Background. Large osseous defects are occasionally present at the site of a primary total knee arthroplasty. Such defects may be treated with the augments and wedges that constitute an integral part of modern knee systems, replacing deficient bone. The use of structural bone grafts is a viable alternative for the treatment of massive bone loss. Material and methods. In 2004 in our department we treated 6 patients with severe gonarthrosis (grade V according to Ahlbäck), with large bone defects involving one-third of the medial tibial condyle. In 4 patients (3 women) we performed unilateral primary arthroplasty, and in 2 patients (1 woman), bilateral. In all 8 cases we implanted a posterior stabilized, cemented, total knee prosthesis. To achieve axial implantation of the prosthesis and stable fixation of the components, we performed osseous reconstruction of the medial tibial condyle using autologous structural bone grafts. Grafts originating from the femoral condyles and lateral tibial condyle were fixed with cancellous screws. Results. In clinical examination we observed an average 70-point postoperative increase in knee function according to the Hospital for Special Surgery system. None of the patients have clinical or radiological signs of implant loosening. Subjective evaluation of the outcome of TKA revealed good and excellent results. Conclusions. Structural autologous bone grafts can be successfully used for reconstruction of large osseous defects in selected cases of severe gonarthrosis.