a randomized, controlled, double-blind study and we will be evaluated and compared the clinical and radiological results of concentrated autologous bone marrow against the hyaluronic acid in patients with bilateral knee osteoarthrosis . In randomization, one knee will be treated with autologous bone marrow concentrate and other knee with hyaluronic acid, then every patient is considered both in control and treatment group, limiting the heterogenity between groups and will not be informed of the knee assigned to the treatment group.