BACKGROUND: With the ineffectiveness of conservative therapy for the knee joints osteoarthritis (OA), arthroscopic debridement (AD) of the affected joints is a common method of surgical treatment. However, the results of studies indicate a low efficiency of the use of AD in gonarthrosis. In order to improve the results of the use of AD in the knee joints OA, it was proposed to use an original implant to communicate the bone marrow cavity and the cavity of the knee joint. In the immediate postoperative period, such arthromedullary bypass surgery revealed a rapid improvement in the condition of the affected joints, a decrease in the severity of symptoms, and a decrease in the need for pain relievers.
 AIM: To compare the results of arthroscopic surgery in patients with knee osteoarthritis without and with the use of arthromedullary bypass (AMB) of joint at 2 years after the intervention.
 MATERIALS AND METHODS: The results of a comparative study involving 147 patients aged 42 to 80 years with knee osteoarthritis were presented. In the control group (67 patients), only arthroscopic debridement was performed; in the study group (80 patients, 90 operations) AMB was additionally performed (10 patients on both knee joints) for the entry of an intraosseous content into the joint cavity. The results were evaluated 3, 6, 12, and 24 months after surgery, using the Lequesne algofunctional index and the WOMAC index and the need for the nonsteroidal antiinflammatory drugs (NSAID) was assessed.
 RESULTS: The positive dynamics of both indicators in both groups during the first 3 months of follow-up was maintained for 24 months, and their more significant changes, as well as a decrease in stiffness and the frequency of nocturnal joint pain, occurred in the study group (p 0.01). 24 months after surgery, 87% of patients in the study group refused to take regular NSAID, and 54% in the control group (p 0.01). During the AMB, the percentage of operations with unsatisfactory and moderate results decreased by 2.53.5 times, and the percentage of cases with good and excellent results was 28% higher compared to the control group (p 0.01).
 СONCLUSIONS: The proposed AMB of joints had a long-term beneficial effect and is promising for the treatment of patients with knee osteoarthritis who do not respond to conservative treatment. Its use can improve joint function, reduce joint pain and dependence on analgesics, and thus ease the severity of the disease in more patients.