Osteoarthritis of the knee is one of the most common causes of disability among elderly. Arthritis rheumatoid is an autoimmune disease which causes multi articular arthritis, such as knee osteoarthritis. As the disease progresses the cartilage become frustrated, surrounding bone react to become thicker and inflammation occurs in subchondral bone seen in T2-weighted MRI as increase in signal density. Patients are treated initially by pain management. In patients who don't response to first line treatment invasive treatment like total knee replacement is done. The investigators designed this clinical study with the aim of evaluating therapeutic effects of intra-articular injection of bone marrow mesenchymal stem cells (BM-MSCs) in 60 patients with knee osteoarthritis.

In this study all eligible patients were randomly allocated into two study groups by a permuted block randomization method: group A (control group) received only routine medical therapies and placebo injected into there knees.. Group B received mesenchymal stem cells in addition of routine medical therapy.

Patients were categorized according to the following stimulation protocols:

To assess the outcomes, after mesenchymal stem cells transplantation at months 1,3,6 and 12 we will examine the patients by: WOMAC questioners, DAS28 scoring , radiographies assessments and biochemical analysis with laboratory tests.

Inclusion Criteria:

1. Age 18 to 65 years
2. Body mass index (BMI) ≤30 kg/m2
3. The presence of osteoarthritis based on MRI and American Rheumatism Association criteria since 6 months before invitation

Exclusion Criteria:

1. Response to routine treatment at last one year.