Level Of Distal Radioulnar Joint Research Articles

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.

Diagnostic value of diffusion-weighted MRI using apparent diffusion coefficient (ADC) in evaluation of median nerve in carpal tunnel syndrome

BackgroundThe diagnosis of carpal tunnel syndrome is based on a combination of clinical history, clinical examination and frequent use of electrodiagnostics as nerve conduction study and electromyography which often do not provide the spatial and anatomical localizing information, especially with small nerves of the extremities. Conventional magnetic resonance imaging can reveal morphological changes in carpal tunnel syndrome patients.AimThe purpose of our study was to assess the efficacy of diffusion magnetic resonance imaging as a functional imaging in evaluation of median nerve in carpal tunnel syndrome.Patients and methodsThis prospective study included a group of 33 patients with carpal tunnel syndrome diagnosed by both clinical examination and electromyography; 40 writs were examined. A control group of 20 subjects of matched age group were also included. All the participants were subjected to conventional and diffusion magnetic resonance imaging studies.ResultsMedian nerve apparent diffusion coefficient values of patients are lower than those of controls. The sensitivity and diagnostic accuracy of diffusion conventional magnetic resonance imaging were 95% and 97.5%, respectively, versus 25% and 62.5% of conventional magnetic resonance imaging. A cut-off apparent diffusion coefficient value ≤ 0.99 obtained at distal radio-ulnar joint level and > 1.07 at pisiform level as well as apparent diffusion coefficient ratio at a cut-off ≤ 0.2 was significantly valid for diagnosing carpal tunnel syndrome.ConclusionsDiffusion magnetic resonance imaging provides functional evaluation of median nerve in patients with carpal tunnel syndrome.

Application of force-monitor ultrasonography to assess distal radioulnar joint instability in patients with triangular fibrocartilage complex injury.

In this study, we evaluated the differences and measurement accuracy in the force-displacement relationship of the distal radioulnar joint (DRUJ) between patients with triangular fibrocartilage complex (TFCC) injury and healthy controls using force-monitor ultrasonography. This study included 11 TFCC injury patients and 22 healthy controls. We evaluated differences in the force-displacement relationship of the DRUJ in these patients using force-monitor ultrasonography. Cyclic compression was applied to the dorsal surface of the ulnar head. Distance between the dorsal surface of the distal radius and ulnar head at the DRUJ level was measured in the initial and pressed-down positions. Changes in radioulnar displacement, applied force, and displacement-to-force ratio were measured. Furthermore, we compared the parameters between the affected and unaffected wrists and between TFCC injury patients and controls. The radioulnar displacement and displacement-to-force ratio were significantly larger in the affected wrists than in the unaffected wrists (P = 0.003 and P = 0.02). The affected/unaffected side ratio of radioulnar displacement and displacement-to-force ratio were significantly larger in the TFCC injury patients than in the controls (P = 0.003 and P = 0.02). The area under the curve was 0.82 for the affected/unaffected ratio of the radioulnar displacement. The optimal cutoff value indicated by the receiver-operating characteristic curve for the affected/unaffected ratio of the radioulnar displacement was 1.71; the sensitivity and specificity were 82% and 86%, respectively. Assessing the DRUJ instability with force-monitor ultrasonography may help identify TFCC-injured wrists.

Efficacy of Diagnosing Carpal Tunnel Syndrome Using the Median Nerve Stenosis Rate Measured on Ultrasonographic Sagittal Imagery: Clinical Case-Control Study.

The purpose of the present study was to evaluate the usefulness of the median nerve stenosis rate (MNSR) measured on sagittal sonographic images of the median nerve in the diagnosis of carpal tunnel syndrome (CTS). The study population consisted of 45 hands from 37 patients with idiopathic CTS (CTS group), and 60 hands from 35 asymptomatic healthy subjects (control group). Carpal tunnel syndrome was diagnosed by clinical findings and positive electrophysiological study results. All patients and control subjects underwent ultrasonographic examination. At the carpal tunnel level, the transducer was placed longitudinally to the median nerve, and an image of the longitudinal median nerve was obtained. The minimum median nerve diameter (MND) was measured at the middle part of the capitate level, while the maximum MND was measured at the distal radioulnar joint level. The MNSR was calculated as (1 - minimum MND/maximum MND) × 100 (%). The cross-sectional area of the median nerve was also measured at the level of the pisiform. On longitudinal sonographic images, the MNSR was significantly larger in the CTS group than the control group. When the cut-off value of the MNSR was 26.73%, the sensitivity and specificity were 91.1% and 80%, respectively. The area under the receiver operating characteristic curve was larger for the MNSR than for the cross-sectional area. The results suggest that the MNSR proposed in the present study may be useful as an auxiliary method for CTS diagnosis on ultrasonographic examination.

Motion of the distal radioulnar joint in extension and flexion of the wrist using axial CT imaging of healthy volunteers

BackgroundThe midcarpal joint and the radiocarpal joint contribute to the extension and flexion of the wrist. Little is known about the contribution of the distal radioulnar joint (DRUJ) to the extension and flexion of the wrist. This study evaluated the ulnar motion in extension and flexion of the wrist using computed tomography (CT) imaging. MethodsA total of 30 wrists of healthy volunteers were enrolled. CT images of the axial sections of the DRUJ were obtained with 3 different positions of the wrist: 0° of extension (straight position), maximum active extension, and maximum active flexion. Each wrist motion was performed with 3 different forearm positions: neutral, pronation, and supination. Ulnar position at the DRUJ level was measured and ulnar position with the wrist in straight position was defined as baseline. The ulnar position was recorded as positive value when the position of the ulnar head was volar side and negative value when the position of the ulnar head was dorsal side. The difference from baseline in a position of maximum extension and flexion was evaluated. ResultsIn forearm neutral position and pronation, a value of ulnar position in maximum wrist flexion is significantly negative compared to that in the wrist straight position: the ulnar head moved dorsally from the wrist straight position to wrist flexion. In forearm supination, a value of ulnar position in maximum wrist extension is significantly positive compared to that in the wrist straight position: the ulnar head moved to the volar side from the wrist straight position to wrist extension. ConclusionsThe ulnar head moves during extension and flexion of the wrist. The direction of the ulnar motion was different according to the wrist and forearm position.

Quantitative assessment of distal radioulnar joint stability with pressure-monitor ultrasonography

BackgroundDiagnosing distal radioulnar joint (DRUJ) instability remains a challenge as it relies on physical examination. To quantitatively assess DRUJ stability, a pressure-monitor ultrasound system was developed. The objective of this study was to evaluate the force-displacement relationship of DRUJ in normal subjects.MethodsNine wrists of 9 asymptomatic volunteers were evaluated. The pressure-monitor ultrasound system was developed to apply pressure to the tissue with a pre-determined cycle and displacement of the transducer. Each subject was imaged sitting with the elbow flexed and forearm pronated. The dorsal surface of the distal radius and the center of the ulnar head were displayed at DRUJ level. The pressure toward palmar direction was applied to the distal ulna with different levels of transducer displacements, i.e., 1 mm, 2 mm, and 3 mm. The distance between the dorsal surface of the ulnar head and the dorsal surface of the distal radius was measured. The first measurement was performed at the initial position, and the second measurement was performed when the transducer pressed down the ulna to the degree that the ulnar head had shifted to the most palmar position. At the same time, the pressure to the transducer was measured. The changes of radioulnar distance (=the measurement at the most palmar position—the measurement at the initial position) and pressure, and pressure/distance ratio were compared among the different transducer displacements.ResultsThe pressure was significantly increased as the transducer displacement became larger (P < 0.01). The changes of radioulnar distance were smaller in the 1 mm displacement condition compared to the 2 and 3 mm displacement conditions (P < 0.05). The pressure/distance ratio was larger in the 1 mm displacement condition compared to the 2 and 3 mm displacement conditions (P < 0.05).ConclusionsA method to assess DRUJ stability by measuring changes in radioulnar distance and force application was developed. It was found that the application of 2 mm displacement and 200 g force was the critical stress for the capsuloligamentous structures to start stabilizing DRUJ. This methodology and the indices may be clinically useful to investigate the mechanical properties of patients with DRUJ instability.

Reliability of Quantitative Assessment of Distal Radioulnar Joint Stability With Force‐Monitor Ultrasonography

The purpose of this study was to evaluate the reliability of ultrasound assessment of the displacement-force relationships for distal radioulnar joint (DRUJ) stability. Non-dominant wrists of 10 healthy male subjects were evaluated by force-monitor ultrasonography. This apparatus was developed to apply cyclic compression to the wrist with pre-determined transducer displacement conditions in the range of 0.1-3.0 mm. The subject's wrist was placed on the table with the forearm in the pronated position. The transducer was placed on the dorsal surface of the distal radius and ulna, perpendicular to the long axis of the forearm. The center of the ulnar head was at the DRUJ level. The distance between the dorsal surface of the distal radius and the ulnar head was measured at an initial and a pressed-down position. Changes in radioulnar displacement, force to the wrist and the displacement/force ratio were evaluated. The measurements were performed independently by two raters. The intra-class correlation coefficients (ICCs) for the radioulnar displacement were 0.76, 0.68, and 0.93, in the 1.0, 2.0, and 3.0 mm transducer displacement conditions, respectively. The ICCs for the force to the wrist were 0.18, 0.67, and 0.34, in different transducer displacement conditions, respectively. The ICCs for the displacement/force ratios were 0.68, 0.67, and 0.97, in different transducer displacement conditions, respectively. The highest ICC for the radioulnar displacement and the displacement/force ratio was observed in the 3.0 mm displacement condition. This assessment of displacement-force relationships may be useful to quantify DRUJ stability. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2053-2060, 2019.

A comparison of the performance of anatomical MRI and DTI in diagnosing carpal tunnel syndrome

PurposeTo compare the performance of anatomical magnetic resonance imaging (MRI) with that of diffusion tensor imaging (DTI) in the diagnosis of carpal tunnel syndrome (CTS). Materials and methodsWe performed 3T anatomical MRI and DTI on 42 patients and 42 age-matched controls. The median nerve cross-sectional area (CSA), relative median nerve signal intensity, and palmar bowing of the flexor retinaculum, assessed with anatomical MRI, and fractional anisotropy (FA) and apparent diffusion coefficient of the median nerve, assessed with DTI, were measured at four locations: the hamate level, the pisiform level (P0), the level located 1cm proximal to the P0 level (P1), and the distal radioulnar joint level (DR). Adding the ratios and differences of the median nerve parameters between the measurements at the DR and other locations to the diagnostic parameters, we evaluated the area under the receiver operating characteristic curves (AUCs) of all the diagnostic parameters of both scans. ResultsThe AUCs of FA(P1) (0.814) and FA(P0) (0.824) in DTI were larger than the largest AUC for anatomical MRI, CSA(P1) (0.759). However, the receiver operating characteristics of the three parameters were not significantly different (P>0.1). The sensitivity and specificity of CSA(P1) (76.2% and 73.8%) and FA(P1) (73.8% and 76.2%) increased after inclusive and exclusive combination to 90.5% each. ConclusionThe individual performances of both scans were not significantly different in diagnosing CTS. Measuring both CSA and FA at P1 may be useful and efficient to utilize the merits of both scans and to increase the CTS diagnostic performance.

Motor Unit Number Estimation and Motor Unit Action Potential Analysis in Carpal Tunnel Syndrome

ObjectiveTo evaluate the clinical significance of motor unit number estimation (MUNE) and quantitative analysis of motor unit action potential (MUAP) in carpal tunnel syndrome (CTS) according to electrophysiologic severity, ultrasonographic measurement and clinical symptoms.MethodWe evaluated 78 wrists of 45 patients, who had been diagnosed with CTS and 42 wrists of 21 healthy controls. Median nerve conduction studies, amplitude and duration of MUAP, and the MUNE of the abductor pollicis brevis were measured. The cross sectional area (CSA) of the median nerve at the pisiform and distal radioulnar joint level was determined by high resolution ultrasonography. Clinical symptom of CTS was assessed using the Boston Carpal Tunnel Questionnaire (BCTQ).ResultsThe MUNE, the amplitude and the duration of MUAP of the CTS group were significantly different from those found in the control group. The area under the ROC curve was 0.944 for MUNE, 0.923 for MUAP amplitude and 0.953 for MUAP duration. MUNE had a negative correlation with electrophysiologic stage of CTS, amplitude and duration of MUAP, CSA at pisiform level, and the score of BCTQ. The amplitude and duration of MUAP had a positive correlation with the score of BCTQ. The electrophysiologic stage was correlated with amplitude but not with the duration of MUAP.ConclusionMUNE, amplitude and duration of MUAP are useful tests for diagnosis of CTS. In addition, the MUNE serves as a good indicator of CTS severity.

Sonographic findings of the median nerve and prevalence of carpal tunnel syndrome in patients with Parkinson's disease

Purpose Parkinson's disease (PD) is a chronic progressive disorder which is characterized by rest tremor, akinesia or bradykinesia and rigidity. Carpal tunnel syndrome (CTS) is caused by compression of median nerve and can occur as a result of repetitive trauma. The aim of this study was to estimate the prevalence of CTS in PD and evaluate the median nerve sonographically. Materials and methods Fifty-three wrist of 29 patients with PD were included in the study according to Hoehn and Yahr (H&Y) clinical stage and divided into two groups. The first group consisted of 29 wrists of patients with mild PD (H&Y stage I–II). The second group consisted of 24 wrists of patients with severe PD (H&Y stage III–IV). Thirty-six wrists of 20 age-matched patients were used as control group. Both of the patients with PD and control group underwent sonography and electromyography (EMG). Axial sonograms of the median nerve were obtained at the level of distal radioulnar joint (level 1) and at the level of pisiform bone in the carpal tunnel (level 2). At each level, the cross-sectional area of the median nerve and flattening ratio were calculated. Results There was no significant difference for all parameters, except one parameter, between the patients with PD and control group, and also among mild and severe groups of PD and control group ( p > 0.05). Interestingly, amplitude of median nerve in the second finger was significantly lower in PD patients than control group within normal limits ( p = 0.010). Of all wrists of PD patients, 13 (24.4%) have been diagnosed as CTS and 7 (19.4%) control wrists had CTS. Median nerve cross-sectional area of CTS patients were more than 10 mm 2 in 6 (46%) wrists of PD patients but in only 1 (14%) control wrist at each level. Although it was not statistically significant, there was higher cross-sectional area at each level in patients with severe PD (level 1: 10.43 ± 2.30 mm 2, level 2: 10.35 ± 3.19 mm 2) than patients with mild PD (level 1: 9.93 ± 2.61 mm 2, level 2: 9.51 ± 2.83 mm 2) and control group (level 1: 9.69 ± 3.19 mm 2, level 2: 9.07 ± 3.61 mm 2). Conclusion PD may pose a risk for the development of CTS due to the repetitive movement of tremor. Although sonography is not an ideal method of diagnosis for CTS, it may take our attention for indicating CTS in patients with PD especially in severe ones.

Quantitative MRI of the wrist and nerve conduction studies in patients with idiopathic carpal tunnel syndrome

Objective: To correlate morphological findings of idiopathic carpal tunnel syndrome (CTS) with the function of the median nerve. Methods: In this study, 105 wrists of 105 women patients with idiopathic...

MR imaging and electrophysiological evaluation in carpal tunnel syndrome.

The objective of this study was to compare the MRI findings of wrists in patients diagnosed with CTS with those of the healthy controls, and to evaluate the correlation between the MRI differences and the electrophysiological findings in the patient group. This study involved 55 wrists, 30 of which were clinically and electrophysiologically diagnosed with CTS and 25 healthy controls. These 55 wrists were evaluated electrophysiologically, and in terms of median nerve diameter, ratio of median nerve diameter at psiform bone level to distal radio-ulnar joint level, the flexor retinaculum bulging ratio and the median nerve intensity by MRI. When the patient group, which were clinically and electrophysiologically diagnosed with CTS, and the healthy control group were compared, a significant difference (p < 0.001) was observed between the two in terms of median nerve diameters (at psiform bone level: 8.47 +/- 1.41mm and 2.91 +/- 1.01 mm, distal radio-ulnar joint level: 4.04 +/- 1.06 mm and 2.42 +/- 0.95 mm), ratio of median nerve diameter at psiform bone level to distal radio-ulnar joint level (2.17 +/- 0.54 and 1.25 +/- 0.12), their flexor retinaculum bulging ratios (26.21 +/- 5.98% and 7.27 +/- 4.53%) and their median nerve intensities. In the patient group, no significant correlation between MRI and the electrophysiological findings was found (p > 0.05). According to the data obtained from the study, we believe that the MRI examination of structural changes that occur in the carpal tunnel, neighboring structures and the median nerve would be useful in the diagnosis of CTS, especially in cases with suspected clinical and electrophysiological diagnosis.