Table 1 Inclusion and exclusion criteria

1. Chronic knee joint pain and or swelling (more than 6 months)

2. Grade II–III KOA confirmed by two observers

3. Absence of local or systemic infection

4. Absence of significant hematological disease

5. Absence of significant biochemical or hematological laboratory tests abnormalities

6. Informed consent form signed by the patient

1. Age less than 18 or older than 65 years

2. Intra-articular treatment in the past 6 months

3. Significant deformity of the knee

4. Knee ligament injury or ruptured meniscus observed by MRI

5. Infection or positive serology for transmissible agents

6. Body mass index (BMI) greater than 30.5

7. Women in childbearing age

8. Malignancy

9. Immunosuppressive drugs