The purpose of the study is to assess the radiological and clinical outcomes comparing two different treatments (Filtered Autologous Adipose Tissue versus Placebo) in patients affecting bilateral knee osteoarthritis.

After be randomized, every patient will be treated in both legs, one leg with Adipose Tissue and the other one with Placebo.

All patients who meet the inclusion criteria and giving written informed consent will be randomized.

Every patient will be treated with a single injection of Filtered Autologous Adipose Tissue in one knee and single injection of Placebo in the other, based on the randomization.

After the treatment patients will be followed up to 24 months.

Inclusion Criteria:

1. bilateral degenerative chondropathy of the knees showing at least a grade 2-3 kellgren-lawrence classification (absence of severe osteoarthritis)
2. An overall Pain subscale score of the Western Ontario and McMaster Universities Osteoarthritis Index between a value of 9 and 19.
3. Failure, intended as the persistence of symptomatology, after at least one conservative treatment cycle (pharmacological, physiotherapeutic or infiltrative treatment);
4. Ability and informed consent of patients to actively participate in the rehabilitation protocol and clinical and radiological follow-up;

Exclusion Criteria:

1. Patients incapable of understanding and wanting;
2. Diagnosis of leukaemia, known presence of metastatic malignant cells, ongoing or planned chemotherapy;
3. Diagnosis of rheumatoid arthritis, Reiter's syndrome, psoriatic arthritis, gout, ankylosing spondylitis or arthritis resulting from another inflammatory disease; infection with human immunodeficiency virus (HIV), viral hepatitis; chondrocalcinosis;
4. Patients with uncontrolled diabetes mellitus;
5. Patients with uncontrolled thyroid metabolic disorders;
6. Patients who abuse alcoholic beverages, drugs or medicines;
7. Patients with misalignment of the lower limbs above 10 degrees;
8. Body Mass Index > 40;
9. Pregnant or lactating state or intention to become pregnant during the period of participation in the study.
10. Patients with a history of trauma or intra-articular infiltration of therapeutic substances in the 6 months prior to screening.
11. Patients who have had knee surgery in the 12 months prior to screening.
12. Patients with insufficient abdominal adipose tissue, assessed by the investigator