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This study aimed to investigate the diagnostic and evaluative significance of combining median nerve (MN) morphological measurements with diffusion tensor imaging (DTI) and T2 mapping metrics for carpal tunnel syndrome (CTS). Morphological and multiparametric magnetic resonance neurography (MRN), along with clinical evaluation, were conducted on 33 CTS patients and 32 healthy controls. The MRN metrics included fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), radial diffusivity (RD), T2 value, cross-sectional area (CSA) and MN flattening ratio (MNFR) at both the pisiform bone and hamate bone levels. Differences in MRN metrics between the above two levels (Delta FA, Delta ADC, Delta AD, Delta RD and Delta T2) were calculated. T-tests, multivariable regression, and receiver operating characteristic (ROC) curve analyses were used to compare and classify patients with CTS and controls. The correlations between MRN metrics and clinical characteristics were analyzed. Comparisons were also made between MRN metrics in patients with and without significant symptom improvement after treatment. FA, AD, T2 value, and CSA at the pisiform bone level were identified as independent predictors of CTS. The combination of these metrics improved diagnostic performance (AUC 0.922, sensitivity 84.85% and specificity 90.62%). Delta ADC, Delta AD, and Delta T2 correlated with function Boston scores. The T2 value at hamate bone level, along with Delta AD and FA, correlated with visual analogue score (VAS). CSA and Delta T2 had higher AUCs for classifying patients with and without significant symptom improvement after treatment. These findings suggest that combining MN morphological and multiparametric MRN metrics can enhance the diagnostic performance of CTS and has the potential to provide an objective and quantitative basis for further study of the degree of entrapment and prognosis., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Introduction: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy syndrome of the upper extremities. The carpal tunnel is an osteofibrous canal that is medially bordered by hamulus ossis hamati and pisiform bone, and laterally by scaphoid and trapezoid bones. In this retrospective case-control study, we investigated the relationship between radiologically measured morphometric indices and CTS in female patients., Methods: Clinical, radiological, and demographic data were collected for 55 hands of 40 female patients diagnosed with CTS and 58 hands of control subjects. Radiological measurements included various morphometric parameters derived from wrist and hand X-rays. Statistical analysis was conducted to assess associations between morphometric indices and CTS., Results: Significant associations were observed between CTS and several morphometric indices, including carpal height, capitate length, palm length, and others. Notably, these values were lower in CTS patients, suggesting a potential link between reduced carpal tunnel volume and increased pressure due to synovial hypertrophy. Additionally, a newly introduced index, Scaphoid Pisiform Width Index (SPWI), showed promise in assessing the proximal part of the carpal tunnel., Conclusion: It was found that the values for Capitate length, Carpal height, Palm length, SPWI, and Palmar ratio were lower in the patient group. These results suggested that decreasing volume of the carpal tunnel allows for an easier increase in carpal tunnel pressure due to increased synovial hypertrophy and the carpal bone configuration affects the proximal part of the carpal tunnel, and influences the compression of the median nerve, in female patients., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Purpose: Our purpose was to compare differences in the incidence of amyloid deposition in tenosynovium (TS) versus transverse carpal ligament (TCL) biopsies obtained during open carpal tunnel release. We hypothesized that the incidence of amyloid would be similar between TCL and TS when obtaining both specimens from the same patient., Methods: All primary, elective open carpal tunnel release cases that underwent biopsy for amyloid between January 2022 and September 2023 were reviewed. Tenosynovial and TCL specimens were independently evaluated by a pathologist to assess for amyloid. Demographic data were collected, and incidence of amyloid deposition was compared between the two samples. Agreement statistics, sensitivity, and specificity were calculated for TCL, using TS as the reference standard., Results: A total of 196 cases met either Tier 1 (n=180) or Tier 2 (n=16) biopsy criteria. Forty-eight cases were excluded for missed biopsies or laboratory processing errors, leaving 148 cases available for analysis. Amyloid deposition was present in 31 out of 148 (21%) TS specimens and 33 out of 148 (22%) TCL specimens. Overall, the results of the TS biopsy agreed with TCL biopsy in 138 out of 148 cases (93%). In the 10 cases for which the results of the TCL and TS biopsy differed, six cases had (+) TCL and (-) TS, and four cases had amyloid deposition in TS without evidence of deposition in the TCL. Sensitivity and specificity values for the TCL specimen were 87% and 95%, respectively. Positive and negative predictive values were 82% and 97%, respectively., Conclusions: For cases of open carpal tunnel release undergoing biopsy, amyloid deposition was noted in 21% of TS specimens and 22% of TCL specimens. Results of TS and TCL biopsies obtained from the same patient agreed in 93% of cases. Single-source biopsy for amyloid represents a reasonable diagnostic approach. Future cost analyses should be performed to determine whether the addition of two biopsy sources to improve diagnostic accuracy is justified., Type of Study/level of Evidence: Prognostic II., Competing Interests: Conflicts of Interest No benefits in any form have been received or will be received related directly to this article., (Copyright © 2024 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

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., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Connective tissue serves a role beyond mere spatial filling. Furthermore, there is increasing evidence that connective tissue plays an important role in the pathogenesis of conditions such as carpal tunnel syndrome (CTS). According to our hypothesis, the median nerve (MN) is surrounded by a system of connective tissue distal to the pronator teres and extending up to, and including, the carpal tunnel., Methods: To visualize the connective tissue surrounding the median nerve, we dissected the forearms of 15 body donors from pronator teres to the carpal tunnel, created plastination slices stained with Periodic Acid-Schiff (PAS), and injected ink into the seen spaces. We verified our findings with a segmentational analysis of radiological data of 10 healthy individuals., Results: We macroscopically describe the median nerve´s system of connective tissue (MC) distal to the pronator teres and up to and including the carpal tunnel. This system creates, connects, and separates spaces. At least from the pronator teres to the carpal tunnel it also creates subspaces from proximal to distal. For the MC, we established a mean cross-sectional area of 153.1 mm 2 (SD=37.15) in the carpal tunnel. The median nerve consistently resides at the center of this MC, which further connects to flexor muscles of the forearm, and to the radius bone. In the carpal tunnel, the MC creates subspaces inside. There, it also acts as the outermost internal layer enveloping flexor tendons, and the MN., Discussion: The term MC does not negate but orders the existence of other "connectives", like subsynovial connective tissue, endo-, epi- or perineuria, epimysia, periostea, or peritendinea, to a hierarchy related to the median nerve. Diseases of the MN are common. Knowing the anatomy of the MC and how it relates to MN function may help clinicians recognize and understand conditions like CTS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Background: Carpal Tunnel Syndrome (CTS) is the most common compressive neuropathy, accounting for 90% of all neuropathies. Its prevalence ranges from 3.8%-7.8% in the population. The gold standard for its diagnosis is the neurophysiological study (85% sensitivity and 95% specificity), with the disadvantage of being invasive, complex and expensive, which means an increase in cost and time for the diagnosis of the disease. The main objective of this diagnostic test evaluation study is to investigate the value of ultrasound in the diagnosis of CTS, and among the secondary objectives, to establish the ultrasound parameters that are predictors of CTS in comparison with neurophysiological studies, attempting to standardize a protocol and reference values that determine the presence or absence of CTS., Methods: Prospective, cross-sectional study. The reference test with which we compared the ultrasound is the neurophysiological test (NPT). Patients will come consecutively from the Neurophysiology Department of the Virgen Macarena Hospital, with clinical suspicion of CTS and fulfilling the inclusion/exclusion criteria. To calculate the sample size (EPIDAT program) we proposed a sensitivity of 78% and specificity of 87% with a confidence level of 95%, requiring 438 patients (264 NPT positive, 174 NPT negative). We followed an ultrasound study protocol that included the ultrasound variables: cross-sectional area at the entrance and exit of the tunnel, range of nerve thinning, wrist-forearm index, flexor retinaculum bulging, power Doppler uptake and the existence of adjacent wrists or masses. We propose a timeline for the study to be performed between 2020 and 2023. Finally, we propose a cost-effectiveness analysis., Discussion: Ultrasound not only allows to objectify the alterations of the median nerve but also the underlying pathological mechanisms in CTS. A multitude of ultrasound parameters have been described that should be regarded in syndrome's study, among which we included the cross-sectional area, the range of nerve thinning, the wrist-forearm index, flexor retinaculum bulging, power Doppler uptake and assessment of anatomical alterations. The use of ultrasound as a diagnostic tool in CTS has many advantages for both doctors and the patients, as it is a non-invasive, convenient, and fast tool increasingly accessible to professionals., Trial Registration: Trials registry number: NCT05556278., Competing Interests: The authors declare that they have no conflict of interest., (Copyright: © 2023 Murciano Casas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Muscular and neurovascular variations in the upper extremity are of utmost clinical significance. Here we report a unique bilateral accessory muscle in the forearm and palm of an 89-year-old male cadaver. The accessory muscle presented two bellies on the right side, one in the forearm, innervated by the anterior interosseous nerve, and the other in the palm, innervated by a branch of the median nerve. A long tendon interconnected the two bellies. On the left side, the muscle had a single belly in the palm, which began at the end of a long tendon that extended from the forearm. However, on both sides, the muscle originated from the posterior surface of the flexor digitorum superficialis belly and inserted along with the first lumbrical muscle into the dorsal digital expansion of the index finger. The proximal parts of the variant muscles were sandwiched between the flexor digitorum muscles. The palmar bellies coursed distally through the carpal canal and lay deep to the superficial palmar arch, and superficial to the first lumbrical, between the thenar muscles and the lateral-most tendon of the flexor digitorum superficialis. Arguably, the accessory muscle might be a variant of a lumbrical muscle, as reported before, but innervation of the proximal belly by the anterior interosseous nerve suggests that the muscle may well be a deep accessory muscle at the forearm, probably appeared as a diverted part of the flexor digitorum profundus. Its space-occupying course through the forearm and palm, especially through the carpal canal, might be clinically significant as it might contribute to nerve compression pathologies in the upper extremity. This accessory muscle also indicates the complex nature of individual muscle formation and evolution of the upper extremity with constant changes in the morphology of muscles based on their changing functions.

Magnetic resonance diffusion tensor imaging (DTI) can detect microstructural changes in peripheral nerves. Studies have reported that the median nerve apparent diffusion coefficient (ADC), a quantification of water molecule diffusion direction, is sensitive in diagnosing carpal tunnel syndrome (CTS). Five databases were searched for studies using ADC to investigate CTS. Apparent diffusion coefficient (measured in mm 2 /s) were pooled in random-effects meta-analyses. Twenty-two studies met criteria yielding 592 patients with CTS and 414 controls. Median nerve ADC were measured at the level of the distal radioulnar joint (CTS ADC: 1.11, 95% CI: 1.07-1.15, I 2 = 54%; control ADC: 1.04, 95% CI: 1.01-1.07, I 2 = 57%), pisiform (CTS ADC: 1.39, 95% CI: 1.37-1.42, I 2 = 0%; control ADC: 1.27, 95% CI: 1.23-1.31, I 2 = 59%), hamate (CTS ADC: 1.40, 95% CI: 1.36-1.43, I 2 = 58%; control ADC: 1.27, 95% CI: 1.25-1.28, I 2 = 47%), and as an combination of several measurements (CTS ADC: 1.40, 95% CI: 1.37-1.47, I 2 = 100%; control ADC: 1.39, 95% CI: 1.24-1.53, I 2 = 100%). Median nerve ADC is decreased in individuals with CTS compared to controls at the levels of the hamate and pisiform. ADC cut-offs to diagnose CTS should be established according to these anatomic levels and can be improved through additional studies that include use of a wrist coil.

Background The median nerve is subjected to compression in the carpal tunnel giving rise to a constellation of symptoms known as carpal tunnel syndrome. It is the most frequent form of peripheral entrapment neuropathies and is most prevalent in the middle age females. The most common cause of this syndrome is idiopathic. One of the known secondary causes is pregnancy. Objective To compare the mean cross sectional area of median nerve using ultrasound in pregnant and non-pregnant females at carpal tunnel inlet and its variations with different trimesters. Method The study was conducted during a period of one year (October 2014 to September 2015). A total of 204 participants were evaluated among which 102 were nonpregnant and 102 were pregnant. Among the 102 pregnant participants, 34 females each were in the first, second, and third trimesters. A convenience sampling technique was used for the selection of the participants. The mean cross-sectional area of the median nerve was calculated in both of these groups in both hands by using the direct method. The mean cross-sectional area of non-pregnant female was used as the reference value to which that of pregnant female were compared. Data obtained were compiled and analyzed using Statistical Package for Social Sciences Version 16. Result The overall mean cross-sectional area of the median nerve in non-pregnant females was 6.76 ± 1.05 mm2 and in pregnant females was 6.84 ± 1.09 mm. No statistically significant difference was noted in the mean cross-sectional area of the median nerve in either hand in both pregnant and non-pregnant females. No statistically significant difference was noted in the overall mean cross-sectional area between the non-pregnant and pregnant females. There was no significant difference in the mean cross-sectional area within the different trimesters in both hands on intergroup comparisons. Conclusion Ultrasound examination of the median nerve and measurement of its crosssectional area is a useful diagnostic tool in the evaluation of carpal tunnel syndrome. Ultrasound has the advantage of easy availability, low cost, quick scan time, able to scan a long segment of nerve and examine the structures in both static and dynamic states. Besides, it also helps in the identification of various anatomic variants and pathologies within or adjacent to carpal tunnel.

Carpal tunnel syndrome (CTS) is a common peripheral nerve disease in adults; it can cause pain, numbness, and even muscle atrophy and will adversely affect patients' daily life and work. There are no standard diagnostic criteria that go against the early diagnosis and treatment of patients. MRI as a novel imaging technique can show the patient's condition more objectively, and several characteristics of carpal tunnel syndrome have been found. However, various image sequences, heavy artifacts, small lesion characteristics, high volume of imagine reading, and high difficulty in MRI interpretation limit its application in clinical practice. With the development of automatic image segmentation technology, the algorithm has great potential in medical imaging. The challenge is that the segmentation target is too small, and there are two categories of images with the proximal border of the carpal tunnel as the boundary. To meet the challenge, we propose an end-to-end deep learning framework called Deep CTS to segment the carpal tunnel from the MR image. The Deep CTS consists of the shape classifier with a simple convolutional neural network and the carpal tunnel region segmentation with simplified U-Net. With the specialized structure for the carpal tunnel, Deep CTS can segment the carpal tunnel region efficiently and improve the intersection over union of results. The experimental results demonstrated that the performance of the proposed deep learning framework is better than other segmentation networks for small objects. We trained the model with 333 images, tested it with 82 images, and achieved 0.63 accuracy of intersection over union and 0.17 s segmentation efficiency, which indicate great promise for the clinical application of this algorithm., (© 2022. The Author(s) under exclusive licence to Society for Imaging Informatics in Medicine.)

Growth-associated protein 43 (GAP-43) has long been used as a marker for nerve regeneration following nerve injury, with numerous in vitro and animal studies showing its upregulation in regenerating neurons. In humans, expression of GAP-43 has predominantly been examined in skin biopsies from patients with peripheral neuropathies; with several studies showing a reduction in GAP-43 immunoreactive cutaneous nerve fibres. However, it remains elusive whether cutaneous GAP-43 is a valid marker for human nerve regeneration. Here, we present a cohort of 22 patients with electrodiagnostically confirmed carpal tunnel syndrome (CTS), used as a model system for focal nerve injury and neural regeneration after decompression surgery. We evaluate GAP-43 immunoreactivity and RNA expression levels in finger skin biopsies taken before and 6 months after surgery, relative to healthy controls. We further classify patients as 'regenerators' or 'non-regenerators' based on post-surgical epidermal re-innervation. We demonstrate that patients with CTS have lower GAP-43 positive intra-epidermal nerve fibre density (IENFD) before surgery than healthy controls. However, this difference disappears when normalising for total IENFD. Of note, we found surgery did not change GAP-43 expression in IENF, with no differences both in patients who were classified as regenerators and non-regenerators. We also did not identify pre-post surgical differences in cutaneous GAP-43 gene expression or associations with regeneration. These findings suggest cutaneous GAP-43 may not be a compelling marker for nerve regeneration in humans., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Carroll et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: Lipoma of the nerve is an uncommon tumor, and usually has the highest incidence in the upper limb, especially in the median nerve. When the lesion is large it can cause peripheral neuropathy such as carpal tunnel syndrome. Therefore, a physical examination is paramount for correct surgery and patient preparation. In this article we present a case that was mainly diagnosed by a complete physical examination, which led to the selection of appropriate surgery for the patient.

Background: Confirmatory methods such as nerve conduction studies are often performed to support a clinical carpal tunnel syndrome diagnosis and to rule out other upper extremity pathologies. Ultrasonography provides another diagnostic option, especially when nerve conduction studies are discordant with history and physical examination. The authors explored the correlation of ultrasound findings with clinical carpal tunnel syndrome diagnosis in patients with normal nerve conduction study results., Methods: A database of 220 patients with carpal tunnel syndrome was analyzed retrospectively to reveal 24 patients (28 hands) with a clinical diagnosis and normal nerve conduction study results. Patient demographics and nerve conduction study and ultrasound findings were compared with those of a control group of patients without carpal tunnel syndrome (42 patients, 52 hands). Median nerve cross-sectional area was recorded; values of 10 mm 2 or greater were considered positive for carpal tunnel. Statistical and correlation analyses were performed between control and carpal tunnel groups comparing key measures of interest., Results: Mean cross-sectional area was significantly increased in patients with carpal tunnel syndrome with normal nerve conduction study results compared with controls. The proportion of carpal tunnel-positive, nerve conduction study-negative patients with cross-sectional area measurements greater than 10 mm 2 was significantly greater than the proportion for control patients. Neither age nor body mass index correlated with cross-sectional area measurements. Nerve conduction study latencies and amplitudes did not correlate with ultrasound abnormalities., Conclusions: Patients diagnosed clinically with carpal tunnel syndrome with normal nerve conduction study results were found to have clinically significant median nerve cross-sectional area on ultrasound (10.1 ±2.1 mm 2 , p < 0.001). Cross-sectional area measurements on ultrasound did not correlate with nerve conduction study measures. These results suggest that ultrasound holds a unique diagnostic utility in the evaluation of carpal tunnel syndrome, especially when nerve conduction studies are negative., Clinical Question/level of Evidence: Diagnostic, II., Competing Interests: Disclosure:The authors have no disclosures or conflicts of interest to report. No funding was received for this article ., (Copyright © 2022 by the American Society of Plastic Surgeons.)

Ultrasound (US) imaging is recognized as a useful support for Carpal Tunnel Syndrome (CTS) assessment through the evaluation of median nerve morphology. However, US is still far to be systematically adopted to evaluate this common entrapment neuropathy, due to US intrinsic challenges, such as its operator dependency and the lack of standard protocols. To support sonographers, the present study proposes a fully-automatic deep learning approach to median nerve segmentation from US images. We collected and annotated a dataset of 246 images acquired in clinical practice involving 103 rheumatic patients, regardless of anatomical variants (bifid nerve, closed vessels). We developed a Mask R-CNN with two additional transposed layers at segmentation head to accurately segment the median nerve directly on transverse US images. We calculated the cross-sectional area (CSA) of the predicted median nerve. Proposed model achieved good performances both in median nerve detection and segmentation: Precision (Prec), Recall (Rec), Mean Average Precision (mAP) and Dice Similarity Coefficient (DSC) values are 0.916 ± 0.245, 0.938 ± 0.233, 0.936 ± 0.235 and 0.868 ± 0.201, respectively. The CSA values measured on true positive predictions were comparable with the sonographer manual measurements with a mean absolute error (MAE) of 0.918 mm 2 . Experimental results showed the potential of proposed model, which identified and segmented the median nerve section in normal anatomy images, while still struggling when dealing with infrequent anatomical variants. Future research will expand the dataset including a wider spectrum of normal anatomy and pathology to support sonographers in daily practice., (© 2022. The Author(s).)

Carpal tunnel syndrome (CTS) is correlated with increased intracarpal canal pressure (ICP). The effect of palmaris longus tendon (PLT) loading on ICP is documented in previous researches. PLT loading induces the greatest absolute increase in ICP. Therefore, to analyze the connection between the PLT and CTS, we newly made the measurement of the PLT cross-sectional area (PLTCSA). We assumed that PLTCSA is a reliable diagnostic parameter in the CTS. PLTCSA measurement data were acquired from 21 patients with CTS, and from 21 normal subjects who underwent wrist magnetic resonance imaging (W-MRI). We measured the PLTCSA at the level of pisiform on W-MRI. The PLTCSA was measured on the outlining of PLT. The two different cutoff values in the analysis were determined using receiver operating characteristic (ROC) analysis. The mean PLTCSA was 2.34 ± 0.82 mm2 in the normal group and 3.97 ± 1.18 mm2 in the CTS group. ROC curve analysis concluded that the best cutoff point for the PLTCSA was 2.81 mm2, with 76.2% sensitivity, 71.4% specificity, and area under the curve of 0.88 (95% CI, 0.78-0.98). PLTCSA is a sensitive, new, objective morphological parameter for evaluating CTS., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

We used high-resolution ultrasound to examine 35 median nerves (35 patients) with failed carpal tunnel decompression to identify the cause of failure. The carpal tunnel was examined before revision surgery, and the results were correlated with surgical findings. The cross-sectional area was measured, and nerve morphology was analysed at the sites of compression. We found persistent median nerve compression in 30 out of 35 patients. In 20 patients, the compression was caused by a residual transverse carpal ligament, in four by perineural fibrosis, in five by both of these causes and in one by tenosynovitis. In four patients, evidence of median nerve injury with an epineural/fascicular lesion was detected; and in one, no abnormalities were found. Surgical findings were consistent with the ultrasound findings except in one patient where tenosynovitis was associated with a giant cell tumour, which was missed by ultrasound. High-resolution ultrasound can provide helpful information in preoperative diagnosis of failed carpal tunnel decompression with good correlation between the ultrasound and surgical findings. Level of evidence: IV.

Cardiac amyloidosis is often preceded by orthopedic manifestations such as carpal tunnel syndrome, and 10% of patients who underwent idiopathic carpal tunnel release surgery will have biopsy-confirmed amyloid deposits in the tenosynovial sheath. Trigger finger is also commonly reported in patients with amyloidosis and involves the same tendon sheath as carpal tunnel syndrome, but the prevalence of amyloid deposition is unclear. This prospective cross-sectional study enrolled 100 patients aged ≥50 years at the time of surgery for idiopathic trigger finger. Patients underwent release surgery, and a sample of the tenosynovium of the affected finger was excised, stained with Congo red, and subtyped with mass spectrometry if amyloid was demonstrated. Further cardiac evaluation was performed in patients with amyloid deposition. Of the 100 patients (mean age 65.5 ± 8.1 years) enrolled, only 2 demonstrated amyloid deposits on Congo red staining. One patient with previous proteinuric kidney disease had fibrinogen A α-chain amyloidosis, and the other patient had untyped amyloidosis. Neither patient had cardiac involvement. A total of 13 of the 100 patients underwent concomitant carpal tunnel release surgery, and 2 of these patients had amyloid deposits in the carpal tunnel with "false-negative" samples from the trigger finger tenosynovium. In conclusion, biopsy during trigger finger release surgery demonstrated a 2% yield for amyloidosis, which is significantly lower than the previously published yield of 10% during carpal tunnel release surgery. This observation has important implications for the development of diagnostic algorithms to screen patients for amyloidosis during orthopedic operations., Competing Interests: Disclosures Dr. Sperry is a consultant for Alnylam Pharmaceuticals Inc. and Pfizer Inc. Dr. Hanna, has served on advisory boards for Alnylam Pharmaceuticals Inc., Eidos, Akcea Therapeutics, and Pfizer Inc. The remaining authors have no conflicts of interest to disclose., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Abstract: Carpal tunnel syndrome (CTS) is a common neuropathy. Although CTS progression is known to be associated with thenar muscle (TM) atrophy, the diagnostic value of TM atrophy for CTS has not been established. In this research, the thenar muscle cross-sectional area (TMCSA) was evaluated to analyze the relationship between the TMCSA and CTS. We assumed that TMCSA is a major diagnostic parameter in the CTS.Both TMCSA and thenar muscle thickness (TMT) samples were acquired from 18 CTS patients, and from 18 control subjects who underwent wrist magnetic resonance imaging with no evidence of CTS. T2-weighted transverse magnetic resonance imaging images were obtained. We measured the TMCSA and TMT at the level of first carpometacarpal joint.The average TMCSA was 296.98 ± 49.39 mm2 in the normal group and 203.36 ± 72.13 mm2 in the CTS group. The average TMT was 8.54 ± 1.45 mm in the normal group and 7.38 ± 1.14 mm in the CTS group. CTS group had significantly lower TMCSA and TMT. Receiver operator characteristics curve analysis showed that the best cutoff point for the TMCSA was 260.18 mm2, with 77.8% sensitivity, 77.8% specificity. The best cutoff point of the TMT was 7.70 mm, with 61.1% sensitivity, 66.7% specificity.Although the TMCSA and TMT were both significantly associated with CTS, the TMCSA was a much more sensitive measurement parameter. Thus, to evaluate CTS patients, the physician should more carefully inspect the TMCSA than TMT., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

The objective of this study was to evaluate the effects of diabetes mellitus (DM) on the rate of carpal tunnel release (CTR) using a large nationwide cohort in Korea and to identify risk factors, including comorbidities and socioeconomic status (SES), associated with CTR. Patients with a primary or secondary diagnosis of carpal tunnel syndrome (CTS; ICD-10 code: G560) were selected and divided into two groups according to the presence of DM. A Cox proportional hazard model was used to assess the rate of CTR between the two groups. To evaluate the influence of demographic factors, comorbidities, and SES on CTR, multivariate Cox proportional hazard regression models were used to adjust for confounding variables. In total, 12,419 patients with CTS were included in the study: 2487 in DM cohort and 9932 in non-DM cohort. DM duration was negatively related with the rate of CTR (HR = 0.89, 95% CI 0.87-0.91) in CTS patients with DM. The rate of CTR was decreased in patients with DM compared to those without DM in the unadjusted model; however, after adjusting for comorbidities, DM had no significant effect on the rate of CTR. Female sex (HR = 1.50, 95% CI 1.36-1.67) correlated with the rate of CTR, and an inverse relationship between the number of comorbidities and CTR was found (p < 0.001) irrespective of DM. Diabetic polyneuropathy (DPN) was not associated with CTR, and we did not find any factors correlating with CTR in DPN patients. We found that CTS patients with more comorbidities or combined with a longer duration of DM were undertreated in real-word practice. Actual outcomes of CTR in CTS patents with various comorbidities should be investigated in future studies for optimal management of CTS., (© 2021. The Author(s).)

Objectives: Median nerve enlargement in leprosy seems to be more proximal than in carpal tunnel syndrome (CTS), but this feature has not been studied systematically. The aim of the study was to compare the sites of median nerve enlargement in patients with leprosy with that of patients with CTS., Materials and Methods: Transverse sections of the median nerve were recorded from wrist to the mid-forearm (at distal wrist crease and at 2-cm: M1, 4-cm: M2, 6-cm: M3, 8-cm: M4 and 10-cm: M5, proximal to the distal wrist crease in the forearm) in patients with leprosy, CTS and healthy subjects using high-resolution ultrasound., Results: Twenty-six patients each with leprosy and CTS were compared with healthy controls. Patients with leprosy included 6 (23.1%), 7 (26.9%), 7 (26.9%) and 6 (23.1%) patients with borderline tuberculoid, borderline-borderline, borderline lepromatous and lepromatous leprosy, respectively. Cross-sectional area (CSA) of median nerve was increased in all patients with leprosy as compared to healthy controls at all points of measurement. CSA was higher among patients with leprosy as compared to CTS at all points except at the wrist. In patients with leprosy, the maximal enlargement was noted 2-cm (M1) proximal to the wrist crease with gradual tapering of the CSA proximally (p < .05). In contrast, in patients with CTS the median nerve was maximally enlarged at the distal wrist crease (p<.05)., Conclusions: Median nerve enlargement 2-cm proximal to the distal wrist crease distinguishes leprosy from CTS. This important discriminating sign can be used at point-of-care to identify patients with leprosy., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Clinical features of soft tissue amyloid light-chain (AL) amyloidosis include macroglossia, arthropathy, muscle pseudohypertrophy, skin plaques, and carpal tunnel syndrome. Vascular manifestations of AL amyloid include periorbital ecchymosis, jaw or limb claudication, and even myocardial infarction caused by occlusion of small vessel coronary arteries. Some of these features, such as macroglossia, periorbital ecchymosis, and the so-called shoulder-pad sign, are pathognomonic for AL amyloidosis. These findings may be the initial presenting features of the disease, and the recognition of these red flag symptoms is very important for the diagnosis and early intervention on the underlying plasma cell disease., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome, affecting a large proportion of the general population. Genetic susceptibility has been implicated in CTS, but the causative genes remain elusive. Here, we report the identification of two mutations in cartilage oligomeric matrix protein (COMP) that segregate with CTS in two large families with or without multiple epiphyseal dysplasia (MED). Both mutations impair the secretion of COMP by tenocytes, but the mutation associated with MED also perturbs its secretion in chondrocytes. Further functional characterization of the CTS-specific mutation reveals similar histological and molecular changes of tendons/ligaments in patients' biopsies and the mouse models. The mutant COMP fails to oligomerize properly and is trapped in the ER, resulting in ER stress-induced unfolded protein response and cell death, leading to inflammation, progressive fibrosis and cell composition change in tendons/ligaments. The extracellular matrix (ECM) organization is also altered. Our studies uncover a previously unrecognized mechanism in CTS pathogenesis.

Background: Non-inflammatory thickening of the subsynovial connective tissue is a common histological finding in carpal tunnel syndrome. This subsynovial connective tissue thickening may precede changes in electrodiagnostic testing. Therefore, measuring subsynovial connective tissue thickness may help in detecting early changes in carpal tunnel syndrome., Methods: To provide an overview of subsynovial connective tissue thickness characteristics in subjects with and without carpal tunnel syndrome, a systematic review of articles, assessing human subsynovial connective tissue, was performed using MEDLINE, CENTRAL and EMBASE., Findings: Seven studies were included for qualitative analysis. Measurements were done ex vivo (laser (n = 3), photographic (n = 1), micrometric (n = 1)) and in vivo (ultrasound (n = 3)). All four case-control studies showed a significant difference in subsynovial connective tissue thickness between subjects with and without carpal tunnel syndrome. One study showed good correlation between ultrasound and anatomical measurements. No correlation was found between subsynovial connective tissue thickness and symptom duration, electrodiagnostic changes, age and sex., Interpretation: Subsynovial connective tissue thickness may be a valuable aid in diagnosing carpal tunnel syndrome. No factors influencing subsynovial connective tissue thickness are identified, although they are not well investigated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare no conflict of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: This study aimed to compare median nerve stiffness measured by ultrasound real-time tissue elastography in patients with and without rheumatoid arthritis (RA and non-RA groups, respectively). Methods: Altogether, 402 hands of 201 RA group and 222 hands of 111 non-RA group were included in the study. Ultrasonography was performed to evaluate the circumference, cross-sectional area (CSA) and strain ratio as an elasticity of the median nerve at the inlet level of the carpal tunnel and the proximal portion of the carpal tunnel inlet. Using propensity score matching, the difference between RA and non-RA group were analyzed. Results: After propensity score matching, 135 hands in 104 RA group and 70 non-RA group were finally analyzed. There were no significant differences in the circumference and CSA of the median nerve between the two groups. The strain ratio of the median nerve was significantly higher in RA group than in non-RA group only at the inlet of the carpal tunnel level. Conclusions: The nerve stiffness in patients with RA measured by ultrasound real-time tissue elastography was higher than without RA. Inflammatory condition of the flexor tendon and wrist joint in patients with RA may generate fibrotic changes in the median nerve. Trial registration: University Hospital Medical Information Network Clinical Trials Registry: UMIN000015314.

The recent diagnostic tools for carpal tunnel syndrome (CTS) include nerve conduction studies (NCS) and ultrasound (US). Quantitative US (QUS) can be used for demonstrating muscle changes according to denervation. The aim of this study was to evaluate if QUS can diagnose and grade the severity of CTS. In this single blinded cross-sectional study, female patients diagnosed with CTS and age-matched healthy female subjects were included in the study. Median and ulnar nerve conduction studies (NCS) were performed for CTS diagnosis. Median and ulnar nerve cross-sectional area (CSA) was measured, and the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles were longitudinally and transversally visualised. Axial images were analysed for echo intensity (EI) via computer-assisted, grayscale analysis. Intra-rater and inter-rater reliability analysis was performed. The Boston questionnaire was used for the evaluation of symptom severity and functional status. Forty-two patients (42 hands) and 32 controls were included. In the CTS group, 17 patients had mild, 13 patients had moderate, and 12 patients had severe CTS. CSA of the median nerve and APB echo intensity was significantly higher in patients with CTS. However, according to the CTS grade, no significant difference was detected for APB EI. The intraclass correlation coefficient (ICC) was calculated as 0.928 for intra-rater reliability and 0.768 for inter-rater reliability. QUS evaluation is helpful for the diagnosis of CTS, but not for grading. Further studies are needed with a larger population including both genders., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study investigated the connections between the median nerve paraneural sheath and myofascial structures near it, from both macroscopic and microscopic points of view. Four samples of median nerve and surrounding tissues were excised from nine non-embalmed upper limbs for microscopic analysis. Ultrasound images were analysed in 21 healthy subjects and 16 carpal tunnel syndrome patients to evaluate median nerve transversal displacement during finger motion at carpal tunnel and forearm levels. An anatomical continuity between epimysium and paraneural sheath and a reduction of paraneural fat tissue from proximal to distal was found in all samples. Median nerve displacements at both levels were significantly reduced in carpal tunnel syndrome subjects (P < 0.001). It was observed that the median nerve is not an isolated structure but is entirely connected to myofascial structures. Therefore, unbalanced tension of epimysial fasciae can affect the paraneural sheath, limiting nerve displacement, and consequently this must be included in carpal tunnel syndrome pathogenesis., (© 2019 Anatomical Society.)

Objectives: To evaluate: a) the prevalence of bilateral idiopathic carpal tunnel syndrome (CTS) in manual workers; b) a correlation between the duration of unilateral and bilateral CTS symptoms; c) a correlation between the onset of CTS symptoms in the unilateral dominant/non-dominant hand and the time of developing bilateral CTS; and d) findings of the nerve conduction study (NCS) in symptomatic and asymptomatic hands of patients with unilateral CTS., Material and Methods: Clinical and neurophysiological examinations were conducted along with a detailed analysis of job exposure of 332 manual workers admitted to the Occupational Medicine Department, the Nofer Institute of Occupational Medicine, with suspected occupational CTS. Eventually, 258 patients were excluded from the study: 34 with associated neuropathies and 206 with other conditions potentially associated with CTS. Cases with work-related CTS (18) were also excluded., Results: A total of 74 patients were diagnosed as idiopathic CTS. In idiopathic CTS, the right hand was affected in 15 (20.3%) patients, the left hand in 4 (5.4%) patients, and both hands in 55 (74.3%) patients. Symptoms duration was longer in the patients with bilateral CTS (4.01 years) than in those with a unilateral right (1.7 years, p = 0.002) or left hand condition (2.8 years, p = 0.313). Median nerve impairment at the wrist was revealed by NCS in 6 left and 2 right asymptomatic hands., Conclusions: The findings of the study indicate the need for "alerting" patients with unilateral CTS about the risk of the disease developing in the contralateral hand. Therefore, NCS should be routinely performed in the asymptomatic hands of patients with unilateral CTS, which is essential for the prevention of neuropathies, especially among manual workers performing repetitive manual tasks. Int J Occup Med Environ Health. 2020;33(2):151-61., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

In carpal tunnel volume measurements, the angle of the hamatum curvature is not considered a variable, and its effect on carpal tunnel volume has not been investigated. We hypothesize that a change in the anatomical angle of the hamatum curvature changes the carpal tunnel volume. To prove our hypothesis, we used a mathematical simulation model considering the carpal tunnel as a truncated cone. We reviewed the wrist CT scans of 91 adults (>18 years of age), including 51 men and 40 women. We measured the angle of the hamatum curvature in the CT scans. We measured cross-sectional areas at the outlet of the carpal tunnel at the level of the trapezium and hook of hamate ( r 1) and at the inlet at the level of the scaphoid and pisiform ( r 2) and the length ( h ) of the carpal tunnel. We attempted to calculate the effect of 2 degree by 2-degree changes in the angle of the hamatum curvature between the angles of 98° and 140° on the carpal tunnel volume. The mean angle of the hook of hamatum of the subjects was 122.55° ± 8.20° (range, 97.20° - 139.31°). No suitable cutoff point was found for the angle values. There was no difference between the gender groups according to the angle value. The data clearly show that there is a high correlation between carpal tunnel volume and the angle of hamatum curvature. The results of our study emphasize the importance of taking into account the anatomical features of the hamatum bone, especially the angle of curvature, which may play a predisposing role in idiopathic carpal tunnel syndrome., Competing Interests: All authors declare that they have no conflicts of interest., (Copyright © 2020 Nazmi Bülent Alp et al.)

New-onset carpal tunnel syndrome (CTS) and trigger finger after distal radius fractures (DRFs) with or without open reduction and internal fixation (ORIF) have been reported inconsistently across different studies. This study assessed the incidence of CTS and trigger finger after DRFs using Taiwan National Health Insurance Research Database. In total, 1454 patients in the case (ORIF) cohort and 1454 patients in the control (non-ORIF) cohort were included in this retrospective study. The mean age was approximately 55 years old, and the female to male ratio was approximately 3/2. Nine patients underwent carpal tunnel release (CTR) surgery after diagnosis of CTS in the case group, and no patients did in the control group; whereas 19 cases of CTS were diagnosed without CTR in the case group, and 4 such cases were observed in the control group. Five cases of trigger finger were diagnosed in the case group, and 3 cases were diagnosed in the control group. CTS were significantly associated with ORIF for DRFs within 9 months after the fracture, whereas trigger finger was not significantly different between groups. Diabetes mellitus was a significant risk factor for CTS and trigger finger within 9 months after the incidence of DRFs.

Recent studies demonstrated the utility of perineural injection with platelet-rich plasma (PRP) and 5% dextrose (D5W) as novel strategies for treatment of carpal tunnel syndrome (CTS). The present study comprised a prospective, randomized, single-blind, head-to head comparative trial to compare the 6-month outcome of perineural injection with PRP or D5W in patients with moderate CTS. Fifty-two patients with unilateral moderate CTS were enrolled and randomized into two groups: The PRP group received a single 3-cc perineural injection of PRP under ultrasound guidance, and dextrose group received a single 3-cc perineural injection of D5W under ultrasound guidance. The Boston Carpal Tunnel Syndrome Questionnaire score was used as the primary outcome. Secondary outcomes included cross-sectional area (CSA) of the median nerve and electrophysiological assessments. Evaluations were performed at baseline and at 1, 3, and 6 months postinjection. All patients (26 patients per group) completed the study. Compared with the dextrose group, the PRP group demonstrated significant reductions in Boston Carpal Tunnel Syndrome Questionnaire function at 3 months (p = .044), distal motor latency at 6 months (p = .028), and CSA at 3 and 6 months (p = .010 and.018, respectively). A single perineural injection of PRP reduced the CSA of the median nerve more effectively than injection of D5W at 3 and 6 months postinjection for patients with moderate CTS., (© 2019 John Wiley & Sons, Ltd.)

Objective: To translate and validate the Arabic version of the Boston carpal tunnel questionnaire (BCTQ-A)., Methods: We recruited consecutive patients with carpal tunnel syndrome (CTS). Reliability was assessed with Cronbach alpha, reproducibility with intraclass correlation coefficients, construct validity with factor analysis, and responsiveness post carpal tunnel release (CTR) with the Wilcoxon signed-rank test., Results: In 134 patients, the mean total scores for the symptom severity scale (SSS) and functional status scale (FSS) were 32.0+/-8.4 (alpha=0.88, ICC=0.88) and 18.5+/-7.6 (alpha=0.87, ICC=0.89), respectively. As in the original Boston carpal tunnel questionnaire (BCTQ), a 3-factor model of the BCTQ-A best fitted the data. The BCTQ-A, SSS, and FSS scores were significantly lower post-CTR., Conclusion: The BCTQ-A is reliable, valid, reproducible, and responsive to interventions. The Arabic version can be now used with Arabic-speaking patients with CTS.

Background: To evaluate the diagnostic accuracy of the median-to-ulnar nerve ratio (MUR) and the median-to-ulnar nerve difference (MUD) in patients with carpal tunnel syndrome (CTS)., Methods: In this study, 32 patients with CTS and 32 healthy volunteers were evaluated. All participants received a series of tests and ultrasound examination for the evaluation of the following criteria: cross-sectional area of the median nerve at the pisiform level (CSA-P), swelling ratio (SR), MUR, MUD, and flattening ratio (FR)., Results: CSA-P, SR, MUR, and MUD were all significantly larger in the patients with CTS than in the healthy volunteers. The areas under the receiver operator characteristic curves of MUD, MUR, CSA-P, and SR were 0.78, 0.75, 0.70, and 0.61 respectively. MUD had higher sensitivity (84%) than MUR, CSA-P, and SR (sensitivity: 63, 63, and 53%, respectively)., Conclusions: By using the ulnar nerve area at the pisiform level as an internal control parameter, the MUD and MUR methods showed higher diagnostic accuracy than SR in patients with CTS. Further application of these methods in research and clinical settings is recommended., Trial Registration: Clinicaltrial.gov NCT03033173. Registered 18 January 2017. Retrospectively registered.

Platelet-rich plasma (PRP) treatment has a potential to become a part of nonsurgical approach in carpal tunnel syndrome (CTS) as a regenerative method. PRP therapies aim to enhance the self-healing ability of human body, by exposing the injured tissue to a high concentration of autologous growth factors. Nerve tissues also seem to benefit from the regenerative effects of PRP concentrates. The aim of this study is to investigate the possible beneficial effects of PRP injection in CTS. A total of 40 hands of 30 patients were included (20 hands per group) with mild to moderate idiopathic CTS. Patients with mild to moderate CTS were placed into either control or PRP groups. Activity modification and night-only wrist splints were suggested in both groups. Additionally, in PRP group, a single perineural PRP injection into the carpal tunnel was applied under ultrasound guidance. Sensibility tests, Boston carpal tunnel questionnaire (BCTQ), and electrophysiological and ultrasonographical findings were measured initially and after 4 weeks. Groups were similar regarding demographics. BCTQ scores and ultrasonographical values were improved in both groups. Delta analyses revealed that the difference of BCTQ scores improved better in PRP group. Electrophysiological values improved in PRP group. Our study demonstrated that a single, perineural PRP injection into carpal tunnel provided further improvements in CTS., (© 2019 John Wiley & Sons, Ltd.)

Objective: The aim of the study was to investigate the overall estimates of cross-sectional areas of the median nerve measured by ultrasonography in accordance with the electrodiagnostic classification of carpal tunnel syndrome severity., Design: MEDLINE (PubMed), Embase (Ovid), and Web of Science were searched for studies reporting the median nerve cross-sectional area measured by ultrasonography for mild, moderate, and severe carpal tunnel syndrome based on electrodiagnostic study. Cross-sectional area values measured at the carpal tunnel inlet were included in the analyses., Results: Overall, 866 citations were retrieved and checked for eligibility. Finally, 16 articles were included for meta-analysis. These studies included a total sample of 2292 wrists including 776 mild, 823 moderate, and 693 severe carpal tunnel syndrome. The pooled analysis revealed a mean cross-sectional area of 11.64 mm (95% confidence interval = 11.23-12.05 mm, P < 0.001) for mild carpal tunnel syndrome, a mean cross-sectional area of 13.74 mm (95% confidence interval = 12.59-14.89 mm, P < 0.001) for moderate carpal tunnel syndrome, and a mean cross-sectional area of 16.80 mm (95% confidence interval = 14.50-19.1 mm, P < 0.001) for severe carpal tunnel syndrome., Conclusions: This is the first meta-analysis that provides the pooled median nerve cross-sectional area values in accordance with the electrodiagnostic classification of carpal tunnel syndrome severity. The values obtained in this study have clinical utility in ultrasonographic assessment of patients with carpal tunnel syndrome.

Introduction: No consensus exists about the upper limit of normal (ULN) of the cross-sectional area (CSA) of the median nerve in diagnosing carpal tunnel syndrome (CTS). Previously, we demonstrated a strong positive correlation between wrist circumference and CSA. ULN depending on wrist circumference turned out to have a low sensitivity, which was hypothesized to be caused by an age mismatch. The aim of this study was to re-evaluate the found invariance by augmentation of the healthy control group, adding older subjects, and to determine the diagnostic accuracy of the updated normal values., Methods: CSA and wrist circumference were measured in an additional 42 healthy controls in the ages of 40-60. Univariable and multivariable linear regression analyses were applied to determine predicting factors for CSA. Diagnostic accuracy was assessed in a prospective cohort of 253 patients., Results: A strong correlation was found between wrist circumference and CSA (r = 0.61). Wrist circumference is the most important independent predictor for ULN (r 2  = 0.37). We managed to simplify our newly derived regression equations, which turned out to be unrelated to age. Sensitivity of our new equations is low, but higher than a general fixed cut-off value (53.4% and 47.4%, respectively)., Discussion: Wrist circumference is the most important independent predicting factor of CSA. By using our updated equations and taking wrist circumference into account, one can determine a more precise ULN for each individual, which will lead to the improvement of the diagnostic accuracy of ultrasonography (US). Sensitivity for US in diagnosing CTS remains low and it can therefore not replace EDX.

Background: Recurrent carpal tunnel syndrome is often associated with perineural scarring around the median nerve. Surgical options include relatively invasive procedures, such as fat pad grafting, ligament reconstruction, muscle transfer, and nerve wraps. All have limited success because of the possibility of repeated recurrent scarring postoperatively., Methods: We discuss a technique involving injection with external hydroneurolysis of the median nerve under ultrasound guidance for recurrent carpal tunnel. Injection enables a gentler dissection of the surrounding tissues compared with open external neurolysis, with less chance of recurrent scarring. This technique is a unique alternative to repeat operative intervention in recurrent carpal tunnel, as well as a prelude to repeat open decompression and salvage procedures., Results: Ultrasound-guided injection with external hydroneurolysis of the median nerve is a safer, more limited procedure compared with repeat open surgery, usually performed in an office setting. This procedure limits risk, anesthesia, and operating/recovery room expenses, offering relief in 70% to 80% of cases. Furthermore, in the 20% to 30% of patients with inadequate relief, surgery remains a viable option. US provides important information on the anatomy of the median nerve and carpal canal and can rule out covert pathology., Conclusions: We offer an alternative treatment for recurrent carpal tunnel syndrome, a difficult problem for which many surgeons recommend nonoperative treatment. US provides objective data concerning residual nerve compression and allows for dynamic assessment. Theoretically, this also offers a viable solution for surgeons and their patients with recurrent carpal tunnel syndrome before being pressed to consider repeat open surgery.

Background: Dupuytren's disease (DD) is a progressive, debilitating condition of the hand that can eventually cause contractures of the affected fingers. Transforming growth factor- β1 (TGF-β1) has been reported to play a key role in DD pathology. Increased expression of TGF-β1 has shown to be the main stimulator of myofibroblast activity and in DD contractures. Pirfenidone (PFD), a small active molecule possess the ability to inhibit TGF-β1-mediated action in various fibrotic disorders. Our recent published findings show that PFD reduced TGF-β1-mediated cellular functions implicated in DD through SMAD signaling pathways. In the present study, the effect of PFD on TGF-β1-mediated non-SMAD signaling pathways were investigated in both carpal tunnel (CT) - and DD-derived fibroblasts., Methods: Fibroblasts harvested from Dupuytren's disease (DD) and carpal tunnel (CT) tissues were cultured in the presence or absence of TGF-β1 (10 ng/ml) and/or PFD (800 μg/ml). Cell lysates were analyzed using Western blots. Equal amounts of proteins were loaded to determine the phosphorylation levels of phosphatidylinositol-3 kinase (PI3K/AKT), extracellular regulated kinases (ERK1/2), p38 mitogen-activated protein kinase and Rho family related myosin light chain (MLC)., Results: We show that the TGF-β1-induced phosphorylation of AKT was significantly decreased by the addition of PFD (800 μg/mL) in both CT- and DD-derived fibroblasts. Interestingly, there was no significant difference in the phosphorylation levels of both ERK and p38 on TGF-β1- induced cells in both CT-and DD-derived fibroblasts. But, PFD significantly decreased the TGF- β1-induced phosphorylation levels of ERK1/2 in both CT- and DD- cells. In contrast, PFD significantly decreased the basal and TGF- β1-induced phosphorylation levels of p38 in DD-derived fibroblasts. TGF- β1-induced phosphorylation levels of MLC was decreased by PFD in DD-derived fibroblasts., Conclusions: These in-vitro results indicate for the first time that PFD has the potential to inhibit TGF-β1-induced non-SMAD signaling pathways in both CT- and DD-derived fibroblasts but pronounced statistically significant inhibition on all molecules was observed only in DD-derived fibroblasts. Our previous studies show that PFD can inhibit TGF-β1- induced SMAD signaling pathway proteins, namely p- SMAD2/SMAD3. These broad and complementary actions suggest PFD as a promising candidate to inhibit the TGF-β1- mediated molecular mechanisms leading to DD fibrosis.

Background: Carpal tunnel syndrome is a common neuropathy disorder for which surgical treatment consists of release and reconstruction of the flexor retinaculum. Reports of postoperative clinical outcomes after carpal tunnel release with or without flexor retinaculum reconstruction in several studies are controversial. This meta-analysis aimed to compare the efficacy and safety of carpal tunnel release with or without flexor retinaculum reconstruction., Methods: The PubMed, EMBASE, Web of Science, Ovid, Cochrane Library and Clinical Tri Org databases were searched for randomized controlled trials that compared carpal release with and without transverse carpal ligament reconstruction for carpal tunnel syndrome. Outcomes included postoperative Boston Carpal Tunnel Questionnaire Symptom Severity Scale (SSS), Functional Status Scale (FSS), grip strength and complications. The follow-up time was categorized into short-term (0-3mon) and long-term(>3mon)., Results: A total of 7 studies with 613 patients met the inclusion criteria and were analyzed in detail. Statistical analysis showed no significant difference between two groups on postoperative long-term grip strength (MD 5.85, 95% CI -1.05 to 12.76) long-term SSS (MD -0.31, 95% CI -0.75 to 0.13) and occurrence of complications (RR 1.14, 95% CI 0.84 to 1.54), whereas statistically significant difference was found between groups regarding short-term grip strength (MD 1.51, 95% CI 0.86 to 2.17) and long-term FSS (MD -0.34, 95% CI -0.47 to -0.21)., Conclusion: Carpal tunnel release with flexor retinaculum reconstruction for carpal tunnel syndrome may result in improved long-term functional status while there's no advantage regarding grip strength, symptom severity and safety over individual carpal tunnel release in short- and long-term outcomes., Competing Interests: The authors have declared that no competing interests exist.

Objective: To study the frequency of multiple vascular risk factors and electrophysiological severity of carpal tunnel syndrome (CTS) in Saudi diabetic patients., Methods: This retrospective cross-sectional study was conducted in Neurology Department, King Fahd Hospital of University, Al-Khobar, Kingdom of Saudi Arabia from April 2017 to March 2018 and included 200 patients with CTS. Body parameters, such as blood pressure (BP), weight, height, and body mass index (BMI), along with laboratory and median nerve electrophysiological parameters, of diabetic and non-diabetic patients were compared, and a p-value<0.05 was considered significant., Results: Frequency of hypertension (HTN) and obesity was significantly higher in diabetic patients (p<0.05). Mean median nerve sensory amplitude (MNSA) was lower in diabetic patients (p<0.05).Non-recordable nerves, as well as bilateral and extremely severe CTS (p<0.05), were more frequently seen in diabetic patients. Age, BMI, systolic BP, low serum high density lipoprotein (HDL), high triglycerides, high fasting blood sugar, and high glycated hemoglobin (Hba1c) levels, known to affect the electrophysiological severity of CTS, had a statistically significant association with diabetes., Conclusion: Diabetes mellitus (DM) and obesity are the most commonly identified risk factors of CTS. Dyslipidemia, HTN and obesity are more frequently seen in diabetic patients with CTS. These concurrent risk factors are confounding the electrophysiological severity of CTS in these patients. Further larger-scale studies with the control of confounding factors are recommended.

Objectives: To evaluate the efficacy of low-level laser therapy on median nerve stiffness by using strain elastography in carpal tunnel syndrome (CTS)., Methods: This study included 37 wrists of 34 patients with mild or moderate CTS between January 2016 and August 2016. The control group comprised 17 patients (18 wrists) with CTS who were treated with wrist splinting for 3 weeks. The low-level laser therapy group included 17 patients (19 wrists) with CTS who were treated with a combination of splinting and low-level laser therapy, which was applied 5 times per week for 3 weeks. Clinical assessment scales, including the Symptom Severity Scale (SSS) and Functional Status Score (FSS), were obtained from our database. The cross-sectional area by ultrasound and strain ratio by elastography were studied. The differences in the strain ratio, cross-sectional area, SSS, and FSS between pretreatment and posttreatment periods in the groups were compared by the paired-sample t test. The correlations between changes in the strain ratio and the cross-sectional area, SSS, and FSS were analyzed by Pearson correlation coefficients., Results: The control group included 13 women and 4 men, and the therapy group included 14 women and 3 men. In the therapy group, the mean values of the strain ratio, cross-sectional area, SSS, and FSS decreased significantly after laser therapy (P < .001) in contrast to the control group. No significant correlation was observed between the decreasing degree of the strain ratio and the cross-sectional area, SSS, and FSS after laser therapy., Conclusions: The strain ratio and cross-sectional area of the median nerve decrease after low-level laser therapy. These changes may be related to the therapeutic effects of low-level laser therapy, such as nerve regeneration and improvement of the vascular supply., (© 2018 by the American Institute of Ultrasound in Medicine.)

Introduction: Patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution may be noted to have exclusive median mononeuropathy at the wrist on subsequent electrodiagnostic testing. There has been limited research looking at the prevalence of this clinical presentation., Methods: A cohort of adults were surveyed to assess for severity and localization of hand symptoms using the Katz hand diagram and Boston Carpal Tunnel Questionnaire Symptoms Severity Scale. Thirty volunteers met our case definition for ulnar neuropathy and underwent a standardized physical examination, electrodiagnostic testing, and nerve ultrasound., Results: Eleven of 30 subjects (37%) were found to have exclusive median mononeuropathy at the wrist., Discussion: Carpal tunnel syndrome should remain high on the differential for patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution. Muscle Nerve 59:60-63, 2019., (© 2018 Wiley Periodicals, Inc.)

Background: The authors' purpose was to evaluate the histopathology of flexor tenosynovium in true, idiopathic recurrent carpal tunnel syndrome for the presence of abnormal inflammatory or pathologic findings that might explain causation or that differ from those previously described for primary, idiopathic carpal tunnel syndrome., Methods: Thirty-five patients (19 women and 16 men; mean age, 72 years) underwent open revision carpal tunnel release a mean 13 years (range, 0.5 to 30 years) after primary carpal tunnel release. Recurrence was confirmed by recurrent symptoms, positive provocative tests, and electrodiagnostic testing. All patients underwent tenosynovial biopsy, including Congo red staining for amyloid., Results: Histopathologic findings demonstrated noninflammatory, fibrous connective tissue in 31 of 35 patients (89 percent); and mild, chronic inflammation (without granulomas) in four of 35 patients (11 percent). Nine of 35 patients (26 percent) had positive results for amyloid, with a statistically higher incidence in men (p = 0.03) and advanced age (p = 0.02). Subtyping performed in eight of nine amyloid-positive specimens confirmed seven cases of transthyretin-type amyloid typically seen in localized (senile) amyloidosis and one case of light-chain amyloid in a patient who was subsequently diagnosed with myeloma., Conclusions: Flexor tenosynovium in patients with recurrent carpal tunnel syndrome does not appear to be substantially different histologically from that previously described in primary idiopathic carpal tunnel syndrome, although a slightly higher prevalence of amyloid was seen in this group (especially older men). No patients have developed systemic amyloidosis. Routine biopsy of tenosynovium in idiopathic, recurrent carpal tunnel syndrome is unnecessary.

Purpose: In this study, we aim to evaluate the diagnostic value of echogenicity ratio with histogram analyses., Materials & Methods: This retrospective study was performed on 22 patients with 44 hands. The patients had clinical presentations consistent with CTS, in at one hand. Quantitative ultrasound scanning and image capture were completed using a diagnostic sonography machine. For gray scale histogram analysis, image J software was used., Results: Mean flexor tendons histogram analysis echogenicity/Mean median nerve histogram analysis echogenicity was significantly high for 1,7 cutoff value., Conclusion: Mean FTE/MNE ratio may be a useful sonographic parameter for CTS., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Aim: To assess the diagnostic value of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of diffusion tensor imaging (DTI) at several anatomical locations in patients with carpal tunnel syndrome (CTS) to explore the optimal parameters and measurement location., Materials and Methods: A search was conducted using the PubMed, EBSCO, Ovid, Web of Science, and Cochrane databases to identify articles relevant to this study published before September 2017. Studies were selected and included according to strict eligibility criteria. Mean differences (MD) and 95% confidence intervals (CIs) were used to compare FA and ADC values between CTS patients and healthy subjects. Potential publication bias was investigated., Results: Eleven studies involving 349 CTS wrists and 278 controls were selected for the meta-analysis. A notable MD: was found for lowered FA at the level of the pisiform bone for CTS versus controls (MD: -0.11, 95% confidence interval [CI]: -1.14 to -0.07, z=5.83, p<0.001). A higher ADC was found at the pisiform bone and hamate bone levels for CTS versus controls (P: MD: 0.15, 95% CI: 0.10 to 0.20, z=5.98, p<0.001, H: MD: 0.15; 95% CI: 0.09 to 0.21, z=4.67, p<0.001)., Conclusions: The meta-analysis demonstrated a significant FA reduction and ADC increase in CTS patients. This result supports the use of DTI parameters in differentiating CTS patients from health subjects. The anatomical site for FA at the pisiform and ADC at the pisiform and hamate levels were more accessible than other sites for the diagnosis of CTS patients., (Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Introduction: The value of needle electromyography (EMG) in thenar muscles in patients with less severe carpal tunnel syndrome is controversial., Methods: Patients referred for electrodiagnostic testing for carpal tunnel syndrome, in which nerve conduction study demonstrated median sensory nerve conduction study abnormalities and either normal median motor nerve conduction study or only prolonged median motor distal latencies (DLs) (with normal amplitudes) were prospectively studied. Patients with low-median compound muscle action potential amplitudes or any other EMG abnormality were excluded. Needle EMG of a thenar muscle was performed to assess for the presence and grade of fibrillation potentials and motor unit potential abnormalities. The frequency of abnormalities was recorded. Statistical comparison between patients with and without needle EMG abnormalities was performed., Results: One-hundred two patients were included (50 with normal median motor DLs and 52 with abnormal DLs). Minimal or equivocal thenar needle EMG abnormalities were found in 12% of subjects with normal DLs. In patients with abnormal DLs, 32.6% had abnormalities, 15.4% with a mild degree of fibrillation potentials, and 25.0% with mild motor unit potential abnormalities. Patients with abnormal DLs and needle EMG abnormalities had significantly lower compound muscle action potential amplitudes compared to those without needle EMG changes., Conclusions: Patients with carpal tunnel syndrome with no involvement of the median motor nerve conduction study are unlikely to demonstrate prominent abnormalities on needle EMG of thenar muscles, and needle EMG of the thenar muscles is not necessary. However, in patients with carpal tunnel syndrome in which the median motor DL is prolonged but compound muscle action potential amplitudes are absolutely normal, needle EMG should be considered, as it may provide value in indicating some axonal loss despite a normal median compound muscle action potential amplitude.

Introduction: Sensory innervation of the dorsomedial surface of the hand usually depends on the dorsal ulnar nerve (DUN). Innervation in this area by the superficial radial nerve (SRN) has been described as a normal variant., Methods: We studied 358 patients using nerve conduction of the DUN and SRN with dorsomedial recording. Each hand was classified into usual innervation (only DUN response), mixed variant (response of both nerves), or complete variant (only SRN response)., Results: Mixed innervation was found in 14.2% of hands and complete innervation was found in 6.8% of hands, mostly unilaterally. No statistically significant differences were observed in age, sex, or clinical suspicion between usual and variant innervation. The potential amplitude after SRN stimulation was greater in the complete variant., Discussion: It is important to know the characteristics of this variant in order to avoid diagnostic errors and to prevent iatrogenic lesions in surgery performed on the dorsum of the wrist. Muscle Nerve 58: 732-735, 2018., (© 2018 Wiley Periodicals, Inc.)

Objective: During ultrasound-guided carpal tunnel release, osseous landmarks may supplement direct visualization of the distal transverse carpal ligament (dTCL) to ensure a complete release. The purpose of this study was to determine the relationship between the apex of the hook of the hamate (aHH) and the dTCL within the transverse safe zone (TSZ) of the carpal tunnel., Design: Twenty unembalmed cadaveric specimens were dissected to determine the aHH-dTCL distance and the aHH-SPA distance (the distance between the aHH and the superficial palmar arch) at the ulnar and radial limits of the TSZ (the distance between the hook of the hamate or ulnar artery to the median nerve)., Results: The aHH-dTCL distance averaged 11-12 mm across the TSZ (maximum, 18.2 mm), whereas the aHH-SPA distance was significantly greater on the radial side of the TSZ compared with the ulnar side (22.6 ± 3.6 mm vs. 14.0 ± 4.0 mm)., Conclusions: The dTCL lies approximately 11-12 mm distal to the aHH across the TSZ, with an upper limit of 18.2 mm. Along with direct sonographic visualization of the dTCL, the aHH can be used with other osseous landmarks to estimate the position of the dTCL during ultrasound-guided carpal tunnel release.