Diagnostic value of ultrasonography in carpal tunnel syndrome

Abstract EN

Objective : to evaluate the diagnostic value of ultrasonography in patients with clinically and electro-physiologically confirmed carpal tunnel syndrome (CTS).

Methodology : Seventy three wrists of 48 patients with clinically and electrophysiological confirmed CTS and 60 wrists of 40 asymptomatic controls were included in the study.

All of them underwent high resolution ultrasonography of the wrists.

Cross sectional area and flattening ratio at the proximal carpal tunnel were measured in both groups.

Results : there was a high degree of correlation between median nerve conduction abnormalities and the measurement of cross sectional area as measured by ultrasound (p < 0.001).

The ultrasonography measurements of median nerves were found to be increased significantly in patients with carpal tunnel syndrome when compared with controls, particularly in terms of cross sectional area (mean, 10.6 mm2 versus 6.1 mm2 p < 0.001) and the flattening ratio (p < 0.001).

A cut off value of cross sectional area larger than 9 mm2 at the level of proximal carpal tunnel provided a diagnostic sensitivity of 75.3 % and specificity of 95 % and in 20.5 % of wrists, morphological changes suggested secondary causes.

Conclusion : Additional diagnostic confirmation can be provided by ultrasonography, which is a sensitive, specific and useful non-invasive method for diagnosis of CTS and evaluation of the morphologic changes of the median nerve in CTS patients.