I read with great interest the study of different diagnostic ultrasound measures of median nerve volume in patients with carpal tunnel syndrome (CTS) by Dejaco et al.1 It is of great value, in my opinion, that this study succeeded in highlighting the diagnostic value and good reliability of ultrasound determination of median nerve cross-sectional area (CSA) in patients with suspected CTS, and confirmed previously reported results on the value of Doppler ultrasonography in classifying the severity of CTS.2–4

I would like though to draw attention to a subgroup of patients with persistent clinical and electrophysiological signs of CTS and condition after unsuccessful carpal tunnel release (CTR). The aetiology of the persistent neurological semiology is in most of the cases an incomplete release of the retinaculum flexorum. Traction neuropathy, …