Background. To investigate the new theory of hydroneurolysis and hydrodissection in the treatment of carpal tunnel syndrome (CTS). Independently of the fluid hydrodissolution works due to mechanical forces and it may have some positive effects in patients with ischemic damage caused by scar tissue pressure at the nerve's surface. Methods. A prospective blind clinical study of 31 patients suffering from carpal tunnel syndrome, established by nerve conduction studies and clinical tests. 14 patients (out of 29), who refused to undergo an open operation as a treatment to their disease at this point of time, were treated with a simple ultrasound-guided injection at the proximal carpal tunnel. In order to exclude the biochemical influence of the fluid in the treating disease we choosed to infiltrate 3 cc. of normal saline 0,9%. In the follow-up period our group was asked to answer to a new Q-DASH score and visual analogue scale (VAS) 100/100 in 2, 4 and 8 weeks. Results. At the end of the second month we found only 2 out of 14 patients of the infiltration's group with clinical improvement. As far as the control group (17 patients), there was just one patient with recovery of the symptoms at the end of the second month who avoided operation. The rest 16 patients experienced insistence or worsening of CTS while they were waiting to be operated (mean time till operation in our department's waiting list: 2 months) and underwent a surgical decompression of the median nerve. Comparing the two groups in Q-DASH score, VAS 100/100 and ultrasound cross sectional area measurements we found no statistical difference between the two groups at the endpoint of our follow-up period. Conclusion. As far as
