Particularities of the bone tissue regenerative properties of the proximal part of the tibia in patients with rheumatoid arthritis with multi-plane knee deformities

Background. Rheumatoid arthritis (RA) has no equal among the musculoskeletal system diseases in terms of the severity of joint damage. Knee joint damage was noted in 65–70 % of RA patients and it is the most common cause of disability. The purpose was to study the indices of osteogenic activity of stromal (mesenchymal) stem cells (MSCs) of the articular bone ends of the knee joint in patients with secondary knee osteoarthritis (KOA) due to RA in the presence of multi-plane deformations. Materials and methods. The studied material was samples of cancellous bone of the anterior and posterior parts of the plateau of the proximal part of the tibia and spongiosa from a depth of 1 cm and 3 cm from the articular surface, namely from the proximal epimetaphysis of the tibia, removed during knee arthroplasty of patients with secon­dary KOA due to RA and in patients with primary KOA in the presence of multi-plane deformations. Using the method of cloning colony-forming units of fibroblasts (CSF) of bone tissues, 38 patients were examined, including 9 patients with RA and 29 patients with primary KOA with damage to the knee joint in the presence of multi-plane deformations. Results. The total number of nucleated cells in 1 cm3 of spongiosa of the front part of the tibial plateau was 2.3 times lower compared to the parameter of this index in the posterior part (p < 0.05). The characteristics of spongy tissue in terms of the number of nucleated cells and the content of CSF in 1 cm3 from a depth of 3 cm from the articular surface of the proximal epimetaphysis of the tibia of patients with RA were almost 3 times higher compared to the indices of patients with primary KOA (p