Inclusion Criteria:  Men and women aged 18 years and older who need elective primary total knee replacement (cement or cementless arthroplasty) Signed informed consent Ability to comply with all protocol requirements Patients' consent to use adequate methods of contraception throughout the study  Exclusion Criteria:  Surgery for an acute fracture 4 weeks before screening; septic inflammation of the joint, revision of the prosthesis or the absence of one leg Venous thrombosis of any localization or a confirmed PE episode at the present time or in the medical history Heparin-induced thrombocytopenia or other thrombocytopathies currently or in the history, hemorrhagic diathesis Obvious coagulopathy ongoing or in the history of the patient or a blood relative Congenital thrombophilia according to the medical history (deficiency of antithrombin III, protein C, protein S, Leiden mutation of coagulation factor V, increased level of coagulation factor VIII, mutation of prothrombin G20210A) Active bleeding (intracranial, intraocular, nasal, digestive or other localization) at present or within 6 months prior to screening, high risk of bleeding Collection of at least one volume unit of donated blood (> 500 mL) or blood transfusion during the previous 12 weeks Surgery on the brain or spinal cord, spine, ophthalmic or major surgery or injury in the last 90 days Gastrointestinal tract disorders that can disrupt the absorption of the study drug (Crohn's disease, ulcerative colitis, irritable bowel syndrome) Acute gastric or duodenal ulcer, erosive gastritis with increased risk of bleeding Significant cardiovascular diseases ongoing or within 6 months prior to screening, including: chronic heart failure of class III or IV (according to the classification of the New York Heart Association), myocardial infarction, unstable angina, surgery on the heart and coronary vessels (including percutaneous coronary intervention with or without coronary artery stenting), significant diseases of the heart valves, hemodynamically significant cardiac arrhythmias, transient ischemic attack, ischemic or hemorrhagic stroke, uncontrolled hypertension Active liver disease (viral hepatitis B or C, cirrhosis of the liver) and biliary tract disease, with the exception of non-alcoholic steatohepatitis with normal levels of hepatic transaminases (ALT and AST) Nephrotic syndrome, significant kidney diseases with the events of nephrotic syndrome (decreased filtration renal function with decreased estimated glomerular filtration rate (eGFR) < 60 according to the MDRD formula (MDRD) Malignant neoplasms during the last 5 years (with the exception of basal cell carcinoma for which radical treatment was carried out). Positive test for HIV, syphilis, hepatitis B or C markers (HBsAg and Anti-HCV) Significant drug or alcohol abuse according to the Investigator in the history or currently The development of trophic disorders of the lower extremities that do not respond to medical treatment Any condition, in which, according to the Investigator, surgical intervention or anticoagulants are contraindicated Body mass index (BMI) less than 18.5 or more than 40 kg/m2. Body weight above 130 kg Systolic BP > 180 mmHg and/or diastolic BP >110 mmHg, reported with two consecutive measurements for 15-30 minutes Hemoglobin < 105 g/L in women or < 115 g/L in men Abnormal laboratory parameters of the coagulation system (platelets, activated partial thromboplastin time (APTT), international normalized ratio (INR) and D-dimer), which, according to the Investigator and Medical Expert of the study, cause suspicion of blood clotting or problems in the hemostasis system in the patient eGFR < 60 mL/min/1.73 m2 (by MDRD formula) ALT or AST > 2 x upper limit of normal (ULN) or total bilirubin > 1.5 x ULN Hypersensitivity or contraindications to Dimolegin - DD217, dalteparin sodium, unfractionated heparin or warfarin; pig tissue preparations, radiopaque preparations (for multislice spiral computed tomography (MSCT) with intravenous enhancing) The need for constant use of parenteral or oral anticoagulants (for example, patients with artificial heart valves, patients with atrial fibrillation who are indicated for warfarin therapy) Systemic therapy with azole group drugs (ketoconazole, fluconazole, etc.), as well as other CYP3A4 inhibitors 7 days before and during screening. Previous and concomitant therapy: taking antiplatelet drugs, therapy with vitamin K antagonists, therapy with unfractionated heparin, low molecular weight heparin (LMWH), direct oral anticoagulants, the use of NSAIDs should be stopped at least 7 days before the start of the study therapy, systemic therapy with strong CYP3A4 and P-glycoprotein inhibitors, systemic therapy with strong inducers of CYP3A4 and P-glycoprotein Women who are pregnant or breastfeeding Women planning pregnancy during a clinical trial (including women who received a positive pregnancy test result during screening or before taking the study drug) Women of childbearing potential (including non-sterilized surgically and in the postmenopausal period less than 2 years) who do not want or cannot use adequate methods of contraception throughout the study. Adequate methods of contraception include the use of a condom or diaphragm (barrier method) with spermicide Participation in another clinical trial currently or within 30 days prior to screening, use of any investigational drug for 30 days or 5 half-lives (which is longer) prior to screening Affiliation to the investigational site: close relatives of the Investigator, dependent persons (for example, an employee or a person studying at the investigational site) Inability to read or write; unwillingness to understand and follow the study protocol procedures; non-compliance with the regimen of treatment or procedures which, according to Investigator, may affect the study results or patient's safety and prevent the patient from further participating in the study; any other concomitant medical or serious mental conditions, which make the patient ineligible for the clinical study, restrict validity of the consent or may affect the patient's ability to participate in the study