Clinical, Biochemical and Neurophysiological Consequences of Intraoperative Tourniquet During Total Knee Arthroplasty

Inclusion Criteria: * Age = 55-85 years * Osteoarthritis of knee joint (degree III or IV) * Physical status (ASA I or II) * Body mass index \< 45 kg/m² * Written informed consent Exclusion Criteria: * Age \<55 or \> 85years * Osteoarthritis knee joint (degree I or II) * Physical status (ASA III or IV) * Body mass index ≥ 45 kg/m² * Unable to provide written consent * Malignant disease * Rheumatoid disease * Infectious disease * Coagulation disorder * History of deep vein thrombosis or pulmonary embolism * Peripheral arterial disease * Immune deficiency * Medication (Glucocorticoid, Aspirin, Heparin, Cumardine, Wafarin) * Neurological dysfunction * Liver insufficiency * Coronary heart disease * Immobility