Aims: To study the survivorship of molded versus modular tibial component of the unconstrained anatomic graduated component (AGC; Biomet) prosthesis design.

Methods: We studied 794 knees of patients with rheumatoid arthritis operated 1985 – 1995 at the Rheumatism Foundation Hospital (=RFH), Heinola, Finland. Larsen score (=LS) of the preoperative radiographs was examined. Data was gathered from patient files and EULAR-database at RFH. A Kaplan-Meier survivorship analysis was performed with an endpoint of revision.

Results: We found no significant differences between survival of the molded (=group A)and the modular tibia (=group B) components. After 11 years cumulative success rate was 95% in A and 94,8% in the B group. The median follow-up was 7,95 years (group A 11,3, group B 7,4 years). 38 knees ended to an revision, and infection and pain were the main causes. Groups did not differ by LS or by demographic factors like age or weight. Fixation of the tibia or of the femur was also of no significance.

Conclusions: In our material there was no difference in the survival of two different designs of tibia component used in TKAs for patients with rheumatoid arthritis. Survival rates in both groups after 11 years follow-up can be considered promising.