We evaluated the survival of moulded monoblock and modular tibial components of the AGC total knee replacement in patients with rheumatoid arthritis. Between 1985 and 1995, 751 knees with this diagnosis were replaced at our institution. A total of 256 tibial components were of the moulded design and 495 of the modular design. The mean follow-up of the moulded subgroup was 9.6 years (0.5 to 14.7), and that of the modular group 7.0 years (0.1 to 14.7).

The groups differed significantly from each other in Larsen grade, cementing of components and patellar resurfacing, but no statistically significant difference between the survival of the components was found (Log rank test, p = 0.91). The cumulative success rate of the moulded group was 96.8% (95% confidence interval 93.6% to 98.4%) at five years and 94.4% (95% confidence interval 90.4% to 96.7%) at ten years, and of the modular group 96.2% (95% confidence interval 94% to 97.6%) and 93.6% (95% confidence interval 89.7% to 96%), respectively. Revision was required in 37 total knee replacements, the main causes were infection, pain, loosening of the tibial component and patellar problems. Survival rates for both components were satisfactory.

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.

Aims: The purpose of the study was to analyse the results of 4 primary and 21 revision total knee replacements performed on 24 patients with rheumatic disease using the Dual Articular Knee prosthesis with a mean follow-up of 2.3 (1–8) years. Methods: Patient documents and pre- and postoperative radiographs were evaluated with respect to radiolucent lines, fractures, lateral patellar displacement, proper resection lines, implant þt and behaviour of bone grafts as well as implant migration or subsidence during the follow-up. One to 8 years after the surgery, an interview of 22 patients was arranged to settle the subjective contentment, functional ability and the longevity of replaced knees. Results: Indication of primary TKR was þxed valgus in one knee and severe instability in 3, and in revision TKR aseptic loosening and instability in 15 knees, instability without implant loosening in 2 and infection in 4 knees. A 2-stage procedure was performed for infected arthroplasties with a mean period of cement interposition of 3 months. All the 2-stage exchange procedures healed without complications. Four patellar tendon avulsions and one deep infection were encountered. Results were excellent in 82% of patients. Conclusion: Dual Articular Knee proved to be favourable both in demanding primary and revision arhroplasties in patients with rheumatic disease.