IRCT20120215009014N491 IRCT 2023-12-02 Iran University of Medical Sciences Effect of memantine versus placebo on pain in patients undergoing knee joint surgery Effect of memantine versus placebo on pain in patients undergoing knee joint surgery: a double-blind randomized clinical trial 2023-12-06 anticipated 42 Complete https://irct.ir/trial/73806 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: Random allocation of patients to intervention and control groups by lottery. For this purpose, we prepare two sheets, write "intervention" on one and "control" on the other. Then, with each patient's visit, one of the sheets is randomly taken and the patient is assigned to the intervention or control group, Blinding description: Both the medications and placebos will have the same shape. Consequently, patients will remain unaware of the type of intervention they receive. Moreover, the randomization process will be conducted by a separate individual from the one who examines the patients, ensuring that the examining person remains unaware of the intervention. Therefore, the trial will be conducted as a double-blind study. 3 knee joint disorders. Intervention 1: Intervention group: Routine treatment plus memantine tablets 20 mg daily three days before surgery and then 10 mg daily after surgery for 2 weeks. Intervention 2: Control group: Routine treatment plus a placebo pill daily three days before surgery and then a placebo pill daily after surgery for 2 weeks. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is It depends on the situations and the results of the study as well as the approval of the financial supporting organization.