Cemented ceramic YMCK total knee arthroplasty in patients with severe rheumatoid arthritis

Total knee arthroplasty (cemented) using a ceramic Yokohama Medical Ceramic Knee (YMCK) (Kyocera Corp; Kyoto, Japan) prosthesis was evaluated in 90 knees of 64 patients with severe rheumatoid arthritis, with a mean age of 59 +/- 11 years. The mean follow-up period was 56 +/- 20 months (range, 27 to 97 months). Larsen's grading of rheumatoid arthritis revealed grade 2 in 3, grade 3 in 36, grade 4 in 36, and grade 5 in 15 of 90 knees. Of 64 patients, 9 were judged to have class 1, 30 were judged to have class 2, and 25 were judged to have class 3 functional disability. The American Knee Society knee score and function score improved from 41 +/- 16 and 29 +/- 22 preoperatively to 83 +/- 14 and 50 +/- 29 at the final follow-up (P<.0001) even in patients with multiple joint involvement. Radiographs at the final follow-up showed satisfactory insertion of all prostheses, with no osteolysis. A radiolucent line measuring <1 mm was observed around the tip of the pegs of the patellar dome in 3 knees. Complications consisted of infection (I case) and femoral fractures (3 cases). There were no cases of ceramic fractures.