients are those indicative of synovial tissue inflammation at carpal tunnel level. Conversely, marked median nerve swelling is the dominant finding in idiopathic CTS. • Intraneural power Doppler signal is a frequent finding in both conditions. • In patients with CTS, differently from electrophysiology, US can provide clues prompting a rheumatology referral in case of prominent inflammatory findings at carpal tunnel level.

Ultrasound-Guided Corticosteroid Injection in Carpal Tunnel Syndrome: Comparison Between Radial and Ulnar Approaches

Purpose

To compare two common approaches for ultrasonography (US)-guided injection.

Patients and Methods

Sixty patients with mild-to-moderate CTS were included in this double-blind randomized controlled trial (RCT). They received a single shot of corticosteroid injection through either the US-guided in-plane approach: radial or ulnar side. Participants were evaluated using Boston Carpal Tunnel Questionnaire (BCTQ) and visual analogue scale (VAS) for pain, as well as electrodiagnosis (EDX) and US parameters before the intervention, and within 12 weeks of follow-up.

Results

In both groups, all outcomes, except for the electrodiagnostic measures, significantly improved within the follow-up. Pain-VAS and both subscales of BCTQ questionnaire, as our main subjective outcomes, revealed dramatic improvement, with the largest amount of changes in VAS (70%; comparing to baseline value), and about 37% for both of BQSS and BQFS scales, all indicating superiority of radial to ulnar in-plane approach. During the first follow-up, we did not detect any remarkable preference between the groups in either subjective or electrodiagnostic variables. However, there was a significant difference at next follow-up time-points in terms of VAS for pain and BQFS favoring radial approach (Table 3). Furthermore, US-measured parameters including nerve-circumference and CSA improved only in the radial in-plane group.

Conclusion

The current data proved that radial in-plane approach for CTS injection could be at least as effective as the more common ulnar in-plane method. Even the pain-relief effect was longer for the radial in-plane approach. Also, patients’ functional status and objective variables all revealed better outcomes via the new approach.

A Review on Advances in Intra-operative Imaging for Surgery and Therapy: Imagining the Operating Room of the Future

With the advent of Minimally Invasive Surgery (MIS), intra-operative imaging has become crucial for surgery and therapy guidance, allowing to partially compensate for the lack of information typical of MIS. This paper reviews the advancements in both classical (i.e. ultrasounds, X-ray, optical coherence tomography and magnetic resonance imaging) and more recent (i.e. multispectral, photoacoustic and Raman imaging) intra-operative imaging modalities. Each imaging modality was analyzed, focusing on benefits and disadvantages in terms of compatibility with the operating room, costs, acquisition time and image characteristics. Tables are included to summarize this information. New generation of hybrid surgical room and algorithms for real time/in room image processing were also investigated. Each imaging modality has its own (site- and procedure-specific) peculiarities in terms of spatial and temporal resolution, field of view and contrasted tissues. Besides the benefits that each technique offers for guidance, considerations about operators and patient risk, costs, and extra time required for surgical procedures have to be considered. The current trend is to equip surgical rooms with multimodal imaging systems, so as to integrate multiple information for real-time data extraction and computer-assisted processing. The future of surgery is to enhance surgeons eye to minimize intra- and after-surgery adverse events and provide surgeons with all possible support to objectify and optimize the care-delivery process.

Case-Control Study of Ultrasound Evaluation of Acute Median Nerve Response to Upper Extremity Circuit Training in Spinal Cord Injury

OBJECTIVE

Individuals with spinal cord injury (SCI) often present signs and symptoms of median nerve (MN) pathology. Preclinical signs identification of MN pathology might facilitate early intervention to prevent or delay carpal tunnel syndrome in SCI. We assessed if ultrasound parameters changed in response to upper extremity (UE) circuit training exercise in individuals with paraplegia and able-bodied individuals.

DESIGN

Case-control study.

PARTICIPANTS

Adults (N=32) with paraplegia (n=16) and age- and sex-matched able-bodied controls (n=16).

INTERVENTION

Circuit training exercise.

MAIN OUTCOME MEASURES

MN ultrasound evaluation at the pisiform and radius before and after UE exercise. Ultrasound parameters included cross-sectional area (CSA), and gray scale (GS). Data presented as mean ± SD.

RESULTS

Pre-exercise CSAs were larger in SCI at the radius (12.0±2.9 vs 9.0±2.1; P=.003), but not the pisiform (9.8±3.1 vs 9.1±1.7; P=.431). There were no statistical differences in MN response to exercise between groups (all P≥.293). Across participants, CSA changes were inversely associated with their pre-exercise values at the pisiform (r=-0.648; P<.001) and the radius (r=-0.366; P=.043). Participants with pre-exercise CSA values ≥10.00 mm² at the pisiform responded to exercise with decreases in CSA (mean change ± SD, -2.0±1.5; P=.002) and GS (-2.8±6.2; P=.029). Participants with pre-exercise CSA ≤9.99 mm² at the pisiform responded to exercise with no change in CSA (mean change ± SD, 0.7±2.5; P=.002) and increased GS (3.2±7.2; P=.029).

CONCLUSIONS

CSA exercise response was more strongly related to pre-exercise MN values than presence or absence of SCI.

Ultrasound-Guided Ankle Lateral Ligament Stabilization

PURPOSE OF REVIEW

Ultrasound (US) is an increasingly popular imaging modality currently used both in clinics and operating rooms. The purpose of this review is to appraise literature describing traditional lateral ankle stabilization techniques and discuss potential advantages of US-guided ankle lateral ligament stabilization. In addition, albeit limited, we will describe our experiences in perfecting this technique.

RECENT FINDINGS

To date, the modified open Broström-Gould technique remains as the gold standard surgical treatment for chronic ankle instability (CAI). In the past decade, modifications of this technique have been done, from a combination of arthroscopic and open procedure to an all-inside arthroscopic technique with a goal of minimizing wound complications, better outcomes, and earlier return to activity. Recently, the use of US as an adjunct to surgical procedures has gained popularity and several novel techniques have been described. The use of US in lateral ankle stabilization could allow accurate placement of the suture anchor at the anatomical attachment of the anterior talofibular ligament (ATFL) without iatrogenic damage to the neurovascular structures such as anterolateral malleolar artery, superficial peroneal nerve, and sural nerve. In summary, the use of US in ankle lateral ligament stabilization is a promising new micro-invasive technique. The theoretical advantages of US-guided ankle lateral ligament stabilization include direct visualization of desired anatomical landmarks and structures which could increase accuracy, decrease iatrogenic neurovascular damage, minimize wound complications, and improve outcomes.

Ultrasound-guided percutaneous release of the carpal tunnel: comparison of the learning curves of a senior versus a junior operator. A cadaveric study

OBJECTIVE

The purpose was to evaluate, in a cadaveric cohort, the feasibility and the learning curve of ultrasound-guided percutaneous carpal tunnel release.

MATERIALS AND METHODS

Fourteen carpal tunnel releases were carried out on unembalmed cadavers by a senior and a junior radiologist. Procedures were realized with an 18-MHz linear probe. An anatomical evaluation was first performed using ultrasound to detect any anatomical variant. After hydrodissection of the carpal tunnel with lidocaine, a 3-mm hook knife was introduced into the security zone to perform a retrograde section of the transverse carpal ligament (TCL) under ultrasound guidance. Anatomical dissection was performed for each wrist. The main evaluation criterion was the complete TCL section. The procedure duration (minutes), skin incision size (millimeters), the integrity of the median nerve, thenar motor branch, and palmar vascular arch were also evaluated.

RESULTS

The senior operator was able to perform a complete release after training on three specimens and the junior operator after four specimens (p > 0.05). In most of the cases when complete release was not achieved, it was due to an incomplete section of the distal TCL (10 mm missing section on average). Mean duration time of procedure was 14 min (11 min for the senior versus 17 min for the junior, p > 0.05). Damage of neither the median nerve nor the vascular structure was observed. Mean size of the skin incision was 3 mm.

CONCLUSION

The ultrasound-guided percutaneous release of the carpal tunnel is demonstrated to be a procedure with a rapid learning curve.

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.

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

Carpal tunnel syndrome (CTS) may be treated surgically if medical treatment fails. The classical approach involves release of the flexor retinaculum by endoscopic or open surgery. Meta-analyses have shown that the risk of nerve injury may be higher with endoscopic treatment. The recent contribution of ultrasound to the diagnosis and therapeutic management of CTS opens new perspectives. Ultrasound-guided carpal tunnel release via a minimally invasive approach enables the whole operation to be performed as a percutaneous radiological procedure. The advantages are a smaller incision compared with classical techniques; great safety during the procedure by visualization of anatomic structures, particularly variations in the median nerve; and realization of the procedure under local anesthesia. These advantages lead to a reduction in postsurgical sequelae and more rapid resumption of daily activities and work. Dressings are removed by the third day postsurgery. Recent studies seem to confirm the medical, economic, and aesthetic benefits of this new approach.