This is a compressive neuropathy n. ulnaris, which occurs in the area of the Guyon’s canal, at the point of entry of the nerve from the forearm into the wrist. The symptoms are similar to those that occur with carpal tunnel syndrome, with the feeling of tingling occurring in the 4th and 5th finger. Like carpal tunnel syndrome surgery, this one is most often performed under regional anesthesia and involves the release of n. ulnaris from the cause of the pressure. The sutures are removed 12 to 14 days after the operation.