The use of methylmethacrylate in primary total knee replacements with large tibial defects.

Bone defects in the tibial plateau present technical problems in primary knee replacement surgery. A variety of techniques is available to solve these problems. Of 59 patients treated with a cement fill and followed an average of 7.1 years (range, five to 11 years), there was only one failure requiring revision. Overall, knee scores averaged 78 points and roentgenogram scores averaged 85 points. Radiolucent lines were noted in 43 of the 59 patients, but none were progressive except in the one failure. There was no clinical correlation between the presence of radiolucent lines and clinical symptoms. Good long-term results might be expected from the cement fill when the bone defects are smaller than 20 mm and affect less than 50% of either plateau.