F Châtain1, T H Gaillard, S Denjean, O Tayot. 1. Clinique des Alpes, 31, rue A.-Dumas, 38100 Grenoble, France; Clinique Belledonne, avenue G.-Péri, 38240 Saint-Martin d'Hères, France. Electronic address: dr.chatain.frederic@wanadoo.fr.
Abstract
INTRODUCTION: The goal of mobile-bearing total knee arthroplasties (TKA) with an anatomical trochlea is to reduce polyethylene wear, the risk of loosening, and patellofemoral complications. Rotating mobile-bearing SCORE(®) TKA was designed according to these principles with standard instrumentation for component placement and a specific computer navigation system, Amplivision(®). HYPOTHESIS: We hypothesized that the results of SCORE(®) TKA would be satisfactory and better using computer navigation with or without patellar resurfacing and that there would be no specific patellofemoral complications associated with this trochlear design. MATERIALS AND METHODS: Four hundred and forty-seven SCORE(®) TKA were performed. Outcome assessment was based on the IKS score, and component survival calculated by Kaplan-Meier analysis. RESULTS: Mean follow-up was 6.6 years (maximum 10.6 years). Six percent of patients were lost to follow-up. Ninety-eight percent of the patients were satisfied or very satisfied. The IKS knee score was 89 points and the function score was 86. The mechanical axis was 180° (174-186), and it was significantly improved if the initial deformity was severe and TKA was computer navigated. There were nine revisions (one for fracture, two for pain, two for stiffness, four for infection). DISCUSSION: This study confirmed our hypothesis: the results of SCORE(®) TKA were very satisfying after at least 5 years of follow-up because there was no mechanical loosening, no bearing dislocation and no patellofemoral complications with or without patellar resurfacing. Results were identical whether patellar resurfacing was performed or not. Although clinical results were not better for computer- navigated TKA, radiological results were. At 98 months of follow-up, component survival in relation to the risk of aseptic loosening or patellofemoral complications was 100%. LEVEL OF EVIDENCE: Level IV continuous retrospective study.
INTRODUCTION: The goal of mobile-bearing total knee arthroplasties (TKA) with an anatomical trochlea is to reduce polyethylene wear, the risk of loosening, and patellofemoral complications. Rotating mobile-bearing SCORE(®) TKA was designed according to these principles with standard instrumentation for component placement and a specific computer navigation system, Amplivision(®). HYPOTHESIS: We hypothesized that the results of SCORE(®) TKA would be satisfactory and better using computer navigation with or without patellar resurfacing and that there would be no specific patellofemoral complications associated with this trochlear design. MATERIALS AND METHODS: Four hundred and forty-seven SCORE(®) TKA were performed. Outcome assessment was based on the IKS score, and component survival calculated by Kaplan-Meier analysis. RESULTS: Mean follow-up was 6.6 years (maximum 10.6 years). Six percent of patients were lost to follow-up. Ninety-eight percent of the patients were satisfied or very satisfied. The IKS knee score was 89 points and the function score was 86. The mechanical axis was 180° (174-186), and it was significantly improved if the initial deformity was severe and TKA was computer navigated. There were nine revisions (one for fracture, two for pain, two for stiffness, four for infection). DISCUSSION: This study confirmed our hypothesis: the results of SCORE(®) TKA were very satisfying after at least 5 years of follow-up because there was no mechanical loosening, no bearing dislocation and no patellofemoral complications with or without patellar resurfacing. Results were identical whether patellar resurfacing was performed or not. Although clinical results were not better for computer- navigated TKA, radiological results were. At 98 months of follow-up, component survival in relation to the risk of aseptic loosening or patellofemoral complications was 100%. LEVEL OF EVIDENCE: Level IV continuous retrospective study.