Usefulness of Ultrasound in the Diagnosis of Carpal Tunnel Syndrome in Orthopedic Patients

Abstract

With the objective of analyzing the usefulness of median nerve ultrasound in patients with clinical suspicion of Carpal Tunnel Syndrome, in relation to electromyography in the “Antonio Lenín Fonseca Martínez” Teaching Hospital, from September to December 2016. An observational, descriptive, correlational, retrospective and analytical study of mixed approach was conducted. Data on the sociodemographic and clinical characteristics, degree of severity, ultrasound measurements of the median nerve area, thickness and distance of the retinaculum, flattening (major axis/short axis ratio), and median nerve echographic changes in patients with Clinical diagnosis of Carpal Tunnel Syndrome, as well as the correlation between the ultrasound findings and the results of electromyography were collected. The predominant gender was the female, mostly housewife. The average age was 54 years, with severe manual labor activity in most cases. The mean area of the median nerve was 11.4mm². Median nerve flattening was 3.3 on average. The decrease in echogenicity was found in 66%. Ultrasound turned out to be a simple study, easy to perform and very useful, with some measurements with very good concordance in contrast to electromyography. This was verified since there is very good agreement (71.4%, k = 0.74, p= 0.000); between electromyography and measurement of the median nerve area, as well as between the EMG and the measurement of the distance of the flexor retinaculum (71.4%, k = 0.741, p = 0.000). Likewise, a very good agreement was found when comparing the decrease in echogenicity (57.1%, Phi = 0.447, p= 0.04)

Key words: ultrasound, median nerve, carpal tunnel syndrome