IRCT20160430027677N7 IRCT 2018-01-05 Oroumia University of Medical Sciences Clinical trial the effect of local Dexmedetomidine injection on post operative pain in patient with total knee arthroplasty surgery Evaluation the effect of local Dexmedetomidine injection on post operative pain in total knee arthroplasty surgery 2017-05-22 anticipated 12 Complete https://irct.ir/trial/22625 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Prevention, Randomization description: Patients will be divided into two groups by random number table, Blinding description: The syringes used are 5 ml and the surgeon will not know its content. Syringes containing drug and placebo in the two groups A and B will be prepared and labeled by someone else. After placing in the box randomly, a syringe with each sticker will be removed from the box and injected into the patient which was without the knowledge of the researcher and the patient and after completing the entire questionnaire, the researcher will be informed. 2-3 Post operative pain. Intervention 1: Intervention group: The study group will be received dexmedetomidine 1 micg/kg of body weight for dexamethasone. Intervention 2: Control group: will be received 25 milliliter isotonic saline. No - There is not a plan to make this available Justification or reason for not sharing IPD is At the beginning of the plan, no data dissemination was approved.