Abstract
Nineteen knees with the tibial condyle defect were treated with a cementless total knee arthroplasty using a sapphire nail for the fixation of grafted bones. The follow-up time was 1 to 4 years, with an average of 36 months. The prostheses used were the ceramic KC-1 type and the Okayama University Mark II type.
At the follow-up, 6 of the 19 knees showed collapse of the grafted bones. In 3 of the 6, bony sclerosis, radiolucent line or bony absorption was seen radiologically at the interface between the sapphire nail and bone. Five of the 6 were suffering from rheumatoid arthritis. In 2 of them, bone slices from the femoral condyle were used. Sapphire nail breakage was seen in 2 knees; one was with collapsed grafted bone and the other was not. However, with or without collapse of the graft bone assessment, there were satisfactory results clinically. Advantages can be expected from using sapphire nails because of their non-degradable and biocompatible nature. Nevertheless, in osteoporotic knees, there is little advantage to using them and these nail are not sufficient for securing grafted bone. The choice of the graft bone can also be one of the main problems in the cementless total knee arthroplasty for treating osteoporotic knees with tibial bony defect.
