Stromal vascular fraction of cells (SVF) will be extracted from lipoaspirate by enzymatic digestion. SVF will be administered in a single dose intraarticularly 4 weeks after arthroscopic debridement. All patients will receive cell therapy.This is a single arm study with no control.

Patients undergone arthroscopic debridement for knee osteoarthritis will be subjected to abdominal liposuction under local anaesthesia. Harvested adipose tissue will be processed according to patent pending technology based on enzymatic digestion, washing and concentration of cell pellet in 5 ml of Hartmann's solution. Isolated SVF will be administered in a single dose into anterior part of knee joint cavity 28 days after arthroscopy.

Inclusion Criteria:

• Pain in the knee joint during more than a half day assessed by Visual Analog Pain Scale (score more than 40 mm)
• At least three of the following 6 criteria: 50 years of age or older, stiffness lasting less than 30 minutes, crepitus, bony tenderness, bony enlargement, no warmth to the touch
• Patient is able to walk without assistance
• Patient is familiar with Participant information sheet
• Patient signed informed consent form

Non-inclusion Criteria:

• Medical history of endoprosthetic knee replacement
• Medical history of lower extremity osteotomy
• Medical history of knee surgery (including arthroscopy) during preceding 1 year prior to enrollment
• Medical history of intraarticular injections during preceding 6 months prior to enrollment
• Secondary osteoarthritis of the knee joint: posttraumatic osteoarthritis (developed after clinically significant injury), intra-articular fractures, clinically significant varus or valgus deformities of lower limbs, septic arthritis, joint's inflammatory disorders, gout, advanced chondrocalcinosis, Paget's disease, ochronosis, acromegaly, hemochromatosis, Wilson's disease, primary synovial osteochondromatosis, osteonecrosis, hemophilia
• Patients prescribed for immunosuppressive treatment
• Medical history of systemic autoimmune and inflammatory diseases
• Significant weight loss (> 10% of body weight in the previous year) of unknown etiology
• Medical history of venous thromboembolism or estimated high risk of venous thromboembolism
• Patients prescribed for systemic corticosteroids or other medications treatment with proven impact on bone or cartilage tissue metabolism
• Clinically significant abnormalities in results of laboratory tests
• Any conditions limiting compliance (dementia, neuropsychiatric disease, drug and alcohol abuse etc.)
• Participation in other clinical trials (or administration of investigational drugs) during 3 months prior inclusion
• Patients with malignant tumors including postoperative period, patients receiving chemotherapy and/or radiotherapy.
• Patient's activated partial thromboplastin time exceeds normal levels more than 1,8 times
• Patients prescribed for anticoagulants treatment or patient received anticoagulants at least one hour prior liposuction
• Medical history of heterotopic ossifications
• Patients prescribed for glycoprotein inhibitors treatment

Exclusion Criteria:

• Patient's refusal from the further participation in trial
• Patient's refusal from compliance with the requirements of contraception during the participation in research
• Chronic kidney disease IV- V stages (creatinine clearance < 30 mL/min estimated by Cockcroft-Gault formula)
• Confirmed syphilis, HIV, hepatitis B or C infections

Dropout Criteria:

• Pregnancy