IRCT20181011041308N4 IRCT 2021-12-11 Iran University of Medical Sciences To asses the effects of adding Dexmedetomidine to Ropivacaine in interscallen block. To Asses the Effects of Adding Dexmedetomidine to Ropivacaine in Interscalen Block with Ultrasound Guide prior to Arthroscopically Repairing the Ruptured Shoulder Tendon Surgery in need of Amount of Anesthetic Drugs during Surgery and Post Operation Analgesia. 2022-01-21 anticipated 42 Complete https://irct.ir/trial/60187 interventional Randomization: Not randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Blinding description: In this study, participants were blinded by a clinical observer, caregiver, and outcome assessor. 2 Rupture of shoulder rotator cuff. Intervention 1: Intervention group: The first group receives 20 cc of Rupivacaine 0.25% plus 2 cc of normal saline under the interscallen block of the brachial plexus with ultrasound guide. . Intervention 2: Intervention group: The second group receives 20 cc of Rupivacaine 0.25% plus 1.5 µ / kg dexmethomidine under interscallen block of the brachial plexus with ultrasound guide. Yes - There is a plan to make this available What will be shared: Only part of the data containing information about the main outcome can be shared. When: Access period starts 3 months after the results are published. To whom: The data will be available only to researchers working in academic and scientific institutions. Conditions: It is necessary to send a request for access to data or documents. Where to obtain: Refer to Dr. Mahmoud Reza Alebouyeh. Phone: 00989121253698 How to obtain: After submitting the request, if approved by the committee and during the legal process, the documents will be sent. Comments: