Abstract
Introduction: Unicompartmental kneearthroplasty became applicated in the past decade also in younger more active patients. Therefore the durability of the bone anchorage and polyethylene wear are at increased risk for failure. Provides the cementless implantation of the AMC-Uniglide prosthesis a reliable fixation? Are the clinical and functional results comparable to the cemented version of this prosthesis?
Methods: The AMC-Uniglide ensures congruent area contact with physiological kinematics resulting from imitation of the healthy morphology of the femoral condyle and unrestricted movement of the polyethylene bearing. This also secures a low intrinsic stability, which relieves the implant-bone fixation. There is a cemented and cementless version of this prosthesis. From 1991 to 12/2003 we performed 477 implantations with cement and 137 cementless. The follow up is (3–14) mean 8 years and seized 96% of the cases. They were assessed according to the Knee Society Rating System and analyzed radiologically (F. C. Ewald).
Results: Knee Score cemented 35/94, cementless 36/94 (pre/post). Function Score cemented 52/90, cementless 54/92 (pre/post). Rang of movement improved from flexion/extension 109/5/0 to 124/2/0. Patient assessment was (cemented/cementless) excellent 72%/75%, good 20%/18%, fair 5%/5%, poor 3%/2%.
Loosenings needing revision: 10 times (2%) in the cemented group, 2 times (1,5%) in then cementless cases.
The radiological investigation showed less radiolucent lines in the cementless cases.
Conclusion: The cementless implantation of the AMC-Uniglide gives excellent results comparable to the cemented version. The loosening rate is even lower. A stable interface at 1 year never deteriorated! The cementless fixation is attractive for younger patients (less 70 years) and is preeminent for the mini-invasive implantation technique.
Correspondence should be addressed to Ms Larissa Welti, Scientific Secretary, EFORT Central Office, Technoparkstrasse 1, CH-8005 Zürich, Switzerland
