Postoperative diagnostic potentials of median nerve strain and applied pressure measurement after carpal tunnel release

Elastosonography and electrodiagnosis in relation to symptomatic and functional grading of carpal tunnel syndrome

Objectives

This study focused on the symptomatic and the functional evaluation in correlations to median nerve elasticity, its ultrasound parameters, and the electrodiagnostic grading of primary carpal tunnel syndrome (CTS) patients.

Patients and methods

In the case-control study, 100 wrists of 57 CTS patients (54 females, 3 males; mean age: 39±9.8 years; range, 20 to 60 years) clinically diagnosed according to the American Academy of Neurology Clinical Diagnostic Criteria were evaluated between December 2019 and December 2020. The control group included 110 nondiseased wrists of 55 sex- and age-matched healthy subjects (males 7, females 48; mean age: 35.7±10.3 years; range 20 to 58 years). Functional assessment using Hi-Ob-Db clinical scale, electrodiagnosis, ultrasonographic screening, and elasticity evaluation were done for all patients.

Results

CTS patients had an increased stiffness of the median nerve compared to controls. Functional stages were positively correlated with the ultrasonographic parameters and the electrodiagnostic stages of CTS. The elastogram of clinically diagnosed patients was revealed more stiffness of the MN, with negative electrodiagnosis results.

Conclusion

Clinically diagnosed CTS could be missed by the electrodiagnosis but then properly figured by ultrasonography and potentially graded by sonoelastography. Sonoelastography may be an effective method for early diagnosis and appropriate grading of CTS.

Ultrasonographic Measurement of Median Nerve Cross-Sectional Area in Evaluating Carpal Tunnel Release Outcomes

PURPOSE

Earlier research has explored carpal tunnel release (CTR) surgery outcomes using electrodiagnostic tests (EDX). However, evaluation of the median nerve before and after CTR by ultrasound (US) is understudied. This study aimed to establish the outcomes of CTR by EDX and US, and examine the correlation between the clinical improvement and US after CTR.

METHODS

The sample consisted of 172 wrists that underwent CTR. Pain was assessed using the visual analog scale (VAS). The Boston Carpal Tunnel Syndrome Questionnaire (BCTQ), including the symptom severity and function subscales, was applied before and 3 months after CTR. The proximal and distal cross-sectional areas (CSAs) of the median nerve were measured using US, and EDX was performed before and 3 months after CTR.

RESULTS

Patients had mean preoperative and postoperative VAS scores of 7.7 ± 1.2 and 1.7 ± 1.2, respectively. The mean preoperative and postoperative proximal CSA measurements were 16.4 ± 4.5 mm2 and 12.1 ± 3.9 mm2, respectively. The mean preoperative and postoperative distal CSA measurements were 13.6 ± 3.7 mm2 and 11.0 ± 3.1 mm2, respectively. A significant improvement was observed in VAS, BCTQ, and EDX 3 months after CTR. A weak, positive correlation was observed between the improvement in the BCTQ symptom severity and function subscales and CSAs following CTR.

CONCLUSIONS

The results of this study demonstrate that preoperative median nerve CSA values may be used in evaluating CTR outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Ultrasound Elastography for Hand Soft Tissue Assessment

Over the past decade, ultrasound elastography has emerged as a new technique for measuring soft tissue properties. Real-time, noninvasive, and quantitative evaluations of tissue stiffness have improved and aid in the assessment of normal and pathological conditions. Specifically, its use has substantially increased in the evaluation of muscle, tendon, and ligament properties. In this review, the authors describe the principles of elastography and present different techniques including strain elastography and shear-wave elastography; discuss their applications for assessing soft tissues in the hand before, during, and postsurgeries; present the strengths and limitations of their measurement capabilities; and describe directions for future research.

Application of shear wave elastography and median nerve cross-section area in the diagnosis and staging of carpal tunnel syndrome: a case-control study

Purpose

Imaging is gaining a more prominent role in the diagnosis of carpal tunnel syndrome (CTS), especially ultrasonography. Shear wave elastography (SWE) is a novel qualitative method to study mechanical changes in tissue. In this study, we aim to assess the role of SWE in diagnosing and staining of the disease.

Material and methods

A total of 124 wrists were included in the study. Seventy wrists had CTS, and 54 were included as the control group. All of the wrists with CTS had staging done with nerve conduction study. All patients underwent ultrasonography by an expert radiologist and had the SWE and cross-section of the median nerve determined. These values were compared among the 2 groups and different stages of CTS. The receiver operating characteristic curve was utilized to assess the diagnostic role of each of the variables.

Results

Cross-section area (CSA) and SWE were significantly different between the 2 groups (p = 0.0001). CSA was also significantly different among various stages of CTS. SWE was not significantly different among moderate and severe stages of CTS. Both of the variables had a good ability to distinguish mild CTS from healthy wrists (p = 0.0001).

Conclusion

SWE can be used in diagnosing CTS and in the staging of the disease.

Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome

With the widespread use of high-resolution ultrasonography, ultrasonic examination has been shown to be useful as a diagnostic method for carpal tunnel syndrome. The main advantages of ultrasonography are that it is simple, quick, non-invasive, and economical. Another advantage is that tissue dynamics can be observed with real-time imaging. In recent reports, it has been shown that ultrasonic examination can provide similar diagnostic accuracy as nerve conduction study in the diagnosis of carpal tunnel syndrome. It has been expected that ultrasound demand in daily medical care will continue to increase. Ultrasonography in carpal tunnel syndrome shows an enlarged median nerve in proximal carpal tunnel, thickening of the flexor retinaculum, and edema around flexor tendons in cross-sectional images. In addition, with the introduction of new technologies such as ultrasonic elastography and speckle tracking, it has become possible to quantify dynamics and material property changes of nerves, tendons, and their surrounding structures. In this review, we describe recent advancements of carpal tunnel syndrome diagnosis based on ultrasound dynamic images, and discuss its pathology.

Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome

With the widespread use of high-resolution ultrasonography, ultrasonic examination has been shown to be useful as a diagnostic method for carpal tunnel syndrome. The main advantages of ultrasonography are that it is simple, quick, non-invasive, and economical. Another advantage is that tissue dynamics can be observed with real-time imaging. In recent reports, it has been shown that ultrasonic examination can provide similar diagnostic accuracy as nerve conduction study in the diagnosis of carpal tunnel syndrome. It has been expected that ultrasound demand in daily medical care will continue to increase. Ultrasonography in carpal tunnel syndrome shows an enlarged median nerve in proximal carpal tunnel, thickening of the flexor retinaculum, and edema around flexor tendons in cross-sectional images. In addition, with the introduction of new technologies such as ultrasonic elastography and speckle tracking, it has become possible to quantify dynamics and material property changes of nerves, tendons, and their surrounding structures. In this review, we describe recent advancements of carpal tunnel syndrome diagnosis based on ultrasound dynamic images, and discuss its pathology.

Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome

With the widespread use of high-resolution ultrasonography, ultrasonic examination has been shown to be useful as a diagnostic method for carpal tunnel syndrome. The main advantages of ultrasonography are that it is simple, quick, non-invasive, and economical. Another advantage is that tissue dynamics can be observed with real-time imaging. In recent reports, it has been shown that ultrasonic examination can provide similar diagnostic accuracy as nerve conduction study in the diagnosis of carpal tunnel syndrome. It has been expected that ultrasound demand in daily medical care will continue to increase. Ultrasonography in carpal tunnel syndrome shows an enlarged median nerve in proximal carpal tunnel, thickening of the flexor retinaculum, and edema around flexor tendons in cross-sectional images. In addition, with the introduction of new technologies such as ultrasonic elastography and speckle tracking, it has become possible to quantify dynamics and material property changes of nerves, tendons, and their surrounding structures. In this review, we describe recent advancements of carpal tunnel syndrome diagnosis based on ultrasound dynamic images, and discuss its pathology.

Radiographic characteristics of wrists in idiopathic carpal tunnel syndrome patients

Background

To determine the radiographic characteristics of wrists in idiopathic carpal tunnel syndrome patients, we compared the radiographic parameters of the wrists between carpal tunnel syndrome patients and non-symptomatic controls.

Methods

We evaluated radiographic parameters of 94 wrists of 62 idiopathic carpal tunnel syndrome patients and 94 asymptomatic wrists of 94 controls. Carpal tunnel syndrome was diagnosed by clinical findings and nerve conduction studies. The lack of symptoms was confirmed with the medical records and interviews for the controls. X-ray images of the postero-anterior and lateral views of the wrist were taken. Using the obtained X-ray images, the indices of radial inclination, volar tilt, ulnar variance, and transverse and antero-posterior diameters of the wrists were measured. Two raters independently performed the measurement. One rater measured without information of clinical symptoms. Inter-rater reliabilities for each parameter were evaluated by the intra-class correlation coefficients. The averages of the measurements of two raters were compared between the carpal tunnel syndrome patients and the controls.

Results

The intra-class correlation coefficients were 0.58 for radial inclination, 0.77 for ulnar variance, 0.99 for transverse diameter, 0.60 for volar tilt, and 0.91 for antero-posterior diameter. Statistically significant correlations were found for all parameters (P < 0.01). The ulnar variance was significantly larger in the carpal tunnel syndrome patients compared to the controls (1.7 +/− 1.8 mm and 0.8 +/− 1.5 mm for the patients and controls, respectively P < 0.01). There were no significant differences in the other parameters.

Conclusions

Significant differences in the ulnar variance were observed between carpal tunnel syndrome patients and controls. This suggests that the imbalance of radioulnar bone length is one of the risk factors to develop carpal tunnel syndrome. The positive ulnar variance may be an index that needs attention to the development of carpal tunnel syndrome.

Level of evidence

level III, a case control study.