Flattening Ratio Research Articles

Comparing the efficacy of multiple quantitative and qualitative ultrasound parameters for the diagnosis of carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is a compression neuropathy causing significant morbidity. Over the years, ultrasound has been evaluated as an alternative to nerve conduction study (NCS) for diagnosing CTS, however, there is no consensus as to which ultrasound parameter is the best. Our study aimed to determine and compare the efficacy of various ultrasound-based variables for diagnosis of CTS. 80 patients with clinical suspicion of CTS underwent ultrasound examination with calculation of cross-sectional area (CSA), delta CSA, wrist forearm ratio (WFR), palmer bowing (PB), flattening ratio (FR), flexor retinaculum thickness (FT), and evaluation of echogenicity and vascularity of median nerve. NCS was taken as the gold standard and the diagnostic efficacy of all these variables was compared, followed by receiver operator curve (ROC) analysis. Delta CSA had the highest accuracy (91.25%), followed by CSAc (80%), WFR (78.75%), and PB (73.75%). Youden's index and sensitivity were highest for delta CSA (0.783 and 96.15% respectively), while specificity was highest for FT (89.29%). The highest area under the curve was noted for delta CSA (97.1%), followed by WFR (AUC = 87.4%) and CSAc (AUC = 86.0%). Delta CSA was found to be the best ultrasound parameter for diagnosis of CTS, followed by CSAc, WFR, and PB, and can be used as an alternative to NCS. Using ROC analysis this study also predicted the best cut-off values for these parameters which could improve their diagnostic accuracy and further research is needed to confirm these findings.

New insights on bonding mechanism of FCC and BCC high entropy alloy microparticles upon supersonic impact using micromechanical adhesion test

Coating buildup in cold spraying (CS) relies on particle bonding upon impact, thus making it a significant area of study. High entropy alloys (HEAs) are a class of materials with superior work-hardening ability and resistance to softening, making their particle impact and bonding particularly important to understand for their cold sprayability. In this study, the splat adhesion strength is measured with a scratch test for FCC CoCrFeMnNi and BCC AlCrFeMnNi HEA microparticles deposited on mirror-polished SS304 substrates. Nanoindentation tests were conducted to estimate the tensile and shear strengths of the HEA powders. The results showed that particle deformation and jetting were dominant in the FCC HEA/SS304 system, while substrate deformation was dominant in the BCC HEA/SS304 system. Focused ion beam cross sections of particles confirmed that the FCC HEA had good bonding and underwent significant deformation and grain refinement at the substrate/particle interface, while the BCC HEA had limited bonding only in the sheared zone of the particles.In spite of the very limited deformation of BCC splats, their average adhesion strength was measured to be 451 ± 141 MPa, which is significantly higher than that of FCC splats, with an average value of 308.7 ± 69.3 MPa. Fracture surface analysis revealed that FCC splats consistently exhibit ductile fracture, regardless of whether it occurs at the particle, substrate, or interface. In contrast, for BCC splats, fracture was ductile when occurring at the interface and substrate sides, while it was cleavage when occurring on the particle side. These findings suggest that the toughness and shear strength of the bonding developed at the interface were higher than those of the particle. It was found that the flattening ratio (FR) of the particles decreases for both FCC and BCC HEA splats with an increase in particle size, resulting in a decrease in adhesion strength. Metallurgical bonding has been identified as the primary factor contributing to the adhesion strength of both FCC and BCC HEA splats. Particle penetration, indicative of mechanical interlocking, appears to have little or no effect on adhesion strength. However, it does positively influence the increase in adhesion energy of the splats.

MRI of wrist and diffusion tensor imaging of the median nerve in patients with carpal tunnel syndrome.

Diagnosis of carpal tunnel syndrome (CTS) is based on the clinical symptoms and nerve conduction study. Magnetic resonance imaging (MRI) is non-invasive objective tool for assessing the median nerve and carpal tunnel. The purpose of this study was to evaluate MRI changes in patients with CTS, and compare them with healthy subjects. Forty-three CTS patients and 43 age matched control were included and scanned in a 3T MRI scanner. Cross-sectional areas (CSA) of median nerve were measured at the level of distal radio-ulnar joint level (CSA1), proximal row of carpal bone (CSA2), and hook of hamate (CSA3). Flattening ratio (FR) of median nerve, thickness of flexor retinaculum, median nerve signal intensity, and thenar muscles were assessed. Fractional anisotropy (FA), average diffusion coefficient (ADC), and radial diffusivity (RD) of median nerve of CTS patients were obtained from diffusion tensor imaging (DTI) and compared with those of controls. Thirty-three patients (76.7%) were female. Mean duration of the pain was 7.4 ± 2.6 months. The mean CSA1 (13.2 ± 4.2 mm2), CSA2 (12.5 ± 3.5 mm2), and CSA3 (9.2 ± 1.5 mm2) in CTS patients were significantly higher compared to control group: CSA1 (10.15 ± 1.64 mm2), CSA2 (9.38 ± 1.37 mm2), and CSA3 (8.4 ± 0.9 mm2), (P = 0.001 in all). The mean FR of median nerve and thickness of flexor retinaculum were increased in CTS patients. The mean FA was reduced in CTS patients compared to control proximal to carpal tunnel and within the tunnel. Mean ADC and RD values were higher in CTS patients as compared to control for both levels. MRI can detect subtle changes in the median nerve and thenar muscles in CTS and may be useful in equivocal cases and to exclude secondary causes of CTS. DTI shows reduced FA and increased ADC and RD in CTS patients.

Ultrasonographic features of ulnar nerve instability around the elbow in fresh cadavers.

Ultrasound (US) is commonly used to evaluate ulnar nerve instability (UNI) and snapping of the medial head of the triceps brachii muscle (ST). We aimed to determine the diagnostic accuracy of US in evaluating UNI, through cadaveric dissection, and to evaluate the US features and relationships of UNI and ST according to elbow flexion. Dynamic US was performed with elbow extension, 90° flexion, and full flexion positions on 18 elbows from 9 fresh cadavers. UNI was classified into N (normal), S (subluxation), and D (dislocation) types. On US exams, the following findings and parameters were evaluated: the presence of UNI and ST; the horizontal distance from the apex of the medial epicondyle (ME) to the margins of the UN and medial head of the triceps brachii muscle (ME_UN and ME_TB, respectively); cross-sectional area and flattening ratio (FR) of UN. After US, all cadavers were dissected to expose the UN and TB, and elbow flexion and extension were simulated to confirm UNI and ST. The gross anatomic findings of UNI and ST were consistent with the US findings. In extension and 90° flexion positions, all cases were type N. In full flexion position, types N and S occurred in 10 (56%) and 8 (44%) elbows, respectively. FR and ME_UN in 90° flexion position, FR, ME_UN, and ME_TB in full flexion position differed significantly between types S and N. Positive correlations were found between ME_UN and ME_TB in 90° flexion and full flexion positions. Dynamic US accurately assessed UNI and ST. UNI was positively correlated to medial TB movement.

Correlation between Electrodiagnostic Study and Imaging Features in Patients with Suspected Carpal Tunnel Syndrome

Electrodiagnostic studies (EDXs) are the confirmative diagnostic tool for carpal tunnel syndrome (CTS). Previous studies have evaluated the relationship between EDXs and ultrasonography (US) but not with X-rays. Recently, many studies on the diagnostic value of X-rays in various diseases have been reported, but data on CTS are lacking. We evaluated the relationship between electrodiagnostic parameters and roentgenographic and ultrasonographic features in CTS and investigated the usefulness of X-rays and US for CTS. This retrospective study included 97 wrists of 62 patients. All patients with suspected CTS underwent EDXs, wrist US, and wrist X-rays. The CTS patients were classified into mild, moderate, and severe groups. The roentgenographic features included the ulnar variance (UV) and the anteroposterior diameter of the wrist (APDW), and the ultrasonographic features included the flattening ratio (FR) and the thickest anteroposterior diameter of the median nerve (TAPDM). Most EDX parameters showed significant correlations with roentgenographic and US features. The electrodiagnostic severity was also correlated with all imaging features. Therefore, both wrist X-rays and wrist US can be useful for the diagnosis of CTS as supplements to EDXs.

Ultrasonographic and electrophysiological outcomes of carpal tunnel syndrome treated with low-level laser therapy: A double-blind, prospective, randomized, sham-controlled study.

Objectives The aim of this study was to investigate the therapeutic effects of low-level laser therapy (LLLT) on clinical, ultrasonographic (US), and electrophysiological findings in carpal tunnel syndrome (CTS).Patients and methods Between January 2015 and August 2015, 42 patients (7 males, 35 females; mean age: 50.4±8.7 years; range, 32 to 65 years) with mild-to-moderate CTS were randomly assigned to one of two groups: active LLLT (therapy group, n=22) 0.8 J/painful point and sham LLLT groups (n=20). Both groups wore neutral wrist orthoses. The patients were evaluated before and after 15 sessions of therapy (670 nm, 4 J/session over the carpal tunnel). Follow-up parameters included the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) Symptom Severity Scale (SSS), Functional Status Scale (FSS), nerve conduction studies and US evaluation of the median nerve cross-sectional area (CSA), vascularization (via power Doppler), flattening ratio (FR), and palmar bowing of the flexor retinaculum.Results Nocturnal paresthesia improved in both groups; however, pain and patients with a positive Phalen’s test reduced only in the therapy group (p=0.031). The FSS and SSS scores also improved only in the therapy group (p<0.001). Electrophysiologically, median sensory nerve conduction velocities showed a significant improvement only in the therapy group (p=0.002). The CSA, FR, and vascularization of the median nerve showed a significant improvement in the therapy group alone (p<0.001, p=0.048, and p=0.021, respectively).Conclusion Improvements in the signs and symptoms of CTS and hand function, the improvements in sensory nerve conduction studies, and reduction in median nerve CSA, FR and vascularity in the LLLT group can be attributed to the anti-inflammatory and analgesic effects of LLLT. This study provides new US data demonstrating efficacy of LLLT along with a clinical and electrophysiological improvement. The LLLT seems to be an easily applied, non-invasive treatment option.

A systematic review of the methodology of sonographic assessment of upper limb activities–associated carpal tunnel syndrome

Various upper limb activities were speculated to be associated with the development of carpal tunnel syndrome (CTS). Nonetheless, there are currently no standardization on the uses of parameters in CTS assessments, nor are there any conclusive findings regarding the usefulness of various sonographic measurements in studies of different upper limb activities. In this review, we intend to evaluate the methodology of assessing CTS induced by upper limb activities with ultrasonographic technique and provide corresponding suggestions. Clinical studies on the association between upper limb activities and prevalence of CTS using ultrasonography were recruited in a database research on the basis of a procedural selection criteria and reviewed. The following qualitative items were extracted: characteristics of studies, scanning methods, selection of sonographic parameters, and related article findings. Eleven studies were qualified for this review. Three studies were computer keyboard typing related, five studies were electronic device related, and three studies were wheelchair-related. All sampled articles included cross-sectional area (CSA) at the pisiform level. The swelling ratio (SR) and flattening ratio (FR) at the hamate level are also used in most studies in addition to the CSA at the pisiform level. The effectiveness of such parameters is subjected to various confounding factors such as age, weight, body mass index, and wrist anthropometrics, suggesting CSA and SR with sufficient levels had significant values as sonographic parameters. Values of parameters were found affecting symptomatic signs and hand dominance. Ultrasound scan is a suitable tool to assess the relationship between upper limb activity and CTS. CSA at the pisiform level and SR and the FR at the hamate levels are generally suitable in upper limb-associated CTS investigations. Specific study designs are required to eliminate different confounding factors accordingly.

Correlation between flattening ratio and wear performance of cold sprayed metal matrix composite coatings

Cold spray is one of the promising coating deposition techniques for fabricating anti-wear composite coatings. These composite coatings contain an even distribution of the two phases, they are Ti-6Al-4V and Al splats if referring to the current study. With the help of image analysis software (Fiji), the flattening ratio (FR) of Al splats was found to be larger than that of Ti-6Al-4V in different composite coatings. The overall FR is more comprehensively correlated to fracture toughness and wear performance for the entire composite structure, rather than comparing the particular FR of Ti-6Al-4V or Al splats only. The higher the FR of the composite coating, the better its wear performance, but this phenomenon only applies to the same type of composite coating, because different composite coatings respond differently to wear.

Very high-resolution ultrasound of the distal median nerve

ObjectiveA very high-resolution (70 MHz) ultrasound device (VHRUS) has recently been approved for use in humans. The aim of this study was to use VHRUS to collect data on healthy subjects to propose some reference values for the digital branches of the median nerves of the hand. MethodsA VHRUS with 70 MHz linear array transducer was used to measure the cross sectional area of the median nerve at the wrist (CSAw) and digital branches (CSAf), largest and smallest fascicles, the fascicles number (Nfasc), the fascicle density (FD), the flattening ratio (FR) and CSAw/CSAf. ResultsData from 20 healthy subjects were obtained for both hands. The median nerve at the wrist and digital branches were properly identified without anatomical alterations. No differences were found between the right and the left hand. In the dominant hand, CSAw was 9.35 mm2 (4.57–12.35) and Nfasc was 24 (18–38). FD and FR were respectively 2.94 (2.47–4.91) and 2.74 (1.70–4.90). ConclusionVHRUS technology can visualize the median nerves at the wrist, their internal structure and their small branches at the fingers, providing both a qualitative and quantitative assessment. Results from this study provide preliminary reference values in a young healthy sample. SignificanceMost conventional ultrasound devices are not able to properly visualize the distal branches of the median nerve. In contrast, VHRUS allows to detect and measure smaller structures of the nerve, assisting in clinical practice.

Analysis of Sonographic Measurement by Anatomical Area in Carpal Tunnel Syndrome and Correlation the Measurement with Electrodiagnostic Study

Purpose: To evaluate effectiveness of ultrasonographic measurement of carpal tunnel by anatomical area and correlation with electrodiagnostic study in diagnosis of carpal tunnel syndrome.Methods: From September 2018 to March 2019, we performed the ultrasonography for 30 cases with carpal tunnel syndrome diagnosed with electrodiagnosis and 30 cases as control group. We measured median nerve diameter, cross-sectional area (CSA), and flattening ratio (FR) by area of carpal tunnel. We analyzed the difference of measurement between two groups and correlate the measurement with electrodiagnosis findings.Results: There was significant statistically differences in sonographic measurement between two groups by independent t-test (CSA zone 1, p=0.01; FR zone 2, p=0.000; FR zone 3; p=0.001). With Pearson correlation test, there was correlation between sonographic measurement and electrodiagnostic findings (terminal latency and nerve conduction velocity) statistically, but the Pearson coefficient was low (r&lt;0.4). Conclusion: By anatomical area, the available value of sonographic measurement was different. But, as the values were has low power to diagnose the carpal tunnel syndrome, ultrasonography is proper to use as a complementary tool in diagnosis of carpal tunnel syndrome.

Role of High Resolution Ultrasound in Assessment of Abnormalities of Median Nerve in Carpal Tunnel Syndrome

Background: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and consists of the compression of the median nerve as it courses through the carpal tunnel. Carpal tunnel syndrome was diagnosed by history and physical examination, electrodiagnostic studies (EDX) were used to confirm the diagnosis. However, these studies are painful for most of the patients with high incidence of false positive or false negative results. Ultrasound is a low cost, short time and non-invasiveness technique that could be used to assess a number of parameters of the median nerve (MN) in cases of CTS. Objective: To assess the utility of high resolution ultrasound (HRUS) in assessment of median nerve in carpal tunnel syndrome through different ultrasound diagnostic criteria in patients with clinical and electrodiagnostic evidence of CTS. Patients and Methods: This study included a total of 60 participants divided into 2 groups; group A, the patients group included 30 patients with a clinical diagnosis of carpal tunnel syndrome (CTS) and group B, the control group who included 30 sex and age-matched healthy individuals. All the included cases were subjected to full history taking, full general and general examination. Nerve conduction studies were performed using a Caldwell Sierra Wave and the NCS consisted of sensory median nerve conduction tests using standard techniques. High resolution US was performed by using an Aplio 400 Ultrasound System. The following measurement was recorded in each of the included subjects including cross sectional area (CSA) of the median nerve, flattening ratio (FR) of median nerve and palmar bowing (PB) of the flexor retinaculum. Results: There was high statistically significant difference in the mean CSA and mean PB between the cases with CTS and healthy control. No statistically significant difference in the mean FR between the cases with CTS and healthy control. Optimal CSA cut-off value to differentiate between cases with CTS and control was (10.2 mm2) and the optimal PB cut-off value to differentiate between cases with CTS and control was (3.3 mm). Positive correlation was detected between the CSA and PB with increasing the severity of CTS. Conclusion: Electrophysiological studies are the most utilized diagnostic methods for diagnosing nerve entrapment including median nerve in CTS. Hugh resolution ultrasound (HRUS) is non- invasive sensitive diagnostic tool in diagnosing CTS.

Ratio and difference of the cross-sectional area of median nerve to ulnar nerve in diagnosing carpal tunnel syndrome: a case control study

BackgroundTo 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).MethodsIn 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).ResultsCSA-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).ConclusionsBy 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 registrationClinicaltrial.gov NCT03033173. Registered 18 January 2017. Retrospectively registered.

Adhesion strength of titanium particles to alumina substrates: A combined cold spray and LIPIT study

The cold spray process and laser-induced projectile impact test (LIPIT) are used to deposit Ti powder particles on sintered polycrystalline Al2O3. Whereas LIPIT allows real-time observations of single particle impact and measurement of particle impact velocity, cold spray rapidly and simultaneously deposits particles with a wide range of deposition velocities and sizes. By use of these two techniques, the effect of particle velocity and substrate morphology on adhesion strength of single splats is investigated. The critical velocity for deposition is identified to be approximately 580 m/s for the Ti/Al2O3 system when using LIPIT and particles of 10 μm. Above the critical velocity, flattening ratio (FR) is also evaluated and observed to be linearly dependent on the particle impact velocity. Splat adhesion testing is performed on LIPIT-deposited as well as on cold spray-deposited powder particles to measure adhesion strength. This analysis shows that adhesion strength is highly affected by local substrate surface morphology, where particles bond more weakly to relatively smooth portions of the substrate. Therefore, mechanical bonding plays a significant role in adhesion. Also, adhesion strength decreases with an increase in FR and therefore velocity. This decrease can be associated with fracture of the ceramic substrate and rebound forces.

Sonographic Measurement of Cross-sectional Area of the Median Nerve in Academic Dentists Without Symptoms or Signs of Carpal Tunnel Syndrome

The objective was to evaluate the distribution of the cross-sectional area (CSA) and flattening ratio (FR) of the median nerve (MN) in asymptomatic academic dentists using ultrasonography (US). Fifty academic dentists underwent US of the MN in transverse section at the pisiform bone level and the CSA (mm2) and FR were measured bilaterally. A CSA of &lt;10 mm2 was considered normal. Paired t-test showed no statistical significance between either hand for CSA and FR ( P&gt; .05). Two independent t-tests showed significant statistical differences ( P= .023) between males and females in the right dominant hand for CSA. Linear correlation analysis showed no significant correlation between CSA and FR for number of years of experience or number of working hours per day in either hand ( P&gt;.05). The CSA was abnormal in the right dominant hand in 20 (40%) of the subjects. These male academic dentists were at increased risk of having an enlarged MN without symptoms.

OBLIGATORY ALTERATIONS IN THE MORPHOLOGY OF MEDIAN NERVE: A SONOGRAPHIC STUDY IN ASYMPTOMATIC INDIVIDUALS

Introduction: Median nerve is formed in axilla by contributions from medial and lateral cords of brachial plexus. It descends in the arm, forearm and then through carpal tunnel in close conjunction with flexor tendons of forearm. Carpal tunnel syndrome (CTS) is a common entrapment neuropathy. Median nerve cross sectional area (CSA) and ratio of nerve major axis to minor axis (flattening ratio) serve as potential diagnostic criteria for carpal tunnel syndrome. Median nerve cross sectional area and flattening ratio (FR) can be assessed by ultrasonography (US). Aim of the study was to assess median nerve by US and tabulate mean values for CSA and FR in asymptomatic population. This would serve to limit the cut-off values that differentiate asymptomatic nerves from neuropathic nerves. Material &amp; Methods: Study was conducted in the Department of Anatomy, KGMU, Lucknow. Fifty randomly selected asymptomatic volunteers (undergraduate students: 30 males, 20 females) participated in the study. Sonography was performed to evaluate certain morphological dimensions of median nerve. Height, weight and wrist circumference of participants were also noted. Ultrasonography was performed using high frequency linear probe and observations were made at two pre-determined sites. Observations were recorded, tabulated and analyzed. Results: Median nerve was easily observable at both sites. It was round in shape in forearm (Fo), and flattened as it reached the carpal tunnel (Ct). Among all 50 study subjects, at both sites, flattening was more on right side (FRFoRt-1.71; FRCtRt-3.08) than on left side (FRFoLt-1.66; FRCtLt-2.78). In right forearm, nerve was flatter in females (FRFoRt-1.77) as compared to males (FRFoRt-1.68). In left forearm, median nerve was slightly rounder in females (FRFoLt-1.65) as compared to males (FRFoLt-1.67). At the distal wrist crease on right side, increased flattening was observed in females (FRCtRt-3.30) as compared to males (FRCtRt-2.94), whereas on left side, at same site flattening was more in females (males FRCtLt-2.74; females FRCtLt-2.83). Conclusion: Altered FR has both diagnostic as well as prognostic values in carpal tunnel syndrome. The database generated from the study will help in facilitating comparisons between normal, asymptomatic and pathological, asymptomatic individuals.

Microstructure, microhardness and tribological behavior of Al2O3 reinforced A380 aluminum alloy composite coatings prepared by cold spray technique

In the present work, Al2O3 particles reinforced A380 aluminum alloy composite coatings with different Al2O3 content were fabricated by cold spraying (CS). The effect of Al2O3 content on surface roughness, microstructure, microhardness and tribological performance of the composite coatings was studied. Laser confocal imaging, optical microscopy (OM) and scanning electron microscopy (SEM) results revealed that; as the Al2O3 content in the coating increases, the surface roughness decreases while the flattening ratio (FR) of the deformed particles increases due to the tamping effect of the impinging particles. Moreover, Al2O3 particles resulted in increased microhardness and low porosity in the composite coatings due to the refinement of A380 grains and the tamping effect, respectively. The degree of fragmentation of Al2O3 particles increases with the increase of Al2O3 content in the composites. Finally, dry sliding wear tests indicated that the addition of Al2O3 significantly improves the wear properties of the A380 coating as well as the AZ31 substrate. The improved wear performance of the composites was explained by continuously evolving adhesive, delamination and abrasive wear mechanisms.

Usefulness of neuromuscular ultrasound in the diagnosis of idiopathic carpal tunnel syndrome

ObjectiveThe aim of the study was to assess the usefulness of neuromuscular ultrasound in the diagnosis of idiopathic carpal tunnel syndrome (CTS) and to determine the relationships of ultrasonographic measurements with the clinical severity and the electrophysiological grading scale.Patients and methodsOne hundred CTS diseased hands and 100 nondiseased hands were assessed clinically and by nerve conduction studies. We measured ultrasonographic cross-sectional area (CSA) of the median nerve at various levels of the carpal canal (inlet and outlet), flattening ratio (FR), palmar bowing of the flexor retinaculum, wrist/ forearm ratio, as well as median nerve mobility and power doppler signals. Data from patients and controls were compared to determine the diagnostic relations and the grade of severity.ResultsMeasures of CSA of the median nerve at the inlet and at the outlet, palmer bowing and inlet/forearm ratio in the CTS group were significantly higher than the control group (P<0.05); 50% of diseased hands showed restriction of mobility of the median nerve, while 31% had doppler signals. Positive correlations of ultrasonographic measurements with patient-oriented measures, clinical severity scale and electrophysiological grade were observed.ConclusionUltrasonographic measurements of CSA at the inlet and flexor retinaculum have a relatively higher diagnostic accuracy than FR for CTS. The correlation between clinical scores, historical-objective-distribution scale, electrophysiological grade and ultrasonographic measurements reflects the usefulness of neuromuscular ultrasound in the diagnosis of idiopathic CTS.

ROLE OF ULTRASONOGRAPHY IN THE DIAGNOSIS OF CARPAL TUNNEL SYNDROME

Background: Carpal tunnel syndrome (CTS) is the most common form of peripheral entrapment neuropathy. The use of sonography for investigation and diagnosis of musculoskeletal conditions has been rapidly increasing over the past few decades. Recent studies have demonstrated advantages of sonographic techniques in the diagnosis of carpal tunnel syndrome (CTS). Objective: Assessing the utility of ultrasonography in the diagnosis of carpal tunnel syndrome (CTS) and grading its severity. Patients and Methods : Sixty hands in 46 patients with clinically and electro-physiologically confirmed carpal tunnel syndrome, and sixty asymptomatic hands in 34 healthy individuals as control group were included in the study and underwent high-resolution ultrasonography of the wrists. In ultrasonographic assessment the cross-sectional area (CSA) of the median nerve at the distal crease of the wrist and flattening ratio (FR) of the median nerve in the carpal tunnel as well as palmar bowing (PB) of the flexor retinaculum were measured. Ultrasonographic Data from the patients group and control group were compared to determine the statistical significance. The accuracy of the ultrasonographic diagnostic criteria for carpal tunnel syndrome was evaluated using receiver-operating characteristic (ROC) curve analysis. Sensitivity and specificity of ultrasonographic measurements were evaluated. Ultrasonographic measurements were correlated with severity of CTS according to nerve conduction studies (NCS). Results: The CSA of the median nerve and PB of the flexor retinaculum were significantly larger in the CTS hands compared to the normal control hands. However, FR of the median nerve showed no significant difference between both groups. Increased cross-sectional area of the median nerve was the most predictive measurement of carpal tunnel syndrome. Using the ROC curve, a CSA cut-off value of 10 mm² provided a diagnostic sensitivity of 93.3 % and specificity of 98.3 % and PB cut-off value of 3.3 mm provided a diagnostic sensitivity of 90 % and specificity of 85 %. No significant differences in CSA and PB were found among patients with mild, moderate and severe carpal tunnel syndrome so that CSA and PB did not reflect the severity of the condition. Conclusion: Ultrasonography is a useful non-invasive method for the diagnosis of carpal tunnel syndrome but not assessing its severity.

Ultrasonographic changes after steroid injection in carpal tunnel syndrome.

To determine the ultrasonographic changes after steroid injection in carpal tunnel syndrome (CTS) and to evaluate the diagnostic value of ultrasound in post-treatment examination with clinical correlation. Twenty-seven wrists with idiopathic CTS after a single injection of 40mg of prednisolone hydrochloride were prospectively studied using a high-resolution ultrasound. Axial images of the wrists were obtained at the level of the distal radius, pisiform and hamate prior to and 1, 4 and 8weeks after steroid injection. The cross-sectional area (CSA, mm2) and flattening ratio (FR) of the median nerve were measured. The bowing of the flexor retinaculum (palmar displacement: PD, mm) and the transverse sliding distance of the median nerve (TSD, mm) during flexion-extension of the index finger were computed. Pre- and post-injection ultrasonographic findings were analyzed in relation to clinical parameters such as pain score. At all levels of the wrist, the CSA decreased significantly at 1week after the injection, which continued to 8weeks post-injection. The PD also diminished significantly 1week after the injection. Furthermore, the TSD significantly increased from 1week after injection, which lasted to the end of this study. The CSA, PD and TSD showed significant correlation with improvement of pain scores. Ultrasound is useful in follow-up examinations of CTS. Significant ultrasound findings after steroid injections in CTS include decreased swelling of the median nerve, decreased bowing of the flexor retinaculum and increased mobility of the median nerve. All of them significantly correlate with clinical symptoms.

Morphologic change of nerve and symptom relief are similar after mini-incision and endoscopic carpal tunnel release: a randomized trial

BackgroundThe symptoms in carpal tunnel syndrome (CTS) can be ameliorated by open and endoscopic release of the transverse carpal ligament. It is unknown whether a mini-incision or endoscopic carpal tunnel release more effectively reverses the pathological changes that are observed in the median nerve in patients with CTS and these morphologic changes correlates with the subjective outcomes after carpal tunnel release. We hypothesized that (1) at 24 weeks after surgery, the subjective outcomes of mini-incision release and endoscopic release would not differ in patients with CTS; and (2) the ultrasonographic (US) morphology of the median nerve reverses similarly after mini-incision and endoscopic release; (3) the subjective outcomes correlates with these morphologic changes.MethodsBetween November 2011 and January 2013, 67 patients with CTS in their dominant wrist were randomized to either mini-incision (n = 32) or endoscopic (n = 35) release. Each patient was assessed by both the Boston Carpal Tunnel Questionnaire (BCTQ) and the Disabilities of the Arm, Shoulder, and Hand (DASH) pre-operatively and 24 weeks’ post-operation. An US examination was conducted at both time points to measure the cross-sectional area (CSA) at the inlet, middle, and outlet (CSA-I, CSA-M and CSA-O) and the flattening ratio (FR) at the middle and outlet (FR-M and FR-O) of the median nerve.ResultsThe post-operative mean BCTQ and DASH scores were improved significantly from the pre-operative scores in both groups (p < 0.001). The mean CSA-I decreased and CSA-M and CSA-O increased similarly in both groups (by 3.3, 3.0, and 3.8 mm2 in the mini-incision group and 2.9, 3.1. and 2.7 mm2 in the endoscopic group. The mean FR-M/FR-O decreased similarly from 3.6/4.2 to 3.2/3.0 in the mini-incision group and 3.8/4.3 to 3.2/2.9 in the endoscopic group. There were no significant differences in the subjective outcome scores or median nerve measures between the two groups. Improvement in the BCTQ-S only was significantly correlated with changes in the CSA at the inlet.ConclusionsMini-incision and endoscopic release both similarly relieved subjective symptoms and functions along with the pathological changes in the median nerve morphology along the carpal tunnel in patients with idiopathic CTS. Symptom relief after surgical decompression seems to correlate with reduced nerve swelling at carpal inlet and reversed nerve flattening inside carpal tunnel.Trial registrationThis study was retrospectively registered in “ClinicalTrials.gov” at Oct 18th, 2013, and the registration number was NCT01972165.