Purpose: This clinical fluoroscopy study investigated knee kinematics of two different cemented fixed‐bearing, posterior‐stabilised (PS) total knee arthroplasty (TKA) designs: an asymmetric tibial... Show morePurpose: This clinical fluoroscopy study investigated knee kinematics of two different cemented fixed‐bearing, posterior‐stabilised (PS) total knee arthroplasty (TKA) designs: an asymmetric tibial component including an asymmetric insert designed to optimise personalised balance and fit and its precursor symmetrical design with symmetric insert. Methods: A consecutive series of patients (16 TKAs from each treatment group) participating in a randomised controlled trial comparing TKA migration was included. The exclusion criterion was the use of walking aids. Flat‐panel fluoroscopic recordings of step‐up and lunge motions were acquired 1‐year postoperatively. Medial and lateral contact points (CPs) were determined to calculate CP displacement, femoral axial rotation and pivot position. Using linear mixed‐effects modelling techniques, kinematics between TKA designs were compared. Results: During knee extension between 20° flexion and full extension, the CPs moved anteriorly combined with a small internal femoral rotation (a screw‐home mechanism). Whereas CP movement was reversed: femoral rollback, external femoral rotation while flexing the knee between full extension and 20° knee flexion, At larger flexion angles, femoral axial rotation (FAR) occurred around a lateral pivot point both during step‐up and lunge. The symmetric design had a 2.3° larger range of FAR compared to the asymmetric design during lunge (p = 0.02). All other kinematics were comparable. Conclusion: Despite the differences in design, this study showed that the asymmetric and symmetric PS TKA designs had mostly comparable knee kinematics during step‐up and lunge motions. It is therefore expected that the functionality of the successor TKA design is similar to that of its precursor design. Show less
What does this dissertation on De Haan and language contribute to the ongoing research on De Haan? As I explain in the introduction, this dissertation does not discuss in detail the person and life... Show moreWhat does this dissertation on De Haan and language contribute to the ongoing research on De Haan? As I explain in the introduction, this dissertation does not discuss in detail the person and life of Jacob Israël de Haan himself. The focus has been on the conceptualisation of language and De Haan’s use of language. By making this choice, I do not reduce De Haan to his decadent period, which is often the case, but rather consider his work from the meta-level of language. This dissertation not only shows how De Haan views the phenomenon of language and its use, but also what he is capable of with language, in which way he uses language as a flexible instrument, which language approaches he uses in the process, which language attitudes he can adopt and to what end. Show less
